Voltage source measurement unit with minimized common mode errors

摘要

A particular configuration of voltage source measurement (VSM) circuitry minimizes common mode errors in measurement of current through a device under test (DUT), even across a wide range of output voltages. The current I_DUT is not affected by common-mode errors, since the current measurement is based on the output voltage of an operational amplifier or a differential amplifier, and the circuit configuration is such that the current measurement is made while the operation amplifier or differential amplifier has very low common-mode input voltage.