ZVS Full-Bridge PWM Controller

The ISL6753 is a high-performance, low-pin-count alternative, 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 trailing-edge modulated with adjustable resonant switching delays. Compared to the more familiar phase-shifted control method, this algorithm offers equivalent efficiency and improved overcurrent and lightload performance with less complexity in a lower pin count package. This advanced BiCMOS design features low operating current, adjustable oscillator frequency up to 2MHz, adjustable soft-start, internal over temperature protection, precision deadtime and resonant delay control, and short propagation delays. Additionally, Multi-Pulse Suppression ensures alternating output pulses at low duty cycles where pulse skipping may occur.