Keithley 7703 High Speed Differential Multiplexer

The Keithley 7703 High Speed Differential Multiplexer is a plug-in module for Keithley data acquisition systems, delivering 32 channels of 2-pole switching with configurable flexibility to 16 channels of 4-pole switching or two independent multiplexer banks. Reed relays with sub-1 ms actuation time enable high-speed scanning across temperature measurement applications including RTD and thermistor monitoring. The module supports both 2-wire and 4-wire measurement configurations, making it suitable for precision differential signal routing in automated test environments.

Technical Specifications

• Channel Count: 32 channels (2-pole) or 16 channels (4-pole)


• Relay Type: Non-latching reed relays


• Actuation Time: < 1 ms


• Maximum Signal Level: 300 V DC or RMS, 0.5 A switched, 10 W maximum per channel; 10 VA power handling


• Contact Resistance: < 1 Ω at end of contact life


• Contact Potential: < ±3 µV typical per contact (6 µV max); 10⁹ Ω with 10⁹ Ω with < 200 pF between any two terminals


• Insertion Loss: < 0.35 dB below 1 MHz; < 3 dB below 2 MHz (50 Ω source, 50 Ω load)


• Crosstalk: < –40 dB at 1 MHz (50 Ω load)


• Common Mode Voltage: 300 V between any terminal and chassis


• Relay Drive Current: 20 mA per channel


• Operating Temperature: 0 °C to 50 °C


• Storage Temperature: –25 °C to 65 °C


• Weight: 0.8 kg

Key Features

• Dual 50-pin D-sub connectors for direct system integration


• Bank-configurable architecture for independent or cascaded operation


• Low contact potential drift for precision analog applications


• High isolation and minimal crosstalk for signal integrity

Typical Applications

• Temperature sensor array monitoring (RTD, thermistor)


• Multi-channel differential signal acquisition


• High-speed automated test and measurement

Compatibility & Integration Direct plug-in compatibility with Keithley Models 2700, 2701, 2750, and DAQ6510.