Description
During a lock-in thermography test, a Keithley SMU displays a message indicating an internal power supply error (specific error message depends on SMU model).
In addition to resistance characteristics, electronic circuits may have significant capacitance and inductance, depending on the specific electronic components included in the circuit. When cycling voltage during lock-in thermography tests, current backflow may occur during the off half cycle. If the selected current range is lower than the backflow current, the SMU output module for the selected range may be damaged.