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contents features .............................................................. 1 applications ......................................................... 1 block diagram ..................................................... 1 selection guide ................................................... 2 pin assignment ................................................... 3 absolute maximum ratings ................................. 3 electrical characteristics ..................................... 4 test circuits ........................................................ 9 operation ............................................................. 10 external parts selection for dc-dc converter ...... 13 standard circuits ................................................. 17 precautions ......................................................... 19 application circuits .............................................. 20 dimensions .......................................................... 25 markings .............................................................. 25 taping ................................................................ 26 temperature characteristics .............................. 29 voltage characteristics ....................................... 31 ripple characteristics ......................................... 32 transient responses .......................................... 33 operation start voltage and operation holding voltage characteristics for output current ......... 35 input voltage characteristics for input current .. . 35 reference data ................................................. . 36 fr e qu ent ly as ke d q u e sti o n s ..................... ........ . 45 www..net
seiko instruments inc. 1 S-8323/8327 series small package pwm control step-up switching regulator the S-8323/8327 series is a cmos pwm-control step-up switching regulator which mainly consists of a reference voltage source, an oscillation circuit, a power mos fet (for S-8323 series) , and an error amplifier. the new pwm control circuit automatically changes the duty ratio from 0% to 83% according to the current load, offering products of a wide range, high efficiency. a step-up switching regulator is constructed by externally connecting only a coil, a capacitor and a diode to the S-8323 series. this feature, along with its small package and low current consumption, makes the S-8323 series ideal for the power supply of portable equipment. for applications requiring a high output current, products used with an external transistor (s-8327 series) are also available. features applications low voltage operation: 0.9 v (i out = 1ma) power supplies for portable equipment such as low current consumption : pagers, handy calculators, and remote controllers during operation: 17.2 m a (typ.) constant voltage power supplies for cameras, (v out = 3 v, 50 khz) video equipment, and communications equipment during shutdown : 0.5 m a (max.) power supply for microcomputers duty ratio: built-in pwm control circuit external parts: coil, diode, and capacitor only (a transistor is needed for the s-8327 series.) output voltage: accuracy of 2.4% soft start function: 6 msec (typ.) shutdown function external transistor type is available (s-8327 series) sot-23-5 small plastic package sot-23-3 small plastic package sot-89-3 miniature power molded plastic package step-down and voltage-inverting type are available. block diagram (1) S-8323 series (2) s-8327 series figure 1 block diagram (on / off) ext (on / off) v ss v out cont pwm control circuit - + vref v ss v out pwm control circuit - + vref soft start circuit soft start circuit www..net small package pwm control step-up switching regulator S-8323/8327 series 2 seiko instruments inc. selection guide 1. product name s - 83 2 x x xx xx - xxx - t2 tape specification product name (abbreviation) package name (abbreviation) ma: sot-23-3 (without shutdown function) mc: sot-23-5 (with shutdown function, v dd /vout separate product) ua: sot-89-3 (without shutdown function) output voltage x 10 product category a: normal product, fosc=50 khz (S-8323 only) b: normal product, fosc=100 khz (s-8327 only) c: for pagers, fosc=30 khz (S-8323 only) d : v dd /vout separate product, fosc=50 khz (S-8323 only) e : v dd /vout separate product, fosc=100 khz (s-8327 only) power transistor 3: built-in switch. 7: external transistor. 2. product list output voltage (v) S-8323axxmc series S-8323axxma series S-8323axxua series S-8323cxxma series S-8323dxxmc series 2.0 S-8323d20mc-eza-t2 2.5 S-8323a25mc-elf-t2 S-8323a25ma-elf-t2 S-8323a25ua-elf-t2 S-8323c25ma-enf-t2 2.7 S-8323a27mc-elh-t2 S-8323a27ma-elh-t2 S-8323a27ua-elh-t2 S-8323c27ma-enh-t2 3.0 S-8323a30mc-elk-t2 S-8323a30ma-elk-t2 S-8323a30ua-elk-t2 S-8323c30ma-enk-t2 S-8323d30mc-ezk-t2 3.3 S-8323a33mc-eln-t2 S-8323a33ma-eln-t2 S-8323a33ua-eln-t2 5.0 S-8323a50mc-eme-t2 S-8323a50ma-eme-t2 S-8323a50ua-eme-t2 S-8323d50mc-e3e-t2 5.2 S-8323a52mc-emg-t2 output voltage (v) s-8327bxxmc series s-8327bxxma series s-8327bxxua series s-8327exxmc series 2.0 s-8327e20mc-eva-t2 2.5 s-8327b25mc-erf-t2 s-8327b25ma-erf-t2 s-8327b25ua-erf-t2 2.7 s-8327b27mc-erh-t2 s-8327b27ma-erh-t2 s-8327b27ua-erh-t2 2.8 s-8327b28mc-eri-t2 3.0 s-8327b30mc-erk-t2 s-8327b30ma-erk-t2 s-8327b30ua-erk-t2 3.3 s-8327b33mc-ern-t2 s-8327b33ma-ern-t2 s-8327b33ua-ern-t2 3.6 s-8327b36mc-erq-t2 5.0 s-8327b50mc-ese-t2 s-8327b50ma-ese-t2 s-8327b50ua-ese-t2 s-8327e50mc-eke-t2 5.4 s-8327b54mc-esi-t2 consult our sales person for products with an output voltage other than specified above. 3. function list product name built in power transistor with external power transistor switching frequency (khz) shutdown function v dd /v out separate type package application reference page S-8323axxmc yes 50 yes sot-23-5 with shutdown function S-8323axxma yes 50 sot-23-3 without shutdown function S-8323axxua yes 50 sot-89-3 without shutdown function S-8323dxxmc yes 50 yes sot-23-5 for variable output voltage by step-up dc/dc converter and step-down, inverted output dc/dc converter with an external resistor page 16 S-8323cxxma yes 30 sot-23-3 for pagers s-8327bxxmc yes 100 yes sot-23-5 for large load current with shutdown function pages 15 and 16 s-8327bxxma yes 100 sot-23-3 for large load current without shutdown function pages 15 and 16 s-8327bxxua yes 100 sot-89-3 for large load current without shutdown function pages 15 and 16 s-8327exxmc yes 100 yes sot-23-5 for variable output voltage by step-up dc/dc converter with an external resistor page 16 www..net small package pwm control step-up switching regulator S-8323/8327 series seiko instruments inc. 3 pin assignment figure 2 absolute maximum ratings note: a protect circuit for static electricity is built into this ic chip. however, prevent a charge of static electricity which exceeds the capacity of the protect circuit. pin no. pin name functions 1 on / off shutdown pin h: normal operation (stepping up operation) l: stop stepping up (whole circuit stop) 2v out output voltage pin and power supply pin 3 n.c. (non connection) 4v ss gnd pin cont external inductor connection pin (for S-8323 series) ext external transistor connection pin (for s-8327 series) pin no. pin name functions 1v out output voltage pin 2v dd power supply pin 3 n.c. (non connection) 4v ss gnd pin cont external inductor connection pin (for S-8323 series) ext external transistor connection pin (for s-8327 series) pin no. pin name functions 1v ss gnd pin 2v out output voltage pin and power supply pin cont external inductor connection pin (for S-8323 series) ext external transistor connection pin (for s-8327 series) parameter symbol ratings unit vout pin voltage v out 11 v on/off pin voltage on/off v ss - 0.3 to 11 v cont pin voltage v cont 11 v cont pin current i cont 300 ma ext pin voltage v ext v ss - 0.3 to v out +0.3 v ext pin current i ext 50 ma power dissipation pd sot-89-3 500 mw sot-23-5, sot-23-3 150 operating temperature t opr -40 to +85 c storage temperature t stg -40 to +125 c 2 3 1 sot-23-3 top view 5 4 3 2 1 sot-23-5 top view 3 2 1 sot-89-3 top view 5 S-8323axxmc, s-8327bxxmc sot-23-5 5 S-8323dxxmc, s-8327exxmc sot-23-5 S-8323axxma, S-8323axxua, S-8323cxxma s-8327bxxma, s-8327bxxua sot-23-3, sot-89-3 3 ( unless otherwise specified: ta=25 c ) www..net small package pwm control step-up switching regulator S-8323/8327 series 4 seiko instruments inc. electrical characteristics 1-1.S-8323axxmc (unless otherwise specified: ta=25 c) parameter symbol conditions min. typ. max. unit test circuit S-8323a52mc 4.075 5.200 5.325 S-8323a50mc 4.880 5.000 5.120 output voltage v out S-8323a33mc 3.221 3.300 3.379 S-8323a30mc 2.928 3.000 3.072 S-8323a27mc 2.635 2.700 2.765 v 1 S-8323a25mc 2.440 2.500 2.560 input voltage v in ??9 operation start voltage v st1 i out =1ma ? ? 0.9 oscillation start voltage v st2 no external parts, voltage applied to v out cont pulled up to 5 v by 10k w ? ? 