The HIP6028 provides the power control and protection for three output voltages in high-performance microprocessor and computer applications. The IC integrates a PWM controller, a linear regulator and a linear controller as well as the monitoring and protection functions into a single package. The PWM controller regulates the microprocessor core voltage with a synchronous-rectified buck converter. The linear controller regulates power for the GTL bus and the linear regulator provides power for the clock driver circuit. The HIP6028 includes an Intel-compatible, TTL 5-input digital-to-analog converter (DAC) that adjusts the core PWM output voltage from 2.1VDC to 3.5VDC in 0.1V increments and from 1.3VDC to 2.05VDC in 0.05V steps. The precision reference and voltage-mode control provide 1% static regulation. The linear regulator uses an internal pass device to provide a fixed 2.5V 2.5%. The linear controller drives an external N-channel MOSFET to provide a fixed 1.5V 2.5%. The HIP6028 monitors all the output voltages. A single Power Good signal is issued when the core is within 10% of the DAC setting and the other levels are above their undervoltage levels. Additional built-in over-voltage protection for the core output uses the lower MOSFET to prevent output voltages above 115% of the DAC setting. The PWM overcurrent function monitors the output current by using the voltage drop across the upper MOSFET's rDS(ON), eliminating the need for a current sensing resistor. The HIP6028 offers integrated ACPI S3 shutdown state support. Through the SD1&3 pin, the microprocessor core and GTL bus supplies can be shut down when entering power-saving standby operation mode.