EC49016 standalone linear lithium battery charger e-cmos corp. ( www.ecmos.com.tw ) page 1 of 8 2006/05/18 package part number marking marking information sot-23-5l EC49016b2-f 016 b starting with 6, a bar on top of 6 is for production year 2005, and underlined 6 is for year 2006. the naming pattern continues with consecutive characters for later years. the last character is the week code. (a-z: 1-26, a-z: 27-52) a dot on top right corner is for lead-free process. introduction (general description) EC49016 is a complete constant-current & constant voltage linear charger for single cell lithium-ion batteries. its sot-23 package and low external component count make EC49016 ideally suited for portable applications. furthermore, the EC49016 is specifically designed to work within usb power specification. at the same time, EC49016 can also be used in the standalone lithium-ion battery charger. no external sense resistor is needed, and no blocking diode is required due to the internal mosfet architecture. thermal feedback regulates the charger current to limit the die temperature during high power operation or high ambient te mperature. the charge voltage is fixed at 4.2v, and the charge current can be programmed externally with a single resistor. the EC49016 automatically terminates the charge cycle when the charge current drops to 1/10 th the programmed value after the final float voltage is reached. when the input supply (wall adapter or usb supply) is removed, the EC49016 automatically enters a low current stage, dropping the battery drain current to less than 2 a. the EC49016 can be put into shutdown mode, reducing the supply current to 20 a. other features include charge current monitor, under-voltage lockout, automatic recharge and a status pin to indicate charge termination and the presence of an input voltage. features z programmable charge current up to 800ma z no mosfet, sense resistor or blocking diode required z constant-current/constant-voltage operation with thermal protection to maximize charge rate without risk of overheating z charges single cell li-ion batteries directly from usb port z preset 4.2v charge volt age with +-1% accuracy z 20 a supply current in shutdown z 2.9v trickle charge threshold z available without trickle charge z soft-start limits inrush current z available in 5-lead sot-23 package applications z cellular telephones, pda, mp3 players z charging docks and cradles z bluetooth applications pin configuration ordering/marking information ordering information EC49016x - f package: b2 = sot-23-5l f: lead-free 016 b*
EC49016 standalone linear lithium battery charger e-cmos corp. ( www.ecmos.com.tw ) page 2 of 8 2006/05/18 absolute maximum rating (1) parameter symbol value units input supply voltage v cc 8 v prog voltage v prog vcc+0.3 v bat voltage v bat 7 v chrg voltage v chrg 10 v bat short-circuit duration ? continuous ? thermal resistance, junction-to-ambient ja 250 (sot-23-5) c/w bat pin current i bat 800 ma prog pin current i prog 800 a maximum junction temperature t j 125 c storage temperature t s -65 to +125 c lead temperature (soldering, 10 sec) ? 300 c recommended operating conditions (2) parameter symbol value units supply input voltage v in -0.3 to +8 v junction temperature t j -40 to +85 c electrical characteristics v in = 5v; t j = 25c; unless otherwise specified. symbol parameter conditions min typ max unit v cc input supply voltage 4.25 ? 6 v charge mode (3) , r prog = 10k ? 110 500 a standby mode (charge terminated) ? 115 160 a i cc input supply current shutdown mode(r prog not connected, v cc < v bat , or v cc < v uv ) ? 20 40 a v float regulated output (float) voltage i bat = 30ma, i chrg = 5ma 4.158 4.2 4.242 v r prog = 10k, current mode 90 110 130 ma r prog = 2k, current mode ? 500 ? ma standby mode, vbat = 4.2v 0 +/-1 +/-5 a shutdown mode (r prog not connected) ? +/-0.5 +/-5 a i bat bat pin current sleep mode, v cc = 0v ? +/-1 +/-5 a i trikl trickle charge current v bat < v trikl , r prog = 10k 12 18 25 ma v trikl trickle charge threshold voltage r prog = 10k, v bat rising 2.8 2.9 3.0 v
EC49016 standalone linear lithium battery charger e-cmos corp. ( www.ecmos.com.tw ) page 3 of 8 2006/05/18 electrical characteristics (continued) v in = 5v; t j = 25c; unless otherwise specified symbol parameter conditions min typ max unit v uv v cc undervoltage lockout threshold from v cc low to high ? 3.4 ? v v uvhys v cc undervoltage lockout hysteresis ? 170 ? mv prog pin rising ? 1.25 ? v v msd manual shutdown threshold voltage prog pin falling ? 1.2 ? v v cc from low to high ? 100 ? mv v asd v cc ? v bat lockout threshold voltage v cc from high to low ? 30 ? mv r prog = 10k (4) ? 0.1 ? ma/ma i term c/10 termination current threshold r prog = 2k ? 0.1 ? ma/ma v prog prog pin voltage r prog = 10k, current mode 0.9 1.03 1.1 v i chrg chrg pin weak pull-down current v chrg = 5v 8 20 40 a v chrg chrg pin output low voltage i chrg = 5ma ? 0.35 0.8 v v rechrg recharge battery threshold voltage v float - v rechrg ? 100 ? mv t lim thermal protection temperature ? 120 ? c t ss soft-start time i bat = 0 to 1000v/r prog ? 100 ? s t recharge recharge comparator filter time v bat high to low ? 2 ? ms t term termination comparator filter time i bat falling below i chg /10 ? 1000 ? s i prog prog pin pull-up current ? 1 ? a note 1: exceeding the absolute maximum rating may damage the device. note 2 : the device is not guaranteed to function outside its operating rating. note 3: supply current includes prog pin current (approximately 100a) but does not include any current delivered to the battery through the bat pin (approximately 100ma). note 4: i term is expressed as a fraction of measured full charge current with indicated prog resistor.
