AD12-16/16F
Analog and Digital I/O Card
FEATURES
- 16
Single-ended or eight differential inputs
- 12-bit
resolution with five input ranges
- Additional
gain setting set by resistor
- 50,000
samples/second (AD12-16)
- 100,000
samples/second with DMA(AD12-16F)
- On-board
pacer clock and counter/timers
- Two
multiplying 12-bit D/A converters
- Eight
digital I/O lines (4-in and 4-out)
- Programmable
scan rate
- Supports
DMA and interrupts
FUNCTIONAL
DESCRIPTION
The
AD12-16 and AD12-16F are multifunction high-speed analog/digital
I/O cards for use in IBM Personal Computers. They are full
length cards that can be installed in expansion slots of
IBM PC/XT/AT and compatible computers. With this card installed,
the computer can be used as a precision data acquisition
and control system or as a signal analysis instrument.
ANALOG
INPUTS
The
cards accept up to eight differential or 16 single-ended
analog input channels. Inputs are protected against over-voltages
up to ±35V and, typically, can survive static discharge
beyond 4000V. When power is off, the inputs are open-circuited
providing fail-safe operation and continue to offer overvoltage
protection up to ±20V. The channel input configuration
is switch selectable on the card providing a choice between
16 single-ended channels or eight differential channels.
In the latter case, common mode rejection ratio is a minimum
86 db and common mode voltage range is ±11V.
For
applications where negligible time skew between channel
samples is desired, AD12-16 or AD12-16F can be used in conjunction
with one or two SSH-08 Simultaneous Sample and Hold cards.
Further, if aliasing of analog input signals is a consideration,
then AD12-16 or AD12-16F can be used with one or two AAF-xx
Anti-Alias Filter cards. In this case, specify AD12-16-S02
or AD12-16F-S02.
Inputs
are amplified by a low-bias-current, fast-settle-time, high-common-mode
rejection, monolithic instrumentation amplifier with switch
selectable gains of 0.5, 1, 2, 5, and 10. Use of those gains
provides voltage ranges of 10, 5, 2, and 1 volts unipolar
and ±10, ±5, ±2.5, ±1, and ±0.5
volts bipolar. The amplifier has exceptionally low input
leakage current; 125 picoamps typical at 25°C.
Competitor designs are rated at 250 nanoamps typical! Also,
the amplifier settles to 0.01% in 4 µSec and CMRR is
90 db at 10 KHz.
In
addition, you can set up a special range by installing a
single gain-setting resistor. Gain selection is via switches
which are accessible from outside the computer through a
cutout in the mounting bracket. Thus, if a card is already
installed, the range can be changed without dismounting
the card.
AD12-16
uses an industry standard, 12-bit successive-approximation
analog-to-digital converter (A/D) with a sample and hold
amplifier input. Under ideal conditions, throughputs of
up to 50,000 conversions per second are possible. (AD12-16F
uses a faster A/D and throughputs up to 100,000 conversions
per second are possible.) A/D conversions may be initiated
in any one of three ways: (a) by software command, (b) by
on-board programmable timer, or (c) by direct external trigger.
In turn, data may be transferred to the computer by any
of three software selectable methods: (a) by program transfer,
(b) by interrupt, or (c) by direct memory access (DMA).
INPUT
SYSTEM EXPANSION
The
card can be used with up to sixteen external AIM-16P analog-input
expansion cards. (This necessitates converting some digital
inputs to digital outputs as will be described later.) Each
AIM-16P card provides capability to 16 differential inputs
and thus, there can be up to a maximum of 256 inputs per
combination of AIM-16P's and AD12-16 (or AD12-16F). The
first AIM-16P is connected to the AD12-16/16F by a CA37
cable adaptor and a flat ribbon cable and any additional
AIM-16P cards are daisy-chained to each other by ribbon
cables.
DISCRETE
DIGITAL I/O
Four
bits of TTL/CMOS-compatible digital input capability are
provided. Digital inputs IP0 and IP2 have dual uses. Input
IP0 provides an external trigger for the A/D or for Counter/Timers
1 and 2. Input IP2 provides an input to enable Counter/Timer
0. These inputs can be converted to output
ports for multiple AIM-16 applicat ions as described under
Input System Expansion. When this is done, you give up capability
for external triggering the A/D and gating Counter/Timer
0. Four bits of digital output are available with LSTTL
logic levels and 10 LSTTL load drive capability. Discrete
outputs OP0 through OP3 provide multiplexer addressing capability
for input expansion card use, as described previously, or
as separate digital outputs.
