November 14, 2006
6A Dual Synchronous Buck Regulator
with Integrated MOSFETs
The ISL65426 is a high efficiency dual output monolithic
synchronous buck converter operating over an input
voltage range of 2.375V to 5.5V. This single chip power
solution provides two output voltages which are selectable
or externally adjustable from 1V to 80% of the supply
voltage while delivering up to 6A of total output current. The
two PWMs are synchronized 180° out of phase reducing
the RMS input current and ripple voltage.
The ISL65426 switches at a fixed frequency of 1MHz and
utilizes current-mode control with integrated compensation
to minimize the size and number of external components
and provide excellent transient response. The internal
synchronous power switches are optimized for good
thermal performance, high efficiency, and eliminate the
need for an external Schottky diode.
A unique power block architecture allows partitioning of six
1A capable blocks to support one of four configuration
options. One master power block is associated with each
synchronous converter channel. Four floating slave power
blocks allow the user to assign them to either channel.
Proper external configuration of the power blocks is verified
internally prior to soft-start initialization.
Independent enable inputs allow for synchronization or
sequencing soft-start intervals of the two converter
channels. A third enable input allows additional sequencing
for multi-input bias supply designs. Individual power good
indicators (PG1, PG2) signal when output voltage is within
The ISL65426 integrates protection for both synchronous
buck regulator channels. The fault conditions include
overcurrent, undervoltage, and IC thermal monitor.
High integration contained in a thin Quad Flat No-lead
(QFN) package makes the ISL65426 an ideal choice to
power many of today’s small form factor applications. A
single chip solution for large scale digital ICs, like field
programmable gate arrays (FPGA), requiring separate core
and I/O voltages.
• High Efficiency: Up to 95%
• Fixed Frequency: 1MHz
• Operates From 2.375V to 5.5V Supply
• ±1% Reference
• Flexible Output Voltage Options
- Programmable 2-Bit VID Input
- Adjustable Output From 0.6V to 4.0V
• User-Partitioned Power Blocks
• Ultra-Compact DC/DC Converter Design
• PWMs Synchronized 180° Out of Phase
• Independent Enable Inputs and System Enable
• Stable All Ceramic Solutions
• Excellent Dynamic Response
• Independent Output Digital Soft-Start
• Power Good Output Voltage Monitor
• Short-Circuit and Thermal-Overload Protection
• Overcurrent and Undervoltage Protection
• Pb-Free Plus Anneal Available (RoHS Compliant)
• FPGA, CPLD, DSP, and CPU Core and I/O Voltages
- Xilinx Spartan IIITM, Virtex IITM, Virtex II ProTM,
- Altera StratixTM, Stratix IITM, CycloneTM, Cyclone IITM
- Actel FusionTM, LatticeSCTM, LatticeECTM
• Low-Voltage, High-Density Distributed Power Systems
• Point-of-Load Regulation
• Distributed Power Systems
• Set-Top Boxes
(Pb-free) DWG. #
ISL65426HRZ* ISL65426 HRZ -10 to +100 50 Ld 5x10 L50.5x10
*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.
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