Tektronix / CDS 73A-308 Relay and High Voltage Logic Driver Module

The Tektronix/CDS 73A-308 is a Relay and High Voltage Logic Driver Module for VXIbus systems. It delivers 80 open-collector relay drivers organized into ten banks of eight channels each, with 300 mA per-channel current handling and 500 mV maximum voltage drop across outputs to common. Control granularity spans individual relay operation, bank-based grouping, or simultaneous actuation of all 80 drivers. Each output can be programmed to inactive (tri-state) or active low state. Built-in transient suppression—clamp diodes or diode networks—eliminates voltage spikes during relay turn-off. Two output connectors (P4 and P5) distribute 40 driver pairs each, with jumperable clamp diode lines assignable to any of five eight-output blocks and dedicated ground returns.

Full system status visibility includes relay driver output states and error reporting. ASCII command and response protocol ensures broad host controller compatibility. The module integrates directly into VXIbus card cages as a printed circuit board assembly.

– Technical Specifications

• Output channels: 80 open-collector relay drivers
• Current per channel: 300 mA
• Maximum voltage drop: 500 mV (output to common)
• Bank organization: Ten banks of eight drivers
• Output connectors: P4 and P5 (40 drivers + 2 clamp diode lines + 8 grounds each)
• Clamp diode lines: Jumperable to any five-block grouping
• Control modes: Individual, bank (8-driver groups), or all-simultaneous
• Output states: Tri-state (inactive) or active low, software-selectable
• Transient suppression: Built-in clamp diodes
• Communication protocol: ASCII commands and responses

– Key Features

• Flexible relay actuation: granular per-channel to bank-wide to simultaneous control
• Integrated voltage spike suppression for relay switching reliability
• Real-time access to driver status and system error data
• ASCII-based interface for universal host compatibility

– Typical Applications

VXIbus test systems requiring programmable relay switching and high-current logic drive capacity.

– Compatibility & Integration

Designed for VXIbus card cage systems. Communicates via ASCII character protocol.