COUNTER/TIMER
The
card contains a type 8254 Counter/Timer which has three
16-bit programmable counters. Counter/ Timer 0 is enabled
by a digital input and uses either an internal 100 KHz clock
or an external clock of up to 10 MHz as selected by user
software. This Counter/Timer is not committed on the card.
It's clock, enable, and output lines are available to you
at the I/O connector. Counter/Timers 1 and 2 are concatenated
and form a 32-bit Counter/Timer for timed A/D trigger pulses
and/or for external frequency generation. The dual Counter/
Timer can be enabled by program control and clocked by a
jumper-selected 1 MHz or 10 MHz on-board crystal oscillator
source.
Counter/Timer
0 and Counter/Timers 1 and 2 can be set up for event counting,
frequency or period measurements, and pulse or waveform
generation. Also, Counter/Timers 1 and 2 can be jumper programmed
to initiate A/D conversions.
ANALOG
OUTPUT
The
card has two multiplying 12-bit digital-to-analog converters
(D/A) connected to output drivers capable of providing 5
mA current drive. Each channel provides an output of 0 to
+5 VDC if the internal -5V reference voltage is used. That
on-board reference voltage can be replaced by an external
ly supplied reference voltage (biased AC or DC) by jumper
selection. In this case, the D/A's will operate as multiplying
D/A's with two quadrant capability. The maximum external
reference voltage that can be applied is -10 volts.
If
the analog outputs are to be used for control, please specify
AD12-16-S01 rather than AD12-16. That variant includes
a modification that forces the D/A converter outputs to
zero at power-up (or whenever there is a hardware reset).
This assures that there will be no accidental output until
a computer write enables these outputs. There is no extra
charge for this modification.
If
analog outputs are not needed in your application, specify
Model AD12-16-S03 which is lower cost.
INTERRUPTS
AND DMA
Interrupts
can be initiated by completion of an A/D conversion or by
DMA terminal count if programmed by software. Interrupt
levels 2 through 7 are available. Software control of direct
memory access for transfer of A/D conversion data to the
computer is supported at either level 1 or level 3 as switch
selected.
TRANSFERRING
DATA INTO THE COMPUTER
The
cards have been designed using state-of-the-art components
to provide high data throughput using the DMA capabilities
of the computer. Direct memory access is the most satisfactory
way to transfer data from the A/D to memory at rates over
10,000 samples/second because, at this speed, program transfers
through the CPU become difficult to handle in the short
time available between conversions.
Also,
program transfers are subject to disruption by other interrupt
processes in the computer. Use of real-time triggering of
the A/D plus DMA assures synchronism in sampling that is
unaffected by other computer operations. That capability
is essential in applications such as signal analysis, fast
Fourier transform, and vibration and transient analysis
where high data rates must be sustained for short intervals
of time.
Thus,
AD12-16/16F's open I/O mapped architecture together with
three modes of data transfer (programmed via CPU, interrupt
via CPU, and DMA) provides considerable application flexibility.
REFERENCE
VOLTAGE AND POWER REQUIRED
A
-5.0V (±0.05) reference voltage is available from the
A/D reference source for external use. This reference output
can source up to 5 mA of current. The card requires only
+5 VDC and +12 VDC from the computer power supply. An on-board
DC-DC converter translates the 12 VDC to low noise, isolated
±15 VDC for the precision analog circuitry.
SPECIFICATIONS
Analog
Inputs
- Channels:
Switch selectable, 8 differential (Hi/Lo/Gnd)
or 16 single-ended.
- Resolution:
12 binary bits.
- Accuracy:
Can be calibrated to 0.01% of reading ±1
bit. At Gain 1, 2, 5, 10: 0.002% typical, 0.04%
max. w/o recalibration.
- Input
Voltage Range: Switch selectable, ±10V,
±5V, ±2.5V, ±1V, ±0.5V,
or 0-10V, 0-5V, 0-2V, 0-1V.