0.8 2 operation holding voltage v hld i out =1ma, measured by decreasing v in voltage graduelly 0.7 ? ? 1 S-8323a52mc ? 31.6 52.6 S-8323a50mc ? 30.2 50.3 current consumption 1 i ss1 v out =output voltage 0.95 S-8323a33mc ? 19.1 31.8 S-8323a30mc ? 17.2 28.7 S-8323a27mc ? 15.5 25.9 S-8323a25mc ? 14.3 23.9 S-8323a52mc ? 3.5 6.9 m a2 S-8323a50mc ? 3.5 6.9 current consumption 2 i ss2 v out =output voltage+0.5 S-8323a33mc ? 3.3 6.5 S-8323a30mc ? 3.2 6.4 S-8323a27mc ? 3.2 6.4 S-8323a25mc ? 3.2 6.3 current consumption during shutdown i sss shutdown pin=0v ? ? 0.5 S-8323a52mc 114 182 ? S-8323a50mc 114 182 ? switching current i sw vcont=0.4v S-8323a33mc 78 125 ? ma ? S-8323a30mc 78 125 ? S-8323a27mc 61 98 ? S-8323a25mc 61 98 ? switchin transistor leak current i swq v out = vcont=10v ? ? 1.0 m a? line regulation d v out1 v in =output voltage 0.4 to 0.6 ? 30 60 mv load regulation d v out2 i out =10 m a to i out (below) 1.25 ? 30 60 S-8323a52mc ? 0.26 ? output voltage S-8323a50mc ? 0.25 ? 1 temperature d v out / d ta ta=-40 c to +85 c S-8323a33mc ? 0.17 ? mv/ c coefficient S-8323a30mc ? 0.15 ? S-8323a27mc ? 0.14 ? S-8323a25mc ? 0.13 ? oscillation frequency fosc v out =output voltage 0.95 measured waveform at cont pin 42.5 50 57.5 khz max. duty ratio maxduty v out =output voltage 0.95 measured waveform at cont pin 75 83 90 % shutdown pin vsh v out =output voltage 0.95 measured the oscillation at cont pin 0.75 ? ? 2 input voltage (on/off type) vsl1 v out =output voltage 0.95 when v out 3 1.5v ? ? 0.3 v vsl2 judged the stop of oscillation at cont pin when v out <1.5v ? ? 0.2 soft start time t ss 3.0 6.0 12.0 ms ? S-8323a52mc ? 87 ? S-8323a50mc ? 87 ? efficiency effi S-8323a33mc ? 83 ? % 1 S-8323a30mc ? 83 ? S-8323a27mc ? 79 ? S-8323a25mc ? 79 ? external parts used: - coil: cd54 (100 m h) of sumida electric co., ltd. - diode: ma720 (schottky type) of matsushita electronic components co., ltd. - capacitor: f93 (16v, 22 m f, tantalum type) of nichicon corporation) applied v in =output voltage 0.6, applied, i out =output voltage/250 w the shutdown pin is connected to v out pin. note 1: the output voltage specified above is the typical value. www..net small package pwm control step-up switching regulator S-8323/8327 series seiko instruments inc. 5 1-2.S-8323axxma, S-8323axxua, S-8323dxxmc (unless otherwise specified: ta=25 c) parameter symbol conditions min. typ. max. unit test circuit S-8323x50xx 4.880 5.000 5.120 S-8323x33xx 3.221 3.300 3.379 output voltage -v out S-8323x30xx 2.928 3.000 3.072 S-8323x27xx 2.635 2.700 2.765 v 1 S-8323x25xx 2.440 2.500 2.560 S-8323x20xx 1.952 2.000 2.048 input voltage v in ??9 operation start voltage v st1 i out =1ma ? ? 0.9 oscillation start voltage v st2 no external parts, voltage applied to v out cont pulled up to 5 v by 10k w ? ? 0.8 2 operation holding voltage v hld i out =1ma, measured by decreasing v in voltage gradually. 0.7 ? ? 1 S-8323x50xx ? 30.2 50.3 S-8323x33xx ? 19.1 31.8 current consumption 1 i ss1 v out =output voltage 0.95 S-8323x30xx ? 17.2 28.7 S-8323x27xx ? 15.5 25.9 S-8323x25xx ? 14.3 23.9 S-8323x20xx ? 11.6 19.4 m a 2 S-8323x50xx ? 3.5 6.9 S-8323x33xx ? 3.3 6.5 current consumption 2 i ss2 v out =output voltage+0.5 S-8323x30xx ? 3.2 6.4 S-8323x27xx ? 3.2 6.4 S-8323x25xx ? 3.2 6.3 S-8323x20xx ? 3.1 6.2 S-8323x50xx 114 182 ? S-8323x33xx 78 125 ? switching current i sw vcont=0.4v S-8323x30xx 78 125 ? ma S-8323x27xx 61 98 ? S-8323x25xx 61 98 ? ? S-8323x20xx 45 71 ? switchin transistor leak current i swq v out = vcont=9v ? ? 1.0 m a line regulation d v out1 v in = output voltage 0.4 to 0.6 ?3060mv load regulation d v out2 i out =10 m a to i out (below) 1.25 ?3060 S-8323x50xx ? 0.25 ? output voltage S-8323x33xx ? 0.17 ? temperature d v out / d ta ta=-40 c to +85 c S-8323x30xx ? 0.15 ? mv/ c 1 coefficient S-8323x27xx ? 0.14 ? S-8323x25xx ? 0.13 ? S-8323x20xx ? 0.10 ? oscillation frequency fosc v out =output voltage 0.95 measured waveform at cont pin 42.5 50 57.5 khz 2 max.duty ratio maxduty v out =output voltage 0.95 measured waveform at cont pin 75 83 90 % soft start time t ss 3.0 6.0 12.0 ms ? S-8323x50xx ? 87 ? S-8323x33xx ? 83 ? efficiency effi S-8323x30xx ? 83 ? % 2 S-8323x27xx ? 79 ? S-8323x25xx ? 79 ? S-8323x20xx ? 75 ? external parts used: - coil: cd54 (100 m h) of sumida electric co., ltd. - diode: ma720 (schottky type) of matsushita electronic components co., ltd. - capacitor: f93 (16v, 22 m f, tantalum type) of nichicon corporation) applied v in =output voltage 0.6, i out =output voltage/250 w the v dd pin is connected to v out pin for v dd /v out separate product. note 1: the output voltage specified above is the typical value. note 2: v dd /v out separate products: boot operation is performed from v dd =0.8v. however, 2.0 v or more for v dd is recommended to stabilize the output voltage and oscilation frequency. www..net small package pwm control step-up switching regulator S-8323/8327 series 6 seiko instruments inc. 1-3. S-8323cxxma (unless otherwise specified: ta=25 c) parameter symbol conditions min. typ. max. unit test circuit S-8323c30ma 2.928 3.000 3.072 output voltage v out S-8323c27ma 2.635 2.700 2.765 S-8323c25ma 2.440 2.500 2.560 v 1 input voltage v in ??9 operation start voltage v st1 i out =1ma ? ? 0.9 oscillation start voltage v st2 no external parts, voltage applied to v out cont pulled up to 5 v by 10k w ? ? 0.8 2 operation holding voltage v hld measured by decreasing v in voltage gradually. 0.7 ? ? 1 S-8323c30ma ? 11.6 19.3 current consumption 1 i ss1 v out =output voltage 0.95 S-8323c27ma ? 10.5 17.5 S-8323c25ma ? 9.8 16.3 S-8323c30ma ? 3.0 5.9 m a 2 current consumption 2 i ss2 v out =output voltage+0.5 S-8323c27ma ? 2.9 5.8 S-8323c25ma ? 2.9 5.8 S-8323c30ma 78 125 ? switching current i sw vcont=0.4v S-8323c27ma 61 98 ? ma S-8323c25ma 61 98 ? ? switching transistor leak current i swq v out = vcont=9v ? ? 1.0 m a line regulation d v out1 v in = output voltage 0.4 to 0.6 ?3060mv load regulation d v out2 i out =10 m a to i out (below) 1.25 ?3060 output voltage S-8323c30ma ? 0.15 ? 1 temperature d v out / d ta ta=-40 c to +85 c S-8323c27ma ? 0.14 ? mv/ c coefficient S-8323c25ma ? 0.13 ? oscillation frequency fosc v out =output voltage 0.95 measured waveform at cont pin 25 30 35 khz 2 max. duty ratio maxduty v out =output voltage 0.95 measured waveform at cont pin 75 83 90 % soft start time t ss 3.0 6.0 12.0 ms ? S-8323c30ma ? 81 ? efficiency effi S-8323c27ma ? 77 ? % 2 S-8323c25ma ? 77 ? external parts used: -coil: cd54 (100 m h) of sumida electric co., ltd. -diode: ma720 (schottky type) of matsushita electronic components co., ltd. -capacitor: f93 (16v, 22 m f, tantalum type) of nichicon corporation) applied v in =output voltage0.6, i out =output voltage/250 w note 1: the output voltage specified above is the typical value of the output voltage. www..net small package pwm control step-up switching regulator S-8323/8327 series seiko instruments inc. 7 2-1. s-8327bxxmc (unless otherwise specified: ta=25 c) parameter symbol conditions min. typ. max. unit test circuit s-8327b54mc 5.270 5.400 5.530 s-8327b50mc 4.880 5.000 5.120 s-8327b36mc 3.514 3.600 3.686 output voltage v out s-8327b33mc 3.221 3.300 3.379 s-8327b30mc 2.928 3.000 3.072 s-8327b28mc 2.733 2.800 2.867 v 3 s-8327b27mc 2.635 2.700 2.765 s-8327b25mc 2.440 2.500 2.560 input voltage v in ??9 operation start voltage v st1 i out =1ma ? ? 0.9 oscillation start voltage v st2 no external parts, voltage applied to v out ? ? 0.8 4 operation holding voltage v hld i out =1ma, measured by decreasing v in voltage gradually. 0.7 ? ? 3 s-8327b54mc ? 41.0 68.3 s-8327b50mc ? 37.6 62.6 s-8327b36mc ? 26.0 43.3 current consumption 1 i ss1 v out =output voltage 0.95 s-8327b33mc ? 23.7 39.5 s-8327b30mc ? 21.4 35.7 s-8327b28mc ? 20.0 33.3 s-8327b27mc ? 19.2 32.0 s-8327b25mc ? 17.8 29.7 m a4 s-8327b54mc ? 4.2 8.3 s-8327b50mc ? 4.2 8.3 s-8327b36mc ? 4.0 7.9 current consumption 2 i ss2 v out =output voltage+0.5 s-8327b33mc ? 4.0 7.9 s-8327b30mc ? 3.9 7.8 s-8327b28mc ? 3.9 7.8 s-8327b27mc ? 3.9 7.7 s-8327b25mc ? 3.9 7.7 current consumption while shutdown i sss shutdown pin=0v ? ? 0.5 s-8327b54mc -5.3 -8.0 ? s-8327b50mc -5.3 -8.0 ? s-8327b36mc -3.5 -5.3 ? i exth vext=-0.4v s-8327b33mc -3.5 -5.3 ? s-8327b30mc -3.5 -5.3 ? s-8327b28mc -2.7 -4.0 ? s-8327b27mc -2.7 -4.0 ? ext pin output current s-8327b25mc -2.7 -4.0 ? ma ? s-8327b54mc 10.7 16.0 ? s-8327b50mc 10.7 16.0 ? s-8327b36mc 7.0 10.5 ? i extl vext=0.4v s-8327b33mc 7.0 10.5 ? s-8327b30mc 7.0 10.5 ? s-8327b28mc 5.3 8.0 ? s-8327b27mc 5.3 8.0 ? s-8327b25mc 5.3 8.0 ? line regulation d v out1 v in =output voltage 0.4 to 0.6 ? 30 60 mv load regulation d v out2 i out =10 m a to i out (below) 1.25 ? 30 60 s-8327b54mc ? 0.27 ? s-8327b50mc ? 0.25 ? output voltage s-8327b36mc ? 0.18 ? 3 temperature d v out / d ta ta=-40 c to +85 c s-8327b33mc ? 0.17 ? mv/ c coefficient s-8327b30mc ? 0.15 ? s-8327b28mc ? 0.14 ? s-8327b27mc ? 0.14 ? s-8327b25mc ? 