SY6912A 2a multi-cell high effici ency switching charger preliminary specification SY6912A rev.0.1 silergy corp. confidential- prepared for internal use only 1 general description SY6912A is a 4.0-23v input, 2a multi-cell synchronous buck li-ion battery charger, suitable for portable application. select pin is convenient for multi-cell charging. 800 khz synchronous buck regulator integrates of 23v rating fets with ultra low on- resistance to achieve high efficiency and simple circuit design. ordering information package code temperature code optional spec code ( ) sy6912 temperature range: - 40c to 85c features ? wide input voltage range: 4.0v to 23v ? high efficiency int. synchronous buck regulator with fixed 800khz switching frequency ? selectable for multi-cell charging ? trickle current / constant current / constant voltage charge mode ? programmable (2a max) constant charge current ? programmable charging timer ? input voltage uvlo and battery ovp ? over temperature protection ? output short circuit protection ? automatic shutdown prevents reverse energy flow ? charge status indication ? normal synchronous buck operation when battery removed ? compact package so8e applications ? cellular telephones, ? pda, mp3 players, mp4 players ? digital cameras ? bluetooth applications ? psp game players, nds game players ? notebook typical applications battery charge control & protection logic figure 1. SY6912A schematic diagram ordering number package type note SY6912Afcc so8e s i l e r g y c o r p . c o n f i d e n t i a l - p r e p a r e d f o r i n t e r n a l
SY6912A SY6912A rev.0.1 silergy corp. confidential- prepared for internal use only 2 pinout (top view) (so8e) top mark: aiq xyz ( device code: aiq , x=year code, y=week code, z= lot number code) name number description rs 1 charge current program pin. connect a current sense resistor from rs pin to bat pin. average charge current is detected for both tc mode and cc mode. bat 2 battery positive pin. ntc 3 thermal protection pin. utp threshold is about 75%v in and otp threshold is about 30%v in . pull up to vin can disable charge logic and make the ic operate as normal buck regulator. pull down to ground can shutdown the ic. cel 4 pull down for single-cell, pull high for 2 cells, open for 3 cells. stat 5 charge status indication pin. it is open drain output pin and can be used to turn on a led to indicate the charge in process. when the charge is done, led is off. lx 6 switch node pin. this pin connects the drains of the integrated main and synchronous power mosfet switches. connect to external inductor. in 7 positive power supply input pin. v in ranges from 4v to 23v for normal operation. it has uvlo function and must be 300mv greater than the battery voltage to enable normal operation. tim 8 charge time limit pin. connect this pin with a capacitor to ground. internal current source charge the capacitor for tc mode and cc mode?s charge time limit. tc charge time limit is about 1/9 of cc charge time. gnd exposed pad ground pin. absolute maximum ratings (note 1) cel, ntc, stat, ---------------------------------------------------------------------------------------------------- -0.5-32 v in, bat, lx, --------------------------------------------------------------------------------------------------- -0.5- 23v tim, ------------------------------------------------------------------------------------------------------------------ -0.5 - 3.6v rs, ------------------------------------------------------------------------------------------------------------- bat-0.3~bat+0 .3 lx pin current continuous -------------------------------------------------------------------------------------------------- 2a power dissipation, p d @ t a = 25c, so8e----------------------------------------------------------------------------- 3.3w package thermal resistance (note 2) ja -------------------------------------------------------------------------------------------------------------- 30c/w jc ------------------------------------------------------------------------------------------------------------- 20c/w junction temperature range ---------------------------------------------------------------------------------- -40c to 125c lead temperature (soldering, 10 sec.) -------------------------------------------------------------------------------- 