Substrate pump circuit and method for I/O ESD protection
AssigneeMacronix International Co., Ltd.
InventorsChun-Hsiang Lai, Meng-Huang Liu, Shin Su, Tao-Cheng Lu
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Abstract
A substrate pump circuit and method for I/O ESD protection including NMOS fingers connected to the interconnection between an I/O pad and an internal circuit comprises a MOS device connected to the interconnection between the I/O pad and the internal circuit and the substrate under the control of a switch to turn it on to conduct a pumping current through the substrate resistor when the I/O pad is under ESD stress, so as to pull up the potential of the substrate adjacent to the NMOS fingers, resulting in the reduction of the triggering voltage of the NMOS fingers.
Claims15
A substrate pump circuit for I/O ESD protection including a plurality of NMOS fingers connected to an I/O pad on a substrate, the substrate pump circuit comprising:
- a resistor connected between a base of the NMOS fingers and a ground pad;
- a pumping apparatus connected to the base of the NMOS fingers;
- and
- a switch for controlling the pumping apparatus to conduct a pumping current through the resistor during an ESD event.
A method for I/O ESD protection including a plurality of NMOS fingers connected to an I/O pad on a substrate, the method comprising the steps of:
- connecting a resistor between a base of the NMOS fingers and a ground pad;
- and
- conducting a pumping current through the resistor during an ESD event.
Dependencies are inferred from the claim text.