ISL6527
®
Data Sheet
April 8, 2005
FN9056.7
Single Synchronous Buck Pulse-Width
Modulation (PWM) Controller
The ISL6527 makes simple work out of implementing a
complete control and protection scheme for a DC-DC
stepdown converter. Designed to drive N-Channel
MOSFETs in a synchronous buck topology, the ISL6527
integrates the control, output adjustment, monitoring and
protection functions into a single package.
Features
• Operates from 3.3V to 5V input
• Utilizes an external reference
• Drives N-Channel MOSFETs
• Simple single-loop control design
- Voltage-mode PWM control
• Fast transient response
- High-bandwidth error amplifier
- Full 0% to 100% duty cycle
The ISL6527 provides simple, single feedback loop, voltage-
mode control with fast transient response. The output voltage
can be regulated to as low as the provided external reference.
A fixed frequency oscillator reduces design complexity, while
balancing typical application cost and efficiency.
• Lossless, programmable overcurrent protection
- Uses upper MOSFET’s r
DS(ON)
The error amplifier features a 15MHz gain-bandwidth
product and 6V/µs slew rate which enables high converter
bandwidth for fast transient performance. The resulting
PWM duty cycles range from 0% to 100%.
• Converter can source and sink current
• Small converter size
- Internal fixed frequency oscillator
-
-
ISL6527: 300kHz
ISL6527A: 600kHz
Protection from overcurrent conditions is provided by
monitoring the r
of the upper MOSFET to inhibit PWM
DS(ON)
- Internal soft-start
- 14 Lead SOIC or 16 Lead, 5x5 QFN
operation appropriately. This approach simplifies the
implementation and improves efficiency by eliminating the
need for a current sense resistor.
• QFN Package:
- Compliant to JEDEC PUB95 MO-220 QFN - Quad Flat
No Leads - Package Outline
- Near Chip Scale Package footprint, which improves
PCB efficiency and has a thinner profile
• Pb-Free Available (RoHS Compliant)
Applications
• Power supplies for microprocessors
- PCs
- Embedded controllers
• Subsystem power supplies
- PCI/AGP/GTL+ busses
- ACPI power control
- DDR SDRAM bus termination supply
• Cable modems, set top boxes, and DSL modems
• DSP and core communications processor supplies
• Memory supplies
• Personal computer peripherals
• Industrial power supplies
• 3.3V-input DC-DC regulators
• Low-voltage distributed power supplies
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
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