Patent ID: 7898783

Claim:
An apparatus comprising: a switching amplifier formed on a substrate of a first conduction type having: a pulse width modulator; a protection circuit that is coupled to pulse width modulator; a high-side driver that is coupled to protection circuit; a low-side driver that is coupled to the protection circuit; a high-side transistor that is coupled to the high-side driver and a switching node; and a low-side transistor that is coupled to the low-side driver and the switching node; a voltage regulator formed on the substrate and coupled to the protection circuit; and a well of the first conduction type located in the substrate; and a substrate clamp having: a shallow well of a second conduction type located in the substrate and that is coupled to the well of the first conduction type; a deep well of the second conduction type located in the substrate and substantially surrounding the shallow well; and a buried layer located in the substrate beneath at least a portion of the deep well.