Aeroflex / Tektronix / CDS 53A-331 Reed Relay Scanner Card

The Aeroflex / Tektronix / CDS 53A-331 Reed Relay Scanner Card is a ten-channel analog signal switching module engineered for automated test systems and data acquisition. Each channel employs a four-pole Form A dry reed relay, delivering low thermal offset and high isolation suitable for precision measurement and signal routing in laboratory and production environments.

Technical Specifications

• Ten individual four-pole Form A reed relays


• Four-wire analog signal acquisition per channel


• Four-line common output bus


• Switching rate: Up to 150 channels per second (random channel selection) Contact and Load Ratings


• Maximum switching voltage: 200V DC


• Maximum switching current: 0.5 A


• Maximum resistive load: 10 W


• Initial contact resistance: <100 mΩ


• Contact resistance at end of reed life: <1 Ω


• Reed life expectancy: ≥10⁷ operations per channel at rated load


• Continuous duty cycle Signal Integrity


• Differential thermal offset: <15 μV (at backplane analog output connector)


• Single-line thermal offset: 500 mΩ


• Signal path resistance at end of reed life: 10 GΩ


• Insulation resistance (closed channel, common bus to ground): 1 MΩ (with 1 MΩ resistors on front connector)


• Insulation resistance (open channel, any input to ground): >10 GΩ

Key Features

• Built-in test equipment: Ten LEDs indicate closure status per corresponding channel


• Random channel selection via ASCII character commands from system controller


• Pluggable card cage module within CDS 53/63 Series Systems

Compatibility & Integration The 53A-331 integrates into CDS 53/63 Series card cages alongside other scanner modules, including the 53A-332 (twenty 2-wire channels) and 53A-336 (sixteen 2-wire high voltage channels). Multiple cards expand capacity within a single cage; multiple cages chain for system-level scaling. Optional OPT 20 backplane output isolation switch available. Recommended cables: 53A-721, 53A-780.