AD12-8G 12-Bit 8-Input Programmable-Gain A/D Converter and Counter/Timer

AD12-8G
12-Bit 8-Input Programmable-Gain A/D Converter and Counter/Timer Card

FEATURES

Eight single-ended or differential analog inputs
12-bit resolution
Nine software programmable voltage ranges
Programmable scan rate
Foreground/background operation
Three 16-bit counter/timers for event counting, pulse and waveform generation, and frequency measurement.
Seven bits of digital I/O
Can assert interrupts

FUNCTIONAL DESCRIPTION

The AD12-8G is an eight-channel, 12-bit, analog/digital card for use in IBM Personal Computers. It is a 3/4 length card that can be installed in expansion slots of ISA-bus computers. All connections are made through a standard 37-pin D type connector that projects through the rear of the computer.

ANALOG INPUTS

The input analog channels are individually switch selectable for either differential or single-ended input signals. A choice of nine software-selectable voltage ranges are available and the card can withstand ±30 VDC overload and transients of several hundred volts. The A/D converter is a successive-approximation type with solid-state input analog multiplexer and sample and hold amplifier. A/D conversion time is typically 25 microseconds.

COUNTER/TIMER

This card also contains a type 8254 counter/timer chip which has three 16-bit counters. These counters can be used as an A/D pacer clock and/or can be used to measure pulse width, count events, measure or generate frequencies, etc. An on-board 1 MHz crystal controlled clock is hard-wired to one counter input and the clock inputs to the other two counters are available at the I/O connector. All the gate inputs and counter outputs are accessible at the I/O connector.

DIGITAL I/O

AD12-8G also can accept three bits of digital input and can provide four bits of digital output both in standard TTL/CMOS logic levels. One of these outputs, for example, can be used to initiate an interrupt upon end of A/D conversion. Jumper positions on the card provide means to assert interrupts on your choice of levels 2 through 7.

SPECIFICATIONS

Analog Inputs

Number of Channels: Eight differential or single- ended, individually DIP switch selectable for S.E. or Diff.
Voltage Range: Programmable, ±5V (default), ±10V, ±0.5V, ±0.05V, ±0.01V, 0-10V, 0-1V, 0-0.1V, 0-0.02V.
Overvoltage Protection: ±30 VDC.
Input Impedance: 10 Megohm or 125 nA at 25°C.
Common Mode Rejection Ratio: 90 db when gain = 1; 125 db when gain = 100.
Multiplexer/Sample and Hold Settle Time: When gain = 1 : 30 µSec; When gain = 100 : 95 µSec
Overall Accuracy: ±0.05% of full scale.
Linearity: ±1 LSB.
Resolution: 12 bit binary.
A/D Trigger Source: Software selectable, external trigger, programmable timer, or program command.
Conversion Time: 35 µSec max., 25 µSec typical.
Temperature Coefficient: ±10 µV per °C zero stability. ±25 µV per °C gain stability.

Digital I/O

Inputs

Logic Low: 0 to 0.8V at -0.4 mA max.
Logic High: 2.4 to 5V at 20 µA max.
Outputs

Logic Low: 0 to 0.5V at 8 mA sink.
Logic High: 2.4 to 5V at 0.4 mA source.

Counter Timer

Type: 8254 type programmable interval timer, three 16-bit counters.
Drive Capability: 5 LSTTL loads (2.5 mA at 0.80 VDC).
Input Load (Gate and Clock): ±10 µA, TTL/CMOS compatible.
Input Clock Frequency: 10 MHz max.
Active Count Edge: Negative edge.
Clock Pulse Width: 30 nSec high / 50 nSec low min.

Interrupts

Level: Jumper selectable, levels 2-7.
Enable/Disable: Via software. (INTE bit of Control Register. Service routines should acknowledge and re-enable interrupts.)
Source: External, positive edge triggered.

Environmental

Operating Temperature Range: 0° to 60°C.
Storage Temperature Range: -40° to +100°C.
Humidity: 0 to 95% RH, non-condensing.

Power Required

+5 VDC at 180 mA max.
+12 VDC at 500 mA max.

Size

9.0 inches long. (229mm)
Requires full-size slot.

Regulatory Compliance

Declaration of Conformity, and Test Reports are on file. Users must use appropriate shielded cables.

Part Number Price(USD)
AD12-8G 325.00

View / Download Manual (in .PDF format)