unisonic technologies co., ltd ub10803 preliminary cmos ic www.unisonic.com.tw 1 of 10 copyright ? 2013 unisonic technologies co., ltd qw-r502-a26.a one-cell standalone linear lithium battery charger ? description the utc ub10803 is a fully-integrated single-cell li-ion/polymer battery charger. the device operates without external fet and blocking diode, and employs a cons tant-current constant-voltage (cc/cv) charging profile. the fast-charge and end-of-charge (eoc) currents are programmable with independent exte rnal resistors. when the battery is deeply discharged to lower than 2.75v, the charger firstly pre-charges the battery with typically 20% of the programmable fast-charge current. when the charge current is reduced to the programmed eoc current level (almost works completely in a constant-voltage (cv) mode), an eoc indication is displayed through the chg pins. the utc ub10803 is protected by thermal regulation technology to prevent the ic from over-heat during charging. two status indication pins (ppr and chg), which are both implemented as an open-drain outputs, can be used to drive leds or work as logic interface to a microprocessor. when no adapter is attached or when the charger is di sabled, the leakage current from battery cell is less than 1ua typically. ? features sop-8 dfn-8(2x3) 1 * a constant-current/constant-voltage linear charger for single-cell li-ion/polymer batteries * integrated pass element and current sensor * highly-integrated, requiring no external fets or blocking diode * 4.2v voltage accuracy: 1.2% all temperatures (available with 4.10v and 4.36v options upon request) * programmable charge current 50ma to 500ma * programmable end-of-charge current by current recharge algorithm * pre-charge for fully discharged batteries * 1 a (typ.) leakage current of the battery when no input power is attached or charger is disabled * power present and charge status indications * thermal regulation on charging current to prevent over-heat * few components, cost-effective solutions ? ordering information ordering number package packing lead free halogen free ub10803l-sh2-t ub10803g-sh2-t hsop-8 tube ub10803l-sh2-r ub10803g-sh2-r hsop-8 tape reel ub10803l- k08-2030-r ub10803g- k08-2030-r dfn-8(23) tape reel
ub10803 preliminary cmos ic unisonic technologies co., ltd 2 of 10 www.unisonic.com.tw qw-r502-a26.a ? pin configuration ? pin description pin no. pin name description 1 v in supply input 2 ppr power present active-low open drain power status indicator 3 chg charge active-low open drain charge status indicator 4 en enable active-low input 5 gnd ground 6 i min end-of-charge current setting input 7 i ref charge current setting input for adaptor mode 8 bat battery terminal
ub10803 preliminary cmos ic unisonic technologies co., ltd 3 of 10 www.unisonic.com.tw qw-r502-a26.a ? block diagram
ub10803 preliminary cmos ic unisonic technologies co., ltd 4 of 10 www.unisonic.com.tw qw-r502-a26.a ? absolute maximum ratings parameter symbol ratings unit input supply voltage v in -0.3 ~ +7.0 v i ref voltage v iref -0.3 ~ +7.0 v i min voltage v imin -0.3 ~ +7.0 v bat voltage v bat -0.3 ~ +7.0 v en voltage v en -0.3 ~ +7.0 v chg voltage v chg -0.3 ~ +7.0 v ppr voltage v ppr -0.3 ~ +7.0 v notes: 1. absolute maximum ratings are those values beyond which the device could be permanently damaged. absolute maximum ratings are stress ratings only and functional device oper ation is not implied. 2. pulse ( sec) noise exceeding the above input voltage (gnd+7.0v) may cause damage to the ic. ? thermal data parameter symbol ratings unit junction to ambient ja 59 c/w junction to case jc 4.5 ? c/w ? recommended operating conditions parameter symbol min typ max unit operating voltage v in 4.5 6.0 v programmable current i chg 50 500 ma operating temperature t a -40 85 ? c ? electrical characteristics (v cc =5v, t a =25 unless otherwise specified) parameter symbol test conditions min typ max unit v in -bat offset voltage rising edge v os v bat =4.0v 90 150 mv v in -bat offset voltage falling edge v bat =4.0v 10 50 rising power on reset threshold v por v bat =3.0v 3.4 3.9 4.3 v falling power on reset threshold v bat =3.0v 3.1 3.6 4.1 dc supply current i dc charge enabled 500 1000 a charge disabled 300 500 bat pin sink current i stby charge disabled or the input is floating 1 a output voltage v ch 4.5v ub10803 preliminary cmos ic unisonic technologies co., ltd 5 of 10 www.unisonic.com.tw qw-r502-a26.a ? operation the utc ub10803 charges a single-cell li-ion/polymer battery wi th a programmed constant current (cc) or a constant voltage (cv) profile. t he constant fast charge current i chg is programmable by setting an external resistor r iref while the constant voltage is factor y-trimmed at 4.2v (4.10v or 4.36v opt ions are available upon request). if the battery voltage is deeply discharged to lower than 2.75v, the utc ub10803 pre-charges the battery with a 20% programmable current until the battery voltage rises above the pre-charge threshold. after pre-charge finishes, constant-current (cc) chargi ng mode begins with the pre-set fast charge current. normally, the battery voltage rises gradually during cc charge phase. when the battery vo ltage reaches nearly 4.2v, the charger enters the constant-voltage (cv) charging mode a nd begins to regulate the battery volt age at 4.2v while diminishing the charging current gradually. when the charging current