1a, single cell linear lithium battery charger e - cmos corp. ( www.ecmos.com.tw ) page 1 of 8 3h20n rev. p001 ec4901 8 general description the ec4 9018 is a complete constant - current & constant - voltage line ar charger for single cell lithium - ion batteries. its sop - 8 (exposed pad) package and low external component count make the EC49018 ideally suited for portable applications. in addition, the EC49018 can work within usb and wall adapter. no blocking diode i s required because of its internal pmosfet architecture which is able to prevent t he negative charge current. thermal feedback regulates the charge current to limit the die temperature during high power operation or high ambient temperature. the charge vol tage is fixed at 4.2v, and the charge current can be programmed externally with a single resistor. the ec4 9018 automatically terminates the charge cycle when the charge current drops to 1/10th the programmed value after the final float voltage is reached. EC49018 other features include current monitor, under voltage lockout, automatic recharge and two status pin to indicate charge termination and the presence of an input voltage. features ? programmable charge current up to 1000ma ? no mosfet, sense resistor or blocking diode required ? complete linear charger in sop - 8 package for single cell lithium - ion batteries ? constant - current/constant - voltage ? charges single cell li - ion batteries directly from usb port ? preset 4.2v charge voltage with 1.5% accuracy ? automatic recharge ? t wo charge st atus output pins ? c/10 charge t ermination ? 2.9v trickle charge threshold ? soft - start limits inrush current ? available radiator in sop - 8(exposed pad) package, the radiator need connect gnd or impending applications ? cellular telephones, pda, mp3 players ? charging docks and cradles ? mp3 mp4 player ? digital still cameras, portable devices ? usb bus - powered chargers, chargers application diagram
1a, single cell linear lithium battery charger e - cmos corp. ( www.ecmos.com.tw ) page 2 of 8 3h20n rev. p001 ec4901 8 pin functions pin pin function description pin pin function description temp connecting temp pin to ntc thermistors output in lithiu m ion battery pack. bat connect the positive terminal of the battery to bat pin prog constant c harge c urrent s etting and c harge c urrent m onitor p in open drain charge status output gnd ground pin open drain c harge status output vcc input voltage pin ce chip enable input ordering information package part number marking marking information sop - 8 (exposed pad) EC49018 nnmhr 49018 lllll yywwt 1. lllll lot no. 2. yyww date code 3. t internal tracking code pin configuration stdby chrg
1a, single cell linear lithium battery charger e - cmos corp. ( www.ecmos.com.tw ) page 3 of 8 3h20n rev. p001 ec4901 8 absol ute maximum rating parameter symbol value units input supply voltage v cc 6.5 v bat voltage v bat 6.5 v temp /ce v temp 6.5 v / v chrg 6.5 v bat pin current i bat 1500 ma prog pin current i prog 1500 ua maximum j unction temperature t j 150 c operating rating parameter symbol value units junction temperature t j - 20 to + 85 c storage temperature t stg - 40 to +125 lead temperature ( soldering, 10sec) t led 260 block diagram chrg stdby
1a, single cell linear lithium battery charger e - cmos corp. ( www.ecmos.com.tw ) page 4 of 8 3h20n rev. p001 ec4901 8 electrical characteristics v in = 5 v; t j = 25c; unless otherwise specified . symbol parameter conditions min typ max unit v cc input supply voltage 4.0 5 6 .5 v i cc input supply current charge mode, r prog = 2k 146 70 prog not connected, v cc < v bat , or v cc < v uv ) 3 0 float regulated output voltage i bat = 3 0ma , r prog = 10k 4.1 37 4.2 4. 26 3 v i bat bat pin curren t r prog = 2k , current mode prog = 1k , current mode prog not c onnected) cc = 0v trikl trickle charge c urrent v bat < v trikl , r p rog = 2k trikl trickle charge threshold voltage r prog = 2k , v bat rising trhys trickle voltage hysteresis voltage r prog =2k uv v cc undervoltage lockout threshold from v cc low to high 3.7 v v uvhys v cc undervoltage loc kout hysteresis 150 mv v asd v cc C bat lockout threshold voltage prog pin rising 150 mv prog pin falling 100 mv i term c/10 termination current threshold r prog = 2k 60 ma r prog = 1k 100 ma v prog prog pin voltage r prog = 2 k, cu rrent mode pin o u t p ut low voltage = 5ma 0.4 v pin output low voltage =5ma 0.4 v v temp - h temp pin voltage of the high - end flip 80 %vcc chrg chrg i stdby v stdby stdby i
1a, single cell linear lithium battery charger e - cmos corp. ( www.ecmos.com.tw ) page 5 of 8 3h20n rev. p001 ec4901 8 electrical characteristics v in = 5 v; t j = 25c; unless otherwise specified . symbol parameter conditions min typ max unit v temp - l temp pin voltage of the low - end flip 45 %vcc rechrg recharge battery threshold voltage v float - v rechrg 150 mv t lim thermal protection temperature 145 c t ss soft - start time i bat = 0 to 1 12 0v/r prog 20 s t recharge recharge comparator filter time v bat high to low 1 ms t term term ination comparator filter time i bat falling below i chg /10 1 ms i prog prog pin pull - up current 0.5 a complete charge cycle (1000mah battery) typical performance characteristics