0.13 ? oscillation frequency fosc v out =output voltage 0.95 measure waveform at ext pin 85 100 115 khz max. duty ratio maxduty v out =output voltage 0.95 measure waveform at ext pin 75 83 90 % shutdown pin vsh v out =output voltage 0.95 judged the oscillation at ext pin 0.75 ? ? v 4 input voltage (on/off type) vsl1 v out =output voltage 0.95 when v out 3 1.5v ? ? 0.3 vsl2 judged the stop of oscillation at cont pin when v out <1.5v ? ? 0.2 soft start time t ss 3.0 6.0 12.0 ms ? s-8327b54mc ? 88 ? s-8327b50mc ? 88 ? s-8327b36mc ? 84 ? efficiency effi s-8327b33mc ? 84 ? % 3 s-8327b30mc ? 84 ? s-8327b28mc ? 80 ? s-8327b27mc ? 80 ? s-8327b25mc ? 80 ? external parts used: - coil: cd54 (47 m h) of sumida electric co., ltd. - diode: ma720 (schottky type) of matsushita electronic components co., ltd. - capacitor: f93 (16v, 47 m f, tantalum type) of nichicon corporation) - transistor: 2sd1628g of sanyo electronics - base resistance (rb): 1. 0k w - base capacitor (cb): 2200 pf applied v in =output voltage 0.6, i out =output voltage/50 w the shutdown pin is connected to v out pin. note 1: the output voltage specified above is the typical value. www..net small package pwm control step-up switching regulator S-8323/8327 series 8 seiko instruments inc. 2-2.s-8327bxxma, s-8327bxxua, s-8327exxmc (unless otherwise specified: ta=25 c) parameter symbol conditions min. typ. max. unit test circuit s-8327x50xx 4.880 5.000 5.120 s-8327x33xx 3.221 3.300 3.379 output voltage v out s-8327x30xx 2.928 3.000 3.072 s-8327x27xx 2.635 2.700 2.765 v 3 s-8327x25xx 2.440 2.500 2.560 s-8327x20xx 1.952 2.000 2.048 input voltage v in ??9 operation start voltage v st1 i out =1ma ? ? 0.9 oscillation start voltage v st2 no external parts, voltage applied to v out ? ? 0.8 4 operation holding voltage v hld i out =1ma, measured by decreasing v in voltage gradually b. 0.7 ? ? 3 s-8327x50xx ? 37.6 62.6 s-8327x33xx ? 23.7 39.5 current consumption 1 i ss1 v out =output voltage 0.95 s-8327x30xx ? 21.4 35.7 s-8327x27xx ? 19.2 32.0 s-8327x25xx ? 17.8 29.7 s-8327x20xx ? 14.5 24.1 m a 4 s-8327x50xx ? 4.2 8.3 s-8327x33xx ? 4.0 7.9 current consumption 2 i ss2 v out =output voltage+0.5 s-8327x30xx ? 3.9 7.8 s-8327x27xx ? 3.9 7.7 s-8327x25xx ? 3.9 7.7 s-8327x20xx ? 3.8 7.6 s-8327x50xx -5.3 -8.0 ? s-8327x33xx -3.5 -5.3 ? i exth vcont=-0.4v s-8327x30xx -3.5 -5.3 ? s-8327x27xx -2.7 -4.0 ? s-8327x25xx -2.7 -4.0 ? ext pin output current s-8327x20xx -1.9 -2.9 ? ma ? s-8327x50xx 10.7 16.0 ? s-8327x33xx 7.0 10.5 ? i extl vcont=0.4v s-8327x30xx 7.0 10.5 ? s-8327x27xx 5.3 8.0 ? s-8327x25xx 5.3 8.0 ? s-8327x20xx 3.8 5.7 ? line regulation d v out1 v in =output voltage 0.4 to 0.6 ?3060mv load regulation d v out2 i out =10 m a to i out (below) 1.25 ?3060 s-8327x50xx ? 0.25 ? output voltage s-8327x33xx ? 0.17 ? temperature d v out / d ta ta=-40 c to +85 c s-8327x30xx ? 0.15 ? mv/ c 3 coefficient s-8327x27xx ? 0.14 ? s-8327x25xx ? 0.13 ? s-8327x20xx ? 0.10 ? oscillation frequency fosc v out =output voltage 0.95 measured waveform at ext pin 85 100 115 khz max. duty ratio maxduty v out =output voltage 0.95 measured waveform at ext pin 75 83 90 % 4 soft start time t ss 3.0 6.0 12.0 ms ? s-8327x50xx ? 88 ? s-8327x33xx ? 84 ? efficiency effi s-8327x30xx ? 84 ? % 3 s-8327x27xx ? 80 ? s-8327x25xx ? 80 ? s-8327x20xx ? 76 ? external parts used: - coil: cd54 (47 m h) of sumida electric co., ltd. - diode: ma720 (schottky type) of matsushita electronic components co., ltd. - capacitor: f93 (16v, 47 m f, tantalum type) of nichicon corporation) - transistor: 2sd1628g of sanyo electronics - base resistor (rb): 1.0k w - base capacitor (cb) : 2200pf (ceramic) applied v in =output voltage 0.6, i out =output voltage/50 w the v dd pin is connected to v out pin for v dd /v out separate product. note 1: the output voltage specified above is the typical value. note 2: v dd/ v out separate products: boot operation is performed from v dd =0.8v. however, 2.0 v or more for v dd is recommended to stabilize the output voltage and oscilation frequency. www..net small package pwm control step-up switching regulator S-8323/8327 series seiko instruments inc. 9 test circuits 1. figure 3 v ss v out cont v - + - + (on/off) 2. 3. 4. v ss v out v - + - + (on/off) rb ext v ss (on/off) v out cont 10k - + a v ss (on/off v out - + a ext cb oscilloscope oscilloscope www..net small package pwm control step-up switching regulator S-8323/8327 series 10 seiko instruments inc. operation 1. step-up dc/dc converter the S-8323/8327 series is a step-up switching regulator using a pulse width modulation method (pwm) and dc/dc converter and features a low current consumption. in conventional pfm dc/dc converters, pulses are skipped at low output load current, causing fluctuation in ripple frequency of the output voltage, with the result of increase in ripple voltage. the S-8323/8327 series operates with the pwm control which changes the pulse width duty from 0% to 83% according to the load current. the ripple voltage generated from switching can be removed easily through the filter because the switching frequency is constant. the built-in soft start circuit controls a rush current and overshoot of the output voltage when powering on or the on/off terminal turns to h level. shutdown pin: stops or starts step-up operation. (only for sot-23-5 package products of a and b series.) turning the shutdown pin low stops operation of all the internal circuits and reduces current consumption significantly. do not use the shutdown pin in floating state because it has a structure shown in figure 4 and is not pulled up or pulled down internally. do not apply voltage of between 0.3 v and 0.75 v to the shutdown pin because applying such voltage increases the current consumption. if the shutdown pin is not used, connect it to v out pin. the shutdown pin doesnt have hysteresis. shutdown pin cr oscillation circuit output voltage h operation fixed l stop ~v in * figure 4 on/off v out v ss * voltage obtained by extracting the voltage drop due to dc resistance of the inductor and the diode forward voltage from v in. figure 5 + - + - osc c out cont m1 v in ldi on/off v out www..net small package pwm control step-up switching regulator S-8323/8327 series seiko instruments inc. 11 the following are basic equations [(1) through (7)] of the step-up switching regulator (see figure 5.) voltage at cont pin the moment m1 is turned on (current i l flowing through l is zero): the change in i l over time: integration of the above equation (i l ): i l flows while m1 is on (t on ). the time of t on is determined by the oscillation frequency of the osc. the peak current (i pk ) after t on : the energy stored in l is represented with 1/2 l (i pk ) 2 . when m1 is turned off (t off ), the energy stored in l is transmitted through a diode to the output capacitor. then reverse voltage (v l ) is generated. v l = (v out +v d ) - v in .........................................................(5) (v d : diode forward voltage) the voltage at cont pin rises only by the voltage corresponding to v out +v d . the change in the current flowing through the diode into v out during t off : integration of the above equation is as follows: during t on , the energy is stored in l and is not transmitted to v out . when receiving output current (i out ) from v out , the energy of the capacitor (c out ) is consumed. as a result, the pin voltage of c out is reduced, and goes to the lowest level after m1 is turned on (t on ). when m1 is turned off, the energy stored in l is transmitted through the diode to c out , and the voltage of c out rises drastically. v out is a time function that indicates the maximum value (ripple voltage: v p-p ) when the current flowing through the diode into v out and load current (i out ) match. next, the ripple voltage is found out as follows: i out vs t 1 (time) from when m1 is turned off (after t on ) to when v out reaches the maximum level: when m1 is turned on (after t off ), il=0 (when the energy of the inductor is completely transmitted). based on equation (7), = = ............................................................(2) di l dt v l l v in - v s l i l = t .......................................................... (3) v in - v s l v a =v s .........................................................................(1) (v s : non-saturated voltage of m1) i pk = t on .........................................................(4) v in - v s l = = .............................................(6) di l dt v l l v out +v d - v in l i l =i pk - t ............................................. (7) v out +v d - v in l i out =i pk - t 1 ................................................ (8) \ t 1 = (i pk - i out ) ................................................ (9) v out +v d - v in l v out +v d - v in l = .............................................