The Tektronix VX4287 is a 32-channel differential analog/digital input module engineered for VXIbus system integration. This single-width C-size module delivers flexible input configurations: 32 digital inputs, 32 comparator inputs with time-tagging, or a hybrid 16 analog + 16 digital arrangement. Each channel features individually programmable threshold voltages and logic sense (active high or active low), with automatic or manual range selection across two threshold windows: ±25 V (125 mV accuracy, 12.5 mV resolution) and ±50 V (200 mV accuracy, 25 mV resolution). Channel isolation is programmable, and front-panel status indication displays real-time threshold comparisons.
Technical Specifications
Module Configuration
• 32 differential input channels
• Single-width, C-size VXI form factor
• Three operational modes: digital only, analog comparator with time-tagging, or mixed analog/digital
• VXIbus Specification compliant
Input Characteristics
• Programmable per-channel threshold voltages
• Selectable logic sense: active high or active low
• Two threshold ranges: ±25 V and ±50 V
• Common mode input: ±90 V protected
• Differential input protection: ±150 V on + input
• Input impedance: 100 kΩ on both + and − inputs
• CMRR: > 50 dB
Accuracy & Resolution
• ±25 V range: 125 mV worst-case accuracy, 12.5 mV resolution
• ±50 V range: 200 mV worst-case accuracy, 25 mV resolution
• Temperature coefficient: 180 ppm/°C
• Calibration interval: 12 months
• Monotonicity guaranteed within either range
Environmental
• Operating: 0°C to +50°C
• Storage: −40°C to +85°C
• Humidity: < 95% R.H. non-condensing (0°C to +30°C); < 45% R.H. non-condensing (+41°C to +50°C)
– Key Features
• Autoranging selects the most sensitive suitable threshold window automatically
• Individual channel enable/disable isolation control
• Dual-range threshold flexibility accommodates both low-amplitude and high-voltage signals
• Real-time front-panel channel status indication
• Time-tagged comparator outputs for precision event marking
– Typical Applications
• Multi-channel signal monitoring and threshold detection
• High-voltage differential measurement systems
• Mixed-signal test and measurement systems requiring combined analog and digital acquisition
• Event timing and transient capture with time-tag correlation
– Compatibility & Integration
The VX4287 integrates directly into VXIbus mainframes, drawing power from standard VXI supplies. Its modular architecture supports mixed-mode operation within a single test system.
