Patent ID: 8090009

Claim:
A test apparatus which applies a jitter to a transmission signal output from a transmitting circuit and inputs the transmission signal to a receiving circuit, thereby to test jitter tolerance of the receiving circuit, the test apparatus comprising: a transmitting-side jitter measuring unit which measures a jitter of the transmission signal output from the transmitting circuit; a jitter applying unit which applies a jitter to the transmission signal output from the transmitting circuit, and inputs the transmission signal to the receiving circuit; a jitter range measuring unit which determines whether or not a logical value of the transmission signal detected by the receiving circuit is equal to a preset expectation value for each amplitude of the jitter which the jitter applying unit applies to the transmission signal, and measures a range of amplitudes of the jitter within which the logical value of the transmission signal is equal to the expectation value; and a jitter tolerance measuring unit which calculates jitter tolerance of the receiving circuit, based on the jitter of the transmission signal measured by the transmitting-side jitter measuring unit, and the range of the amplitudes of the jitter measured by the jitter range measuring unit, wherein the jitter tolerance measuring unit calculates the jitter tolerance of the receiving circuit, by adding an amplitude value of the jitter of the transmission signal measured by the transmitting-side jitter measuring unit, to an upper limit of the range of the amplitudes of the jitter measured by the jitter range measuring unit.