Design Support


This document introduces the potential faults that can occur in class-D amplifier solutions, and describes how most faults are intrinsically protected for and how to extend coverage to protect against all short-circuit faults. Of particular focus is the case when an output is shorted to a battery voltage higher than the device supply voltage. This fault allows the parasitic body diode found in the H-Bridge to conduct large fault currents. Preventing damage to the amplifier and other system components is crucial in environments where safety is paramount, such as automotive environments. This application report proposes protection strategies and selection guidance to avoid damaging the class-D device and other system devices.