Patent ID: 7276896

Claim:
Test apparatus for testing a circuit unit to be tested, having: a) a test system; b) a control bus for transferring control data from the test system to the circuit unit to be tested; c) an address bus for transferring addressing data from the test system to the circuit unit to be tested; and d) a data bus for exchanging test data between the test system and the circuit unit to be tested, wherein the test apparatus furthermore has: e) a voltage generating device connected between the test system and the circuit unit to be tested and serving for generating a predeterminable operating voltage output signal for the voltage supply of the circuit unit to be tested in a manner dependent on a control signal that is provided by the test system and fed via the control bus; f) wherein the voltage generating device connected between the test system and the circuit unit to be tested provides a ground output potential in a manner dependent on the control signal such that the ground potential of the circuit unit to be tested can be varied relative to a ground potential of the test system.