The ISL95855C is a compliant voltage regulator from Renesas, that provides a complete power solution for Intel® microprocessors supporting core, graphics, and system agent rails. The controller provides control and protection for three voltage regulator (VR) outputs. The VR A output can be configured for 3-, 2-, or 1-phase operation. The VR B output is configurable for 2- or 1-phase operation, and the VR C output supports 1-phase operation. The address options for these three outputs allow for maximum flexibility to support the IMVP8 CPU. All three VRs share a common serial control bus to communicate with the CPU and achieve lower cost and smaller board area compared with a two-chip approach. The ISL95855C has expanded I_CCMAX register tables for VR A and VR C to support Intel CFL-H. Based on Intersil’s Robust Ripple Regulator (R3™) technology, the R3 modulator has many advantages compared to traditional modulators. These include faster transient settling time, 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 ISL95855C has several other key features. The controller provides PWM outputs, which support Intel DrMOS power stages (or similar) and discrete power stages using the Intersil ISL95808 high voltage synchronous rectified buck MOSFET driver. The controller complies with IMVP8 PS4 power requirements and supports compatible power stages and drivers. The controller supports DCR current sensing with a single NTC thermistor for DCR temperature compensation, or more precision through resistor current sensing.