is reduced to an amount smaller than the programmed end-of-charge (eoc) current level, t he charger gives out a ?full-charge? i ndication through the chg pin, but the charger still continues to regulate the battery voltage at 4.2v with safe & small current. the end-of-charge (eoc) current level (i min ) can be easily programmed with an external resistor r imin . the chg signal turns to low when pre-charge starts and rises to high when eoc is reached. after reaching eoc, the charge current has to rise again to typically 76% of i chg before the chg signal will turn on again. the current surge after eoc can be caused by a load connected to the battery. when the die temperature reaches 115c (typically), a thermal regulation function is employed to reduce the charge current accordingly to maintain the temperature from increasing furthermore. this is an important function to achieve safe operation even when the printed circuit board (pcb) is not effective in l eaking out the heat generated by the linear charger. 1. ppr indication the ppr pin is implemented as an open- drain output to provide a power-good in dication of the input power source such as an ac adapter. when the input voltage is higher than the por (power-on reset) threshold, the ppr pin turns on the internal open-drain mosfet to indicate logic low signal. the ppr indication is designed to be independent on t he chip enable (en-pin) input. w hen the internal open-drain fet is turned off, the ppr pin should leak less than 1 a current. when turned on, the ppr pin should be able to sink at least 5ma current under all operating conditions. the ppr pin can be used to drive an led or worked as logic interface to a microprocessor. 2. power-good range the input voltage is considered as power good when it meets the following three conditions: (1). v in > v por (2). v in - v bat > v os where the v os is the offset voltage, it determines if the battery voltage is even higher than the input voltage. all v por and v os are realized with sufficient hysteresis, as given in the electrical specification table. all charging activities are disabled when the input voltage falls out of the power-good range. 3. input and output comparator obviously, when the input source voltage is lower than the battery voltage, no charging activity could be started and the charger will disable the internal pass element to prevent battery leakage. charge begins when the input voltage is higher than the battery voltage by a defined offset voltage (v os ). this scheme also ensures that the charger is completely turned off when the input power is removed from the charger. 4. chg indication the chg pin is implemented as an open- drain output to give a logic low when a charge cycle begins and turn high when an end-of-charge (eoc) condition is reached. this pin is designed with a sinking ability of more than 5ma so as to drive an led. when the charger is disabled through en-pin, t he chg output is high impedance. the chg pin can also be used to interface with a microprocessor. 5. en input the chip is enabled by a logic low signal applied to the en pin. this pin is realized with a 200k ? internal pull-down resistor such that even the en pin is left floatin g, the input is equivalent to logic low and the chip is enabled by default. similarly, the chip is disabled when the en pin receives a logic high signal.
ub10803 preliminary cmos ic unisonic technologies co., ltd 6 of 10 www.unisonic.com.tw qw-r502-a26.a ? operation(cont.) 6. i min indication the i min pin can be used to program the end-of-charge (eoc) current by connecting a resistor between this pin and the gnd pin. the programming is defined by the following equation: min imin 800 i(ma)= r where r imin is usually in k ? . 7. i ref pin the i ref pin is for fast charge-current programming. by con necting a resistor between this pin and the gnd pin, the fast charge current limit is det ermined by the following equation: chg iref 4000 i(ma)= r where r iref is in k ? . the actual charge current is guar anteed to have 10% accuracy of i chg with the charge current set at 150ma. 8. bat pin always connect the bat pin to a single-cell li-ion/polymer battery in parallel with a 1 f (or larger) x5r ceramic capacitor for decoupling and guaranteeing system stability. when the en pin is pulled to logic high, the bat output is disabled. the utc ub10803 relies on a battery for stability and is not guaranteed to be stable if the battery is not connected. 9. dropout voltage when the input voltage is low while the battery voltage is high, the charging current may not be maintained according to the equation i chg (ma) = 4000/r iref due to a limited internal on-resistance (r ds(on) ) of the internal pass element. the worst resistance of the pass fet is about 1.2 ? at the maximum operating tem perature, thus if tested with 500ma current and 4.2v battery volt age, constant current could still be maintained when the input voltage is as low as 4.62v. 10. thermal foldback the bottom big exposed pads in both hsop-8 and dfn-8( 2x3) packages are used for thermal foldback. for reducing the chip ambient temperature as much as possibl e, it is recommended to connect as much copper as possible to this pad either on the component layer or ot her layers through thermal vias. the thermal regulation function starts to reduce the charge current when th e internal temperature reaches a typical value of 115c .
