The MAX712/MAX713 fast charge Nickel Metal Hydride (NiMH) and Nickel Cadmium (NiCd) batteries from a DC source at least 1.5V higher than the maximum battery voltage. 1 to 16 series cells can be charged at rates up to 4C. A voltage-slope detecting analog-to-digital converter, timer, and temperature window comparator determine charge completion. The MAX712/MAX713 are powered by the DC source via an on-board +5V shunt regulator. They draw a maximum of 5mA from the battery when not charging. A low-side current-sense resistor allows the battery charge current to be regulated while still supplying power to the battery's load.
The MAX712 terminates fast charge by detecting zero voltage slope, while the MAX713 uses a negative voltage-slope detection scheme. Both parts come in 16- pin DIP and SO packages. An external power PNP transistor, blocking diode, three resistors, and three capacitors are the only required external components.
For high-power charging requirements, the MAX712/ MAX713 can be configured as a switch-mode battery charger that minimizes power dissipation. Two evaluation kits are available: Order the MAX712EVKIT-DIP for quick evaluation of the linear charger, and the MAX713EVKITSO to evaluate the switch-mode charger.
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Battery-Powered EquipmentLaptop, Notebook, and Palmtop ComputersHandy-TerminalsCellular PhonesPortable Consumer ProductsPortable StereosCordless Phones
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© Fast Charge NiMH or NiCd Batteries© Voltage Slope, Temperature, and Timer Fast-Charge Cutoff© Charge 1 to 16 Series Cells© Supply Battery's Load while Charging (Linear Mode)© Fast Charge from C/4 to 4C Rate© C/16 Trickle-Charge Rate© Automatically Switch from Fast to Trickle Charge© Linear or Switch-Mode Power Control© 5A Max Drain on Battery when Not Charging© 5V Shunt Regulator Powers External Logic
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V+ to BATT- ................................................................-0.3V, +7V
BATT- to GND........................................................................±1V
BATT+ to BATTPower
Not Applied............................................................ ±20V
With Power Applied ................................ The higher of ±20V or
±2V x (programmed cells)
DRV to GND ..............................................................- 0.3V, +20V
FASTCHG to BATT- ................................................... -0.3V, +12V
All Other Pins to GND...................................... -0.3V, (V+ + 0.3V)
V+ Current........................................................................100mA
DRV Current. ....................................................................100mA
REF Current........................................................................1 0mA
Continuous Power Dissipation (TA = +70°C)
Plastic DIP (derate 10.53mW/°C above +70°C............ 842mW
Narrow SO (derate 8.70mW/°C above +70°C ............. 696mW
CERDIP (derate 10.00mW/°C above +70°C ................ 800mW
Operating Temperature Ranges
MAX71_C_E ....................................................... 0°C to +70°C
MAX71_E_E .................................................... -40°C to +85°C
MAX71_MJE ................................................. -55°C to +125°C
Storage Temperature Range .......................... -65°C to +150°C
Lead Temperature (soldering, 10sec) .............................+300°C
Post a Buying Lead
Required Field 
