Input-output esd protection
OwnerMichael P. MACK, Sunetra Mendisinventors
Life of this patent
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Abstract
A method and apparatus for protecting an input-out (I/O) circuit against electro-static discharge (ESD) events. An ESD circuit used to protect the I/O circuit against an ESD event is coupled to the I/O circuit. The ESD circuit includes a diode clamp circuit that couples an I/O pad to a power supply and a ground pad. The ESD circuit further includes an active clamp circuit that is configured to clamp the I/O pad without turning on the diode clamp circuit during the ESD event.
Claims20
An integrated circuit device, comprising:
- an input-out (I/O) pad;
- an I/O circuit coupled to the I/O pad;
- and
- an electro-static discharge (ESD) circuit coupled to the I/O pad, the ESD circuit including:
- a diode clamp circuit;
- and
- a first active clamp circuit, wherein the first active clamp circuit is configured to clamp the I/O pad without turning on the diode clamp circuit during a first ESD event.
The device of claim 12, wherein the second ESD event comprises applying a negative voltage to the I/O pad with respect to the supply voltage pad.
An integrated circuit device, comprising:
- an input-out (I/O) pad;
- an I/O circuit coupled to the I/O pad;
- and
- an electro-static discharge (ESD) circuit coupled to the I/O pad, the ESD circuit including:
- a diode clamp circuit connected between a power supply pad and a ground pad;
- and
- a first active clamp circuit coupled to the I/O pad and the I/O circuit, wherein the first active clamp circuit is configured to provide a discharge current path that is separate from the diode clamp circuit for a first ESD event, wherein the first ESD event comprises applying a positive voltage to the I/O pad with respect to a ground pad of the integrated circuit device.
Dependencies are inferred from the claim text.