ISL6527 Datasheet, PDF (1/16 Pages) Intersil Corporation – Single Synchronous Buck Pulse-Width Modulation PWM Controller

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Data Sheet
ISL6527, ISL6527A
November 18, 2008
FN9056.10
Single Synchronous Buck Pulse-Width
Modulation (PWM) Controller
The ISL6527, ISL6527A make simple work out of
implementing a complete control and protection scheme for
a DC/DC step-down converter. Designed to drive N-Channel
MOSFETs in a synchronous buck topology, the ISL6527,
ISL6527A integrate the control, output adjustment,
monitoring and protection functions into a single package.
The ISL6527, ISL6527A provide 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.
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%.
Protection from overcurrent conditions is provided by
monitoring the r_DS(ON) of the upper MOSFET to inhibit PWM
operation appropriately. This approach simplifies the
implementation and improves efficiency by eliminating the
need for a current sense resistor.
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
• Lossless, Programmable Overcurrent Protection
- Uses Upper MOSFET’s r_DS(ON)
• Converter Can Source and Sink Current
• Small Converter Size
- Internal Fixed Frequency Oscillator
- ISL6527: 300kHz
- ISL6527A: 600kHz
• Internal Soft-Start
• 14 Ld SOIC or 16 Ld 5x5 QFN
• 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 (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
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CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
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