ISL6526A

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)




Application

• 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




Pinout






Specifications

Supply Voltage, VCC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +7.0V
Absolute Boot Voltage, V_BOOT . . . . . . . . . . .... . . . . . . . . . . . +15.0V
Upper Driver Supply Voltage, V_BOOT - V_PHASE ... . . . . . . . . . . +7.0V
Input, Output or I/O Voltage . . . . . . . ................ . . . GND -0.3V to VCC +0.3V
ESD Classification . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . .Class 2




Description

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/s 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.