Technical data

Module 8

Capacitance Measurement

8-18

To CMU Hpot/Hcur

ASU 2

ASU 1

To HRSMU 1

CMUH or Force

CMUL or

Force

Sense

CMU return path

To CMU Lpot/Lcur

To HRSMU 2

ASU – for IV/CV Switching

The ASU (Atto Sense and Switch Unit) is available for the B1500A installed with the HRSMU.

Using the ASU permits use of the 1 pA range. Also the ASU can switch the measurement resources,

HRSMU or an instrument connected to the AUX input connectors.

The ASU has input connectors, one triaxial and two coaxial. The triaxial connector must be

connected to the HRSMU Force terminal, and the coaxial connectors must be connected to the other

resource such as CMU. Also the ASU has the control connector to be connected to the HRSMU by

using the ASU cable.

The ASU has output connectors, two triaxial, that must be connected to the DUT interface such as

manipulators or probe card. When the measurement resource is the HRSMU, they are the

Force/Sense connectors for the Kelvin connection. And when the resource is not the HRSMU, the

CMU/AUX is connected to the Force, and the Sense is not used.

If you connect the CMU, two ASUs are required. Then the ASU’s CMU-pot/CMU-cur connectors

must be connected to the Hpot/Hcur of the CMU. And the other one must be connected to the

Lpot/Lcur in like manner.

To realize accurate impedance measurements using the four-terminal pair measurement method,

connect the CMU return terminals of ASUs together.

Note:

For the accurate measurement, it is recommended to make the return path at the point as close as

possible to the device side.