The APW6020 provides the power control and protection for four output voltages in high-performance , graphics intensive microprocessor and computer applications. The IC integrates two voltage-mode PWM controllers and two linear controllers , as well as the monitoring and protection functions into a single package. One PWM controller regulates the microprocessor core voltage with a synchronous-rectified buck converter. The second PWM controller supplies the computer's AGP 1.5V or 3.3V bus power with a standard Buck converter. The linear controllers requlate the power for the 1.5V GTL bus , and the 1.8V power for the North/South Bridge core voltage and/or cache memory circuits. The APW6020 includes an Intel-compatible , TTL 5-input digital-toanalog converter (DAC) that adjusts the core PWM output voltage from 1.3 VDC to 2.05 VDC in 0.05V steps and from 2.1 VDC to 3.5 VDC in 0.1V increments. The precision reference and voltage-mode control provide 1% static regulation. The second PWM controller's output is user-selectable , through a TTL-compatible signal applied at the SELECT pin , for levels of 1.5V or 3.3V with 3% accuracy. The two linear regulators provide fixed output voltages of 1.5V 3% (VOUT3 ) and 1.8V3% (VOUT4 ).