![]() |
|
If you can't view the Datasheet, Please click here to try to view without PDF Reader . |
|
Datasheet File OCR Text: |
primary side control ic for off-line ba ttery chargers ap3706 data sheet 1 bcd semiconductor manufacturing limited jan. 2013 rev. 1. 5 general description the ap3706 is a high performance ac/dc power sup- ply controller for battery charger and adapter applica- tions. the device uses pulse frequency modulation (pfm) method to build discontinuous conduction mode (dcm) flyback power supplies. the ap3706 provides constant voltage, constant cur- rent (cv/cc) regulation without requiring an opto- coupler and secondary control circuitry. it also elimi- nates the need of loop compensation circuitry while maintaining stability. the ap3706 achieves excellent regulation and high power efficiency, the no-load power consumption is less than 200mw at 265vac input. the ap3706 is available in soic-8 and dip-8 pack- ages. features primary side control for rectangular constant current and constant voltage output eliminates opto-coupler and secondary cv/cc control circuitry eliminates control loop compensation circuitry flyback topology in dcm operation random frequency modulation to reduce system emi valley turn on of external power npn transistor built-in soft start open circuit protection over voltage protection short circuit protection applications adapters/chargers for cell/cordless phones, pdas, mp3 and other portable apparatus standby and auxiliary power supplies figure 1. package types of ap3706 soic-8 dip-8
primary side control ic for off-line ba ttery chargers ap3706 data sheet 2 bcd semiconductor manufacturing limited jan. 2013 rev. 1. 5 pin configuration figure 2. pin configurations of ap3706 (top view) pin description pin number pin name function 1 cs the primary current sense 2 vcc supply voltage 3 out this pin drives the base of external power npn switch 4 gnd ground 5 fb the voltage feedback from the auxiliary winding 6 vdd the 5v output of the internal voltage regulator 7 bias this pin sets the bias current inside ap3706 with an exte rnal resistor to gnd 8 comp this pin connects a bypa ss capacitor for cc function m package (soic-8) cs out vcc gnd comp bias vdd fb 1 2 3 4 8 7 6 5 1 2 3 4 8 7 6 5 p package (dip-8) cs out vcc gnd comp bias vdd fb primary side control ic for off-line ba ttery chargers ap3706 data sheet 3 bcd semiconductor manufacturing limited jan. 2013 rev. 1. 5 functional block diagram figure 3. functional block diagram of ap3706 vcc out gnd vdd bias fb comp cs regulator & bias ovp & ockp tonsec detector s&h 0.1v 4.0v pfm tons uvlo vea comp comp ea tons v+ pfm_d uvlo pro cv_ctrl comp comp leb delay 430ns pfm_d pfm pfm driver rq s rq s v dd i tons 0.5v 0.46v 0.75*i 3.75v cc_ctrl vea v+ t comp primary side control ic for off-line ba ttery chargers ap3706 data sheet 4 bcd semiconductor manufacturing limited jan. 2013 rev. 1. 5 parameter value unit supply voltage vcc -0.3 to 30 v voltage at cs, bias, out, vdd, comp to gnd -0.3 to 7 v fb input (pin 5) -40 to 10 v output current at out internally limited a power dissipation at t a =25 o c 0.657 w operating junction temperature 150 o c storage temperature -65 to 150 o c lead temperature (soldering, 10s) 300 o c thermal resistance junction-to-ambient soic-8 190 o c/w dip-8 100 esd (machine model) 200 v note 1: stresses greater than those li sted under "absolute maximum ratings" may cause permanent dama ge to the device. these are stress ratings only, and functiona l operation of the device at these or any other conditions be yond those indicated under "recommended operating conditions" is not implied. exposure to "absolute maximum ratings" for extended periods may affect device reliability. absolute maximum ratings (note 1) package temperature range part number marking id packing type lead free green lead free green soic-8 -40 to 85 o c ap3706m-e1 ap3706m-g1 3706m-e1 3706m-g1 tube ap3706mtr-e1 ap3706mtr-g1 3706m-e1 3706m-g1 tape & reel dip-8 ap3706p-e1 ap3706p-g1 ap3706p-e1 ap3706p-g1 tube bcd semiconductor's pb-free products, as design ated with "e1" suffix in the part number, are rohs compliant. products with "g1" suffix are available in green packages. ordering information circuit type e1: lead free ap3706 - tr: tape and reel blank: tube package m: soic-8 g1: green p: dip-8 primary side control ic for off-line ba ttery chargers ap3706 data sheet 5 bcd semiconductor manufacturing limited jan. 2013 rev. 1. 