Patent ID: 8780511
Filing Date: 2014-07-15
Classification: H01L,H02H

Abstract:
1. An electrostatic discharge protection circuit, comprising: a diode chain coupled between a power supply voltage end and a control node; a control voltage generator configured to generate a control voltage to the control node in response to a first current flowing through the diode chain; a discharger configured to discharge a second current from the power supply voltage end to a ground voltage end in response to the control voltage, wherein the diode chain comprises a plurality of P-well regions formed in an N-well region, diodes formed in the respective P-well regions, and a resistor coupled between the diodes, wherein the diodes include a PN junction formed by implanting an N-type impurity into a first upper portion of the each P-well region; and a plurality of parasitic polar transistors each having an emitter in the first upper portion of the P-well region, a base in the P-well region, and a collector in the N-well region.