ISL6522A
Buck and Synchronous Rectifier Pulse-Width Modulator (PWM) Controller
Typical Diagram
Key Features
- Drives two N-Channel MOSFETs
- Operates from +5V or +12V input
- Simple single-loop control design
- Voltage-mode PWM control
- Fast transient response
- High-bandwidth error amplifier
- Full 0-100% duty ratio
- Excellent output voltage regulation
- 0.8V internal reference
- ±0.5% over line voltage and temperature
- Overcurrent fault monitor
- Does not require extra current sensing element
- Uses MOSFETs rDS(ON)
- Converter can source and sink current
- Small converter size
- Constant frequency operation
- 200kHz free-running oscillator programmable from 50kHz to over 1MHz
- 16 Lead 5x5mm QFN Package
- QFN Package
- Compliant to JEDEC PUB95 MO-220 QFN-Quad Flat No Leads-Product Outline.
- Near Chip-Scale Package Footprint; Improves PCB Efficiency and Thinner in Profile
Description
The ISL6522A provides complete control and protection for a DC-DC converter optimized for high-performance microprocessor applications. It is designed to drive two N-Channel MOSFETs in a synchronous rectified buck topology. The ISL6522A integrates all of the control, output adjustment, monitoring and protection functions into a single package.
The output voltage of the converter can be precisely regulated to as low as 0.8V, with a maximum tolerance of ±0.5% over temperature and line voltage variations.
The ISL6522A provides simple, single feedback loop, voltage-mode control with fast transient response. It includes a 200kHz free-running triangle-wave oscillator that is adjustable from below 50kHz to over 1MHz. 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 ratio ranges from 0-100%.
The ISL6522A protects against overcurrent conditions by inhibiting PWM operation. The ISL6522A monitors the current by using the rDS(ON) of the upper MOSFET which eliminates the need for a current sensing resistor.
Applications
- Power supply for Pentium®, Pentium Pro, PowerPC® and AlphaPC™ microprocessors
- High-power 5V to 3.xV DC-DC regulators
- Low-voltage distributed power supplies
