Compliant with Intel IMVP8™, the ISL95857 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. VR A and VR C outputs support 1-phase operation
only, while VR B is configurable for 2- or 1-phase operation. The
address options programmable for these three outputs allow
for maximum flexibility in support of 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.
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 ISL95857 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 power stages and drivers which
are compatible. The ISL95857 supports the system input
power monitor (PSYS) option. The controller supports either
DCR current sensing with a single NTC thermistor for DCR
temperature compensation or more precision through resistor
current sensing if desired. All three outputs feature remote
voltage sense, programmable IMAX, adjustable switching
frequency, OC protection and a single VR_READY power-good
indicator.

Features
• Supports Intel serial data bus interface
• System input power monitor (PSYS) supported
• Three output controller
- VR A supports 1-phase VR design
- VR B configurable for 2-, 1-phase VR design
- VR C supports 1-phase VR design
• 0.5% system accuracy over temperature
• Low supply current in PS4 state
• Supports multiple current sensing methods
- Lossless inductor DCR current sensing
- Precision resistor current sensing
• Differential remote voltage sensing
• Programmable SVID address
• Programmable VBOOT voltage at start-up
• Resistor programmable address selection, IMAX, and
switching frequency
• Adaptive body diode conduction time reduction

Applications
• IMVP8 compliant notebooks, desktops, ultrabooks and
tablets