Figure 1: Typical systems using a switch matrix
Matrix card types
The recommended Keithley Instruments matrix cards are:
• Model 7071 8 x 12 General Purpose Matrix Card, <100 pA offset current
• Model 7072 8 x 12 Semiconductor Matrix Card, <1 pA offset current
• Model 7136 (not available to purchase)
• Model 7174A 8 x 12 Low Current Matrix Card, <100 fA offset current
• Model 9174 8 x 12 Semiconductor Matrix Card , <100 fA offset current (not available to purchase)
Note that a key characteristic of these cards is low offset current to minimize the negative effects of
offset currents on low-current measurements.
7071 General Purpose Matrix Card
The 7071 provides cost-effective switching of I-V and C-V signals. This matrix card uses 3-pole
switching (high, low, and guard) with <100 pA offset current. The card is equipped with screw
terminals and 38-pin connectors for signal connections.
The following figure shows a test system using 7071 matrix cards. The triaxial and BNC cables are
unterminated on one end to allow direct hard-wire connections to the screw terminals of the matrix
card. It shows how signals are routed through the 7071 matrix switches to a DUT.
The test system in the following figure uses remote sensing. Notice that each FORCE and SENSE
terminal-pair of the 4200A-SCS shares the same path (row).