High-impedance mode for precision measurement unit

摘要

A high-impedance mode is provided for an output of a precision measurement unit (PMU). The PMU includes an output amplifier that that provides a forcing voltage or current to a device under test. When the high-impedance mode is activated, the output amplifier is decoupled from an output terminal of the PMU and the output amplifier is disabled. This prevents the voltage on the output terminal from rising in an uncontrolled manner, and prevents current spikes from forming on the output terminal when connected to a device under test. The high-impedance mode is deactivated to permit connection of the PMU to another device under test by re-coupling the output amplifier to the output terminal and enabling operation of the output amplifier.