The HP/Agilent 34908A is a 40-channel single-ended multiplexer module engineered for the Agilent 34970A and 34972A Data Acquisition/Switch Units. It delivers high-density switching for common-low applications, routing 40 individual one-wire inputs with break-before-make relay control. The module supports all two-wire internal measurements except current and includes an integrated thermocouple reference junction for direct thermocouple measurements.
Technical Specifications
Switching Architecture
• 40 single-ended channels
• Break-before-make relay configuration—only one relay connected at any time
• Scanning speed up to 60 channels per second
Voltage and Current
• Maximum switching voltage: 300 VDC or AC peak
• Maximum switching current: 1 A
• Module low connection isolated from earth, capable of floating to 300 V
Measurement Support
• All two-wire internal measurements except current
• Built-in thermocouple reference junction for direct thermocouple operation
• Current measurements require user-supplied shunt resistors on the 34970A system
Physical and Integration
• Plug-in module format for 34970A/34972A mainframe
• Dimensions: 12 × 10 × 8 inches
• Shipping weight: 4 lbs
– Key Features
• High-density 40-channel architecture for compact test benches
• Isolated floating low connection supports floating signal sources to 300 V
• Integrated thermocouple reference junction eliminates external reference requirements
• Break-before-make relay logic prevents cross-talk and signal contamination
– Typical Applications
• Battery testing and characterization
• Component electrical parameter measurement
• General benchtop data acquisition and switching
• Thermocouple temperature monitoring
– Compatibility & Integration
Designed exclusively for Agilent 34970A and 34972A Data Acquisition/Switch Units. Installs as an internal plug-in module. Included with one functional test certificate.
