Abstract: This disclosure relates to systems and methods for measuring impedance characteristics of a cryogenic device under test (DUT). A channel select circuit can be configured in a first state to electrically isolate a channel output circuit from the cryogenic DUT and in a second state to electrically couple the channel output circuit to the cryogenic DUT, and at least one resistor can be positioned along a transmission path that couples a pattern generator circuit to a channel output circuit that includes the channel select circuit. A controller can be configured to cause respective test current signals to be provided along the transmission path when the channel select circuit is in respective first and second states to establish respective first and second voltages across the at least one resistor, determine first and second impedance characteristics of the transmission path for determining an impedance of the cryogenic DUT.

Abstract: This disclosure relates to systems and methods for current source temperature compensation for use during cryogenic electronic testing. A temperature compensation circuit can provide a temperature compensation signal to a current source circuit configured to provide an electrical current for testing a cryogenic device under test to compensate for temperature effects on the current source circuit based on a time constant adjustment signal. The time constant adjustment signal can adjust a time constant of the temperature compensation circuit to delay by a given amount of time that the temperature compensation circuit compensates for the temperature effects on the current source circuit. A controller can be configured to execute a temperature compensation method to provide the time constant adjustment signal based on at least one temperature signal characterizing a temperature of an environment that includes the current source circuit or a temperature of the current source circuit.

Abstract: A ground fault detection circuit can include a band-pass filter that can have a first node and a second node that can be coupled to an earth ground. The first node can be coupled to a local ground of an automatic test equipment (ATE) system for an electrical device that can be coupled via at least one wire to the ATE. The band-pass filter can be configured to pass and amplify a test current signal established at the first node in response to a coupling of one of a conductor of the at least one wire carrying the test current signal to the local ground, and a conductive element of the electrical device carrying the test current signal to the local ground. A fault alert signal can be provided to provide an indication of ground fault based on a comparison of the amplified test current signal.

Abstract: A current source circuit can include a first amplifier circuit and a second amplifier circuit. Each of the first and second amplifier circuits can be configured to generate respective amplifier output voltages based on a corresponding input voltage and respective feedback voltage. The current source circuit can further include a cross-coupling circuit that can include a first set of resistors and a second set of resistors. The first set of resistors can be configured to establish a first cross-coupling voltage based on the first amplifier output voltage and the second set of resistors can be configured to establish a second cross-coupling voltage based on the second amplifier output voltage. The first and second amplifier circuits can be configured to maintain the first and second cross-coupling voltage at a given voltage amplitude to provide a constant current at an output node of the current source circuit.

Abstract: A ground fault detection circuit can include a band-pass filter that can have a first node and a second node that can be coupled to an earth ground. The first node can be coupled to a local ground of an automatic test equipment (ATE) system for an electrical device that can be coupled via at least one wire to the ATE. The band-pass filter can be configured to pass and amplify a test current signal established at the first node in response to a coupling of one of a conductor of the at least one wire carrying the test current signal to the local ground, and a conductive element of the electrical device carrying the test current signal to the local ground. A fault alert signal can be provided to provide an indication of ground fault based on a comparison of the amplified test current signal.

Abstract: A current source circuit can include a first amplifier circuit and a second amplifier circuit. Each of the first and second amplifier circuits can be configured to generate respective amplifier output voltages based on a corresponding input voltage and respective feedback voltage. The current source circuit can further include a cross-coupling circuit that can include a first set of resistors and a second set of resistors. The first set of resistors can be configured to establish a first cross-coupling voltage based on the first amplifier output voltage and the second set of resistors can be configured to establish a second cross-coupling voltage based on the second amplifier output voltage. The first and second amplifier circuits can be configured to maintain the first and second cross-coupling voltage at a given voltage amplitude to provide a constant current at an output node of the current source circuit.