1a, single cell linear lithium battery charger e - cmos corp. ( www.ecmos.com.tw ) page 6 of 8 3h20n rev. p001 ec4901 8 the ec4 9018 is a complete constant C current & constant - voltage linear charger for s ingle cell lithium - ion batteries. constant - current & constant - voltage to charger batter by internal mosfet .it can deliver up to 1a of charge current .no blocking diode or external current sense resistor is required. ec4 9018 include two open - drain charge status pins: charge status indicator and battery failure status output .the internal thermal regulation circuit reduces the programmed charge current if the die temperature attempts to rise above a preset value of approximately 145 . this feature protects the ec4 9018 from excessive temperature, and allows the user to push the limits of the power handling capability of a given circuit board without risk of damaging the ec4 9018 or the external components. another benefit of adopting thermal regulation is tha t charge current can be set according to typical, not worst - case, ambient temperatures for a given application with the assurance that the charger will automatically reduce the current in worst - case conditions . the charge cycle begins when the voltage at t he v cc pin rises above the uvlo level, a current set resistor is connected from the prog pin to ground, and the ce pin is pulled above the chip enable threshold. the pin outputs a logic low to indicate that the charge cycle is on go ing. at the beginning of the charge cycle, if the battery voltage is below 2.9v, the charge is in recharge mode to bring the cell voltage up to a safe level for charging. the charger goes into the fast charge constant - current mode once the voltage on the bat pin rises above 2.9 v. in constant current mode, the charge current is set by r prog . when the battery approaches the regulation voltage 4.2v, the charge current begins to decrease as the ec4 9018 enters the constant - voltage mode. when the current drops to charge termination threshold, the charge cycle is terminated, and pin assumes a high impedance state to indicate that the charge cycle is terminated and pin is pulled low. the charge termination threshold is 10% of the current in constant current mode. to restart the charge cycle, remove the input voltage and reapply it, or momentarily force ce pin to 0v. the charge cycle can also be automatically restarted if the bat pin voltage falls below the recharge thre shold. the on - chip reference voltage, error amplifier and the resistor divider provide regulation voltage with 1% accuracy which can meet the requirement of lithium - ion and lithium polymer batteries. when the input voltage is not present, or input voltage is below v bat , the charger goes into a sleep mode, dropping battery drain current to less than 3a. this greatly reduces the current drain on the battery and increases the standby time. the charger can be shutdown by forcing the ce pin to gnd. programmin g charge current the charge current is programmed using a single resistor from the prog pin to ground. the program resistor and the charge current are calculated using the following equations.: in application, according the charge curre nt to determine r prog , the relation between r prog and charge current application s chrg stdby
1a, single cell linear lithium battery charger e - cmos corp. ( www.ecmos.com.tw ) page 7 of 8 3h20n rev. p001 ec4901 8 can reference the following chart r prog (k) i bat (ma) r prog (k) i bat (ma) 28 4 0 1.86 60 0 18.6 6 0 1. 55 720 9.3 1 2 0 1. 4 80 0 4.6 2 4 0 1. 24 900 3.73 300 1.12 1000 2.8 400 --- --- charge termination a charge cycle is terminated when the charge current falls to 1/10 th the programmed val ue after the final float voltage is reached. this condition is detected by using an internal filtered comparator to monitor the prog pin. when the prog pin voltage falls below 100mv for longer than t temp (typically 1.8ms), charging is terminated. the charg e current is latched off and the ec4 9018 enters standby mode, where the input supply current drops to 70 a (note:c/10 termination is disabled in trickle charging and thermal limiting modes). when charging, transient loads on the bat pin can cause the prog pin to fall below 100mv for short periods of time before the dc charge current has dropped to 1/10 th the programmed value. the 1.8ms filter time (t temp ) on the termination comparator ensures that transient loads of this nature do not result in premature charge cycle termination. once the average charge current drops below 1/10 th the programmed value, the ec4 9018 terminated the charge cycle and ceases to provide any current through the bat pin. in this state all loads on the bat pin must be supplied by the battery. charge status indicator ec4 9018 has two open - drain status indicator output and . is pull - down when the ec4 9018 in a charge cycle. in other status in high impedance . and are all in high impedance when the battery out of the normal temperature. represent in failure state, when temp pin in typical connecting, or the charger with no battery: red led and green led all dont light. the battery temperature sense function is disabled by connecting temp pin to gnd. if battery is not connected to charger, pin outputs a pwm level to indicate no battery. if bat pin connects a 10f capacitor, the frequency of flicker about 1 - 4s, if not use status indicator should set status indicator output connected to gnd . chrg stdby
1a, single cell linear lithium battery charger e - cmos corp. ( www.ecmos.com.tw ) page 8 of 8 3h20n rev. p001 ec4901 8 outline drawing sop - 8(exposed pad)
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