The 4210-CVU Multi-Frequency (1 kHz to 10 MHz) Capacitance-Voltage Unit is an impedance
measurement module that can be installed in the 4200A-SCS.
The AC test signal (10 mVRMS to 100 mVRMS) can be DC voltage biased from 30 V to +30 V.

The 4210-CVU makes AC impedance measurements (ZDUT) of the device under test (DUT) by
sourcing an AC test voltage across the device and measuring the resulting AC current and AC
voltage.
The AC current is measured as shown in Typical 4210-CVU test connections to a DUT (on page 4-8).
The HCUR/HPOT and LCUR/LPOT terminal pairs are interchangeable. Each provides the full
capability of the other pair.
The simplified model of a device-under-test (DUT) is a resistor and a capacitor. As shown in the next
figure, the 4210-CVU can measure the DUT as a series configuration of the resistor-capacitor (RC) or
as a parallel RC configuration.

The 4210-CVU can measure these parameters:

• Parallel capacitance and conductance (Cp-Gp)
• Parallel capacitance and dissipation factor (Cp-D)
• Series capacitance and resistance (Cs-Rs)
• Series capacitance and dissipation factor (Cs-D)
• Resistance and reactance (R-jX)
• Impedance and phase angle (Z-theta)

The time domain of the AC current and AC voltage must be processed into the frequency domain to
produce the phasor form of the DUT impedance.
The capacitive impedance (and conductance) are calculated based on the measured AC impedance
and phase.
The next figure shows the vector diagram and fundamental equations for impedance