PARALLELING HIGH DENSITY DC/DC (mu)MODULE REGULATORS EASES HIGH CURRENT POWER SUPPLY DESIGN

摘要

Minimising development time and saving board space are critical for many high performance systems such as network routers, blade servers, cellular base stations and test instruments. The board-mounted point-of-load (POL) DC/DC power supplies in these systems are subject to the same demanding development schedule and solution size. They require fully integrated POL power modules with a built-in inductor, power MOSFET, PWM controller and supporting circuitry. To reduce thermal stress and achieve high reliability, current sharing is very important when paralleling DC/DC regulator modules. Conceptually, due to the part-to-part variation and output voltage regulation errors, the output voltages of two identical POL supplies can be different even though they are programmed to have the same target value. For example, a 1.5V output POL can have a +-1percent error on its output voltage.