Abstract: A power supply for testing an integrated circuit includes a source voltage input terminal for receiving an input voltage. A plurality of switches are coupled in parallel to the input terminal, where each of the switches is coupled to an associated resistor. Each resistor, in turn, is coupled to an output terminal that is connected to the device under test (DUT). A soft switch is connected to both the input terminal and output terminal, where the soft switch is configured to condition the output terminal voltage when one of the switches is opened or closed. The soft switch quickly stabilizes the output voltage and reduces transients in the VDUT output signal.