85-V Half-Bridge MOSFET Driver Automatically Sets Dead Time

The MIC4605, an 85-V half-bridge MOSFET driver, integrates adaptive dead time (ADT) and shoot-through protection to maximize power efficiency. ADT circuitry actively monitors the MOSFETs in the half bridge switch, allowing only one MOSFET to be active at a time, which assures no cross-conduction condition. It also keeps transitions between the high- and low-side MOSFETs as short as possible to minimize power losses caused by long dead time. Anti-shoot through prevents erroneous inputs and noise from turning both MOSFETs on at the same time. Developed by Micrel, the driver operates from 5.5 to 16 V; the 5.5-V operating voltage allows for longer run times in battery-powered applications. Other features include 30-ns propagation delay times and 35-ns rise/fall times for a 1-nF capacitive load. TTL inputs for the MIC4605-1 provide independent control of the low- and high-side gate drivers. The MIC4605-2 has a single PWM input for both low- and high-side gate drivers. Operating junction temperature ranges from −40 to +125°C. They come in 8-pin SOIC and 10-pin 2.5- by 2.5-mm TDFN packages.

MICREL INC.