Multioutput Flyback DC-DC Converter for MIL Applications

Abstract This paperwork explains the design and development of isolated triple output dc-dc converter for military applications. Converter has designed with flyback topology with opto-coupler based feedback for regulated main output and regulators are used to provide another two outputs. It is realized with switching frequency of 190KHz (internal free run frequency) and can be able to operate up to 210KHz with external synchronization. LTM46xx micro-modules are used as buck regulators to provide required lower output voltages. Current mode pulse width modulation controller IC is used to drive the MOSFET switch. It has following features like inbuilt EMI filter, external inhibit function, external synchronization capability, input under voltage and over voltage protection, primary side over current, output over current and short circuit protection. Converter is designed to operate for wide input range from 18V to 36V with efficiency of more than 75% in full load conditions.