(10) v out +v d - v in l i pk t off www..net small package pwm control step-up switching regulator S-8323/8327 series 12 seiko instruments inc. when substituting equation (10) for equation (9), electric charge d q1 which is charged in cout during t1: when substituting equation (12) for equation (9): a rise in voltage (vp-p) due to d q1: when taking into consideration i out to be consumed during t1 and esr (electric series resistance) of cout, namely resr: v p-p = = t1 + r esr - ................... (15) when substituting equation (11) for equation (15): therefore to reduce the ripple voltage, it is important that the capacitor connected to the output pin has a large capacity and a small esr. t 1 =t off - t off ............................................................(11) i pk i out d q 1 = i l dt = i pk dt - tdt =i pk t 1 - = t 1 2 ...............................(12) t 1 0 v out +v d - v in l v out +v d - v in l2 1 0 t 1 0 t 1 d q 1 =i pk - (i pk - i out ) t 1 = t 1 .............................. (13) 2 1 2 i pk +i out v p-p == t1 ............................ (14) c out d q 1 c out 1 2 i pk +i out c out d q 1 c out 1 2 i pk +i out c out i out t 1 2 i pk +i out v p-p = + r esr ................ (16) 2i pk (i pk - i out ) 2 c out t off 2 i pk +i ou www..net small package pwm control step-up switching regulator S-8323/8327 series seiko instruments inc. 13 external parts selection for dc-dc converter the relationship between majorcharacteristics of the step-up circuit and characteristics parameters of the external parts are shown in figure 6. figure 6 relationship between major character stics of the step-up circuit and external parts for large output current? for high efficiency? operation efficiency stand-by efficiency for small ripple voltage small inductance large inductance small dc resistance of inductor large output capacitance built-in switching transistor external switching transistor (small on resistance) small resistance of external resistor rb when an external switching transistor is used large resistance of external resistor rb when an external switching transistor is used . www..net small package pwm control step-up switching regulator S-8323/8327 series 14 seiko instruments inc. 1. inductor an inductance has strong influence on max. output current i out and efficiency h . figure 7 shows i out h characteristics for inductance of S-8323 and s-8327. the peak current i pk increases by decreasing l and i out is at max. value at l value. further decreasing l decreases i out due to the lack of the current driving capacity of the switching transistor. the loss of i pk by the switching transistor decreases by increasing l and the efficiency becomes max. at l value. further increasing l decreases efficiency due to the loss of dc resistance of the coil. 47 to 220 m h inductor for S-8323 and 22 to 100 m h inductor for s-8327 are recommended. choose a value for l by refering to the reference data because the maximum output current is due to the input voltage in an actual case. choose an inductor so that the peak current i pk does not exceed the allowable current. exceeding the allowable current of the inductor causes magnetic saturation, remarkable low efficiency and destruction of the ic chip due to a large current. the peak current i pk in uncontinuous mode is caluculated from the following formula: i pk = fosc: oscillation frequency vd @ 0.4v for instance, when you choose 100 m h at fosc=50 khz for l using the S-8323a50mc at the following conditions, i pk is caluculated to 170 ma from the (17) formula. input voltage v in =3 v output voltage v out =5 v load current i out =30 ma the switching current limit circuit is not built into this ic chip. i pk current must be 500 ma or less. 2 i out (v out +v d -v in ) f osc l (a) (17) S-8323 i out d75 h h i out 47 220 recommended range recommended range l ( m h ) v out =5.0v, v in =3.0v s-8327 i out cd105 h h i out 22 100 l ( m h ) v out =5.0v, v in =3.0v figure 7 www..net small package pwm control step-up switching regulator S-8323/8327 series seiko instruments inc. 15 2. diode use an external diode that meets the following requirements: low forward voltage: (v f <0.3v) high switching speed: (500 ns max.) reverse voltage: v out +v f or more rated current: i pk or more 3. capacitors (c in , c out ) a capacitor at the input side (c in ) improves the efficiency by reducing the power impedance and stabilizing the input current. select a c in value according to the impedance of the power supply used. the capacitor value should be around 10 m f. a capacitor at the output side (c out ) is used for smoothing the ripple voltage. therefore select a capacitor with a small esr (electric series resistance) and a large capacitance. the capacitor value should be 10 m f min. a tantalum electrolytic capacitor and an organic semiconductor capacitor are especially recommended because of their superior low-temperature characteristic and leakage current characteristic. 4. external transistor (s-8327 series) for the s-8327 series, connecting an external transistor increases the output current. a bipolar (npn) transistor or an enhancement (n-channel) mos fet transistor can be used as external transistor. 4.1. bipolar (npn) transistor a circuit example using a bipolar transistor (npn), sanyo 2sd1628g (h fe =280 to 560) is shown in figure 11. the h fe value and the rb value determine the driving capacity to increase the output current using a bipolar transistor. a peripheral circuit example of the transistor is shown in figure 8. 1 k w is recommended for rb. rb is caluculated from the following formula: rb= - ib=ipk/h fe a small rb increases output current, however, the efficiency decreases. the current flows pulsating and there is voltage drop due to wiring resistance in an actual circuit, therefore optimum rb value should be determined by experiment. a speed-up capacitor connected in parallel with rb resistance as shown in figure 9 decreases the switching loss and improves the efficiency. cb is caluculated from the following formula: cb v out i pk ext nch pch rb s-8327 figure 8 external transistor 2200pf 2 p rb f osc 0.7 1 ib |i exth | v out - 0.7 0.4 cb www..net small package pwm control step-up switching regulator S-8323/8327 series 16 seiko instruments inc. 4.2. enhancement mos fet type 5. others (S-8323d and s-8327e only) the S-8323d and s-8327e are applicable to the following uses because the power pin for ic chip and vout pin for output voltage are separated: when changing the output voltage with an external resistance. when outputing the high voltage such as +12 v or +15 v. when making the step-down dc/dc converter when making the voltage inverting type dc/dc converter. choose the products in the following table according to applications for ?@ to ?b . use step-up step-down output voltage v cc 2v v cc <3v 3v v cc <5v 5v v cc <9v 9v v cc ref. circuit 2v v cc <3v 3v v cc <5v 5v v cc <9v ref. circuit S-8323d20 std. circuit (5) appl. circuit 3 S-8323d30 std. circuit (5) appl. circuit 3 S-8323d50 std. circuit (5) appl. circuit 3 s-8327e20 std. circuit (6) s-8327e50 std. circuit (6) connection to v dd pin v in or v cc v in or v cc v in or v cc v in v in v in v in the operational precautions are follows: i. this ic starts to oscillate and step up operation at vdd = 0.9 v, but frequency of the oscillator doest stabilize. input the voltage from 2 v to 9 v for v dd pin to get the stabilized output voltage and oscilation frequency. the input voltage from 2 v to 9 v for v dd pin allows the connection of v dd pin to both input power pin v in and output power pin vout. ii. choose external resistors r a and r b not to affect to the output voltage with the consideration of the impedance between v out and v ss pins in the ic chip. internal resistance between v out and v ss pins are as follows: S-8323d20 and s-8327e20: 3.0 m w to 19.6 m w S-8323d30: 3.3 m w to 22.6 m w S-8323d50 and s-8327e50: 2.1 m w to 19.1 m w iii. attach the capacitor c c in parallel to r a resistance when the oscilation of the output voltage occurs. caluculate c c from the following formula: v out figure 9 circuit example using 2sk1959 figure 9 is a circuit example using nec 2sk1959 mos fet transistor (n-channel). for a mos fet, an n-channel power mos fet should be used. in particular the ext pin of the s-8327 can drive a mos fet with a gate capacity of around 1000 pf. because the gate voltage and current of the external power mos fet are supplied from the stepped out output voltage v out , the mos fet is driven more effectively. since the on resistor of the mos fet might affect the output amperage as well as the efficiency, the threshold voltage should be low. when the output voltage is as low as 2.0v the same as in the s-8327e20, the circuit operates only when the mos fet has the threshold voltage lower than 2.0v. ext v out - + (on/off) v s + - c c (f)= 2 p r a 20 khz 1 www..net small package pwm control step-up switching regulator S-8323/8327 series seiko instruments inc. 17 standard circuits figure 10 (1) S-8323axxmc pwm control circuit