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www.ams.com/dc-dc_step-up/as1329 revision 1.12 1 - 20 a s1 3 2 9 l o w vo lt a g e, m i c ro p o w e r, d c- dc s t ep - u p c o n v e r te r s 1 general description the as1329a, as1329b and the as1329c are synchronou s, fixed frequency, very high-efficiency dc-dc boost convert ers capable of supplying 3.3v at 160ma from a single aa-supply. co mpact size and minimum external parts requirements make these devi ces perfect for modern portable devices. high-speed switching frequency (1.2mhz) and interna lly compensated pwm current mode design provide highly- reliable dc- dc conversion, especially when driving white leds. the converters are available as the standard products listed in table 1 . the devices contain two internal mosfet switches: o ne nmos switch and one pmos synchronous rectifier. anti-rin ging control circuitry reduces emi by damping the inductor in di scontinuous mode, and the devices exhibit extremely low quiesce nt current (< 1a) in shutdown. in shutdown mode the battery is connected directly to the output enabling the supply of real-time-clocks. the as1329 is available in a 6-pin tsot-23 package. figure 1. typical application diagram C single cel l to 3.3v synchronous boost converter 2 key features low start-up voltage: 0.85v output range: 2.5v to 5.0v single-cell operation operating with coils down to 2.2h delivers 160ma @ 3.3v (from single aa cell) delivers 220ma @ 5.0v (from two aa cells) delivers 570ma @ 3.3v (from two aa cells) 95% efficiency high-speed fixed-frequency: 1.2mhz internal pmos synchronous rectifier automatic powersave operation (as1329a&b) continuous switching at light loads (as1329c) logic controlled shutdown (< 1a) 6-pin tsot-23 package 3 applications the as1329 is ideal for low-power applications wher e ultra-small size is critical as in medical diagnostic equipment , hand-held instruments, pagers, digital cameras, remote wirele ss transmitters, mp3 players, lcd bias supplies, cordless phones, gp s receivers, and pc cards. table 1. standard products model light load switching as1329a medium load automatic powersave operation as1329b light load automatic powersave operation as1329c continuous switching aa battery as1329 c 2 10f r 2 604k w 1% r 1 1.02m w 1% on off l1 4.7h c 1 10f gnd 2 sw 1 v out 3.3v 160ma 4 shdnn 3 fb 6 vin 5 vout
www.ams.com/dc-dc_step-up/as1329 revision 1.12 2 - 20 as1329 datasheet - p i n a s s i g n m e n t s 4 pin assignments figure 2. pin assignments (top view) 4.1 pin descriptions table 2. pin descriptions pin number pin name description 1 sw switch pin . connect an inductor between this pin and v in . keep the pcb trace lengths as short and wide as is practical to reduce emi and vo ltage overshoot. if the inductor current falls to zero, or pin shdnn is low, an internal 100 w anti-ringing switch is connected from this pin to v in to minimize emi. note: an optional schottky diode can be connected between this pin and v out . 2 gnd signal and power ground . provide a short, direct pcb path between this pin and the negative side of the output capacitor(s). 3 fb feedback pin . feedback input to the g m error amplifier. connect a resistor divider tap to this pin. the output voltage can be adjusted from 2.5 to 5v by: v out = 1.23v[1 + (r 1 /r 2 )] 4 shdnn shutdown pin . logic controlled shutdown input. 1 = normal operation, 1.2mhz typical operating freq uency. 0 = shutdown; quiescent current <1a. if shdnn is u ndefined, pin sw may ring. note: in a typical application, shdnn should be connected to v in through a 1m w pull-up resistor. 5 vout output voltage sense input and drain of the interna l pmos synchronous rectifier . bias is derived from v out when v out exceeds v in . pcb trace length from v out to the output filter capacitor(s) should be as short and w ide as is practical. 6 vin input voltage . the as1329 gets its start-up bias from v in unless v out exceeds v in , in which case the bias is derived from v out . thus, once started, operation is completely independent from v in . operation is only limited by the output power lev el and the internal series resistance of the supply. 1 sw as1329 2 gnd 3 fb 6 vin 5 vout 4 shdnn
