Abstract: A test circuit of the presently disclosed technology may include a “stacked precision parametric measurement unit (PMU)” having a precision PMU connected in series with a common-mode (CM) power supply (e.g., higher voltage supply). The common-mode voltage source may include a voltage source configured to supply a relatively large range of voltages (e.g., ?100 V to 100 V), such as might be suitable for testing battery management system integrated circuits (BMS ICs). By contrast, the precision PMU may include a voltage source that supplies/measures voltages over a relatively smaller range (e.g., ?2 V to 6 V relative to the common-mode voltage source) at higher precision (e.g., 30 to 300 uV voltage steps).