preliminary datasheet LP28007 lp280 07 C 0 2 may . - 2013 email : marketing@lowpowersemi.com www.lowpowersemi.com page 1 of 11 single and dual cell li+ battery charger ic ? LP28007 general description the LP28007 is a fully integrated low cost single - cell li - ion battery charger ic ideal for portable applications. the LP28007 is capable of being powered up from ac a dapter. the LP28007 enters sleep mode when ac adapter is removed. the LP28007 optimizes the charging task by using a control algorithm including preconditioning mode, fast charge mode and constant voltage mode. the charging task is terminated as the charge current drops below the preset threshold. the ac adapter charge current can be programmed up to 1a with an external resister. the internal thermal feedback circuitry regulates the die temperature to optimize the charge rate for all ambient temperatures. t he LP28007 features 18v maximum rating voltages for ac adapter. the other features is under voltage protection . order information LP28007 f: pb - free package type ms: msop - 8 output voltage 42: 4.2v 84: 8.4v applications ? portable media players/mp 3 players ? cellular an d smart mobile phone ? pda/dsc ? bluetooth applications features ? 18v maximum rating for ac adapter ? internal integrate p - mosfets ? ac adapter power good status indicator ? charge status indicator ? under voltage protection ? automatic recharge feature ? battery temperature monitoring ? small 8 - lead msop(ep) package ? thermal feedback optimizing charge rate ? r ohs compliant and 100% lead (pb) - free typical application circuit marking information device marking p ackage shipping LP28007 lps LP28007 xxxx sp:msop - 8 3k/reel 8 .4v li - ion b attery pack
preliminary datasheet LP28007 lp280 07 C 0 2 may . - 2013 email : marketing@lowpowersemi.com www.lowpowersemi.com page 2 of 11 functional pin description package type pin configurations e msop - 8 acin chg _s pgood gnd batt en nc iseta 1 2 3 5 6 7 8 pgnd 9 4 pin description pin no pin name pin function 1 acin wall adaptor charge input supply. 2 chg_s charge status indicator output (open drain). 3 pgood power good indicator output (open drain). 4 gnd ground. 5 iseta wall adaptor supply charge current set point. 6 en charge e n able input ( active low). 7 nc no internal connection. 8 batt battery charge current output. this pin provides charge current to the battery and regulates the final float voltage to 4.2 or 8.4v. an internal precision resistor divider from this pin sets the float volt age which is disconnected in shutdown mode. 9(exposed pad) pgnd exposed pad should be soldered to pcb board and connected to gnd. note: lp28 007 - 42msf and LP28007 - 84msf of battery (pin8) is output pin, the pin connects to battery.
preliminary datasheet LP28007 lp280 07 C 0 2 may . - 2013 email : marketing@lowpowersemi.com www.lowpowersemi.com page 3 of 11 function block diagram
preliminary datasheet LP28007 lp280 07 C 0 2 may . - 2013 email : marketing@lowpowersemi.com www.lowpowersemi.com page 4 of 11
preliminary datasheet LP28007 lp280 07 C 0 2 may . - 2013 email : marketing@lowpowersemi.com www.lowpowersemi.com page 5 of 11
preliminary datasheet LP28007 lp280 07 C 0 2 may . - 2013 email : marketing@lowpowersemi.com www.lowpowersemi.com page 6 of 11 absolute maximum ratings (notes 1.2) v in , v batt ,v chgsb ,v pg ood ,v en ----------------------------------------------------------------------------- - 0.3v to 1 8 v storage temperature range ------------------- ------------------------------------------------------- - 65 to 150 v iseta ------------------------------------------------------------------------------------------------------------------------ - 0.3v to 3.6v junction temperature (tj ) -------------------------------------------------------------------- ------------------- 150 lead temperature (soldering, 10 sec.) ------------------------------------------------------------------------------------------ 260 operating ratings ( note 1, 2) supply voltage -------------------------------------------------- ------------------- ----------------------------- ------- 4.5 v to 13.5v thermal resistance( ja , note 3)) -------------------------------------------------------------------------------------------- 20/w operating temperature range -------------------- --------------------------------------------------------- - 40 to 85 thermal resistance( ja , note 4)) ------------------------------------------------------------------------------------------- 8.5/w electrical characteristics ( ta=25 , vin=10v; u nless otherwise specified. ) symbol parameter condit ions min typ max units vin input operating voltage range 9 15 v icc input supply current charge mode. rset=30k 300 ua standby mode (charge terminated) 250 ua shutdown mode (rset not con nected vin < vbatt or vin < vuv) 190 ua vfloat regulated output(float) voltage 0 Q ta Q 85 8.316 8.4 8.484 v ibatt batt pin current rset=1.5k,current mode 500 ma rset=0.75k,current mode 1000 ma standby mode, vbatt=8.4v - 1 0 1 ua shutdown mode - 1 0 1 ua sleep mode, vin=0v - 1 0 1 ua itrickle trickle charge current vbatt preliminary datasheet LP28007 lp280 07 C 0 2 may . - 2013 email : marketing@lowpowersemi.com www.lowpowersemi.com page 7 of 11 v trhys trickle charge hysteresis voltage rset=1.5k 250 mv vmsd manual shutdown threshold voltage i seta pin rising 2.15 v iseta pin falling 2.05 v vasd vin C vbatt lockout threshold voltage vin from high to low 30 mv vin from low to high 60 mv iterm c/10termination current threshold rset=1.5k 0.1 ma/ ma rset=0.75k 0.1 ma/ ma vset iseta pin voltage rset=1.5k,current mode 1.5 v ichg_sb chg_sb pin weak pull - down current vchg_sb=5.0v 25 ua vchg_sb chg_sb pin output low voltage ichg_sb=5ma 0.35 v vpgood pgood pin output low voltage ipgood_sb=5ma 0.35 v p arameter s ymbo l t est c ondition s m in t yp m ax u nits precharge batt pre - charge rising threshold v prech 2.6 2.8 3 v batt pre - charge threshold hysteresis ? v prech 50 100 200 mv pre - charge current i pchg v batt =2v 8 10 12 % recharge threshold batt pre - charge falling threshold hysteresis ? v prech_l v reg C v batt 60 100 150 mv c harge termination detection termination current ratio(default) i term v batt =4.2v -- 10 -- % l ogic input/output chg_s ______________ v pull down voltage chg_s tbd, i chg_s =5ma _________________ -- 65 -- mv pgood pull down voltage v pgood tbd, i pgood =5ma -- 220 -- mv en ______ l ogic - high voltage threshold v ih 1.5 -- -- v l ogic - low voltage v il -- -- 0.4 v en ______ i en pin input current i en =2v -- -- 2 a protection t hermal regulation -- 125 --
