DS2715 NiMH Battery Pack Charge Controller www.maxim-ic.com DESCRIPTION PIN CONFIGURATION The DS2715 is well suited for cost-sensitive charger applications where the battery pack is either internal C V BIAS BATT or external to the application. It has been optimized for V THM CH safe and reliable charging of 1 to 10 NiMH cells in series. The internal gain block can be selected as V R SS T either a comparator or transconductance amplifier for LED1 V DD charge current regulation. This makes the DS2715 DNC SNS- configurable as a switched DC charger, a linear current regulator, or a switchmode current source. V SNS+ SS The DS2715 pre-conditions severely depleted cells CTG DIV before entering full charge mode. It terminates full CTG MODE charge using the dT/dt technique, which requires an external sensing thermistor. Over-temperature, under- temperature, and over-voltage detection prevents 16 SO charging under unsafe conditions. A user selectable See Table 1 for Ordering Information. charge timer allows charge rates from 0.167C to 2C. FAST-CHARGE, TOPOFF and DONE modes are included for highly reliable, safe charging of NiMH cells. Discharge mode allows the DS2715 to enter a low power sleep state while the cell pack is being Table 1. ORDERING INFORMATION discharged. PART MARKING PIN-PACKAGE DS2715Z+ D2715 16 SO FEATURES DS2715Z+T&R D2715 16 SO Charges 1 to 10 NiMH Cells DS2715BZ+ D2715B 16 SO FAST-CHARGE at up to a 2C Rate DS2715BZ+T&R D2715B 16 SO + Denotes a lead(Pb)-free/RoHS-compliant package. PRECHARGE and TOPOFF Charge Modes Help T&R = Tape and reel. Cell Conditioning Functional Diagrams Load Detection Allows the DS2715 to Enter Low Power Sleep Mode (Less than 10A) while the OPERATIONAL DIAGRAM Cell Pack is Discharged dT/dt Charge Termination Eliminates Cell Charge Stress Monitors Voltage, Temperature, and Time for Safety and Secondary Termination Regulates Current through Either Linear Control or Switch-Mode Control LED Output Displays Charge State Small 16-Pin SO Package APPLICATIONS Portable DVD Players Portable Television Sets Handheld Gaming Test Equipment Pin Configurations appear at end of data sheet. Handheld POS Terminals Functional Diagrams continued at end of data sheet. UCSP is a trademark of Maxim Integrated Products, Inc. For pricing, delivery, and ordering information, please contact Maxim Direct 19-4592 4/09 at 1-888-629-4642, or visit Maxims website at www.maxim integrated.com. AVAILABLEDS2715: NiMH Battery Pack Charge Controller ABSOLUTE MAXIMUM RATINGS* Voltage on V and V Pins with Respect to V -0.3V to +18V DD CH SS Voltage on LED1 Pin -0.3V to +18V Voltage on SNS- -0.3V to +0.3V Voltage on C -0.3V to 6V BIAS Voltage on all Other Pins -0.3V to V Cbias Continuous Sink Current V and LED1 28mA CH Operating Temperature Range -20C to +85C Storage Temperature Range -55C to +125C Soldering Temperature See IPC/JEDEC J-STD-020 Human Body Model (HBM) ESD Limit of V Pin 500V CH HBM ESD Limit of all Other Pins 2KV *This is a stress rating only and functional operation of the device at these or another y conditions above those indicated in the operation sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods of time may affect reliability. RECOMMENDED DC OPERATING CONDITIONS (4.5V V 16.5V T = 0 C to +70 C.) DD A PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Supply Voltage V (Note 1) 4.5 16.5 V DD LED1 Voltage V (Note 1) 0.0 16.5 V LED Mode Voltage V (Note 1) 0.0 V V MODE Cbias V Voltage V (Note 1) 0.0 16.5 V CH VCH C Capacitor Range C .02 .15 F BIAS Cbias R Resistor Range R 20 240 K T Rt DC ELECTRICAL CHARACTERISTICS (4.5V V 16.5V, T = 0 C to +70C, unless otherwise noted.) DD A PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Linear Mode, V = 16.5V 1.3 1.6 mA DD Operating Current I DDA Comparator Mode, (Note 2) 150 250 A V = 16.5V DD Idle Current I V < V 10 A DDS DD UVLO Discharge Current I Discharge latch set (Note 2) 200 A DDD UVLO Threshold V V Rising (Note 3) 3.8 3.9 4.0 V UVLO DD UVLO Hysteresis V V Falling 35 mV UVLO-HYS DD V Sink Current I V = 1.5V 20 mA CH OL-Vch OL LED1 Sink Current I V = 1.0V 20 mA OL-LED OL Leakage Current, V , CH I Pin Inactive or Device Idle -1 +1 A LKG LED1 THM Pin Leakage I -1 +1 A LKG-THM Current V Pin Leakage BATT I -50 +50 nA LKG-Vbatt Current C Voltage V 0 < I < 0.4mA 3.9 4.0 4.3 V BIAS Cbias Cbias DIV Pin Load Current I 500 uA Div Current Sense Amplifier -1 G 100 A < I < 20mA 5 6.25 7.5 ERR Vch Gain