The ISL6353 is a three-phase PWM buck regulator controller for VR12 DDR memory applications. The multi-phase implementation results in better system performance, superior thermal management, lower component cost and smaller PCB area. The ISL6353 has two integrated power MOSFET drivers for implementing a cost effective and space saving power management solution. The PWM modulator of the ISL6353 is based on Renesas' Robust Ripple Regulator™ (R3) technology. Compared with the traditional multi-phase buck regulator, the R3modulator commands variable PWM switching frequency during load transients, achieving faster transient response. R3also naturally goes into pulse frequency modulation operation in light load conditions to achieve higher light load efficiency. The ISL6353 is designed to be completely compliant with VR12 specifications. The ISL6353 has a serial VID (SVID) bus communicating with the CPU. The output can be programmed for 1-, 2- or 3-phase interleaved operation. The output voltage and power state can also be controlled independent of the serial VID bus. The ISL6353 has several other key features. It supports DCR current sensing with a single NTC thermistor for DCR temperature compensation or accurate resistor current sensing. It also has remote voltage sense, adjustable switching frequency, current monitor, OC/OV protection and power-good. Temperature monitor and thermal alert is available too.