Microchip Technology Inc

MCP1630 Low-Cost NiMH Battery Charger Reference Design

Part Number: MCP1630RD-NMC1

Low Cost NiMH Battery Charger board preprogrammed to charge 3 NiMH cells. Charge profile and number of batteries can be changed with firmware. The design uses the MCP1630 High-Speed Analog PWM combined with the PIC microcontroller. Charge current is initially set for 1.35A fast charge.

    • Programmed parameters - modified in firmware
    • Factory Settings:

                - Preconditioning Charge Current =170 mA

                - Preconditioning Threshold = 3 V

                - Constant Current Fast Charge = 1.35 A

                - Charge Termination based on delta - VBATT / delta time

                - Charge Termination based on delta + TBATT / delta time, with external thermistor installed

    • Top Off Charge Current = 130 mA for 1 Hour
    • Overvoltage protection (battery removed)
    • Overcharge protection to prevent damaging the battery
    • Overcurrent protection in the event of a shorted battery
    • Battery reversal protection
    • Input short circuit protection
    • Overtemperature protection to prevent the battery from reaching too high a temperature during charge
    • Soft-start capability by holding the reference voltage low during power-up
    • The MCP1630 Low-Cost NiMH Battery Charger has the flexibility to optimize the charging algorithm for new battery technology, different battery chemistries or different battery pack configurations
    • Proprietary features can be added by modifying the firmware contained in the PIC12F683
    • The factory-programmed source code is available
    • Ability to adapt to environmental effects, such as ambient temperature

     

    Low Cost NiMH Battery Charger board preprogrammed to charge 3 NiMH cells. Charge profile and number of batteries can be changed with firmware. The design uses the MCP1630 High-Speed Analog PWM combined with the PIC microcontroller. Charge current is initially set for 1.35A fast charge.