The Keithley DAS-8/AO is a 12-bit successive approximation analog-to-digital converter designed for precision data acquisition in IBM PC and compatible systems. This ISA bus card provides 8 analog input channels with software-programmable input ranges, 2 analog output channels, and an onboard 1 MHz crystal oscillator for sample timing. Unlike fixed-range variants in the DAS-8 series, the DAS-8/AO delivers flexible input and output configurations with simultaneous output capability.
## Technical Specifications
• **Analog Input Channels:** 8
• **Analog Output Channels:** 2 (12-bit)
• **ADC Resolution:** 12-bit successive approximation
• **A/D Conversion Time:** 25 µs typical, 35 µs maximum
• **Input Ranges:** Software-programmable—±10 V, ±5 V, ±0.5 V, ±0.05 V, ±0.01 V, 0 to +10 V, 0 to +1 V, 0 to +0.02 V
• **Output Ranges:** Independently switch-selectable—±10 V, ±5 V, ±2.5 V, 0 to +10 V, 0 to +5 V, 4 to 20 mA
• **Sampling Rate:** Up to 4 ksamples/s; maximum per-channel rate is 4 kHz divided by the number of channels
• **Clock Source:** Onboard 1 MHz crystal oscillator; external clock input supported
• **Counter/Timer:** Onboard 82C54 programmable counter-timer with three 16-bit counters for event counting, pulse/waveform generation, and frequency/period/pulse-width measurements
• **Digital I/O:** 7 bits TTL (one 4-bit output port, one 3-bit input port)
• **Reference Output:** +10.00 V (±0.1 V) precision reference; 2 mA source/sink capability
• **Interrupts:** Jumper-selectable external interrupt input (levels 2–7)
## Key Features
• Simultaneous update of both analog output channels
• Software-programmable input ranges eliminate fixed-range limitations
• External interrupt capability with six selectable levels
• Dual D-type connectors for analog and digital signal routing
## Typical Applications
Data acquisition, sensor signal conditioning, analog monitoring, and real-time laboratory measurement in DOS and Windows 95/98 environments.
## Compatibility & Integration
**Bus:** ISA (Industry Standard Architecture)
**Host Systems:** IBM PC, AT, 386, Pentium-compatible
**Operating Systems:** MS-DOS/PCDOS 3.1 or higher; Windows 95/98
**Memory:** Minimum 2 MB
