ISL95825: Three Phase PWM Controller for VR12.5/VR12.6 CPUs

The ISL95825 Pulse Width Modulation (PWM) controller IC provides a complete solution for VR12.5™/VR12.6™ compliant microprocessor core power supplies. It provides the control and protection for a Voltage Regulator (VR). The VR can operate in 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 numerous advantages compared to traditional modulators, including faster transient response, variable switching frequency during load transients, and improved light load efficiency due to its ability to automatically change switching frequency.

The ISL95825 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. The output comes with remote voltage sense, programmable V_BOOT voltage, I_CCMAX, voltage transition slew rate and switching frequency, adjustable overcurrent protection and Power-Good signal.

Key Features

Serial data bus
Configurable 3-, 2- or 1-phase for the output
R3 Modulator
- Excellent transient response
- High light load efficiency
0.5% system accuracy over-temperature
Supports multiple current sensing methods
- Lossless inductor DCR current sensing
- Precision resistor current sensing
Differential remote voltage sensing
Resistor programmable ICCMAX, VBOOT at start-up, voltage transition slew rate and switching frequency
Adaptive body diode conduction time reduction
Low supply current at PS4 state