The Keithley DAS-8PGA and DAS-8PG2 are 8-channel, 12-bit successive approximation analog-to-digital converters designed for ISA bus-based data acquisition on IBM PC and compatible systems. Both models integrate programmable gain amplification, sample-and-hold circuitry, digital I/O, and counter/timer functionality in a single board, delivering flexible signal conditioning and acquisition capabilities for scientific research, industrial automation, and quality control applications.
## Technical Specifications
**Analog Input Subsystem**
• 8 channels with 12-bit resolution and 25 µs typical conversion time (35 µs maximum)
• Switch-selectable single-ended or differential input configuration per channel
• Input impedance >1 GΩ typical; input current ±30 nA @ 25°C, ±250 nA over temperature
• Maximum overvoltage rating ±35 V per channel
• DAS-8PGA: Software-programmable ranges of ±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
• DAS-8PG2: Software-programmable ranges of ±5 V, ±2.5 V, ±1.25 V, ±0.625 V, 0 to +5 V, 0 to +2.5 V, 0 to +1.25 V, 0 to +0.625 V
• Linearity ±1 bit; throughput up to 4 ksamples/s with DriverLINX software
**Digital I/O**
• 3-bit input port and 4-bit output port; TTL-compatible levels
• Non-clocked data transfer without hardware overrun detection
**Counter/Timer**
• Three 16-bit internal counters using Intel 8254 or equivalent 82C54 chip
• Supports event counting, pulse and waveform generation, frequency, period, and pulse-width measurements
• Counter 2 clock source: internally selectable between PC bus clock or 1 MHz crystal oscillator
## Key Features
• Programmable gain amplification across eight input channels
• Integrated sample-and-hold per conversion cycle
• Flexible input range selection tailored to signal amplitude
• TTL-compatible digital I/O for system integration
• Multi-function counter/timer for timing and measurement tasks
## Typical Applications
Data acquisition in laboratory environments, sensor signal digitization, industrial process monitoring, and test automation where programmable input conditioning and modest sampling rates are sufficient.
## Compatibility & Integration
ISA bus architecture supports IBM PC and compatible systems. Supplied DriverLINX software provides software control and real-time sampling.
