Preventing Shoot Through Current in an H Bridge

Shoot through current usually leads to catastrophic damage in an H Bridge. Shoot through happens when both the High Side and Low Side Power MOSFETs or IGBTs are ON at the same time.

Even in well-designed systems logic propagation, delays and MOSFET gate capacitances can create a situation where both the High and Low Side devices are concurrently switched ON. When this condition occurs the current flows directly to ground and bypasses the load.

For more information please read Application Notes AN896, AN893, and AN857 which provide descriptions of techniques useful in preventing shoot through current.

The PWM modules on some Microchip devices, such as the dSPICxxGS and dsPICxxMC families, have built-in features to prevent shoot through.

© 2024 Microchip Technology, Inc.
Notice: ARM and Cortex are the registered trademarks of ARM Limited in the EU and other countries.
Information contained on this site regarding device applications and the like is provided only for your convenience and may be superseded by updates. It is your responsibility to ensure that your application meets with your specifications. MICROCHIP MAKES NO REPRESENTATIONS OR WARRANTIES OF ANY KIND WHETHER EXPRESS OR IMPLIED, WRITTEN OR ORAL, STATUTORY OR OTHERWISE, RELATED TO THE INFORMATION, INCLUDING BUT NOT LIMITED TO ITS CONDITION, QUALITY, PERFORMANCE, MERCHANTABILITY OR FITNESS FOR PURPOSE. Microchip disclaims all liability arising from this information and its use. Use of Microchip devices in life support and/or safety applications is entirely at the buyer's risk, and the buyer agrees to defend, indemnify and hold harmless Microchip from any and all damages, claims, suits, or expenses resulting from such use. No licenses are conveyed, implicitly or otherwise, under any Microchip intellectual property rights.