The present disclosure provides functional test equipment for a device under test and method of testing the device under test. The functional test equipment includes a first power supply, a second power supply and a relay system. The first power supply is configured to generate a first supply voltage. The second power supply is configured to generate a second supply voltage different from the first supply voltage. The relay system is configured to electrically couple the first power supply or the second power supply to the device under test, wherein the first supply voltage is applied to the device under test for a first duration and the second supply voltage is applied to the device under test for a second duration less than the first duration.