260c storage temperature range ---------------------------------------------------------------------------------- - 65c to 125c recommended operating conditions (note 3) cel, ntc, stat, ---------------------------------------------------------------------------------------------------less than 32 v in, bat, lx, ---------------------------------------------------------------------------------------------------less than 23v tim, ------------------------------------------------------------------------------------------------------------------less tha n 3.6v rs, ------------------------------------------------------------------------------------------ in the range of bat- 0.3~bat+0.3lx pin current continuous ---------------------------------------------------------------------------------------- less than 2a junction temperature range ---------- --------------------------------------------------------------------- -20c to 100c ambient temperature range --------------------------------------------------------------------------------- -40c to 85c s i l e r g y c o r p . c o n f i d e n t i a l - p r e p a r e d f o r i n t e r n a l
SY6912A SY6912A rev.0.1 silergy corp. confidential- prepared for internal use only 3 electrical characteristics t a =25c, v in =15v, gnd=0v, c in =1uf, l b =2.2uh, r s =25m ? , c tim =470nf, unless otherwise specified. symbol parameter conditions min typ max unit bias supply (v in ) v in supply voltage 4.0 23 v v uvlo v in under voltage lockout threshold v in rising and measured from v in to gnd 3.9 v ? v uvlo v in under voltage lockout hysteresis measured from v in to gnd 190 mv v ovp input overvoltage protection v in rising and measured from v in to gnd 24 v ? v ovp input overvoltage protection hysteresis measured from v in to gnd 750 mv quiescent current i bat battery discharge current ntc pull down to gnd 25 ua i in input quiescent current disable charge 2.0 ma oscillator and pwm f osc oscillator frequency 640 800 960 khz d pfet duty cycle 100 % power mosfet r nfet r ds(on) of n-fet 150 m ? r pfet r ds(on) of p-fet 160 m ? voltage regulation single-cell cv charge mode 4.16 4.20 4.24 2-cell cv charge mode 8.32 8.40 8.48 v cv 3-cell cv charge mode 0c <=t a <=70c 12.48 12.60 12.72 v single-cell voltage threshold for recharge 50 100 150 2-cell voltage threshold for recharge 100 200 300 v rch 3-cell voltage threshold for recharge 0c <=t a <=70c 150 300 450 mv single-cell tc charge mode voltage threshold 2.2 2.5 2.8 2-cell tc charge mode voltage threshold 4.4 5.0 5.6 v trk 3-cell tc charge mode voltage threshold 0c <=t a <=70c 6.6 7.5 8.4 v battery connect detection v det detect voltage threshold 80% 90% v in t det detect delay time v shot < v bat < v rch 30 ms charge current internal charge current accuracy for constant current mode i cc =25mv/r s -10% 10% internal charge current accuracy for trickle current mode i tc =2.5mv/r s -50% 50% output voltage ovp v ovp output voltage ovp threshold 108% 113% 118% v cv output short protection v shot output short protection threshold v bat falling edge 1.70 2.00 2.30 v f fbk frequency fold back v bat <2v 12.5% f osc i lm power fet current limit 4.0 a timer t tc trickle current charge timeout 0.23 0.5 0.67 hour t cc constant current charge timeout c tim =330nf 3.0 4.5 6.0 hour t mc charge mode change delay time 30 ms t term termination delay time 30 ms t rchg recharge time delay 30 ms battery thermal protection ntc under temperature protection 70% 75% 80% utp under temperature protection hysteresis falling edge 5% over temperature protection 28% 30% 32% otp over temperature protection hysteresis rising edge 2% v in automatic shutdown ? v asd asd voltage threshold hysteresis measured from v in to v bat 140 280 420 mv s i l e r g y c o r p . c o n f i d e n t i a l - p r e p a r e d f o r i n t e r n a l
SY6912A SY6912A rev.0.1 silergy corp. confidential- prepared for internal use only 4 note 1 : stresses beyond the ?absolute maximum ratings? may cause permanent damage to the device. these are stress ratings only. functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specification is not implied. exposure to absolute maximum rating conditions for extended periods may affect device reliability. note 2 : ja is measured in the natural convection at t a = 25c on a low effective four-layer thermal conductivity test board of jedec 51-3 thermal measurement standard. note 3 : the device is not guaranteed to function outside its operating conditions basic li-ion battery char ge operation flow chart s i l e r g y c o r p . c o n f i d e n t i a l - p r e p a r e d f o r i n t e r n a l
