The Keithley 3761 10-Channel Low-Current Multiplexer Card provides quality low-current switching. The offset current error generated is specified < 1pA, with typical performance at < 30fA. When used with a voltage source and an electrometer or picoammeter, this card can easily automate insulation resistance tests, reverse leakage tests on semiconductor junctions, or gate leakage tests on FETs.

The Keithley 3761 features both current and voltage modes. In current mode, the current path is maintained even when the channel is open. This eliminates cable charging time between measurements. In voltage mode, the input is broken and is high impedance. Input connectors are SMA for shielding of the sensitive measurements. The 3761 does not connect to the 6 common buses on the 3706A backplane, but two outputs allow for chaining several scanner cards to one measurement instrument, allowing up to 60 channels, while an isolation relay in the output HI minimizes the interaction between cards.