www.ams.com/dc-dc_step-up/as1329 revision 1.12 3 - 20 as1329 datasheet - a b s o l u t e m a x i m u m r a t i n g s 5 absolute maximum ratings stresses beyond those listed in table 3 may cause permanent damage to the device. these ar e stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in section 6 electrical characteristics on page 4 is not implied. exposure to absolute maximum rating conditions for extended per iods may affect device reliability. table 3. absolute maximum ratings parameter min max units notes vin to gnd -0.3 7 v shdnn, sw to gnd -0.3 7 v fb to gnd -0.3 5 v vout -0.3 7 v operating temperature range -40 +85 oc storage temperature range -65 +125 oc package body temperature +260 oc the reflow peak soldering temperature (body temperature) specified is in accordance with ipc/ jedec j-std-020 moisture/reflow sensitivity classification for non-hermetic solid state surface mount devices. the lead finish for pb-free leaded packages is matte tin (100% sn). moisture sensitive level 1 represents an unlimited floor life time
www.ams.com/dc-dc_step-up/as1329 revision 1.12 4 - 20 as1329 datasheet - e l e c t r i c a l c h a r a c t e r i s t i c s 6 electrical characteristics t amb = -40c to +85oc, v in = +1.2v, v out = +3.3v, v shdnn = +1.2v (unless otherwise specified). typ values @ t amb = +25oc. note: all limits are guaranteed. the parameters with min and max values are guaranteed with production tests or sqc (statistical quality control) methods. table 4. electrical characteristics symbol parameter conditions min typ max units minimum start-up voltage i load = 1ma 0.85 1 v minimum operating voltage shdnn = v in 1 1. minimum v in operation after start-up is only limited by the ba tterys ability to provide the necessary power as i t enters a deeply dis- charged state. 0.65 0.85 v maximum operating voltage shdnn = v in 1 5 v output voltage adjust range t amb = 25oc 2.5 5 v v fb feedback voltage t amb = t min to t max 1.192 1.23 1.268 v i fb feedback input current v fb = 1.25v 2 2. specification is guaranteed by design and not 100 % production tested. 1 na i qpws quiescent current (powersave operation) v fb = 1.4v 3 , as1329a only 3. i qpws is measured at v out . multiply this value by v out /v in to get the equivalent input (battery) current. 30 50 a i shdnn shutdown current v shdnn = 0v 0.01 1 a i q quiescent current (active) v fb = 1.4v 3 , as1329b&c only 150 300 a i nmosswl nmos switch leakage v sw = 5v 0.1 5 a i pmosswl pmos switch leakage v sw = 0v 0.1 5 a r onnmos nmos switch on resistance v out = 3.3v 0.35 0.8 w v out = 5v 4 4. specification is guaranteed by design and not 100 % production tested. 0.20 0.7 r onpmos pmos switch on resistance v out = 3.3v 0.45 0.8 w v out = 5v 4 0.30 0.7 i nmos nmos current limit v in = 2.5v 850 ma i ps powersave operation current threshold as1329a only 2 3 ma as1329b only 2 0.3 ma max duty cycle v fb = 1v, t amb = t min to t max 80 87 % f sw switching frequency t amb = 25oc 0.95 1.2 1.5 mhz t amb = t min to t max 0.85 1.2 1.5 v shdnnh shdnn input high 1 v v shdnnl shdnn input low 0.35 v i shdnn shdnn input current v shdnn = 5.0v 0.01 1 a
www.ams.com/dc-dc_step-up/as1329 revision 1.12 5 - 20 as1329 datasheet - ty p i c a l o p e r a t i n g c h a r a c t e r i s t i c s 7 typical operating characteristics all measurements are performed with as1329a, v out = 3.3v, t amb = +25oc, unless otherwise specified. parts used for measurements: l= 10h (mos6020-103ml ), c in and c out = 10f (grm31cr70j106ka01l) figure 3. v out vs. battery voltage; i out = 10ma figure 4. v out vs. temperature; i out = 10ma 0 0.5 1 1.5 2 2.5 3 3.5 0 0.5 1 1.5 2 2.5 3 3.5 battery voltage (v) output voltage (v) . 3.24 3.26 3.28 3.3 3.32 3.34 3.36 -50 -25 0 25 50 75 100 temperature (c) output voltage (v) . figure 5. startup voltage vs. output current figure 6. powersave threshold vs. input voltage 0.7 0.8 0.9 1 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 0.1 1 10 100 output current (ma) startup voltage (v) . vout = 3.3v vout = 5.0v 0 20 40 60 80 100 120 1 1.25 1.5 1.75 2 2.25 2.5 battery voltage (v) output current (ma) . as1329a as1329b figure 7. i out vs. v batt ; v out = 3.3v, 3% tolerance figure 8. i out vs. v batt ; v out = 5.0v, 3% tolerance 0 100 200 300 400 500 600 700 800 900 1000 0.5 1 1.5 2 2.5 3 battery voltage (v) output current (ma) . 0 100 200 300 400 500 600 700 800 900 0.5 1 1.5 2 2.5 3 3.5 4 battery voltage (v) output current (ma) .
