DESCRIPTION
The LT®3781 controller simplifies the design of high power synchronous dual transistor forward DC/DC converters. The part employs fixed frequency current mode control and supports both isolated and nonisolated topologies. The IC drives external N-channel power MOSFETs and operates with input voltages up to 72V.

FEATURES
■ High Voltage Operation up to 72V
■ Synchronizable Operating Frequency and Output Switch Phase for Multiple Controller Systems
■ Synchronous Switch Output
■ Undervoltage Lockout Protection with 6V Hysteresis for Self-Biased Power
■ Fixed Frequency Operation to 350kHz
■ Local 1% Voltage Reference
■ Input Overvoltage Protection
■ Low Start-Up Current
■ Programmable Start Inhibit for Power Supply Sequencing and Protection
■ Optocoupler Support
■ Soft-Start Control

APPLICATIONS
■ Isolated Telecommunication Systems
■ Personal Computers and Peripherals
■ Distributed Power Step-Down Converters
■ Lead Acid Battery Backup Systems
■ Automotive and Heavy Equipment