ISL6526_07 Datasheet, PDF (1/15 Pages) Intersil Corporation – Single Synchronous Buck Pulse-Width Modulation (PWM) Controller

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Data Sheet
ISL6526, ISL6526A
March 20, 2007
FN9055.8
Single Synchronous Buck Pulse-Width
Modulation (PWM) Controller
The ISL6526, ISL6526A make 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 ISL6526,
ISL6526A integrate the control, output adjustment,
monitoring and protection functions into a single package.
The ISL6526, ISL6526A provide simple, single feedback
loop, voltage-mode control with fast transient response. The
output voltage can be precisely regulated to as low as 0.8V,
with a maximum tolerance of ±1.5% over temperature and
line voltage variations. 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
• 0.8V to V_IN Output Range
- 0.8V Internal Reference
- ±1.5% Over Load, Line Voltage and Temperature
• 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
- ISL6526: 300kHz
- ISL6526A: 600kHz
• Internal Soft-Start
• 14 Lead SOIC or 16 Lead 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 Plus Anneal Available (RoHS Compliant)
Applications
• Power Supplies for Microprocessors
- PCs
- Embedded Controllers
• Subsystem Power Supplies
- PCI/AGP/GTL+ Buses
- 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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