Full-bridge PWM Controllers with Integrated MOSFET Gate Drivers

NATIONAL SEMICONDUCTOR CORP. introduced the industry's first full-bridge pulse width modulation (PWM) controllers to integrate all four primary-side bridge MOSFET gate drivers. The LM5045 and LM5046 deliver higher efficiency and higher power density in quarter-brick and eighth-brick power modules used in various high input voltage communications infrastructure applications. Members of National's PowerWise® energy-efficient product family, the LM5045 and LM5046 PWM controllers ease the design of full-bridge topology-based power converters into small form factor power supplies by reducing the number of external power components needed with existing full-bridge solutions.

The LM5045 PWM controller contains all of the features needed to implement a conventional full-bridge topology power converter using either current mode or voltage mode control. For applications requiring zero-voltage switching (ZVS) to minimize electro-magnetic interference (EMI) due to switching noise, the LM5046 PWM controller contains all the features necessary to implement a phase-shifted full-bridge topology. The full-bridge controllers operate on the primary side of an isolated DC-DC converter with inputs up to 100V. These controllers provide 2A high and low side gate drivers for the four external bridge MOSFETs, in addition to the control signals for the secondary side synchronous rectifier MOSFETs and an internal high voltage start-up regulator.

National Semiconductor
Santa Clara, CA
www.national.com/analog