SY6912A SY6912A rev.0.1 silergy corp. confidential- prepared for internal use only 5 general function description SY6912A is a 4.0-23 input, 2a multi-cell synchronous buck li-ion battery charger, suitable for portable application. select pin is convenient for multi-cell charging. integrated 800 khz synchronous buck regulator consists of 23v rating fets with extremely low on-resistance to achieve high charge efficiency and simple circuit design. charging status indication description 1. charge-in-process ? pulls and keeps stat pin to low; 2. charge done ? pulls and keeps stat pin to high; 3. fault mode ? outputs high and low voltage alternatively with 0.5hz frequency. connects a led from vin to stat pin, led on indicates charge-in-process , led off indicates charge done , led flash indicates fault mode . buck regulator operation description if the li-ion battery is removed suddenly, the voltage on ntc pin increases higher than 90% vin. then, it operates as a normal peak current mode controlled synchronous buck converter and the output voltage on bat pin is regulated at v cv . in this operation mode, the constant output current loop is still active, however the charge timeout and the trickle current charge are disabled. protection description thermal protection- thermal shutdown is active for both battery and ic. ic resumes normal work when the temperature backs in normal range again. short circuit protection- when v bat voltage is lower than the short circuit protection threshold, short circuit protection is active. in charger operation mode, the switching frequency is folded back to 12.5% of the default value and vc is folded back to 20% of the maximum value. the trickle charge timer is still active and would timeout the ic finally. in buck operation mode, the switching frequency is folded back to 12.5% of the default value, and the vc initiates softstart periodically. over current protection- the internal current loop with different constant current capability is always active no matter in buck mode or battery charging mode for the over current protection. over voltage protection- when v bat voltage is higher than the over voltage protection threshold no matter with or without battery connecting, ic shuts down and recovers to normal work when v bat backs to normal level. input voltage has uvlo and ovp, which would make ic shutdown and recover to normal work when the v in backs to normal range. timeout protection- programmable timeout protection is for both trickle current charge mode and constant current charge mode. once timeout is active, ic stops the charge operation and latches off. only power or battery re-plug in can get the latch logic reset and the ic restarted. s i l e r g y c o r p . c o n f i d e n t i a l - p r e p a r e d f o r i n t e r n a l
SY6912A SY6912A rev.0.1 silergy corp. confidential- prepared for internal use only 6 so8e package outline & pcb layout design 5.40 0.60 1.27 typ 1.55 2.55 3.20 0.30 ? 0.50 5.80 - 6.10 3.80 - 4.00 0.30 ? 0.50 5.80 - 6.20 3.80 - 4.00 recommended pad layout 4 5 0.25 base 0 - 8 0.18 - 0.2 5 0.25 - 0.50 0.60 - 0.85 4 5 0.25 base 0 - 8 0.18 - 0.2 5 0.25 - 0.50 0.60 - 0.85 1.27 (typ) 1.30 - 1.60 0.00 - 0.25 4.80 - 5.00 1.27 (typ) -1.60 0 - 0.25 4.80 - 5.00 notes: all dimensions are in millimeters. all dimensions don?t include mold flash & metal burr. s i l e r g y c o r p . c o n f i d e n t i a l - p r e p a r e d f o r i n t e r n a l
SY6912A SY6912A rev.0.1 silergy corp. confidential- prepared for internal use only 7 taping & reel specification 1. taping orientation so8e feeding direction 2. carrier tape & reel speci fication for packages package types tape width (mm) pocket pitch(mm) reel size (inch) reel width(mm) trailer length(mm) leader length (mm) qty per reel so8e 12 8 13" 12.4 400 400 2500 3. others: na 11.7/12.3 3.9/4.1 1.45/1.55 s i l e r g y c o r p . c o n f i d e n t i a l - p r e p a r e d f o r i n t e r n a l
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