www.ams.com/dc-dc_step-up/as1329 revision 1.12 6 - 20 as1329 datasheet - ty p i c a l o p e r a t i n g c h a r a c t e r i s t i c s figure 9. no load battery current vs. battery volt age; figure 10. efficiency vs. battery voltage; as 1329a 10 100 1000 1.2 1.4 1.6 1.8 2 2.2 2.4 2.6 2.8 3 battery voltage (v) battery current (a) . 20 30 40 50 60 70 80 90 100 0.7 1.2 1.7 2.2 2.7 3.2 battery voltage (v) efficiency (%) . il oad = 80a il oad = 800a il oad = 11ma figure 11. efficiency vs. output current of as1329 a figure 12. efficiency vs. output current of as132 9b 20 30 40 50 60 70 80 90 100 0.1 1 10 100 1000 output current (ma) efficiency (%) . vi n = 1.0v vi n = 1.5v vi n = 2.2v vi n = 2.4v 20 30 40 50 60 70 80 90 100 0.1 1 10 100 1000 output current (ma) efficiency (%) . vi n = 1.0v vi n = 1.5v vi n = 2.2v vi n = 2.4v figure 13. efficiency vs. output current of as1329 c figure 14. efficiency vs. i out comparison; v in = 2.0v 20 30 40 50 60 70 80 90 100 0.1 1 10 100 1000 output current (ma) efficiency (%) . vin = 1.0v vin = 1.5v vin = 2.2v 20 30 40 50 60 70 80 90 100 1 10 100 output current (ma) efficiency (%) . as1329a as1329b as1329c
www.ams.com/dc-dc_step-up/as1329 revision 1.12 7 - 20 as1329 datasheet - ty p i c a l o p e r a t i n g c h a r a c t e r i s t i c s figure 15. sw pin antiringing operation; v in = 1.3v, l = 10h, c = 10f, i out = 5ma figure 16. sw pin fixed frequency continuous curre nt; v in = 1.3v, l=10h, c=10f, i out = 100ma 100ns/div 0v 1v/div v sw 100ns/div v sw 0v 1v/div figure 17. v out transient response; v in = 1.3v, l = 10h, c = 10f figure 18. fixed frequency vs. powersave operation ; v in = 1.3v, l = 10h, c = 10f 100s/div v out(ac) i out 40ma 100ma 100mv/div 10ms/div v out(ac) 1ma 60ma 100mv/div i out
www.ams.com/dc-dc_step-up/as1329 revision 1.12 8 - 20 as1329 datasheet - d e t a i l e d d e s c r i p t i o n 8 detailed description the as1329 can operate from a single-cell input vol tage (v in ) below 1v, and features fixed frequency (1.2mhz) a nd current mode pwm control for exceptional line- and load-regulation. with low r ds(on) and gate charge internal nmos and pmos switches, t he device maintains high- efficiency from light to heavy loads. modern portable devices frequently spend extended t ime in low-power or standby modes, switching to hig h power-drain only when certain functions are enabled. the as1329a, as1329b and as1 329c are ideal for portable devices since they main tain high-power conversion efficiency over a wide output power range, thus inc reasing battery life in these types of devices. in addition to high-efficiency at moderate and heav y loads, the as1329a as well as the as1329b include s an automatic powersave mode that improves efficiency of the power converter at light loads. the powersave mode is initiated if the outp ut load current falls below a factory programmed threshold (see figure 6 on page 5) . note: the as1329c does not support powersave mode and pro vides continuous operation at all loads, eliminatin g low-frequency v out rip- ple at the expense of light load efficiency. figure 19. as1329 - block diagram 8.1 low-voltage start-up the as1329 requires v in of only 0.85v (typ) or higher to start up. the low -voltage start-up circuitry controls the internal n mos switch up to a maximum peak inductor current of 850ma (typ), with 1.5ms (approx.) off-time during start-up, allowing the devices to start up into an output load. with a v out > 2.3v, the start-up circuitry is disabled and nor mal fixed-frequency pwm operation is initiated. in this mode, the as1329 operates independent of v in , allowing extended operating time as the battery c an drop to several tenths of a volt without affecti