US Patent 9042064 Electrostatic discharge protection for class D power amplifiers

Electrostatic discharge protection for Class D power amplifiers is disclosed. In an exemplary embodiment, an apparatus includes an amplifier having an output transistor coupled to an interface pad, a snapback supply clamp coupled across first and second supplies of the amplifier and configured to provide a clamp voltage across the first and second supplies during ESD event; and a trigger circuit coupled to the output transistor, the trigger circuit configured to detect the clamp voltage and to enable the output transistor to provide a discharge path from the interface pad to the second supply when the clamp voltage is detected.