Patent ID: 7333311

Claim:
A clamping circuit operable to provide ESD protection for protected circuitry of automatic test equipment (ATE), comprising: a first ESD rail and a second ESD rail comprising a corresponding first voltage potential and second voltage potential, wherein one or more signal rails of the protected circuitry are operable to be coupled to the first ESD rail and to the second ESD rail, and the first ESD rail and the second ESD rail are AC coupled to a reference potential; a first one or more capacitive elements coupled in parallel to the first ESD rail; a second one or more capacitive elements coupled in parallel to the second ESD rail; a first one or more resistive elements coupled in series to the first ESD rail; a second one or more resistive elements coupled in series to the second ESD rail; and one or more ESD devices coupled to the first ESD rail, coupled to the second ESD rail and coupled to the corresponding one or more signal rails, wherein in a disable mode, the first voltage potential and the second voltage potential are substantially equivalent to the reference potential resulting in the clamping circuit providing a nominal clamping voltage to the protected circuit so that an ESD event having a voltage between the first voltage potential and the second voltage potential is shunted to the reference potential via the first and second ESD rails, wherein the ESD event is received on a device under test (DUT) node coupled to the one or more signal rails of the protected circuit.