ng output regulation. the limiting factor for the application is the ability of the battery to supply sufficient energy to the o utput. as1329 + C start up osc pwm control a/b mux slope compensator 1.2mhz ramp generator +C powersave operation control C shutdown control pwm comp s + C 1.23v ref sync drive control ab v out good 2.3v g m error amp shutdown powersave 0.35 w 0.45 w r 2 640k w 1% r 1 1.02m w 1% c ff * c out 4.7f 3.3v output c in 1f 1.5v single cell * optional current sense r c 80k w c p2 2.5pf c c 150pf gnd 2 sw 1 4 shdnn 3 fb 6 vin 5 vout l1 4.7h
www.ams.com/dc-dc_step-up/as1329 revision 1.12 9 - 20 as1329 datasheet - d e t a i l e d d e s c r i p t i o n 8.2 low-noise fixed-frequency operation 8.2.1 oscillator the as1329 switching frequency is internally fixed at 1.2mhz allowing the use of very small external c omponents. 8.2.2 error amplifier the integrated error amplifier is an internally com pensated trans-conductance (g m ) type (current output). the internal 1.23v referen ce voltage is compared to the voltage at pin fb to generate an er ror signal at the output of the error amplifier. a voltage divider from v out to gnd programs the output voltage from 2.5 to 5v via pin fb as: v out = 1.23v(1 + (r 1 /r 2 )) (eq 1) 8.2.3 current sensing a signal representing the internal nmos-switch curr ent is summed with the slope compensator. the summe d signal is compared to the error amplifier output to provide a peak current control command for the pwm. peak switch current is limited to approximately 850ma independent of v in or v out . 8.2.4 zero current comparator the zero current comparator monitors the inductor c urrent to the output and shuts off the pmos synchro nous rectifier once this current drops to 20ma (approx.). this prevents the inductor current from reversing polarity and results in improved con verter efficiency at light loads. 8.2.5 anti-ringing control anti-ringing control circuitry prevents high-freque ncy ringing on pin sw as the inductor current appro aches zero. this is accomplished by damping the resonant circuit formed by the inductor and the capacitance on pin sw (c sw ). 8.3 powersave operation (as1329a, as1329b) in light load conditions, the integrated powersave feature removes power from all circuitry not requir ed to monitor v out . when v out has dropped approximately 1% from nominal, the as1329a & b powers up and begins normal pwm operation. c out (see figure 19 on page 8) recharges, causing the as1329a and as1329b to re-e nter powersave mode as long as the output load remains below the powersave threshold. the frequenc y of this intermittent pwm is proportional to load current; i.e., as the load current drops further below the powersave threshold, the as1329a and as1329b turns on less frequently. when the load current increases above the powersave threshold, the as1329a and as1329b will r esume continuous, seamless pwm operation. while the as1329a switches to automatic powersave m ode already at medium loads, the as1329b will do so only at very light loads. the as1329c is a continuous switching device, hence the output voltage ripple is very low and no addit ional frequencies are produced which may cause interference. notes: 1. an optional capacitor (c ff ) between pins v out and fb in some applications can reduce v outp-p ripple and input quiescent current during powersave mode. typical values for c ff range from 15 to 220pf. 2. in powersave mode, the as1329a and as1329b draw s only 30a from the output capacitor(s), greatly i mproving converter efficiency. 