DAS1155_15 Datasheet, PDF (1/4 Pages) Analog Devices – 14 BIT 15 BIT LOW LEVEL DATA ACQUISITION SYSTEMS

~ ANALOG
W DEVICES
14-Bit& 15-BitLowLevel
DataAcquisitioSnystems
I
DAS1155/DAS115I 6
FEATURES
Functionally Complete:
Includes Instrumentation Amplifier, Sample/Hold
Amplifier, and Analog to Digital Converter
Differential Nonlinearity: :to.OO2% FSR max (DAS1156)
Guaranteed Nonlinearity: :to.OO5% FSR (DAS1155)
:to.OO3% FSR (DA~1156)
High Common Mode Rejection: -BOdB (up to 500Hz)
High Feedthrough Rejection: - 96dB
Resistor Programmable Gain: 1VN to 1000VN
OBSOLETE ^{Byte Selectable Tri-State Buffer Outputs}
Internal Gain and Offset Potentiometers
APPLICATIONS
low level High Accuracy Data Acquisition Systems
Process Control
Nuclear Instrumentation
Automated Test Equipment
Medical Instrumentation
GENERAL DESCRIPTION
The OAS1l55/OAS1l56 are 14-/15-bitlow level data acquisition
systems having a minimum throughput rate of 25kHz/20kHz.
These data acquisition systems provide high accuracy, high
stability, and functional completeness all in a 2" x 4" x 0.44"
metal case.
Guaranteed high accuracy system performance such as nonlinearity
of ::,::0.005%FSR (OAS1155)/::,::0.003% FSR (01\51156) and
mance and small size. Incorporated in these devices are a gain
programmable instrumentation amplifier, precision sample/hold
amplifier, high accuracy 14-/15-bit analog to digital converter,
tri-state output buffers, gain and offset trim potentiometers, and
power supply bypass capacitors (as shown in Figure 1).
Unipolar coding is provided for true binary format with bipolar
coding displayed in offset binary or two's complement. Tri-state
buffers are available for easy interface to bus structured applica-
tions.
differential nonlinearity of ::,::0.003%FSR (OA51155)/::,::0.002%
OPERATION
FSR (OASI156) are provided. Guaranteed stability such as
The OASl155/0A51156 are designed, built, and tested to meet
differential nonlinearity T.e. of ::':2:ppm/oC maximum, offset
system data acquisition requirements. These units can significantly
T.e. of ::'::(1 + SO/G) f-lV/oC(RTI) and gain T.e. (RT!) of
reduce design and debug time by providing, in one package, all
::':1: 6ppm/oC are also provided by the OAS1155/OAS1156.
of the circuitry necessary for low level data acquisition and
Each OAS1155/0AS1156 makes extensive use of both integrated
microprocessor bus interface.
circuit and thin-film components to obtain its excellent perfor-
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For operation, the only connections necessary to the OAS1155/
DA51156 are the::,:: 15V and + 5V power supplies, analog input
signal, trigger pulse, and the HI-ENABLE/LO-ENABLE tri-state
controls. Digital output programming is user selectable via
III
external jumper connections.
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Figure 1. DAS1155/DAS1156 Block Diagram
ANALOG INPUT SECTION
The analog input section consists of a true differential instru-
mentation amplifier used to obtain high accuracy measurements
in the presence of noise (as shown in Figure 2). It also provides
input impedance of (lOOM!!) and high common mode rejection
of (- 80dB). User selectable gain of IVN to 1O00VN via an
external resistor enables either low level or high level full scale
ranges to be applied to the input (+ lOmV to + lOV unipolar,
::':S: mV to :: SV bipolar) with gain dctcrmincd by thc following
formula:
20k
GAI~ = I ...
( R(, )
--
- - _{DATA ACQUISITION SU8§YSTEA!§ YOi-.. '115-17 - --}