PWM Outfits Intelligent Power Supplies

Operating from a 3V to 5.5V supply, the MCP1631 2-MHz pulse-width modulator (PWM) integrates a 1A MOSFET driver, comparator for over-voltage protection, and both battery-current and voltage-sense amplifiers. The chip’s main function is to close the feedback loop in switch-mode power supplies that use microcontrollers for general system intelligence and control. Control is via an easily-programmable MCU, allowing for accurate charge profiles for a variety of battery-charging systems while closing the feedback loop at the speed required for safe charging and long battery life. Protection features include under-voltage lock out and over temperature. The device is capable of charging multiple battery chemistries including Li-Ion, NiHM, NiCd, and lead acid. High-voltage versions of the MCP1631 PWM are available (MCP1631HV) that operate from 6V to 16V and include a linear regulator (LDO). Available in 4 mm x 4 mm QFN and 20-pin TSSOP and SSOP options, prices range from $1.06 to $1.21 each/10,000 depending upon device and package option. MICROCHIP TECHNOLOGY INC., Chandler, AZ. (888) 628-6247.