Keithley 7710 20 Channel Solid State/Long Life Differential Multiplexer Card with Auto CJC

The Keithley 7710 is a 20-channel solid-state differential multiplexer card built for high-speed, high-reliability switching in data acquisition systems. It configures as 20 channels of 2-pole relay input or up to 10 channels of 4-pole operation, organized into two independent multiplexer banks. Opto-coupled FET relays deliver switching actuation in less than 0.5 ms and enable scanning at up to 500 channels/second.

Solid-state design eliminates mechanical relay wear, extending operational life beyond 10⁵ hours at full signal level or 10¹⁰ operations by design specification. Built-in automatic cold junction compensation (CJC) streamlines thermocouple measurements to within 1°C accuracy for K-type devices.

Technical Specifications

• Maximum signal: 60 VDC or 42 Vrms, 100 mA switched, 6 W, 4.2 VA


• Common mode voltage: 300 VDC or 300 Vrms (425 V peak) maximum to chassis


• Channel resistance: Less than 5 Ω per conductor


• Contact potential: Less than 1 µV per pair


• Offset current: Less than 3 nA @ 23°C, +0.13 nA/°C above 23°C


• Isolation (channel-to-channel): Greater than 10⁹ Ω, less than 100 pF


• Isolation (channel-to-earth): Greater than 10⁹ Ω, less than 100 pF


• Crosstalk (300 kHz, 50 Ω load): Less than –40 dB


• Insertion loss: Less than 0.5 dB below 100 kHz; less than 3 dB below 2 MHz


• Relay drive current: 6 mA continuous, 25 mA initial pulse Temperature


• Operating: 0°C to 50°C at 80% RH @ 35°C


• Storage: –25°C to 65°C

Key Features

• Opto-coupled FET relay technology for long-term reliability


• Configurable 2-pole and 4-pole channel modes


• Dual independent multiplexer banks


• Automatic CJC for thermocouple applications


• Sub-0.5 ms switching with 100 mA load


• 500 channels/second scanning speed


• 3.5 mm screw terminals, #20 AWG compatible

Typical Applications

• Thermocouple and RTD data logging


• High-speed multi-channel switching


• Low-level analog signal multiplexing


• Long-duration automated test systems


• Resistance and 4-wire measurements

Compatibility & Integration Designed for Keithley Model 2700 (Rev. B05 firmware or later) and Model 2701 mainframes.