Extended temperature phase modulated full-bridge controller

April 04, 2013 // By Graham Prophet
Linear Technology has announced the H-grade version of the LTC3722-1, a phase-modulated full bridge DC/DC controller with adaptive or manual zero voltage switching (ZVS), that features -40°C to 150°C operating junction temperature range.

The device’s ZVS delay control and adjustable synchronous rectification timing optimise efficiency while reducing transformer size and electromagnetic interference, in isolated high power applications of up to several kilowatts. The LTC3722-1’s adaptive zero voltage technology is accomplished by sensing the bridge MOSFETs and input voltage, allowing the converter to adapt to any change in load current, temperature, component tolerances, driver circuitry delay or input voltage variations. Additional features include fixed frequency current mode control, adjustable current limit, leading edge blanking, soft start, short-circuit protection and programmable slope compensation. It operates over the range 100kHz to 600kHz and can be synchronised anywhere in that range. An accurate 5V low dropout regulator provides up to 15mA to power auxiliary circuits.

The H-grade version operates up to a junction temperature of 150°C, compared to the E- and I-grade versions’ 85°C maximum junction temperature. The H-grade product is tested and guaranteed to the maximum junction temperature of 150°C, for automotive and industrial applications which are subjected to high ambient temperatures. In an SSOP-24 package it costs $6.24 (1000).

For more information, www.linear.com/product/LTC3722