Microchip announced a sophisticated power supply pulse width modulation (PWM) controller. The MCP1630 enables power-system designers to add precision control, digital communication and programmability to their designs. The device consists of a high-speed comparator with a high-performance error amplifier and a PWM latch to perform the analog power-supply PWM function. When used with a microcontroller, it supports the development of high-speed, intelligent power-system controllers.
The microcontroller can control the output voltage (or current), switching frequency, maximum duty cycle and other features making the power system more intelligent and adaptable. This enables the power system to adapt to many external signals and variables in order to optimise performance and allow calibration. The device supports all Switch Mode Power Supply (SMPS) topologies and is best suited for applications requiring medium-to-high levels of intelligence and operating at frequencies exceeding 200kHz.
The PWM device features internal protection, including under-voltage lockout (UVLO), output short circuit and over-temperature protection. It has a low operating current of 2.8 mA (typical). In addition, the device supports peak-current mode operation up to 1 MHz, and has a precise peak-current limit of ±5%. Typical applications include battery chargers for Lithium-Ion and Nickel Metal Hydride chemistries, AC power-factor correction, multiple output-power supplies and multiple-phase power supplies.
As an example application, Microchip is offering a battery-charger demonstration board. On this board is a SEPIC (Single End Primary Inductor Circuit) converter that provides a constant charge current to the battery. The MCP1630 regulates this charge current by monitoring it through a battery-sense resistor and by providing the proper pulse width.
Additional features, including trickle charge, fast charge, over-voltage protection, can be added to the system using the programmability of the microcontroller and the flexibility of the MCP1630 . The circuit is available in an 8-pin MSOP package, and operates over an extended temperature range of -40 to +125°C. Samples and volume production are available.
Microchip Technology , Wokingham, Berks RG41 5TU, UK.