8.4 shutdown when pin shdnn is low the as1329 is switched off an d <1a current is drawn from battery; when pin shdn n is high the device is switched on. if shdnn is driven from a logic-level output, the l ogic high-level (on) should be referenced to v out to avoid intermittently switching the device on. note: if pin shdnn is not used, it should be connected di rectly to pin out. in shutdown the battery input is connected to the o utput through the inductor and the internal synchro nous rectifier p-fet. this allows the input battery to provide backup power for devices such as an idle microcontroller, memory, or real-time-cloc k, without the usual diode forward drop. in this way a separate backup battery is not needed. in cases where there is residual voltage during shu tdown, some small amount of energy will be transfer red from pin out to pin batt immediately after shutdown, resulting in a momentar y spike of the voltage at pin batt. the ratio of c in and c out partly determine the size and duration of this spike, as does the current-sink ab ility of the input device.
www.ams.com/dc-dc_step-up/as1329 revision 1.12 10 - 20 as1329 datasheet - a p p l i c a t i o n i n f o r m a t i o n 9 application information the as1329 is perfectly suited for led matrix displ ays, bar-graph displays, instrument-panel meters, d ot matrix displays, set-top boxes, white goods, professional audio equipment, medical equipm ent, industrial controllers to name a few applicati ons. along with figure 1 on page 1 , figures 20-23 depict a few of the many applicatio ns for which the as1329 converters are perfectly su ited. figure 20. single aa cell to 3.3v synchronous boos t converter with load disconnect in shutdown figure 21. single lithium cell to 5v, 250ma as1329 c 2 4.7f r 2 604k w 1% on off q1 l1 4.7h aa battery c 1 4.7f r 3 510k w r 3 510k w v out 3.3v, 160ma d1 r 1 1.02m w 1% gnd 2 sw 1 4 shdnn 3 fb 6 vin 5 vout as1329 c 2 4.7f r 2 332k w 1% r 1 1.02m w 1% on off l1 4.7h lithium battery c 1 4.7f d1 c 3 100pf 100nf 2 w optional snubber gnd 2 sw 1 4 shdnn 3 fb 6 vin 5 vout
www.ams.com/dc-dc_step-up/as1329 revision 1.12 11 - 20 as1329 datasheet - a p p l i c a t i o n i n f o r m a t i o n figure 22. single aa cell to 3v synchronous boost converter figure 23. single aa cell to 2.5v synchronous boos t converter as1329 r 2 750k w 1% r 1 1.02m w 1% on off l1 4.7h aa battery c 1 4.7f c 3 1f d1 v out2 -3v, 10ma v out1 3v, 90ma c 2 4.7f c 4 10f d2 gnd 2 sw 1 4 shdnn 3 fb 6 vin 5 vout as1329 c 2 10f r 2 1.02m w 1% r 1 1.02m w 1% on off l1 4.7h aa battery c 1 10f v out 2.5v, 230ma d1 gnd 2 sw 1 4 shdnn 3 fb 6 vin 5 vout
www.ams.com/dc-dc_step-up/as1329 revision 1.12 12 - 20 as1329 datasheet - a p p l i c a t i o n i n f o r m a t i o n 9.1 output voltage ripple the as1329 is designed to work at high efficiency. in order to reduce the output ripple the following improvements are recommended: use a higher output capacitor, up to 44f and a hig her input capacitor (22f). use smaller values for the resistor divider. r1 sho uld be about 300k w . to avoid a high leakage current from pin vout thr ough the resistor divider to gnd, r1 should not be less than 100k w .. to reduce the output ripple its also possible to s peed up the feedback loop. to achieve this, place a 22pf (c4 in figure 24 ) capacitor in parallel to r1. via c4 the fast transients are shor ted to the fb pin and the feedback loop is even fas ter. a 1m w resistor for r1 slows down the fb loop. due to noise and to their non linear behavior, the use of potentiometers is not recommended. figure 24. as1329 - typical application for lower output voltage ripple note: for correct measurements of the output ripple conne ct the oscilloscope probe as close as possible to t he positive plate of the c out and connect the gnd of the oscilloscope probe to th e negative plate