August 21, 2006
Four-Phase Buck PWM Controller with
Integrated MOSFET Drivers for Intel VR10,
VR11, and AMD Applications
The ISL6312 four-phase PWM control IC provides a
precision voltage regulation system for advanced
microprocessors. The integration of power MOSFET drivers
into the controller IC marks a departure from the separate
PWM controller and driver configuration of previous
multiphase product families. By reducing the number of
external parts, this integration is optimized for a cost and
space saving power management solution.
One outstanding feature of this controller IC is its
multi-processor compatibility, allowing it to work with both Intel
and AMD microprocessors. Included are programmable VID
codes for Intel VR10, VR11, as well as AMD DAC tables. A
unity gain, differential amplifier is provided for remote voltage
sensing, compensating for any potential difference between
remote and local grounds. The output voltage can also be
positively or negatively offset through the use of a single
The ISL6312 also includes advanced control loop features
for optimal transient response to load apply and removal.
One of these features is highly accurate, fully differential,
continuous DCR current sensing for load line programming
and channel current balance. Active Pulse Positioning (APP)
modulation is another unique feature, allowing for quicker
initial response to high di/dt load transients.
This controller also allows the user the flexibility to choose
between PHASE detect or LGATE detect adaptive dead time
schemes. This ability allows the ISL6312 to be used in a
multitude of applications where either scheme is required.
Protection features of this controller IC include a set of
sophisticated overvoltage, undervoltage, and overcurrent
protection. Furthermore, the ISL6312 includes protection
against an open circuit on the remote sensing inputs.
Combined, these features provide advanced protection for the
microprocessor and power system.
• Integrated Multiphase Power Conversion
- 2 or 3-Phase Operation with Internal Drivers
- 4-Phase Operation with External PWM Driver Signal
• Precision Core Voltage Regulation
- Differential Remote Voltage Sensing
- ±0.5% System Accuracy Over Temperature
- Adjustable Reference-Voltage Offset
• Optimal Transient Response
- Active Pulse Positioning (APP) Modulation
- Adaptive Phase Alignment (APA)
• Fully Differential, Continuous DCR Current Sensing
- Accurate Load Line Programming
- Precision Channel Current Balancing
• User Selectable Adaptive Dead Time Scheme
- PHASE Detect or LGATE Detect for Application
• Variable Gate Drive Bias: 5V to 12V
• Multi-Processor Compatible
- Intel VR10 and VR11 Modes of Operation
- AMD Mode of Operation
• Microprocessor Voltage Identification Inputs
- 8-bit DAC
- Selectable between Intel’s Extended VR10, VR11, AMD
5-bit, and AMD 6-bit DAC Tables
- Dynamic VID Technology
• Overcurrent Protection
• Multi-Tiered Overvoltage Protection
• Digital Soft-Start
• Selectable Operation Frequency up to 1.5MHz Per Phase
• Pb-Free Plus Anneal Available (RoHS Compliant)
(Pb-Free) DWG. #
ISL6312CRZ ISL6312CRZ 0 to +70 48 Ld 7x7 QFN L48.7x7
ISL6312IRZ ISL6312IRZ -40 to +85 48 Ld 7x7 QFN L48.7x7
NOTE: Intersil Pb-free plus anneal products employ special Pb-free
material sets; molding compounds/die attach materials and 100%
matte tin plate termination finish, which are RoHS compliant and
compatible with both SnPb and Pb-free soldering operations. Intersil
Pb-free products are MSL classified at Pb-free peak reflow
temperatures that meet or exceed the Pb-free requirements of
IPC/JEDEC J STD-020.
*Add “-T” suffix for tape and reel.
1 CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
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Copyright Intersil Americas Inc. 2006. All Rights Reserved
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