Patent ID: 6163445
Filing Date: 2000-12-19
Classification: G01R,H02H

Abstract:
An extended bandwidth low voltage protection circuit for protecting a test signal path from overvoltages and voltage transients appearing in a test signal being conducted by the test signal path, comprising:a guard signal circuit having an input coupled to the test signal path for producing a guard signal that replicates the test signal between an upper signal limit and a lower signal limit; anda test signal path isolation circuit having an interior side that is electrically coupled to the test signal path, the test signal isolation circuit having an exterior side coupled to receive the guard signal; andthe test signal isolation circuit, operating such that:while the test signal is between the upper signal limit and the lower signal limit, the guard signal replicates the test signal, the test signal isolation circuit does not conduct current, and there is no material signal differential between the interior side and the exterior side of the test signal isolation circuit; andwhile the test signal is not between the upper signal limit and the lower signal limit, the guard signal does not replicate the test signal and the test signal isolation circuit conducts current.