vref + - l cont sd v out v in v ss on / off - + c out figure 11 (2) s-8327bxxmc pwm control circuit vref + - sd v out v ss - + c out 2200pf 1 k w - + c in v in - + c in on / off ext s o f t start c i rcu i t s o f t start c i rcu i t figure 12 (3) S-8323axxma S-8323axxua S-8323cxxma pwm control circuit vref + - l cont sd v out v in v ss - + c out - + c in s o f t start c i rcu i t note: the power supply for ic chip is supplied from vout pin. note: the power supply for ic chip is supplied from vout pin. note: the power supply for ic chip is supplied from vout pin. www..net small package pwm control step-up switching regulator S-8323/8327 series 18 seiko instruments inc. (4) s-8327bxxma s-8327bxxua figure 13 pwm control circuit vref + - sd v out v ss - + c out 2200pf 1k w v in - + c in ext s o f t start c i rcu i t v cc v cc v out figure 14 (5) S-8323dxxmc (output voltage adjustment circuit with external resistors) pwm control circuit vref + - l l cont sd v dd v in - + c out - + c in soft start circuit c c v out v ss r b r a (6) s-8327exxmc (output voltage adjustment circuit with external resistors) figure 15 pwm control circuit + - sd 2200pf 1k w v in - + c in ext soft start circuit v dd - + c out c c v out v ss r b r a l r 1 r 2 r 1 r 2 note: the power supply for ic chip is supplied from vout pin. note: the power supply for ic chip is supplied from v dd pin. note: the power supply for ic chip is supplied from v dd pin. vref www..net small package pwm control step-up switching regulator S-8323/8327 series seiko instruments inc. 19 precautions mount external capacitors, a diode, and a coil as near as possible to the ic. ripple voltage and spike noise occur in switching regulators. because they largely depend on the coil and the capacitor used, check them using an actually mounted model. seiko instruments shall not be responsible for any patent infringement by products including S-8323/8327 series in connection with the method of using S-8323/8327 series in such products, the specification of such products, or the country of destination thereof. make sure dissipation of the switching transistor (especially at a high temperatures) does not exceed the allowable power dissipation of the package. power dissipation p d (mw) amb. temperature ta ( c) figure 16 power dissipation of the package (before mounting) 600 400 200 0 50 100 150 sot-23-5, sot-23-3 sot-89-3 www..net small package pwm control step-up switching regulator S-8323/8327 series 20 seiko instruments inc. application circuits 1. backup circuit reduces the backup battery voltage from 3 v to 1.5 v (from 2 cells to 1 cell). 2. 5v/backup change the S-8323a/8327b is provided with a power off function, where v out becomes approx. v in -0.6v. this characteriistic allows the backup voltage of the microcomputer to be supplied with low current consumption. 3. step-down dc/dc converter the start circuit is not needed because the power supply is supplied from v dd to the ic. the maximum input voltage for v dd is 9 v. do not mount r a and r b resistors when v cc is 2v for S-8323d20mc and 5v for S-8323d50mc. the external resistor rb must be 60 w or more and r e must be 6k w or less. a large value for r e raises efficiency due to the reduction of reactive current for r e and r b . too large value of r e lowers efficiency due to the large switching loss of the external transistor (tr). choose a suitable value of r e under the operating conditions. figure 17 cont on/ off S-8323a v out v s - + - + s-ram 1.5v main power (5v) figure 18 cont on/off S-8323a v out v s - + - + voltage detector ce cpu figure 19 v dd S-8323d - + - + v out v s c out r e r b cont c in v in v in tr v cc r a r b c c www..net small package pwm control step-up switching regulator S-8323/8327 series seiko instruments inc. 21 4. pda/digital camera power supply the following are a circuit example and its characteristics showing a 3-v system drive (3v/200ma) powered by 4 secondary nicd batteries (3.6 to 4.8v), 2 lithium-ion batteries (4.8 to 8.8v) or 4 alkaline-manganese batteries ( 3.6 to 6.0v ) . 2.95 2.97 2.99 3.01 3.03 3.05 0.01 0.1 1. 10. 100. 1000. (ma) vin=3.3v vin=3.6v vin=4.8v vin=7.2v 0 20 40 60 80 100 0.01 0.1 1. 10. 100. 1000. (ma) vin=3.3v vin=3.6v vin=4.8v vin=7.2v (a) output current - output voltage (b)output current - efficiency output voltage v out (v) efficiency h (%) output current i out output current i out t (10 m sec/div) output voltage (10mv/div) 0v point a voltage (1v/div) 3v vin=3.6v iout=300ma figure 22 v dd s-8324d30 - + - + v out v s c out r e r b cont c in v in 3v 2sa1213/toshiba 5.1k w 750 w a ma720 sd cd54/100 m h f93 22 m f l figure 20 figure 21 (c) ripple characteristics www..net small package pwm control step-up switching regulator S-8323/8327 series 22 seiko instruments inc. 5. voltage inverting type dc/dc converter the start circuit is not needed because the power is supplied from v dd to the ic. set v in to 9v-|v cc | or less. when v cc is -2 v, - 3 v and - 5 v, use the S-8323d20mc, the S-8323d30mc and the S-8323d50mc respectively. always connect v out to gnd without attaching r a , r b . set r b to 60 w or more and r e to 6 k w or less. the larger r e , the smaller the reactive current through r e and r b , allowing the efficiency to be improved. on the other hand, the switching loss of the tr becomes large and consequently the efficiency will be worsend. select r e to ensure high efficiency under operating conditions. 6. power supply for gaas and mr head the following are an application negative power supply circuit for gaas and mr head, and its characteristics when 3v (3v 10%) and 5v (5v 10%) are used for the applied power. set v in to 9v-|v cc | or less. figure 25 -3.05 -3.03 -3.01 -2.99 -2.97 -2.95 0.01 0.1 1. 10. 100. (ma) vin=2.7v vin=3.0v vin=4.5v vin=5.0v 0 20 40 60 80 100 0.01 0.1 1. 10. 100. (ma) vin=2.7v vin=3.0v vin=4.5v vin=5.0v (a)output current - output voltage (b)output current - efficiency output current i out output current i out output voltage v out (v) efficiency h (%) figure 24 v dd S-8323d30 - + + - v ss v out c out r e r b cont c in v in -3v 2sa1362/toshiba 750 w 2k w a cd54/100 m h f93 47 m f ma720 sd v cc figure 23 v dd S-8323d - + + - v ss v out c out r e r b cont c in v in tr v cc r b r a www..net small package pwm control step-up switching regulator S-8323/8327 series seiko instruments inc. 23 when output current i out exceeds 50 ma, the current capacitance in the external transistor 2sa1362 becomes in short supply and the ic may be broken. select a large current capacitance transistor. the start circuit is not needed because the power supply is supplied from v dd to the ic. set vin to 9 v - |v cc | or less. the output voltage cannot be changed with external resistors. set r b to 60 w or more and r e to 6 k w or less. the larger r e , the smaller the reactive current through r e and r b , allowing the efficiency to be improved. on the other hand, the switching loss of the tr becomes large and consequently the efficiency will be worsened. select r e to ensure high efficiency under operating conditions. 7. lcd power supply (standard circuit (6)) the following are an application power supply circuit (30v/5ma) for intermidiate and large size lcd, and its characteristics when 3v (3v 10%) and 5v (5v 10%) are used for the applied power. s-8327e50 - + - + v out 4.7 m f/50v 2 ext c in v in to 30v f93 c out cd54/100 m h 1k w 0.022 m f r b v s ma720 sd l cb v dd r a 100k w c c 15pf 482k w r b figure 27 figure 26 t (10 m sec/div) 10mv/div 0v -3v cont (2v/div) output voltage (c) ripple characteristics www..net small package pwm control step-up switching regulator S-8323/8327 series 24 seiko instruments inc. figure 28 8. flash memory power supply the following are a circuit example and its characteristics for a 5 v flash memory, 16 mbit (5v/120ma) on a single lithium battery (2.4 v to 4.4 v). 4.90 4.94 4.98 5.02 5.06 5.10 0.01 0.1 1. 10. 100. 1000. (ma) vin=2.0v vin=2.4v vin=3.6v vin=4.4v 0 20 40 60 80 100 0.01 0.1 1. 10. 100. 1000. (ma) vin=2.0v vin=2.4v vin=3.6v ( a ) output current - output volta g e ( b ) output current - efficienc y output current i out output current i out output voltage v out (v) efficiency h (%) vin=4.4v 27 28 29 30 31 32 33 0.01 0.1 1. 10. 100. (ma) vin=2.7v vin=3.0v vin=4.5v vin=5.0v 0 20 40 60 80 100 0.01 0.1 1. 10. 