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