The ISL95820 Pulse Width Modulation (PWM) controller IC provides a complete low-cost solution for Intel VR12. 5™ compliant microprocessor core power supplies. It provides the control and protection for a Voltage Regulator (VR). The VR incorporates 3 integrated drivers and can operate in 4-, 3-, 2- or 1-phase configurations. The VR uses a serial control bus to communicate with the CPU and achieve lower cost and smaller board area. The VR utilizes Intersil’s Robust Ripple Regulator R3 Technology™. The R3™ modulator has many advantages compared to traditional modulators, including faster transient response, variable switching frequency in response to load transients, and improved light load efficiency due to diode emulation mode with load-dependent low switching frequency. The ISL95820 has several other key features. It supports either DCR current sensing with a single NTC thermistor for DCR temperature compensation or more precise resistor current sensing if desired; remote voltage sense; programmable VBOOTvoltage, IMAX, voltage transition slew rate and switching frequency; adjustable overcurrent protection; and Power-Good signal.