100. (ma) vin=2.7v vin=3.0v vin=4.5v vin=5.0v (a)output current - output voltage (b)output current - efficiency output current i out output current i out output voltage v out (v) efficiency h (%) s-8327b50 - + - + v out 47 m f ext c in v in 5v f93 c out cd54/47 m h 1 k w 0.0022 m f r b on/off control signal v s ma720 sd l 2sd1628 cb fi g ure 29 fi g ure 30 www..net small package pwm control step-up switching regulator S-8323/8327 series seiko instruments inc. 25 dimensions markings unit : mm 0.95 0.1 2.8 0.4 0.1 0 min. 1.1 0.1 1.3 max. 1.6 2.9 (3.1 max.) +0.2 -0.3 0.95 0.1 1.9 0.2 0.16 +0.1 -0.06 0.45 ( 1 ) sot-23-5 unit : mm 0.95 0.1 2.8 0.4 0.1 0 min. 1.1 0.1 1.3 max. 1.5 2.9 (3.1 max.) +0.2 -0.6 0.95 0.1 1.9 0.2 0.16 +0.1 -0.06 0.25 ( 2 ) sot-23-3 (3) sot-89-3 (1) sot-23-5 to product no. (abbreviation) to lot no. figure 31 0.8 min. 2.5 0.2 0.45 0.1 1.5 0.1 1.5 0.1 4.5 0.2 1.6 0.2 0.4 0.1 0.4 0.1 4.0 1.5 0.2 0.4 0.05 +0.25 -0.35 (0.4) unit : mm 2.5 45 (0.4) (0.2) (2) sot-23-3 figure 32 (3) sot-89-3 product no. (abbreviation) lot no. to product no. (abbreviation) to lot no. 1 2 www..net small package pwm control step-up switching regulator S-8323/8327 series 26 seiko instruments inc. taping 3 or less 3.2 0.1 0.270.05 1.40.1 3 or less 4.00.1 f 1.0 f 1.5 +0.1 -0 +0.2 -0 2.0 0.05 4.0 0.1 ( total10 : 40.0 0.2 ) 1.750.1 3.50.05 8.0 0.2 type t2 unit : mm ? feed direction figure 33 1. tape specification 1-1 sot-23-5 type t2 unit : mm ? feed direction figure 34 1-2 sot-23-3 3.230.1 2.850.2 0.250.05 1.60.1 4.00.1 f 1.10.1 f 1.5 +0.1 -0.05 2.00.1 4.00.1 1.750.1 3.50.1 8.00.2 3.05 0.2 (3.1) 0.3 (3.2) 0.3 www..net small package pwm control step-up switching regulator S-8323/8327 series seiko instruments inc. 27 1-3 sot-89-3 2. reel specifications 2-1 sot-23-5/sot-23-3 one reel holds 3000 regulators. type t2 feed direction f 180 0 -3 12.5 max. f 60 +1 0 (dimension of external reel core) ( 1.5 ) unit: mm 3 or less 9.00.3 (dimension of inner reel core) 2.00.05 11.41.0 f 1.5 (dimension of inner reel core) 4.00.1(total10 : 40.00.2) 4.750.1 8.00.1 10.50.4 +0.1 -0 0.30.05 2.00.1 f 130.2 (60 ) (60 ) 20.2 unit: mm figure 36 5 or less figure 35 4.350.1 1.50.1 5.650.05 120.2 www..net small package pwm control step-up switching regulator S-8323/8327 series 28 seiko instruments inc. 2-2 sot-89-3 one reel holds 1000 regulators. f 180 0 -3 16.5 max. f 60 +1 0 (dimension of external reel core) (1.5) 13.00.3 (dimension of inner reel core) 15.41.0 (dimension of inner reel core) 10.50.4 f 130.2 (60 ) (60 ) 20.2 unit: mm figure 37 www..net small package pwm control step-up switching regulator S-8323/8327 series seiko instruments inc. 29 temperature characteristics v st1 - ta v st2 - ta i ss1 - ta i ss2 - ta i sss - ta i sw - ta i swq - ta f osc - ta 20 80 60 40 0 -20 -40 100 0.0 v out =3.0v, fosc=50khz type 1.2 1.0 0.8 0.6 0.4 0.2 20 80 60 40 0 -20 -40 100 0.0 v out =3.0v, fosc=50khz type 0.2 0.4 0.6 0.8 1.0 20 80 60 40 0 -20 -40 100 0 v out =3.0v, fosc=50khz type 10 20 30 40 50 v st1 (v) v st2 (v) 20 80 60 40 0 -20 -40 100 0 S-8323 v out =3.0v, fosc=50khz type 1 2 3 4 5 20 80 60 40 0 -20 -40 100 0.0 S-8323 v out =3.0v, fosc=50khz type 0.2 0.4 0.6 0.8 1.0 ta ( c) ta ( c) ta ( c) ta ( c) i ss1 ( m a) i ss2 ( m a) S-8323 S-8323 S-8323 S-8323 20 80 60 40 0 -20 -40 100 0 v out =3.0v, fosc=50khz type 200 175 150 125 100 75 50 25 ta ( c) ta ( c) i sss (( m a) i sw (ma) 20 80 60 40 0 -20 -40 100 0.0 v out =3.0v, fosc=50khz type 0.2 0.4 0.6 0.8 1.0 20 80 60 40 0 -20 -40 100 30 v out =3.0v, fosc=50khz type 70 65 60 55 50 45 40 35 i swq (( m a) fosc (khz) S-8323 S-8323 ta ( c) ta ( c) www..net small package pwm control step-up switching regulator S-8323/8327 series 30 seiko instruments inc. maxduty - ta v sh - ta v sl1 - ta v sl2 - ta t ss - ta i exth - ta i extl - ta 20 80 60 40 0 -20 -40 100 50 S-8323 v out =3.0v, fosc=50khz type 60 70 80 90 100 20 80 60 40 0 -20 -40 100 0.0 S-8323 v out =3.0v, fosc=50khz type 0.2 0.4 0.6 0.8 1.0 maxduty (%) ta ( c) 20 80 60 40 0 -20 -40 100 0.0 S-8323 v out =3.0v, fosc=50khz type 0.2 0.4 0.6 0.8 1.0 v sh (v) v sl1 (v) 20 80 60 40 0 -20 -40 100 0.0 S-8323 v out =3.0v, fosc=50khz type 0.2 0.4 0.6 0.8 1.0 ta ( c) ta ( c) 20 80 60 40 0 -20 -40 100 S-8323 v out =3.0v, fosc=50khz type 14.0 12.0 10.0 8.0 6.0 4.0 2.0 0.0 ta ( c) ta ( c) 20 80 60 40 0 -20 -40 100 -0 s-8327 v out =3.0v, fosc=100khz type -16 s-8327 v out =3.0v, fosc=100khz type -14 -12 -10 -8 -6 -4 -2 20 80 60 40 0 -20 -40 100 0 16 14 12 10 8 6 4 2 v sl2 (v) t ss (ms) i exth (ma) i extl (ma) ta ( c) ta ( c) www..net small package pwm control step-up switching regulator S-8323/8327 series seiko instruments inc. 31 voltage characteristics i ss1 , 2 - v out i sw - v out f osc - v out 2 8 6 4 0 10 0 S-8323 ta=25 c, v out =5.0v, fosc=50khz type 10 20 30 40 50 S-8323 1 4 3 2 0 5 0 ta=25 c, v out =5.0v, fosc=50khz type 50 100 150 200 250 v out (v) v out (v) i ss1 i ss2 ( m a) i sw (ma) 1 4 3 2 0 5 30 S-8323 ta=25 c, v out =5.0v, fosc=50khz type 40 50 60 70 f osc (khz) v out (v) www..net small package pwm control step-up switching regulator S-8323/8327 series 32 seiko instruments inc. ripple characteristics S-8323a30 1. light load (i out =200 m a) v in =1.8v 2. medium load (i out =10ma) 3. heavy load (i out =60ma) t (10 m sec / div) output voltage (10mv/div) (10mv/div) 0v 3v cont voltage (1v/div) t (10 m sec / div) 0v 3v cont voltage (1v/div) t (10 m sec / div) 0v 3v cont voltage (1v/div) output voltage ( 10mv/div ) output voltage (10mv/div) v in =1.8v v in =1.8v s-8327b30 1. light load (i out =200 m a) 2. medium load (i out =10ma) 3. heavy load (i out =200ma) t (5 m sec / div) output voltage (10mv/di v) output voltage (10mv/di v) output voltage (10mv/di v) output voltage (10mv/di v) output voltage (10mv/di v) output voltage (10mv/di v) output voltage (10mv/div) 0v 3v cont voltage (1v/div) t (5 m sec / div) 0v 3v cont voltage (1v/div) t (5 m sec / div) 0v 3v cont voltage (1v/div) output voltage (10mv/div) output voltage (20mv/div) v in =1.8v v in =1.8v v in =1.8v www..net small package pwm control step-up switching regulator S-8323/8327 series seiko instruments inc. 33 transient responses 1. powering on due to v in (v in : 0v ? 1.8v) S-8323a30 (light load:i out =1ma) S-8323a30 (heavy load:i out =60ma) s-8327b30 (light load:i out =1ma) s-8327b30 (heavy load:i out =200ma) t (1msec/div) 2v input vol. (1v/div) 0v output v. (1v/div) 3v 0v t (1msec/div) 2v input vol. (1v/div) 0v output v. (1v/div) 3v 0v t (1msec/div) 2v input vol. (1v/div) 0v output v. (1v/div) 3v 0v t (1msec/div) 2v input vol. (1v/div) 0v output v. (1v/div) 3v 0v 2. powering on due to shutdown pin (von/off : 0v ? 3.0v) S-8323a30 (light load:i out =1ma) S-8323a30 (heavy load:i out =60ma) s-8327b30 (light load:i out =1ma) v in =1.8v s-8327b30 (heavy load:i out =200ma) v in =1.8v t (1msec/div) 3v input vol. (1v/div) 0v output v. (1v/div) 3v 0v v in =1.8v t (1msec/div) 3v input vol. (1v/div) 0v output v. (1v/div) 3v 0v t (1msec/div) 3v input vol. (1v/div) 0v output v. (1v/div) 3v 0v t (1msec/div) 3v input vol. (1v/div) 0v output v. (1v/div) 3v 0v v in =1.8v www..net small package pwm control step-up switching regulator S-8323/8327 series 34 seiko instruments inc. 3. load fluctuations S-8323a30 (i out :100 m a ? 50ma) v in =1.8v S-8323a30 (i out :50ma ? 100 m a) v in =1.8v s-8327b30 (i out :100 m a ? 100ma) v in =1.8v s-8327b30 (i out :100ma ? 100 m a) v in =1.8v t (100 m sec/div) 3v output vol. (50mv/div) 100 m a 50ma load current t (5msec/div) 3v output vol. (50mv/div) 100 m a 50ma load current t (100 m sec/div) 3v output vol. (50mv/div) 100 m a 100ma load current t (5msec/div) 3v output vol. (50mv/div) 100 m a 100ma load current 4. power voltage fluctuations S-8323a30 (v in :1.8v ? 2.4v) i out =50ma S-8323a30 (v in :2.4v ? 1.8v) i out =50ma s-8327b30 (v in :1.8v ? 2.4v) i out =100ma s-8327b30 (v in :2.4v ? 1.8v) i out =100ma t (100 m sec/div) 3v output vol. (25mv/div) input vol. (0.2v/div) 1.8v 2.4v t (100 m sec/div) 3v output vol. (25mv/div) input vol. (0.2v/div) 1.8v 2.4v t (100 m sec/div) 3v output vol. (25mv/div) input vol. (0.2v/div) 1.8v 2.4v t (100 m sec/div) 3v output vol. (25mv/div) input vol. (0.2v/div) 1.8v 2.4v www..net small package pwm control step-up switching regulator S-8323/8327 series seiko instruments inc. 35 operation start voltage and operation holding voltage characteristics for output current S-8323a30 S-8323a50 s- 8327b30 s-8327b50 0.0 0.2 0.4 0.6 0.8 1.0 0246810 output current i out (ma) input voltage v in (v) vst1 vhld 0.0 0.2 0.4 0.6 0.8 1.0 0246810 output current i out (ma) vst1 vhld 0.0 0.2 0.4 0.6 0.8 1.0 0246810 output current i out (ma) input voltage v in (v) vst1 vhld 0.0 0.2 0.4 0.6 0.8 1.0 0246810 output current i out (ma) input voltage v in (v) vst1 vhld input voltage v in (v) input voltage characteristics for input current S-8323a s-8327b 0 100 200 300 400 012345 input voltage v in (v) input current i in ( m a) input current i in ( m a) vout=2v vout=3v vout=5v 0 10 20 30 40 50 012345 input voltage v in (v) vout=3v,rb=300 w vout=3v,rb=1k w vout=5v,rb=300 w vout=5v,rb=1k w www..net small package pwm control step-up switching regulator S-8323/8327 series 36 seiko instruments inc. reference data use reference data to choose the external parts. reference data give yor the procedure to choose the recommended external parts for various applications and its characteristics data. 1. procedure to choose the most suitable condition from reference data. start choose the desired output voltage choose the condition for desired output current operation efficiency is more important rather than stand-by efficiency? *1 *2 *3 no yes choose the best condition for operation efficiency. stand-by efficiency is ok? *4 choose next best condition for operation efficiency choose the best condition for stand-by efficiency. operation efficienc y is ok? *4 *4 choose next best condition for stand-by efficiency no *4 *5 ripple voltage is ok? increase output current yes *5 no end yes *4 *4 *1) choose desired output voltage from conditions (1) to (17) shown in table 1 and 2. when desired output voltage does not exist in tables, choose the next higher voltage. for instance, when v out =3v for S-8323, choose from conditions (3) to (6). *2) choose all conditions from conditions choosed above for output current needed for input voltage (min) of the operational condition from reference data 1 (a) output voltage characteristics for output current . for instance, when 10ma output current is needed at v in =0.9v, choose from conditions (4) to (6). *3) stand-by efficiency means the efficiency when the output current is small (approx. 