5 parameter symbol conditions min typ max unit uvlo section start-up threshold v th (st) 17 18.5 20 v minimal operating voltage v opr (min) after turn on 6.5 7.3 8.1 v reference voltage section bias pin voltage v bias r bias =200k ? , before turn on 1.170 1.205 1.240 v vdd pin voltage vdd 4.75 5.0 5.25 v standby current section start-up current i st v cc = v th (st) -0.5v, r bias =200k ? , before turn on 70 80 a operating current i cc(opr) r bias =200k ? 680 900 a drive output section out maximum current sink i out r bias =200k ? 50 ma source 25 30 current sense section current sense threshold v cs 485 505 525 mv pre-current sense v cs(pre) 385 410 435 mv leading edge blanking 430 ns feedback input section feedback pin input leakage current i fb v fb =4v 10.0 12.5 15.0 a feedback threshold v fb 3.90 4.00 4.10 v enable turn-on voltage v fb(en) -0.9 -0.7 -0.5 v comp threshold voltage section turn-on threshold voltage v comp 3.42 3.60 3.78 v protection section over voltage protection v fb(ovp) 789v (v cc =15v, t a =25 o c, unless otherwise specified.) electrical characteristics primary side control ic for off-line ba ttery chargers ap3706 data sheet 6 bcd semiconductor manufacturing limited jan. 2013 rev. 1. 5 typical performance characteristics figure 6. operating curren t vs. ambient temperature figure 4. start-up voltage vs. am bient temperature figure 5. start-up current vs. ambient temperature figure 7. v dd vs. ambient temperature -40-20 0 20406080100120 400 450 500 550 600 650 700 750 800 operating current ( a) ambient temperature ( o c) r bias =200k ? -40-20 0 20406080100120 4.80 4.85 4.90 4.95 5.00 5.05 5.10 5.15 5.20 v dd (v) ambient temperature ( o c) -40-20 0 20406080100120 16.5 17.0 17.5 18.0 18.5 19.0 19.5 start-up voltage (v) ambient temperature ( o c) r bias =200k ? -40 -20 0 20 40 60 80 100 120 20 30 40 50 60 70 80 90 100 startup current ( a) ambient temperature ( o c) r bias =200k ? primary side control ic for off-line ba ttery chargers ap3706 data sheet 7 bcd semiconductor manufacturing limited jan. 2013 rev. 1. 5 typical performance ch aracteristics (continued) figure 8. start-up current vs. bias resistor figure 9. out source current vs. bias resistor 100 150 200 250 300 350 400 0 10 20 30 40 50 60 70 80 out source current (ma) bias resistor (k ? ) t a =25 o c 100 150 200 250 300 350 400 40 50 60 70 80 90 100 110 120 start-up current ( a) bias resistor (k ? ) t a =25 o c primary side control ic for off-line ba ttery chargers ap3706 data sheet 8 bcd semiconductor manufacturing limited jan. 2013 rev. 1. 5 operation description figure 10 illustrates a si mplified flyback converter controlled by ap3706. constant primary peak current the primary current ip(t) is sensed by a current sense resistor r cs as shown in figure 10. the current rises up linearly at a rate of: as illustrated in figure 11, when the current ip(t) rises up to ipk, the switch q1 turns off. the constant peak current is given by: the energy stored in th e magnetizing inductance lm each cycle is therefore: so the power transferring fr om the input to the output is given by: where the fsw is the switching frequency. when the peak current ipk is constant, the output power depends on the switching frequency fsw. constant voltage operation the ap3706 captures the auxiliary winding feedback voltage at fb pin and operates in constant-voltage (cv) mode to regulate the output voltage. assuming the secondary winding is master, the auxiliary winding is slave during the d1 on-time. the auxiliary voltage is given by: figure 10. simplified flyback converter controlled by ap3706 m l t vg dt t dip ) ( ) ( = ................ (1) ip 0a see equation 2 figure 11. primary current waveform rcs vcs ipk = ................ (2) 2 2 1 ipk l eg m ? = sw m f ipk l p = 2 2 1 ................ (4) () vd vo n n v s aux aux + = ................ (5) + bridge c1 + & 2 v o d1 q1 9 6 out fb & |