preliminary datasheet LP28007 lp280 07 C 0 2 may . - 2013 email : marketing@lowpowersemi.com www.lowpowersemi.com page 8 of 11 note 1. stresses listed as the above absolute maximum ratings may cause permanent damage to the device. t hese are for str ess ratings. f unctional operation of the device at these or any other conditions beyond those indicated in the operational section s of the specification s is not implied . e xposure to absolute maximum rating condition s for extended periods may remain possibi lity to affect device reliability . note 2. ja is measure d in the natural convection at ta=25 on a high effective thermal conductiv ity test board 4 layers,1s of jedec 51 - 7 thermal measurement standard. the case point of jc is on the expose pad for the package . note 3. devices are esd sensitive. handling precaution is recommended. note 4. the device is not guaranteed to function outside its operating conditions. vset vs. temperature (vbatt > 5.8v) vset vs. temperature (vbatt 5.8v) charge current vs.battery voltage(vin=10v) charge current vs.vin(vbatt=8.0v) regulated output voltage vs.su pply voltage regulated output voltage vs.temperature rset=3k
preliminary datasheet LP28007 lp280 07 C 0 2 may . - 2013 email : marketing@lowpowersemi.com www.lowpowersemi.com page 9 of 11 a pplication information automatically power source selection the LP28007 is a battery charger i c which is designed for li - ion battery with 4.2v rated voltage. acin mode : when the acin input voltage is higher than the uvp voltage level (4.4v), the LP28007 will turn on acinp - mosfet. sleep mode : the LP28007 will enter sleep mode when acin input volt age are removed. this feature provides low leakage current from the battery during the absence of input supply. fast - charge current setting the LP28007 offers iseta pin to determine the acin charge rate from 100ma to 1 200m a. the charge current can be cal culated as following equation. pre - charge current setting during a charge cycle if the battery voltage is below the vprech threshold, the LP28007 applies a pre - charge mode to the battery. this feature revives deeply discharged cell sand protects batte ry life. the LP28007 internal determines the pre - charge rate as 10% of the fast - charge current. battery voltage regulation the LP28007 monitors the battery voltage through the batt pin. once the battery voltage level closes to the vreg threshold, the lp2 8007 voltage enters constant phase and the charging current begins to taper down. when battery voltage is over the vreg threshold, the LP28007 will stop charge and keep to monitor the battery voltage. however, when the battery voltage decreases 100mv below the vreg, it will be recharged to keep the battery voltage. charge status outputs . the open - drain chg_s and pgood outputs indicate various charger operations as shown in the following table. these status pins can be used to drive leds or communicate to the host processor. note that on indicates the open - drain transistor is turned on and led is bright. temperature regulation and thermal protection in order to maximize the charge rate, the LP28007 features a j unction temperature regulation loop. if the power dissipation of the ic results in a junction temperature greater than the thermal regulation
preliminary datasheet LP28007 lp280 07 C 0 2 may . - 2013 email : marketing@lowpowersemi.com www.lowpowersemi.com page 10 of 11 threshold (125c), theLP28007 throttles back on the charge current in order to maintain a junction temperature aro und the thermal regulation threshold (125c). the LP28007 monitors the junction temperature, tj, of the die and disconnects the battery from the input if tj exceeds 125c. this operation continues until junction temperature falls below thermal regulation t hreshold (125c) by the hysteresis level. this feature prevents the chip from damage. selecting the input and output capacitors in most applications, the most important is the high - frequency decoupling capacitor on the input of the LP28007.a 1uf ceramic c apacitor, placed in close proximity to input pin and gnd pin is recommended. in some applications depending on the power supply characteristics and cable length, it may be necessary to add an additional 10ufceramic capacitor to the input. the LP28007 requi res a small output capacitor for loop stability. a 1uf ceramic capacitor placed between the batt pin and gnd is typically sufficient. layout consideration the LP28007 is a fully integrated low cost single - cell li - ion battery charger ideal for portable app lications. careful pcb layout is necessary. for best performance, place all peripheral components as close to the ic as possible. a short connection is highly recommended. the following guide lines should be strictly followed when designing a pcb layout fo r the LP28007.input capacitor should be placed close to ic and connected to ground plane. the trace of input in the pcb should be placed far away the sensitive devices or shielded by the ground. the gnd should be connected to a strong ground plane for hea t sinking and noise protection. the connection of rseta should be isolated from other noisy traces. the short wire is recommended to prevent emi and noise coupling. output capacitor should be placed close to ic and connected to ground plane to reduce nois e coupling. when pcb has poor layout, the 10uf is recommended to prevent noise.
preliminary datasheet LP28007 lp280 07 C 0 2 may . - 2013 email : marketing@lowpowersemi.com www.lowpowersemi.com page 11 of 11 packag ing information
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