M9601A PXIe Precision Source/Measure Unit

Industry high-performance PXIe SMU enabling faster precise dynamic measurement from DC to 20 μs pulse with lowest source noise

Introduction

The Keysight M9601A is a PXIe precision source/measure unit (SMU). It covers currents from 10 fA to 315 mA and voltage from 500 nV to 210 V and can make DC measurements to pulsed measurements with 20 μs pulse width, with a sampling rate up to 1.25 MSa/s. That makes the M9601A ideal for a variety of current versus voltage measurement tasks that require high resolution and accuracy, such as semiconductor test, active / passive component test, and general electronic device.

This guide provides step-by-step instructions to help you configure an SMU and its related accessories to meet specific test requirements. For detailed specifications, refer to the M9601A PXIe precision SMU data sheet (publication number 5992-4192EN).

Configure Your Keysight M9601A Precision SMU

Step 1. Define the required number of M9601A modules

The M9601A PXIe precision SMU occupies two slots in the PXIe chassis. You need to define the required number of modules based on your application requirements.

Step 2. Select optional accessories for each module

Step 2-1. Determine if you need to make low terminals grounded

The low terminals of the M9601A are a floating configuration, enabling you to connect them to any potential up to ± 40 V. If your device-under-test interface is floating and you need to make the M9601A’s low terminals grounded, you may do so by attaching a short bar, as shown in Figure 1. The M9601A ships with the short bar attached.

Step 2-2. Determine whether you need to make four-wire measurements

The M9601A supports both two-wire and four-wire measurement. The simpler two-wire configuration uses only the force terminals. In two-wire mode, the sense terminals remain open.

If you are measuring very small resistances or applying very large current, you should use the four-wire measurement method (also known as the Kelvin method). This technique uses both force and sense terminals. Making the measurement through the sense terminals (in which no current is flowing) eliminates the effects of cable resistance.

Low current measurements (< 1 nA) require guarding to prevent leakage through the measurement cable. Figure 3 provides a simplified overview of the guarding technique. Guarded measurements require the use of triaxial cables. A follower (x1) buffer amplifier keeps the guard conductor at the same potential as the center conductor. Since there is no voltage difference, no current can flow from the center conductor to the guard.

Note: In this example, even the device interface has a guarded shield to prevent leakage at the device interface

Step 2-3. Consider interlock circuit

The M9601A has a safety interlock to prevent accidental exposure to dangerously high voltages. It cannot source voltages greater than ± 42 V (or the specified voltage within ± 42 V) unless the interlock circuit is closed. You can engage the safety lock using interlock pins on the connector at the front panel. Normally, these pins are routed to a shielding box or test fixture that must be closed to complete the interlock circuit.

You can install an interlock circuit as shown in Figure 4. If your shielding box has the BNC connector for the interlock circuit, you can use the PX0101A-001 or 002 BNC to ferrule terminal cable with a connector-terminal block to connect the M9601A’s interlock pins to it. For more detailed information, please refer to the Keysight M9601A Startup Guide.

Step 2-4. Consider external trigger connection

Although the PXIe trigger lines in the chassis are available to synchronize the M9601A with the other PXIe modules, two external trigger lines are available if you need to synchronize it with the external instrument. You can use the PX0101A-001 or 002 BNC to ferrule terminal cable with a connector terminal block to connect the M9601A’s external trigger lines to the external instrument.