ISL6520A_07 Datasheet, PDF (1/12 Pages) Intersil Corporation – Single Synchronous Buck Pulse-Width Modulation (PWM) Controller

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Data Sheet
March 28, 2007
ISL6520A
FN9016.5
Single Synchronous Buck Pulse-Width
Modulation (PWM) Controller
The ISL6520A 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 ISL6520A
integrates the control, output adjustment, monitoring and
protection functions into a single 8-Lead package.
The ISL6520A provides 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 8V/ms 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.
Pinouts
ISL6520A
(6 LD SOIC)
TOP VIEW
BOOT 1
UGATE 2
GND 3
LGATE 4
8 PHASE
7 COMP/SD
6 FB
5 VCC
ISL6520A
(16 LD QFN)
TOP VIEW
16 15 14 13
BOOT 1
UGATE 2
GND 3
12 NC
11 COMP/OCSET
10 NC
NC 4
9 FB
5678
Features
• Operates from +5V Input
• 0.8V to V_IN Output Range
- 0.8V Internal Reference
- ±1.5% Over 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)
• Small Converter Size
- 300kHz Fixed Frequency Oscillator
- Internal Soft-Start
- 8 Ld SOIC or 16 Ld 4mmx4mm 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
- SSTL-2 and 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
• 5V-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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