High performance, low pin number, zero voltage switching (ZVS) full bridge PWM controller

The ISL6753 is a high performance, low pin number, zero voltage switching (ZVS) full bridge PWM controller. Like the ISL6551, it achieves ZVS operation by driving the upper bridge FETs at a fixed 50% duty cycle, while the lower bridge FETs are modulated at the trailing edge with a tunable resonant switch delay.

Pinout

Compared with more familiar phase shift control methods, this algorithm provides equivalent efficiency and improved overcurrent and light load performance, and has lower complexity in lower pin number packages.

This advanced BiCMOS design features low operating current, adjustable oscillator frequencies up to 2MHz, adjustable soft start, internal overtemperature protection, precise dead zone and resonant delay control, and short propagation delay. In addition, multi-pulse suppression ensures alternate output pulses at low duty ratios, where pulse hops may occur.

Functional Block Diagram

Features

● Adjustable Resonant Delay for ZVS Operation

● Voltage-or Current-Mode Operation

● 3% Current Limit Threshold

● Supply UVLO

● Adjustable Deadtime Control

● Adjustable Soft-Start

● Adjustable Oscillator Frequency Up to 2MHz

● Tight Tolerance Error Amplifier Reference Over Line,Load, and Temperature

● 5MHz GBWP Error Amplifier

● Adjustable Cycle-by-Cycle Peak Current Limit

● Fast Current Sense to Output Delay

● 70ns Leading Edge Blanking

● Multi-Pulse Suppression

● Buffered Oscillator Sawtooth Output

● Internal Over Temperature Protection

● Pb-Free Plus Anneal Available and ELV, WEEE,RoHS Compliant

Applications

● ZVS full bridge converter

● Telecommunications and data communication power

● Wireless base station power supply

● Power supply for the file server

● Industrial power systems