of the c out . this will reduce the inductive coupling and will deliver a more accurate measurement result. the output ripple is getting higher as v in is getting closer to v out . figure 25 shows that the above mentioned improvements reduce the output voltage ripple. if v in is higher than v out the as1329 stops switching and v in is connected to v out via the inductor and the internal p-fet. figure 25. output voltage ripple vs. input voltage ; v out = 2.8v, i out = 0.8ma as1329 c 2 22f r 2 196k w r 1 250k w on off l1 4.7h 2xaa battery c 1 22f v out = 2.8v gnd 2 sw 1 4 shdnn 3 fb 5 vout c 3 22f c 4 22pf 6 vin 0 25 50 75 100 125 0.5 1 1.5 2 2.5 3 3.5 input voltage (v) output voltage ripple (mvpp) cout = 44f cout = 66f cout = 44f + c4 = 22pf
www.ams.com/dc-dc_step-up/as1329 revision 1.12 13 - 20 as1329 datasheet - a p p l i c a t i o n i n f o r m a t i o n 9.2 smallest external components the as1329 is also able to work with smallest capac itors and inductors (see figure 26) . figure 26. as1329 - typical application for smalle st external components figure 27. efficiency vs. output current with smal lest external components table 5. recommended smallest components part number value code rating size manufacturer c1 grm188r61a225ke34 2.2f x5r 10v 0603 murata www.murata.com c2 grm188r60j475ke19 4.7f x5r 6.3v 0603 l1 lqm31pn2r2m00 2.2h 238m w 0.9a 1206 as1329 c 2 4.7f r 2 k w r 1 k w on off l1 2.2h 2xaa battery c 1 2.2f v out = 5v gnd 2 sw 1 4 shdnn 3 fb 5 vout 6 vin 20 30 40 50 60 70 80 90 100 1 10 100 1000 output current (ma) efficiency (%) . vi n = 3.3v vi n = 3.5v vi n = 3.8v
www.ams.com/dc-dc_step-up/as1329 revision 1.12 14 - 20 as1329 datasheet - a p p l i c a t i o n i n f o r m a t i o n 9.3 external component selection 9.3.1 inductor selection the fast switching frequency (1.2mhz) of the as1329 allows for the use of small surface mount or chip inductor for the external inductor (see figure 19 on page 8) . the required minimum values for the external induct or are: 3.3h for applications 3.6v 4.7h for applications > 3.6v larger inductor values allow greater output current capability by reducing the inductor ripple current . increasing the inductance above 10h will increase size while providing negligible improvemen t in output current capability. the approximate output current capability of the as 1329 versus inductor value is given in: where: h is the estimated efficiency; i p is the peak current limit value (0.6a); v in is the input voltage; d is the steady-state duty ratio = (v out - v in )/v out ; f is the switching frequency (1.2mhz typ); l is the inductor value. the inductor current ripple is typically set for 20 to 40% of the maximum inductor current (i p ). high-frequency ferrite core inductor materials reduce frequency dependent power losses compared to less expensive powdered iron types, which result i n improved converter efficiency. the inductor should have low esr to reduce the i2r power losses, and must be able to handle the peak i nductor current without saturating. molded chokes and some chip inductors normally do n ot have enough core to support the peak inductor cu rrents of the as1329 (850ma typ). to minimize radiated noise, use a toroid, pot core, or shielded bobbin inductor. table 6. recommended inductors part number l dcr current rating dimensions (l/w/t) manufacturer mos6020-103ml 10h 93m w 1a 6.8x6.0x2.4mm coilcraft www.coilcraft.com mos6020-472ml 4.7h 50m w 1.5a 6.8x6.0x2.4mm mos6020-332ml 3.3h 46m w 1.8a 6.8x6.0x2.4mm cdrh4d18-100 10h 200m w 0.61a 6.9x5.0x2.0mm sumida www.sumida.com cdrh4d18-6r8 6.8h 200m w 0.76a 6.9x5.0x2.0mm cr43-6r8 6.8h 131.2m w 0.95a 4.8x4.3x3.5mm cdrh4d18-4r7 4.7h 162m w 0.84a 6.9x5.0x2.0mm (eq 2) i out max ( ) h i p v in d f l 2 ------------------ C ? ? ? ? 1 d C ( ) =
