1
DATASHEET
To request the full datasheet, please visit www.intersil.com/products/ISL95821
Three Phase PWM Controller for Intel VR12.5™ CPUs
ISL95821
The ISL95821 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 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 ISL95821 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
MAX,
voltage transition
slew rate and switching frequency, adjustable overcurrent
protection and Power-Good signal.
Features
•Serial data bus
• Configurable 3-, 2- or 1-phase output with integrated gate
drivers
•R3™ modulator
- Excellent transient response
- Phase shedding with power state selection
- Diode emulation in single-phase for 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
•Programmable V
BOOT
voltage at start-up
• Resistor programmable I
MAX
, loadline, diode emulation,
slope compensation, and switching frequency
• Adaptive body diode conduction time reduction
Applications
• Intel VR12.5 desktop computers
ISL95821
V
IN
V
CORE
V
IN
V
IN
PHASE3
PHASE2
PHASE1
FIGURE 1. SIMPLIFIED APPLICATION CIRCUIT
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
1-888-INTERSIL or 1-888-468-3774
| Copyright Intersil Americas LLC 2013. All Rights Reserved
Intersil (and design) and R3 Technology are trademarks owned by Intersil Corporation or one of its subsidiaries.
All other trademarks mentioned are the property of their respective owners.
August 21, 2013
FN8438.0