EC49016 standalone linear lithium battery charger e-cmos corp. ( www.ecmos.com.tw ) page 4 of 8 2006/05/18 float voltage vs supply voltage 4.185 4.190 4.195 4.200 4.205 4.210 4.215 4.220 4.225 4.230 4.0 4.5 5.0 5.5 6.0 6.5 v cc (v) v bat (v) r prog =10k t a =25 charge current vs supply voltage 0 100 200 300 400 500 600 4.04.55.05.56.06.57.0 v cc (v) i bat (m a ) r prog =2k r prog =10k v bat =4v t a =25 onset of thermal regulation trickle charge current vs supply voltage 0 10 20 30 40 50 60 70 4.0 4.5 5.0 5.5 6.0 6.5 7.0 v cc (v) i trikl (m a) r prog =2k v bat =2.5v t a =25 r prog =10k float voltage vs temperature 4.185 4.190 4.195 4.200 4.205 4.210 4.215 20 40 60 80 100 120 temperature ( ) v float (v) EC49016 vcc bat prog gnd 4.2v li-ion battery 1.65k 600ma vin 4.5v to 6.5v 600ma single cell li-ion charger led 330 chrg figure 1. figure 2. figure 3. figure 4. typical performance characteristics application diagram
EC49016 standalone linear lithium battery charger e-cmos corp. ( www.ecmos.com.tw ) page 5 of 8 2006/05/18 operation the EC49016 is a single cell lithium-ion battery charger us ing a constant-current/const ant-voltage algorithm. it can deliver up to 800ma of charge current (using a good therma l pcb layout) with a final float voltage accuracy of 1%. the EC49016 includes an internal p-channel power mosfet and thermal regulation circuitry. no blocking diode or external current sense resistor is r equired; thus, the basic charger circuit requires only two external components. furthermore, the EC49016 is capable of operating from a usb power source. normal charge cycle a charge cycle begins when the voltage at the vcc pin ri ses above the uvlo threshold level and a 1% program resistor is connected from the prog pin to ground or when a battery is connected to the charger output. if the bat pin is less than 2.8v, the charger enters trickle charge mode. in this mode, the EC49016 supplies approximately 1/10 the programmed charge current to bring the battery volt age up to a safe level for full current charging. when the bat pin voltage rises above 2.8v, the charger ent ers constant-current mode, where the programmed charge current is supplied to the battery. when the bat pin app roaches the final float voltage (4.2v), the EC49016 enters constant-voltage mode and the charge current begins to decrease. when the charge current drops to 1/10 of the programmed value, the charge cycle ends. programming charge current the charge current is programmed using a single resistor from the prog pin to ground. the battery charge current is 1100 times the current out of the prog pin. the program re sistor and the charge current are calculated using the following equations: prog chg chg prog r v i i v r 1100 , 1100 = = , the charge current out of the bat pin can be determined at any time by moni toring the prog pin voltage using the following equation: 1100 ? = prog prog bat r v i charge termination a charge cycle is terminated when the charge current falls to 1/10th the programmed value 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 term (typically 1ms), charging is terminated. the charge current is latched off and the EC49016 enters standby mode, where t he input supply current drops to 200ma. (note: c/10 termination is disabled in trickle charging and thermal lim iting 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 1/10th the programmed value. the 1ms filter time (t term ) on the termination comparator en sures that transient loads of this nature do not result in premature charge cycle term ination. once the average charge current drops below 1/10th the programmed value, the EC49016 terminates the charge cy cle and ceases to provide any current through the bat pin. in this state, all loads on the bat pin must be supp lied by the battery.the EC49016 co nstantly monitors the bat pin voltage in standby mode. if this voltage dr ops below the 4.05v recharge threshold (v rechrg ), another charge cycle begins and current is once again supplied to the battery. to manually restar t a charge cycle when in standby mode, the input voltage must be removed and reapplied, or the charge r must be shut down and restarted using the prog pin. figure 1 shows the state diagram of a typical charge cycle.
