The LT 1619 is a fixed frequency PWM controller for implementing current mode DC/DC converters with minimum external parts. The LT1619 operates with input voltages ranging from 1.9V to 18V and is suitable for a variety of battery-powered and distributed DC/DC converters. The internal rail-to-rail N-channel MOSFET driver operates either from the input in the nonbootstrapped mode or from the output in bootstrapped operation. The driver is designed to drive a low side power transistor in boost, SEPIC, flyback and other topologies.