Advanced PWM and Triple Linear Power Controller for Gateway Applications

The ISL6440A provides the power control and protection for four output voltages required by microprocessors used in high-performance, graphics-intensive gateway applications. The IC integrates a voltage-mode PWM controller and three linear controllers, as well as the monitoring and protection functions into a 28 lead SOIC package.

Features

• Provides four regulated voltages

- Microprocessor core, AGP bus, memory, and GTL bus power

• Drives N-Channel MOSFETs

• Linear regulator drives compatible with both MOSFET and bipolar series pass transistors

• Fixed or externally resistor-adjustable linear outputs

• Simple single-loop control design

- Voltage-mode PWM control

• Fast PWM converter transient response

- High-bandwidth error amplifier

- Full 0–100 duty ratio

• Excellent output voltage regulation

- Core PWM output: ±1 over temperature

- Other outputs: ±3 over temperature

• TTL-compatible 5-bit DAC core output voltage selection

- Shutdown feature removed when all inputs high

- Wide range 1.3VDC to 3.5VDC

• Power-good output voltage monitor

• Overvoltage and overcurrent fault monitors

- Switching regulator does not require extra current Sensing element, uses upper MOSFET’s rDS(ON)

• Small converter size

- Constant frequency operation

- 200kHz free-running oscillator; programmable from 50kHz to over 1MHz

- Small external component count

Applications

• Power regulation for gateway processors