EC49016 standalone linear lithium battery charger e-cmos corp. ( www.ecmos.com.tw ) page 6 of 8 2006/05/18 charge status indicator (chrg) the charge status output has three different stat es: strong pull-down (~10ma), weak pull-down (~20 a) and high impedance. the strong pull-down state i ndicates that the EC49016 is in a charge cycle. once the charge cycle has terminated, the pin state is determined by undervoltage lo ckout conditions. a weak pu ll-down indicates that v cc meets the uvlo conditions and the EC49016 is ready to c harge. high impedance indicates that the EC49016 is in undervoltage lockout mode: either v cc is less than 100mv above the bat pin voltage or insufficient voltage is applied to the v cc pin. thermal limiting an internal thermal feedback loop reduces the programmed ch arge current if the die temperature attempts to rise above a preset value of approximately 120 . this feature protects the EC49016 from excessive temperature and allows the user to push the limits of t he power handling capability of a given circuit board without risk of damaging the EC49016 . the charge current can be set according to typical (not worst-case) ambient temperature with the assurance that the charger will automatically redu ce the current in worst-case conditio ns. thin sot power considerations are discussed further in the applications information section. undervoltage lockout (uvlo) an internal undervoltage lockout circuit monitors the i nput voltage and keeps the charger in shutdown mode until vcc rises above the undervoltage lockout threshol d. the uvlo circuit has a built-in hy steresis of 200mv. furthermore, to protect against reverse current in the power mosfet, the uv lo circuit keeps the charger in shutdown mode if vcc falls to within 30mv of the battery voltage. if the uvlo compar ator is tripped, the charger will not come out of shutdown mode until vcc raises 100mv above the battery voltage. trickle charge mode 1/10 th of full current chrg led: strong pull-dn cc/cv charge mode full current chrg led: strong pull-dn standby mode no charge current chrg led: weak pull-dn shutdown mode i cc drops to < 20 a chrg: hi-z in uvlo weakpull-dn otherwise v bat <2.8v v bat >2.8v v bat >2.8v v prog <100mv 4.05v>v bat >2.8v power on prog reconnected or uvlo connection stops prog floated or uvlo connection figure5. state diagram of a typical charge cycle
EC49016 standalone linear lithium battery charger e-cmos corp. ( www.ecmos.com.tw ) page 7 of 8 2006/05/18 stability considerations the constant-voltage mode feedback loop is stable without an output capacitor pr ovided a battery is connected to the charger output. with no battery present, an output capacitor is recommended to reduce ripple voltage. when using high value, low esr ceramic capacitors, it is recom mended to add a 1 ? resistor in series with the capacitor. no series resistor is needed if tantalum capacitors are used. in constant-current mode, the prog pin is in the feedback loop, not the battery. the constant-current mode stability is affected by the impedance at the prog pin. with no addition al capacitance on the prog pin, the charger is stable with program resistor values as high as 20k. however, additional capacitance on this node reduces the maximum allowed program resistor. the pole frequency at the prog pin should be kept above 100khz. v cc bypass capacitor many types of capacitors can be used for input bypassing, however, caution must be exercised when using multilayer ceramic capacitors. because of the self-resonant and high q ch aracteristics of some types of ceramic capacitors, high voltage transients can be generated under some start-up conditions, such as connecting the charger input to a live power source. adding a 1.5 ? resistor in series with a ceramic capacitor will minimize start-up voltage transients. power dissipation the conditions that cause the se9016 to reduce charge current through thermal feedback can be approximated by considering the power dissipated in the ic. nearly all of this power dissipation is generated by the internal mosfet?this is calculated to be approximately: p d = (v cc ? v bat ) ? i bat the approximate ambient temperature at which the thermal feedback begins to protect the ic is: t a = 120c ? p d ja t a = 120c ? (v cc ? v bat ) ? i bat ? ja thermal considerations because of the small size of the thin sot23 package, it is very important to use a good thermal pc board layout to maximize the available charge current. the thermal path for the heat generated by the ic is from the die to the copper lead frame, through the package lead, (especially the gr ound lead) to the pc board copper. the pc board copper is the heat sink. the footprint copper pads should be as wi de as possible and expand out to larger copper areas to spread and dissipate the heat to the surrounding ambient. other heat sources on the board, not related to the charger, must also be considered when designing a pc board layout because they will affect over all temperature rise and the maximum charge current. application hints
EC49016 standalone linear lithium battery charger e-cmos corp. ( www.ecmos.com.tw ) page 8 of 8 2006/05/18 outline drawing sot-23-5l dimensions dimn inches mm min max min max a 0.110 0.120 2.80 3.05 b 0.059 0.070 1.50 1.75 c 0.036 0.051 0.90 1.30 d 0.014 0.020 0.35 0.50 e ? 0.037 ? 0.95 f ? 0.075 ? 1.90 h ? 0.006 ? 0.15 j 0.0035 0.008 0.090 0.20 k 0.102 0.118 2.60 3.00 b k a f d e c h j
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