The LM5046 PWM controller contains all of the features necessary to implement a
phase-shifted full-bridge topology power converter using either current mode or voltage mode
control. This device is intended to operate on the primary side of an isolated DC-DC converter with
input voltage up to 100 V. This highly integrated controller-driver provides dual 2-A high- and
low-side gate drivers for the four external bridge MOSFETs, plus control signals for the
secondary-side synchronous rectifier MOSFETs. External resistors program the dead-time to enable
zero-volt switching of the primary FETs. Intelligent startup of the synchronous rectifiers allows
monotonic turnon of the power converter even with prebias load conditions. Additional features
include cycle-by-cycle current limiting, hiccup mode restart, programmable soft-start, synchronous
rectifier soft-start, and a 2-MHz capable oscillator with synchronization capability and thermal
shutdown.
