Patent ID: 7903008

Claim:
A source-measure unit (SMU) comprising: output terminals configured to couple the SMU to a device under test (DUT), and further configured to convey an analog output signal to the DUT to effect: an output current flowing into the DUT; and an output voltage in the DUT; a first converter configured to generate a first digital value representative of the output current; a second converter configured to generate a second digital value representative of the output voltage; a digital control loop configured to receive the first digital value and the second digital value, and generate a digital control signal based on the first digital value and the second digital value to regulate a specified function of the output current and the output voltage to remain at a value corresponding to a setpoint; and a third converter comprising: a digital-to-analog converter (DAC) configured to generate an analog control signal based on the digital control signal; a gain circuit configured to adjust a level of the analog control signal to generate an adjusted analog control signal, to increase dynamic range of the SMU; and an output stage configured to generate the analog output signal based on the adjusted analog control signal.