100 m a), operation efficiency means the efficiency when the output current is large (several ma). for instance, go to yes when operation efficiency is more important rather than stand-by efficiency. *4) read the efficiency for input voltage and output current in operational condition from reference data 1 (b) efficiency characteristics for output current . for instance, when v in =0.9v at i out =10ma, the efficiency is max. (75%) in condition (6) in (4) to (6). there is no difference between conditions (4) to (6) when the output current is 100 m a at stand-by condition. therefore, choose condition (6). *5) read the ripple voltage under the operational condition selected above from reference data 2 ripple voltage characteristics for output current . for instance, when condition (6) is selected above, the ripple voltage is mv at v in =0.9v and i out =10ma. no yes www..net small package pwm control step-up switching regulator S-8323/8327 series seiko instruments inc. 37 table 1 S-8323 series no. v out model name of l l value d c out (1) (2) (3) (4) (5) (6) (7) (8) (9) 2v 2v 3v 3v 3v 3v 5v 5v 5v lqh3c lqh4n lqh4n cd54 cd54 cd54 cd54 cd54 cd54 220 m h 220 m h 220 m h 47 m h 100 m h 220 m h 47 m h 100 m h 220 m h ma720 - - - - - - - - 22 m f - - - - - - - - table 2 s-8327 series no. v out model name of l l value rb cb d c out (10) (11) (12) (13) (14) (15) (16) (17) 3v 3v 3v 3v 5v 5v 5v 5v cd105 cd105 cd54 d75c cd105 cd105 cd54 d75c 22 m h 22 m h 47 m h 47 m h 22 m h 22 m h 47 m h 47 m h 300 w 1k w 1k w 1k w 300 w 1k w 1k w 1k w 0.01 m f 0.0022 m f 0.0022 m f 0.0022 m f 0.01 m f 0.0022 m f 0.0022 m f 0.0022 m f ma735 ma735 ma720 ma720 ma735 ma735 ma720 ma720 47 m f 2 47 m f 2 47 m f 47 m f 47 m f 2 47 m f 2 47 m f 47 m f table 3 shows the efficiency of the external parts. table 3 part model name vendor l value dc resistance max allowable current diameter height cd105 sumida 22 m h 0.10 w 1.95a 10.0mm 5.4mm cd54 - 47 m h 0.37 w 0.72a 5.8mm 4.5mm -- 100 m h 0.70 w 0.52a -- -- 220 m h 1.57 w 0.35a -- inductor lqh4n murata 220 m h 5.40 w 0.11a 4.5mm 2.6mm lqh3c - 220 m h 8.40 w 0.07a 3.2mm 2.0mm d75c toko 47 m h 0.20 w 0.76a 7.6mm 5.1mm -- 100 m h 0.40 w 0.50a -- diode ma720 matsushita forward current 500ma (at v f =0.55v) (schottkey) ma735 - forward current 1a (at v f =0.5v) output capacitor f93 nichicon external transistor 2sd1628g sanyo www..net small package pwm control step-up switching regulator S-8323/8327 series 38 seiko instruments inc. choose a suitable inductor according to the figure 31, referring to table 3. (a) output voltage characteristics for output current and (b) efficiency characteristics for output current under conditions (1) to (17) shown in tables 1 and 2 are shown below. (1) S-8323a20 (lqh3c:220 m h) (a)outpur current - output voltage (b)output current - efficiency 1.95 1.97 1.99 2.01 2.03 2.05 0.01 0.1 1. 10. 100. output current i out (ma) output voltage v out (v) vin=0.9v vin=1.0v vin=1.2v vin=1.6v 50 60 70 80 90 100 0.01 0.1 1. 10. 100. output current i out (ma) efficiency h (%) vin=0.9v vin=1.0v vin=1.2v vin=1.6v (2) S-8323a20 (lqh4n:220 m h) (a)output current - output voltage (b)output current - efficiency 1.95 1.97 1.99 2.01 2.03 2.05 0.01 0.1 1. 10. 100. output current i out (ma) output voltage v out (v) vin=0.9v vin=1.0v vin=1.2v vin=1.6v efficiency h (%) 50 60 70 80 90 100 0.01 0.1 1. 10. 100. output current i out (ma) vin=0.9v vin=1.0v vin=1.2v vin=1.6v reference data 1 S-8323 (built-in switching transistor lqh3 2v 3v 5v lqh4 cd5 cd10 cd5 s-8327 (with an external switching transistor) 10ma 100ma 1a figure 38 inductors for output current output voltage output current www..net small package pwm control step-up switching regulator S-8323/8327 series seiko instruments inc. 39 (3) S-8323a30 (lqh4n:220 m h) (a)output current - output voltage (b)output current - efficiency 2.95 2.97 2.99 3.01 3.03 3.05 0.01 0.1 1. 10. 100. 1000. output current i out (ma) output voltage v out (v) vin=0.9v vin=1.2v vin=1.8v vin=2.4v 50 60 70 80 90 100 0.01 0.1 1. 10. 100. 1000. output current i out (ma) efficiency h (%) vin=0.9v vin=1.2v vin=1.8v vin=2.4v (4) S-8323a30 (cd54:47 m h) (a)output current - output voltage (b)output current - efficiency 2.95 2.97 2.99 3.01 3.03 3.05 0.01 0.1 1. 10. 100. 1000. output current i out (ma) output voltage v out (v) vin=0.9v vin=1.0v vin=1.2v vin=1.6v 50 60 70 80 90 100 0.01 0.1 1. 10. 100. 1000. output current i out (ma) efficiency h ( % ) vin=0.9v vin=1.0v vin=1.2v vin=1.6v (5) s-5323a30 (cd54:100 m h) (a)output current - output voltage (b)output current - efficiency 2.95 2.97 2.99 3.01 3.03 3.05 0.01 0.1 1. 10. 100. 1000. output current i out (ma) output voltage v out (v) vin=0.9v vin=1.2v vin=1.8v vin=2.4v 50 60 70 80 90 100 0.01 0.1 1. 10. 100. 1000. output current i out (ma) efficiency h (%) vin=0.9v vin=1.2v vin=1.8v vin=2.4v (6) S-8323a30 (cd54:220 m h) (a)output current - output voltage (b)output current - efficiency 2.95 2.97 2.99 3.01 3.03 3.05 0.01 0.1 1. 10. 100. 1000. output current i out (ma) output voltage v out (v) vin=0.9v vin=1.2v vin=1.8v vin=2.4v 50 60 70 80 90 100 0.01 0.1 1. 10. 100. 1000. output current i out (ma) efficiency h (%) vin=0.9v vin=1.2v vin=1.8v vin=2.4v www..net small package pwm control step-up switching regulator S-8323/8327 series 40 seiko instruments inc. (7) S-8323a50 (cd54:47 m h) (a)output current - output voltage (b)output current - efficiency 4.90 4.94 4.98 5.02 5.06 5.10 0.01 0.1 1. 10. 100. 1000. output current i out (ma) output voltage v out (v) vin=0.9v vin=1.8v vin=3.0v vin=4.0v 50 60 70 80 90 100 0.01 0.1 1. 10. 100. 1000. output current i out (ma) efficiency h (%) vin=0.9v vin=1.8v vin=3.0v vin=4.0v (8) S-8323a50 (cd54:100 m h) (a)output current - output voltage (b)output current - efficiency 4.90 4.94 4.98 5.02 5.06 5.10 0.01 0.1 1. 10. 100. 1000. output current i out (ma) output voltage v out (v) vin=0.9v vin=1.8v vin=3.0v vin=4.0v 50 60 70 80 90 100 0.01 0.1 1. 10. 100. 1000. output current i out (ma) efficiency h (%) vin=0.9v vin=1.8v vin=3.0v vin=4.0v (9) S-8323a50 (cd54:220 m h) (a) output current - output voltage (b)output current - efficiency 4.90 4.94 4.98 5.02 5.06 5.10 0.01 0.1 1. 10. 100. 1000. output current i out (ma) output voltage v out (v) vin=0.9v vin=1.8v vin=3.0v vin=4.0v 50 60 70 80 90 100 0.01 0.1 1. 10. 100. 1000. output current i out (ma) efficiency h (%) vin=0.9v vin=1.8v vin=3.0v vin=4.0v www..net small package pwm control step-up switching regulator S-8323/8327 series seiko instruments inc. 41 (10) s-8327b30 (cd105:22 m h,rb=300 w ,cb=0.01 m f) (a)output current - output voltage (b)output current - efficiency 2.95 2.97 2.99 3.01 3.03 3.05 0.01 0.1 1. 10. 100. 1000. output current i out (ma) vin=0.9v vin=1.2v vin=1.8v vin=2.4v 0 20 40 60 80 100 0.01 0.1 1. 10. 100. 1000. output current i out (ma) vin=0.9v vin=1.2v vin=1.8v vin=2.4v output voltage v out (v) efficiency h (%) (11) s-8327b30 (cd105:22 m h,rb=1k w ,cb=0.0022 m f) (a)output current - output voltage (b)output current - efficiency 2.95 2.97 2.99 3.01 3.03 3.05 0.01 0.1 1. 10. 100. 1000. output current i out (ma) vin=0.9v vin=1.2v vin=1.8v vin=2.4v 0 20 40 60 80 100 0.01 0.1 1. 10. 100. 1000. output current i out (ma) vin=0.9v vin=1.2v vin=1.8v vin=2.4v output voltage v out (v) efficiency h (%) (12) s-8327b30 (cd54:47 m h,rb=1k w ,cb=0.0022 m f) (a)output current - output voltage (b)output current - efficiency 2.95 2.97 2.99 3.01 3.03 3.05 0.01 0.1 1. 10. 100. 1000. output current i out (ma) vin=0.9v vin=1.2v vin=1.8v vin=2.4v 0 20 40 60 80 100 0.01 0.1 1. 10. 100. 1000. output current i out (ma) vin=0.9v vin=1.2v vin=1.8v vin=2.4v output voltage v out (v) efficiency h (%) (13) s-8327b30 (d75c:47 m h,rb=1k w ,cb=0.0022 m f) (a)output current - output voltage (b)output current - efficiency 2.95 2.97 2.99 3.01 3.03 3.05 0.01 0.1 1. 10. 100. 1000. output current i out (ma) vin=0.9v vin=1.2v vin=1.8v vin=2.4v 0 20 40 60 80 100 0.01 0.1 1. 