Patent ID: 7280332
Filing Date: 2007-10-09
Classification: H01L

Abstract:
1. An electrostatic discharge protection circuit for an input/output signal terminal in an integrated circuit, coupled to ground comprising: a diode string coupled to the input/output signal terminal; a transistor switch having its gate coupled to the diode string, the transistor switch coupling the input/output signal terminal to ground in parallel to the diode string; a reverse diode coupling ground to the input/output signal terminal; and a capacitive element in series with the transistor switch to reduce the capacitance contributed by the transistor switch, thereby reducing signal distortion where the transistor switch comprises a Darlington pair and further comprising a series diode and a series resistor combined in any order and coupled between the gate of the transistor switch and the diode string on one hand and ground on the other hand whereby voltage overload protection for RF power amplifiers is provided for the conditions of (1) output impedance mismatch, (2) RF overdrive, and (3) modulated input signal.