www.ams.com/dc-dc_step-up/as1329 revision 1.12 15 - 20 as1329 datasheet - a p p l i c a t i o n i n f o r m a t i o n figure 28. efficiency comparison of different indu ctors, v in = 1.5v, v out = 3.3v 9.3.2 output capacitor selection low esr capacitors should be used to minimize v out ripple. multi-layer ceramic capacitors are recomme nded since they have extremely low esr and are available in small footprints. a 2.2 to 10f output capacitor is sufficient for most appli cations. larger values up to 22f may be used to obtain extremely low output voltage ripple and improve transient response. an additional phase lead capacitor may be required with output capacitors larger than 10f to maintain acceptable phase margin. x5r and x7r dielectric materials are recommended due to their a bility to maintain capacitance over wide voltage an d temperature ranges. input capacitor selection. low esr input capacitors reduce input switching noi se and reduce the peak current drawn from the batte ry. ceramic capacitors are recommended for input decoup ling and should be located as close to the device a s is practical. a 4.7f input capacitor is sufficient for most applications. larger values may be used without limitations. diode selection. a schottky diode should be used to carry the output current for the time it takes the pmos synchronous rectifier to switch on. for v out < 4.5v a schottky diode is optional, although usin g one will increase device efficiency by 2% to 3%. note: do not use ordinary rectifier diodes, since the slo w recovery times will compromise efficiency. table 7. recommended output capacitor part number c tc code rated voltage dimensions (l/w/t) manufacturer jmk212bj226mg-t 22f 20% x5r 6.3v 2x1.3x1.3mm taiyo yuden www.t-yuden.com table 8. recommended input capacitor part number c tc code rated voltage dimensions (l/w/t) manufacturer grm31cr70j106ka01l 10f 10% x7r 6.3v 3.2x1.6x1.6mm murata www.murata.com 100 10 76 78 80 82 84 86 88 90 92 output current (ma) efficiency (%) 10uh - coi l c r af t (m os6020-103m l) 10uh - sumi da(cdrh4d18-100) 6. 8uh - sumi da(cdrh4d18-6r8) 6. 8uh - sumi da(cr43-6r8) 4. 7uh - coi l c r af t (m os6020-472m l) 4. 7 uh - sumi da(cdrh4d18-4r7) 3. 3 uh - coi l cr af t (m os6020-332m l) 40 45 50 55 60 65 70 75 80 85 90 0.1 1 10 output current (ma) efficiency (%) 10uh - coi l cr af t (m os6020-103m l) 10uh - sumi da(cdrh4d18-100) 6. 8uh - sumi da(cdrh4d18-6r8) 6. 8uh - sumi da(cr43-6r8) 4. 7uh - coi l cr af t(m os6020-472m l) 4. 7 uh - sumi da(cdrh4d18-4r7) 3. 3 uh - coi l c r af t (m os6020-332m l)
www.ams.com/dc-dc_step-up/as1329 revision 1.12 16 - 20 as1329 datasheet - a p p l i c a t i o n i n f o r m a t i o n 9.4 pcb layout guidelines the high-speed operation of the as1329 requires pro per layout for optimum performance. figure 29 shows the recommended component layout. a large ground pin copper area will help to lower t he device temperature. a multi-layer board with a separate ground plane is recommended. traces carrying large currents should be direct. trace area at pin fb should be as small as is pract ical. the lead-length to the battery should be as short a s is practical. figure 29. recommended single-layer component plac ement 1 as1329 23 6 5 4 optional shdnn v in fb v out gnd sw v out v in shdnn r 2 r 1 c out c in
www.ams.com/dc-dc_step-up/as1329 revision 1.12 17 - 20 as1329 datasheet - p a c k a g e d r a w i n g s a n d m a r k i n g s 10 package drawings and markings the device is available in a 6-pin tsot-23 package. figure 30. 6-pin tsot-23 package
