EVALUATION KIT AVAILABLE MAX8844Z/MAX8844Y 28V Dual Input Linear Li+ Battery Chargers with Battery Detection and Overvoltage-Protected Output General Description Features The MAX8844Z/MAX8844Y intelligent, stand-alone con- CCCV, Thermally Regulated Linear One-Cell Li+ stant-current, constant-voltage (CCCV), thermally regulated Battery Charger dual input linear chargers are designed for charging a sin- No External MOSFET, Reverse Blocking Diode, or gle-cell lithium-ion (Li+) battery. The MAX8844Z/MAX8844Y Current-Sense Resistor integrates a current-sense circuit, MOSFET pass element, thermal-regulation circuitry, and eliminates the external Programmable Fast-Charge Currents (1A max) RMS reverse-blocking Schottky diode to create the simplest and Programmable Top-Off Current Threshold smallest charging solutions for handheld equipment. Input Overvoltage Protected 4.7V Output The IC controls the charging sequence from the prequali- (SAFEOUT) from IN fication state through constant current fast-charge, top-off charge, and full-charge indication. Proprietary thermal- Input Overvoltage Protected 4.7V Output regulation circuitry limits the die temperature during (SAFEUSB) from USB fast-charging or when the IC is exposed to high ambient Proprietary Die Temperature Regulation Control temperatures, allowing maximum charging current with- (+115C) out damaging the IC. 4.25V to 28V Input Voltage Range with Input The MAX8844Z/MAX8844Y achieve high flexibility by providing adjustable fast-charge currents (SETI) and an Overvoltage Protection Above +7.5V adjustable top-off current threshold (MIN) through external Low-Dropout Voltage (300mV at 500mA) resistors. The IC features a booting assistant circuit that Input Power-Source Detection Output (POK), distinguishes input sources and battery connection and provides an enable signal (ABO, ABO) for system booting. Charge Status Output (CHG), Charge-Enable Input (EN) The ICs also integrate two input overvoltage protected LDO outputs (SAFEOUT, SAFEUSB) for low voltage Output for Autobooting (ABO, MAX8844Z) rated USB or charger inputs in system, and a battery pack Output for Autobooting (ABO, MAX8844Y) detection circuit (DETBAT) that disables the charger when the battery pack is absent. Other features include an Tiny 3mm x 3mm, 14-Pin TDFN Package, 0.8mm active-low control input (EN), an active-low input power Height (max) source detection output (POK), and a fully charged top-off threshold detection output (CHG). Ordering Information The MAX8844Z/MAX8844Y automatically select between either the USB or IN source. If both sources are present at PIN- ABO ACTIVE PART TOP MARK the same time, highest priority is given to the IN source. The PACKAGE STATE IN source is selected to insure the shortest charging time 14 TDFN-EP* for the system since it is able to deliver the highest current. MAX8844ZETD+ AEK Active high 3mm x 3mm The MAX8844Z/MAX8844Y accept an input supply range 14 TDFN-EP* from 4.25V to 28V (IN and USB), but disables charging MAX8844YETD+ AEN Active low 3mm x 3mm if the input voltage exceeds +7.5V to protect against unqualified or faulty AC adapters. The ICs operate over +Denotes a lead(Pb)-free/RoHS-compliant package. the extended temperature range (-40C to +85C) and are *EP = Exposed pad. available in a compact 14-pin, thermally enhanced TDFN Note: All devices are specified over the -40C to +85C operat- 3mm x 3mm package (0.8mm max height). ing temperature range. Applications Cellular and Cordless USB Appliances Typical Operating Circuit and Pin Configuration appear at Phones Charging Cradles and end of data sheet. Smart Phones and PDAs Docks Digital Still Cameras Bluetooth Equipment MP3 Players Bluetooth is a registered trademark of Bluetooth SIG. 19-4279 Rev 1 3/09MAX8844Z/MAX8844Y 28V Dual Input Linear Li+ Battery Chargers with Battery Detection and Overvoltage-Protected Output Absolute Maximum Ratings IN, USB to GND ....................................................-0.3V to +30V Junction Temperature ......................................................+150C ABI, BATT, EN, POK, ABO, ABO, CHG, DETBAT, SETI, Storage Temperature Range ............................ -65C to +150C MIN, SAFEOUT, Lead Temperature (soldering, 10s) .................................+300C SAFEUSB to GND ...............................................-0.3V to +6V IN to BATT Continuous Current .......................................1A RMS Continuous Power Dissipation (T = +70C) A 14-TDFN (derate 24.4mW/C above 70C) (multilayer PCB) .....................................................1951.2mW BATT Short-Circuit Duration ......................................Continuous Operating Temperature Range ........................... -40C to +85C Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Electrical Characteristics (V = 5V or V = 5V, V = 4V, R = 1M to BATT, EN = unconnected, R = 2.8k to GND, V = 0V, C = 2.2F, IN USB BATT POK SETI DETBAT BATT T = -40C to +85C, unless otherwise noted. Typical values are at T = +25C.) (Note 1) A A PARAMETER CONDITIONS MIN TYP MAX UNITS IN, USB Input Supply Voltage Range 0 28 V Input Supply Operating Voltage 4.25 7.00 V Range Overvoltage Lockout Trip V rising, 100mV hysteresis (typ) 7.0 7.5 8.0 V IN Threshold Constant current charging 0.25 0.50 I - I , I = 0A IN BATT BATT Constant current charging 1 I - I , I = 500mA IN BATT BATT Input Current mA IC disabled, V = 5V 0.23 0.50 EN T = +25C 0.02 V = 4V, A IN V = 4.2V BATT T = +85C 0.03 A BATT, CHG, POK Minimum BATT Bypass 2.2 F Capacitance V Prequalification Threshold BATT V rising, 100mV hysteresis (typ) 2.3 2.5 2.7 V BATT Voltage T = 0C to +85C 4.175 4.200 4.225 A Battery Regulation Voltage I = 0A V BATT T = -40C to +85C 4.158 4.200 4.242 A Regulator Dropout Voltage (V - IN V = 4.1V, I = 425mA 260 mV BATT BATT V ) BATT V = 0 to 4V, IN 5 10 BATT Input Current V = 4.2V BATT A (Note 2) IC disabled 3 T = 0C to +85C 1120 Current-Sense Amplifier Gain A I = 500mA A/A BATT (I to I ) BATT SETI T = -40C to +85C 1120 A Maxim Integrated 2 www.maximintegrated.com