10. 100. 1000. output current i out (ma) vin=0.9v vin=1.2v vin=1.8v vin=2.4v output voltage v out (v) efficiency h (%) www..net small package pwm control step-up switching regulator S-8323/8327 series 42 seiko instruments inc. (14)s-8327b50 (cd105:22 m h,rb=300 w ,cb=0.01 m f) (a)output current - output voltage (b)output current - efficiency 4.90 4.94 4.98 5.02 5.06 5.10 0.01 0.1 1. 10. 100. 1000. 10000. output current i out (ma) vin=0.9v vin=1.8v vin=3.0v vin=4.0v 0 20 40 60 80 100 0.01 0.1 1. 10. 100. 1000. 10000. output current i out (ma) vin=0.9v vin=1.8v vin=3.0v vin=4.0v output voltage v out (v) efficiency h (%) (15)s-8327b50 (cd105:22 m h,rb=1k w ,cb=0.0022 m f) (a)output current - output voltage (b)output current - efficiency 4.90 4.94 4.98 5.02 5.06 5.10 0.01 0.1 1. 10. 100. 1000. 10000. output current i out (ma) vin=0.9v vin=1.8v vin=3.0v vin=4.0v 0 20 40 60 80 100 0.01 0.1 1. 10. 100. 1000. 10000. output current i out (ma) vin=0.9v vin=1.8v vin=3.0v vin=4.0v output voltage v out (v) efficiency h (%) (16)s-8327b50 (cd54:47 m h,rb=1k w ,cb=0.0022 m f) (a)output current - output voltage (b)output current - efficiency 4.90 4.94 4.98 5.02 5.06 5.10 0.01 0.1 1. 10. 100. 1000. 10000. output current i out (ma) vin=0.9v vin=1.8v vin=3.0v vin=4.0v 0 20 40 60 80 100 0.01 0.1 1. 10. 100. 1000. 10000. output current i out (ma) vin=0.9v vin=1.8v vin=3.0v vin=4.0v output voltage v out (v) efficiency h (%) (17)s-8327b50 (d75c:47 m h,rb=1k w ,cb=0.0022 m f) (a)output current - output voltage (b)output current - efficiency 4.90 4.94 4.98 5.02 5.06 5.10 0.01 0.1 1. 10. 100. 1000. 10000. output current i out (ma) vin=0.9v vin=1.8v vin=3.0v vin=4.0v 0 20 40 60 80 100 0.01 0.1 1. 10. 100. 1000. 10000. output current i out (ma) vin=0.9v vin=1.8v vin=3.0v vin=4.0v output voltage v out (v) efficiency h (%) www..net small package pwm control step-up switching regulator S-8323/8327 series seiko instruments inc. 43 the ripple voltage characteristics data is shown below: (1)S-8323a20 (2)S-8323a20 (lqh3c:220 m h, c out :22 m f) (lqh4n:220 m h, c out :22 m f) similar to (2) (3)S-8323a30 (lqh4n:220 m h, c out :22 m f) similar to (6) (4)S-8323a30 (7)S-8323a50 (cd54:47 m h, c out :22 m f) (cd54:47 m h, c out :22 m f) 0 20 40 60 80 100 0.1 1. 10. 100. 1000. output current i out (ma) ripple voltage vr(mv) vin=0.9v vin=1.8v vin=2.4v 0 20 40 60 80 100 120 0.1 1. 10. 100. 1000. output current i out (ma) vin=0.9v vin=3.0v vin=4.0v ripple voltage vr(mv) (5)S-8323a30 (8)S-8323a50 (cd54:100 m h, c out :22 m f) (cd54:100 m h, c out :22 m f) 0 20 40 60 80 100 0.1 1. 10. 100. 1000. output current i out (ma) ripple voltage vr(mv) vin=0.9v vin=1.8v vin=2.4v 0 20 40 60 80 100 0.1 1. 10. 100. 1000. output current i out (ma) vin=0.9v vin=3.0v vin=4.0v ripple voltage vr(mv) reference data 2 0 20 40 60 80 100 0.1 1. 10. 100. 1000. output current i out (ma) ripple voltage vr(mv) vin=0.9v vin=1.2v vin=1.6v www..net small package pwm control step-up switching regulator S-8323/8327 series 44 seiko instruments inc. (6)S-8323a30 (9)S-8323a50 (cd54:220 m h, c out :22 m f) (cd54:220 m h, c out :22 m f) 0 20 40 60 80 100 0.1 1. 10. 100. 1000. output current i out (ma) ripple voltage vr(mv) vin=0.9v vin=1.8v vin=2.4v 0 20 40 60 80 100 0.1 1. 10. 100. 1000. output current i out (ma) ripple voltage vr(mv) vin=0.9v vin=3.0v vin=4.0v (10)(11)s-8327b30 (14)(15)s-8327b50 (cd105:22 m h, c out :47 m f 2) (cd105:22 m h, c out :47 m f 2) 0 20 40 60 80 100 0.1 1. 10. 100. 1000. output current i out (ma) ripple voltage vr(mv) 0 20 40 60 80 100 0.1 1. 10. 100. 1000. output current i out (ma) ripple voltage vr(mv) vin=0.9v vin=3.0v vin=4.0v vin=0.9v vin=1.8v vin=2.4v (12)s-8327b30 (16)s-8327b50 (cd54:47 m h, c out :47 m f) (cd105:47 m h, c out :47 m f) 0 20 40 60 80 100 0.1 1. 10. 100. 1000. output current i out (ma) ripple voltage vr(mv) vin=0.9v vin=1.8v vin=2.4v 0 20 40 60 80 100 0.1 1. 10. 100. 1000. output current i out (ma) ripple voltage vr(mv) vin=0.9v vin=3.0v vin=4.0v (13)s-8327b30 (16)s-8327b50 (d75c:47 m h, c out :47 m f) (d75c:47 m h, c out :47 m f) similar to (12) similar to (16) www..net 4 5 collection of product faqs author: tachibana midori date: 98/11/12 (thursday) 10:17 (modified:) 4 6 2200pf on/off pwm control circuit (r1 + r2)/r2 c out ss r2 r1 vref vref vout v v out sd ext 1k w l soft-start circuit c in v in waveforms t (1msec/div) 2v input voltage (1v/div) 0v output voltage (1v/div) 3v 0v vout vref 4 7 collection of product faqs author: tachibana midori date: 98/11/12 (thursday) 10:17 (modified:) 48 the minimum value (veemin.) and maximum value (veemax.) of the output-voltage adjustment range are defined as follows: 1. disregard tr2 and re, and set ra, rb, and cc such that the output voltage will be less than veemin. the procedure for this should comply with faq no. 11s8323007. (in particular, use of the software is recommended.) 2. then, set an re that will allow the output voltage to exceed veemax. when tr2 comes on. such a value can be found using the following equation, where outmin. is the minimum deviation value (outmin. resulting from software calculation) of the voltage vee computed in 1. above, vdacmax. is the maximum value of the dac output, and vbe is the base-emitter voltage of tr2. (however, deviations in the resistance values of ra and rb must be taken into consideration.) ( ) ( ) ra outmin veemax vbe vdacmax re tr2 is a transistor designed for small signals. select one that features a withstand voltage that is higher than the output voltage vee to be set. moreover, select an output voltage vout of the s- 8327/8e that will allow the following condition to be met and will not allow saturated operation of tr2. vout 3 vdacmax+vbe 49 collection of product faqs author: tachibana midori date: 98/11/ 12 (thursday) 10:17 (modified:) 50 waveform 1 -13.0 -11.0 -9.0 -7.0 -5.0 -3.0 -1.0 1.0 3.0 5.0 7.0 -0.001 0.000 0 .001 0.001 0 .002 0.002 time (sec) cont voltage (v) -0.1 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 coil current ( a ) cont il soft-start motion fault phenomenon q1 on in the output-voltage boosting circuit shown in figure 1, when the vdd switch (q1) comes on to initiate voltage boosting, full-duty switching is observed prior to the soft-start motion, as can be seen in waveform 1, and a failure occurs, causing a large rush current to flow from vin and the vin voltage to drop. this occurs if the vout terminal voltage falls (vin x rb ? (ra+rb)) due to the addition of ra and rb when the vdd switch (q1) comes on. as a result, an extended period is required to set the output voltage of the internal error amplifier circuit. one means of preventing this malfunction of the internal error amplifier circuit is turning off q2 at the moment the vdd switch (q1) goes off, so that vout will be m ade equal to the vdd level via ra, as shown in figure 2. (normally, ra and rb are cut off in order to eliminate the reactive current generated when the power is switched off.) gnd ext 10uf + - vss vout cin sd l tr1 s-8327e50 out vdd vin 150uh 3.3v 15v cout 20uf figure 2 q1 internal circuit ra rb cc coil current cont voltage on/off on/off q2 51 collection of product faqs author: tachibana midori date: 98/11/12 (thursday) 10:17 (modified:) 52 collection of product faqs author: tachibana midori date: 98/11/12 (thursday) 10:17 (modified:) 53 control circuit m1 vout vss cont vin l c + - sample boosting circuit: vin 54 collection of product faqs author: tachibana midori date: 98/11/12 (thursday) 10:17 (modified:) 55 waveforms 4.88 4.90 4.92 4.94 4.96 4.98 5.00 -0.00001 -0.000005 0 0.000005 0.00001 time (sec) output voltage vout (v) 0.40 0.60 0.80 1.00 1.20 1.40 1.60 coil current icoil (a) vout icoil s-8328b50 vin=1.8v,iout=200ma iout=200ma l contave ton 56 collection of product faqs author: tachibana midori date: 98/11/12 (thursday) 10:17 (modified: ) 57 collection of product faqs author: tachibana midori date: 98/11/12 (thursday) 10:17 (modified: ) 58 0 5 10 15 20 25 0.001 0.01 0.1 1 10 100 time (sec) ?C e 1? ? (w ) 0 5 10 15 20 25 0.001 0.01 0.1 1 10 100 (w) tpk (sec) power dissipation 59 collection of product faqs author: tachibana midori date: 98/11/12 (thursday) 10:17 (modified: ) 6 0 compared with figure 1, additional external parts are also required (two trs and a capacitor). gnd ext + - vss vout cin sd l tr1 s-8327/8e out vdd vin cout1 figure 2 internal circuit ra rb cc cout2 tr4 tr5 tr3 on/off on/off tr2 r1 r2 rc 61 collection of product faqs author: tachibana midori date: 98/11/12 (thursday) 10:17 (modified: ) 62 gnd ext + - vss vout cin sd l tr1 s-8327/8e out vdd vin cout1 figure 2 internal circuit ra rb cc tr3 on/off on/off tr2 r1 r2 63 collection of product faqs author: tachibana midori date: 98/11/12 (thursday) 10:17 (modified: ) 64 collection of product faqs author: tachibana midori date: 98/11/12 (thursday) 10:17 (modified: ) |
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