- Coding:
True binary for unipolar inputs and offset binary
for bipolar inputs.
- Overvoltage:
Continuous single channel, to ±35V without
damage.
- Input
Current: 1.1 nA maximum, 125 pA typical at 25°C.
-
Temp. Coefficient:Gain: ±50 PPM/°C
at gain 0.5, 1, and 10, 78 PPM/°C at gain
2, and 63 PPM/°C at gain 5.
Zero: ±27 PPM/°C maximum at
gain 10, ±107 PPM/°C maximum at gain
1.
A/D
Specification
- Type:
Successive approximation.
- Resolution:
12 binary bits.
- Conversion
Time: AD12-16: 15 uSec max., 12 µSec typical.
AD12-16F: 9.5 µSec max., 7.5 µSec
typical.
- Monotonicity:
Guaranteed over operating temperature range.
-
Linearity: ±1 bit.
- Zero
Drift: ±10 PPM/°C maximum.
- Gain
Drift: ±45 PPM/°C maximum.
- Trigger
Source: Software selectable, external trigger,
programmable timer, or program command.
Sample
and Hold Amplifier
- Acquisition
Time: 1 µSec to 0.01% typical for full
scale step input.
- Aperture
Uncertainty: 0.3 nSec typical.
- Reference
Voltage Output: -5.0 VDC ±0.05 VDC.
- Temperature
Coefficient: ±30 PPM/°C.
- Load
Drive: ±5 mA maximum.
D/A
Specification
- Channels:
2, independent.
- Type:
12-bit, double-buffered, multiplying.
-
Linearity: ±1/2 bit.
- Monotonicity:
±1/2 bit.
- Output
Ranges: 0 to +5 VDC when using the -5V reference.
May also be used with other DC or AC reference
input. Maximum output limit ±10V.
- Output
Drive: ±10 mA minimum.
- Output
Resistance: <0.1 ohm.
- Reference
Input Range: ±10V.
- Gain:
1.000, adjustable 1%.
- Settling
Time: 2 µSec to 0.01% for full scale step
input.
Digital
I/O
Inputs
Outputs
Interrupt
Channel
- Levels
2 through 7, software selectable.
- Enable:
Via INTE of Control Register. Interrupts are
latched in an internal flip-flop on the card.
The state of this flip-flop corresponds to the
INT bit in the Status Register. Service routines
should acknowledge and re-enable the interrupt
flip-flop.
Direct
Memory Access Channel
- Levels
1 or 3, switch selectable.
- Enable:
Via DMA bit of Control Register.
- Termination:
By interrupt on terminal count(or auto-initialize).
- Transfer:
Capable of 150,000 transfers per second. User
is responsible for initialization of the DMA
controller in the computer. With the DMA bit
set, double-byte requests are generated at the
end of each A/D conversion. The transfer sequence
is low byte/high byte.
Programmable
Timer
- Type:
82C54-2 programmable interval timer.
- Counters:
Three 16-bit down counters, two permanently
concatenated with 1/10 MHz clock as programmable
timer. One is uncommitted.
- Output
Drive: 2.2 mA at 0.45V (5 LSTTL loads).
- Input
Gate: TTL/DTL/CMOS compatible.
- Clock
Input Frequency: DC to 10 MHz.
- Active
Count Edge: Negative edge.
- Minimum
Clock Pulse Width: 30 nS high / 50 nS low.
- Timer
Range: 2.5 MHz to <1 pulse/hr.
Environmental
- Operating
Temperature Range: 0° to 50°C.
- Storage
Temperature Range: -20° to +70°C.
- Humidity:
0 to 90% RH, non-condensing
- Weight:
10 oz.
Power
Required
- +5
VDC at 900 mA typical.
- +12
VDC at 250 mA typical.
Regulatory
Compliance 
Declaration of Conformity, and Test Reports are on file.
Users must use appropriate shielded cables.
| Part
Number |
Price(USD)
|
| AD12-16 |
499.00
|
| AD12-16-S02 |
519.00
|
| AD12-16-S03 |
474.00
|
| AD12-16F |
519.00
|
| AD12-16F-S02 |
549.00
|
| AD12-16F-S03 |
494.00
|
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