www.ams.com/dc-dc_step-up/as1329 revision 1.12 18 - 20 as1329 datasheet - p a c k a g e d r a w i n g s a n d m a r k i n g s figure 31. 6-pin tsot-23 marking zzzz xxxx top bottom pin1 pin1 package code: zzzz - marketingcode xxxx - encoded datecode
www.ams.com/dc-dc_step-up/as1329 revision 1.12 19 - 20 as1329 datasheet - o r d e r i n g i n f o r m a t i o n 11 ordering information the device is available as the standard products li sted in table 9 . note: all products are rohs compliant. buy our products or get free samples online at icdi rect: http://www.ams.com/icdirect technical support is found at http://www.ams.com/technical-support for further information and requests, please contac t us mailto:sales@ams.com or find your local distributor at http://www.ams.com/distributor table 9. ordering information ordering code marking description delivery form package as1329a-bttt aspa low voltage, micropower, dc-dc step-up converter wi th automatic powersave operation beginning at medium loads tape and reel 6-pin tsot-23 AS1329B-BTTT aspb low voltage, micropower, dc-dc step-up converter wi th automatic powersave operation beginning at light lo ads tape and reel 6-pin tsot-23 as1329c-bttt aspc low voltage, micropower, dc-dc step-up converter wi th continuous switching tape and reel 6-pin tsot-23
www.ams.com/dc-dc_step-up/as1329 revision 1.12 20 - 20 as1329 datasheet - o r d e r i n g i n f o r m a t i o n copyrights copyright ? 1997-2010, ams ag, tobelbaderstrasse 30 , 8141 unterpremstaetten, austria-europe. trademark s registered ?. all rights reserved. the material herein may not be reproduced , adapted, merged, translated, stored, or used with out the prior written consent of the copyright owner. all products and companies mentioned are trademarks or registered trademarks of their respective compa nies. disclaimer devices sold by ams ag are covered by the warranty and patent indemnification provisions appearing in its term of sale. ams ag makes no warranty, express, statutory, implied, or by descri ption regarding the information set forth herein or regarding the freedom of the described devices from patent infringement. ams ag reserves t he right to change specifications and prices at any time and without notice. therefore, prior to designing this product into a system, it is nece ssary to check with ams ag for current information. this product is intended for use in normal commercial applications. applications requiring ext ended temperature range, unusual environmental requ irements, or high reliability applications, such as military, medical life-suppor t or life-sustaining equipment are specifically not recommended without additional processing by ams ag for each application. for shipments of le ss than 100 parts the manufacturing flow might show deviations from the standard production flow, such as test flow or test location . the information furnished here by ams ag is believe d to be correct and accurate. however, ams ag shall not be liable to recipient or any third party for any damages, including but not limited to personal injury, property damage, loss of profits, loss of use, interruption of business or indi- rect, special, incidental or consequential damages, of any kind, in connection with or arising out of the furnishing, performance or use of the tech- nical data herein. no obligation or liability to re cipient or any third party shall arise or flow out of ams ag rendering of technical or other services. contact information headquarters ams ag tobelbaderstrasse 30 a-8141 unterpremstaetten, austria tel: +43 (0) 3136 500 0 fax: +43 (0) 3136 525 01 for sales offices, distributors and representatives , please visit: http://www.ams.com/contact

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