ub10803 preliminary cmos ic unisonic technologies co., ltd 7 of 10 www.unisonic.com.tw qw-r502-a26.a ? application information input capacitor selection the input capacitor is employed to decouple the powe r supply from load transients and suppress noise from power lines. typically, a 1 f x5r ceramic capacitor is recommended to be placed very close between the v in pin and gnd pin to stabilize the operation during the start up, especially when the input supply is passing the por threshold and the v in -bat comparator offset voltage. once passing through the por threshol d, there is a voltage hysteresis to provide sufficient guard band from noise or load transient to trigger the system to reset. output capacitor selection the criterion for selecting the output capacitor is to mainta in the stability of the charger as well as to bypass any transient load current. typicall y, a minimum capacitance of 1 f x5r ceramic capacitor is recommended and sufficient for stabilizing the system. for systems that ma y happen to occasionally see hi gh load transient s, the output capacitor may be increased to further bypass any ripples so caused. charge current limit during the constant-current (cc) charging mode, the charging curren t is primarily determined by i chg as calculated in previous formula. howeve r, the actual charge current in t he cc mode could also be limited by other factors. when the input (v in ) and output (v bat ) voltages are too close to each other , the on-resistance of the internal pass element may limit the amount of current that passes through it. when the input voltage is sufficiently higher than the battery voltage, yet has not increased the die temperature over the thermal limit. when the input voltage is reduced (or the battery voltage increases towards the input voltage), the charge current is limited by the on-resistance of the pass element. therefor e, it is recommended to employ sufficiently high input voltage for applications that require constant charging curr ent over the entire charging period. but for applications that needs to minimize the heat dissipat ion, a current-limiting adapter maybe a pplied to maintain constant charging current at whole charging phase. in addition, if the input voltage increases, the charge cu rrent may also be reduced due to the thermal fold back function. the high voltage drop across the pass element in creases the power dissipation therein and thus causing the die temperature to increase significantly. layout guidance the utc ub10803 employs thermally-enhanced dfn package, wh ich has an exposed thermal pad at its bottom side. it is recommended to connect as much copper as possible between the exposed pad and pcb to make it effective in taking the heat away from the die. for app lications requiring high char ging current, the thermal impedance should be further reduced by employing more la yers of copper to connect with the exposed pad through thermal via. input power sources the utc ub10803 works with different types of ac/dc adapter or usb port (any type) with no special requirements. the utc ub10803 accepts input voltage ranges from 4. 5v to 6.5v for normal operation.
ub10803 preliminary cmos ic unisonic technologies co., ltd 8 of 10 www.unisonic.com.tw qw-r502-a26.a ? typical charge profile
ub10803 preliminary cmos ic unisonic technologies co., ltd 9 of 10 www.unisonic.com.tw qw-r502-a26.a ? typical application circuit fig1. typical application circuit for led display component description for figure 1 part description c1 1 f x5r ceramic cap c2 1 f x5r ceramic cap riref 29.4k ? , 1% for 135ma charge current rmin 29.4k ? , 1% for 27ma eoc current r1, r2 300 ? , 5% d1, d2 leds for indication fig2. typical application circuit interfacing to a mcu component description for figure 2 part description c1 1 f x5r ceramic cap c2 1 f x5r ceramic cap riref 29.4k ? , 1% for 135ma charge current rmin 29.4k ? , 1% for 27ma eoc current r1, r2 100k ? , 5%
ub10803 preliminary cmos ic unisonic technologies co., ltd 10 of 10 www.unisonic.com.tw qw-r502-a26.a utc assumes no responsibility for equipment failures that result from using products at values that exceed, even momentarily, rated values (such as maximum ratings, operating condition ranges, or other parameters) listed in products specifications of any and all utc products described or contained herein. utc products are not designed for use in life support appliances, devices or systems where malfunction of these products can be reasonably expected to result in personal injury. reproduction in whole or in part is prohibited without the prior written consent of the copyright owner. the information presented in this document does not form part of any quotation or contract, is believed to be accurate and reliable and may be changed without notice.
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