Patent ID: 8218275
Filing Date: 2012-07-10
Classification: H01L

Abstract:
1. An electrostatic discharge protection circuit for a transistor circuit having electrostatic discharge protection elements coupled to an input terminal of the electrostatic discharge protection circuit that is connected to a supply voltage and to an output terminal of the electrostatic discharge protection circuit, the electrostatic discharge protection circuit comprising a resistor and a capacitor having a predetermined delay time that corresponds to a product of the resistance of the resistor and the capacitance of the capacitor and a second transistor circuit, wherein the electrostatic discharge protection circuit is configured to sense an electrostatic discharge at the input terminal of the electrostatic discharge protection circuit and to short a gate terminal of the transistor circuit to a source terminal of the transistor circuit such that the transistor circuit is turned off during the electrostatic discharge, wherein the input terminal of the electrostatic discharge protection circuit that is connected to the supply voltage is connected to the gate terminal of the transistor circuit through the resistor and the capacitor and through the second transistor circuit, wherein the resistor and the capacitor are configured for activating the second transistor circuit for the predetermined delay time in response to the electrostatic discharge at the input terminal of the electrostatic discharge protection circuit, wherein the resistor and the capacitor are connected in series between the input terminal of the electrostatic discharge protection circuit and the gate terminal of the transistor circuit such that the resistor is directly connected to a gate terminal and a source terminal of the second transistor circuit and the input terminal of the electrostatic discharge protection circuit and the capacitor is directly connected to the gate terminal and a drain terminal of the second transistor circuit and the gate terminal of the transistor circuit, wherein the source terminal of the second transistor circuit is directly connected to the input terminal of the electrostatic discharge protection circuit, and wherein the drain terminal of the second transistor circuit is directly connected to the gate terminal of the transistor circuit.