April 4, 2005
Buck and Synchronous Rectifier
Pulse-Width Modulator (PWM) Controller
The ISL6522B provides complete control and protection for a
DC-DC converter optimized for high-performance
microprocessor applications. It is designed to drive two
N-Channel MOSFETs in a synchronous rectified buck topology.
The ISL6522B integrates all of the control, output adjustment,
monitoring and protection functions into a single package.
The output voltage of the converter can be precisely
regulated to as low as 0.8V, with a maximum tolerance of
±1% over temperature and line voltage variations.
The ISL6522B provides simple, single feedback loop, voltage-
mode control with fast transient response. It includes a 200kHz
free-running triangle-wave oscillator that is adjustable from
below 50kHz to over 1MHz. The error amplifier features a
15MHz gain-bandwidth product and 6V/µs slew rate which
enables high converter bandwidth for fast transient perform-
ance. The resulting PWM duty ratio ranges from 0-100%.
The ISL6522B protects against overcurrent conditions by
inhibiting PWM operation. The ISL6522B monitors the
current by using the rDS(ON) of the upper MOSFET which
eliminates the need for a current sensing resistor.
16 15 14 13
• Drives two N-Channel MOSFETs
• Operates from +5V or +12V input
• Simple single-loop control design
- Voltage-mode PWM control
• Fast transient response
- High-bandwidth error amplifier
- Full 0–100% duty ratio
• Excellent output voltage regulation
- 0.8V internal reference
- ±1% over line voltage and temperature
• Overcurrent fault monitor
- Does not require extra current sensing element
- Uses MOSFETs rDS(ON)
• Converter can source and sink current
• Pre-Biased Load Start Up
• Small converter size
- Constant frequency operation
- 200kHz free-running oscillator programmable from
50kHz to over 1MHz
• 14-lead SOIC package and 16-lead 5x5mm QFN Package
• QFN Package
- Compliant to JEDEC PUB95 MO-220 QFN-Quad Flat
No Leads-Product Outline
- Near Chip-Scale Package Footprint; Improves PCB
Efficiency and Thinner in Profile
• Pb-Free Available (RoHS Compliant)
• Power supply for Pentium®, Pentium Pro, PowerPC® and
• FPGA Core DC/DC Converters
• Low-voltage distributed power supplies
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
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Copyright © Intersil Americas Inc. 2004, 2005. All Rights Reserved. All other trademarks mentioned are the property of their respective owners.
PowerPC® is a trademark of IBM. AlphaPC™ is a trademark of Digital Equipment Corporation. Pentium® is a registered trademark of Intel Corporation.