US 11,721,974 B2
Electrostatic discharge (ESD) protection circuit and chip
Qian Xu, Hefei (CN)
Assigned to CHANGXIN MEMORY TECHNOLOGIES, INC., Hefei (CN)
Filed by CHANGXIN MEMORY TECHNOLOGIES, INC., Hefei (CN)
Filed on Aug. 25, 2021, as Appl. No. 17/412,178.
Application 17/412,178 is a continuation of application No. PCT/CN2021/103520, filed on Jun. 30, 2021.
Claims priority of application No. 202110004426.4 (CN), filed on Jan. 4, 2021.
Prior Publication US 2022/0216693 A1, Jul. 7, 2022
Int. Cl. H02H 9/04 (2006.01)
CPC H02H 9/046 (2013.01) 14 Claims
OG exemplary drawing
 
1. An electrostatic discharge (ESD) protection circuit, comprising:
an ESD protection module, arranged inside a protected chip and connected to a protected circuit; and
a control module, connected to the ESD protection module and configured to output a low-level signal to the ESD protection module to trigger the ESD protection module to discharge an electrostatic current when an ESD event occurs in the protected chip, and output a high-level signal to the ESD protection module to reduce a static leakage current of the ESD protection module when the ESD event does not occur in the protected chip; and, wherein the ESD protection module comprises:
a silicon controlled rectifier, having an anode, a cathode, and a trigger terminal, wherein the control module is connected between the anode and the cathode of the silicon controlled rectifier; and
a diode string, comprising a plurality of diodes connected in series, wherein an anode of the diode string is connected to the trigger terminal of the silicon controlled rectifier, a cathode of the diode string is connected to the control module; when the ESD event occurs in the protected chip, the control module outputs a low-level signal to the cathode of the diode string to trigger the silicon controlled rectifier to discharge the electrostatic current and when the ESD event does not occur in the protected chip, the control module outputs a high-level signal to the cathode of the diode string to reduce a voltage drop across the diode string.