Patent ID: 7518841

Claim:
A circuit for protecting a power amplifier from electrostatic discharge (ESD), comprising: a connection line to conduct an ESD current, the connection line floats during normal operation of the power amplifier; a first diode connected between the connection line and a conductive pad and coupled to the power amplifier and the connection line; a first clamp circuit connected between a first power line and the connection line, the first clamp circuit including a transistor that includes a substrate connected to a second power line; a second clamp circuit connected between the connection line and the second power line, the second clamp circuit including a transistor that includes a substrate connected to the second power line; and a detecting circuit connected between the connection line and the second power line for detecting whether an ESD event occurs at the conductive pad, wherein the detecting circuit activates the first clamp circuit in response to an ESD event to conduct an ESD current to the first power line, and activates the second clamp circuit in response to the ESD event to conduct the ESD current to the second power line, and wherein the first and second clamp circuits are connected independently of one another between the first power line and the connection line and between the connection line and the second power line, respectively.