The Keithley 7702 is a 40-channel differential multiplexer module engineered for precision data acquisition and multi-parameter signal routing. It delivers low-noise, high-isolation switching across general-purpose and specialized measurement configurations, supporting two-wire and four-wire resistance measurements with automatic channel pairing. The module features latching relays that retain closure state through power cycles, making it ideal for unattended logging and complex measurement sequences in laboratory and industrial environments.
Technical Specifications
Channel Configuration
• 40 channels at 2-pole configuration for general-purpose measurements
• 20 channels at 4-pole configuration for precision resistance measurement
• 2 dedicated protected channels (41 & 42) for current measurement
Voltage & Current Ratings
• Standard channels: 300 V DC or RMS maximum, 1 A maximum switch current, 60 W maximum power, 125 VA maximum
• Current channels: 60 V DC or 30 V RMS maximum, 3 A maximum switch current, 60 W maximum power, 125 VA maximum
Relay Performance
• Contact life: >10⁵ operations at maximum signal level; >10⁸ operations no-load
• Contact resistance: <1 Ω at end of contact life
• Contact potential: <±500 nV typical, 1 µV maximum per contact
Signal Integrity
• Offset current: 10⁹ Ω with 10¹⁰ Ω with 10⁹ Ω with 10⁹ Ω with <200 pF
• Crosstalk (50 Ω load): <–40 dB at 1 MHz and 10 MHz
• Insertion loss: <0.35 dB below 1 MHz, <3 dB below 2 MHz
• Common-mode voltage: 300 V between any terminal and chassis
• Minimum signal level: 10 mV, 10 µA
Physical & Environmental
• Connector: Screw terminal, maximum #20 AWG wire
• Operating temperature: 0°C to 50°C
• Storage temperature: –25°C to 65°C
• Humidity: 40% R.H. or 80% R.H. at 35°C
• Weight: 0.8 kg or 0.5 kg
– Key Features
• Configurable as two independent multiplexer banks for flexible system architecture
• Latching relays store closure state in onboard memory—ideal for power-loss conditions
• Low contact potential (10⁹ Ω) and low crosstalk (<–40 dB) ensure measurement integrity across channels
• Oversize screw terminals simplify field wiring
– Typical Applications
• Multi-channel temperature sensing and data logging
• Precision resistance and impedance measurement networks
• Automated electrical characterization and burn-in test systems
• High-voltage and high-current signal routing in industrial monitoring
– Compatibility & Integration
The 7702 integrates with Keithley mainframe systems: DAQ6510, Model 2700/2701/2750/2790 series, and Tektronix 2750 Multimeter/Switch System.
