ZVS Full Bridge PWM Controller

The ISL6551 is a zero voltage switching (ZVS) full-bridge PWM controller designed for isolated power systems. This part implements a unique control algorithm for fixedfrequency ZVS current mode control, yielding high efficiency with low EMI. The two lower drivers are PWM-controlled on the trailing edge and employ resonant delay while the two upper drivers are driven at a fixed 50 duty cycle.

Features

• High Speed PWM (up to 1MHz) for ZVS Full Bridge Control

• Current Mode Control Compatible

• High Current High-Side and Low-Side Totem-Pole Drivers

• Adjustable Resonant Delay for ZVS

• 10MHz Error Amplifier Bandwidth

• Programmable Soft-Start

• Precision Bandgap Reference

• Latching Shutdown Input

• Non-latching Enable Input

• Adjustable Leading Edge Blanking

• Adjustable Dead Time Control

• Adjustable Ramp for Slope Compensation

• Fast Short-Circuit Protection (Hiccup Mode)

• Adjustable Cycle-by-Cycle Peak Current Limiting

• Drive Signals to Implement Synchronous Rectification

• VDD Under-voltage Lockout

• Current Share Support

• ±5 “In Regulation” Indication

• 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

• Full-Bridge and Push-Pull Converters

• Power Supplies for Off-line and Telecom/Datacom

• Power Supplies for High End Microprocessors and Servers