Patent ID: 6466520
Filing Date: 2002-10-15
Classification: G01R

Abstract:
A phase discriminator for producing a test clock signal having a period determined by a signal-propagation time required for one of a low-to-high signal transition and a high-to-low signal transition to traverse a test circuit from a test-circuit input node to a test-circuit output node, the phase discriminator comprising:a. a pulse generator having a pulse-generator output node connected to the test-circuit input node, the pulse generator configured to provide the test-circuit input node with a pulse; and b. a phase detector having a phase-detector input node connected to the test-circuit output node and a phase-detector output node connected to the pulse-generator, the phase-detector input node adapted to receive a delayed version of the pulse; i. wherein the low-to-high signal transitions of the delayed version of the pulse are delayed by the first signal-propagation time required for low-to-high signal transitions to traverse the test circuit; and ii. wherein the high-to-low signal transitions of the delayed version of the pulse are delayed by a second signal-propagation time required for a high-to-low signal transition to traverse the test circuit.