April 21, 2006
4-Phase PWM Controller with 8-Bit DAC
Code Capable of Precision DCR
Differential Current Sensing
The ISL6326B controls microprocessor core voltage
regulation by driving up to 4 synchronous-rectified buck
channels in parallel. Multiphase buck converter architecture
uses interleaved timing to multiply channel ripple frequency
and reduce input and output ripple currents. Lower ripple
results in fewer components, lower component cost, reduced
power dissipation, and smaller implementation area.
Microprocessor loads can generate load transients with
extremely fast edge rates. The ISL6326B utilizes Intersil’s
proprietary Active Pulse Positioning (APP) and Adaptive
Phase Alignment (APA) modulation scheme to achieve the
extremely fast transient response with fewer output
Today’s microprocessors require a tightly regulated output
voltage position versus load current (droop). The ISL6326B
senses the output current continuously by utilizing patented
techniques to measure the voltage across the dedicated
current sense resistor or the DCR of the output inductor. The
sensed current flows out of FB pin to develop the precision
voltage drop across the feedback resistor for droop control.
Current sensing also provides the needed signals for
channel-current balancing, and overcurrent protection. A
programmable integrated temperature compensation
function is implemented to effectively compensate for the
temperature coefficient of the current sense element. The
current limit function provides the overcurrent protection for
the individual phase.
A unity gain, differential amplifier is provided for remote
voltage sensing. Any potential difference between remote
and local grounds can be completely eliminated using the
remote-sense amplifier. Eliminating ground differences
improves regulation and protection accuracy. The threshold-
sensitive enable input is available to accurately coordinate
the start up of the ISL6326B with any other voltage rail.
Dynamic-VID™ technology allows seamless on-the-fly VID
changes. The offset pin allows accurate voltage offset
settings that are independent of VID setting.
• Proprietary Active Pulse Positioning and Adaptive Phase
Alignment Modulation Scheme
• Precision Multiphase Core Voltage Regulation
- Differential Remote Voltage Sensing
- ±0.5% System Accuracy Over Life, Load, Line and
- Adjustable Precision Reference-Voltage Offset
• Precision resistor or DCR Current Sensing
- Accurate Load-Line Programming
- Accurate Channel-Current Balancing
- Differential Current Sense
• Microprocessor Voltage Identification Input
- Dynamic VID™ Technology
- 8-Bit VID Input with Selectable VR11 Code and
Extended VR10 Code at 6.25mV Per Bit
• Thermal Monitoring
• Integrated Programmable Temperature Compensation
• Overcurrent Protection and Channel Current Limit
• Load Current Indicator and External Overcurrent
Protection Threshold Setup
• Overvoltage Protection
• 2, 3 or 4 Phase Operation
• Adjustable Switching Frequency up to 1MHz Per Phase
• Package Option
- QFN Compliant to JEDEC PUB95 MO-220 QFN - Quad
Flat No Leads - Product Outline
- QFN Near Chip Scale Package Footprint; Improves
PCB Efficiency, Thinner in Profile
• Pb-Free Plus Anneal Available (RoHS Compliant)
(Pb-Free) DWG. #
ISL6326BCRZ ISL6326BCRZ 0 to70 40 Ld 6x6 QFN L40.6x6
ISL6326BIRZ ISL6326BIRZ -40 to 85 40 Ld 6x6 QFN L40.6x6
Add “-T” suffix for tape and reel.
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.
1 CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
1-888-INTERSIL or 1-888-468-3774 | Intersil (and design) is a registered trademark of Intersil Americas Inc.
Copyright Intersil Americas Inc. 2006. All Rights Reserved
All other trademarks mentioned are the property of their respective owners.