DAS1151_15 Datasheet, PDF (1/4 Pages) Analog Devices – LOW LEVEL INPUT 12 BIT DATA ACQUISITION MODULES

-.. ANALOG
W DEVICES
LowLevelInput,12-Bit
DataAcquisitionModules
PRELIMINARY TECHNICAL DATA
FEATURES
DAS1150
Resistor-ProgrammableGain (1 =1000V!V)
High Accuracy with Low Level Input Signals
Low Cost
High Throughput Rate and High Gain
OBSOLETE DAS1151
Software-Programmable Gain (1, 2, 4, 8V!V)
Provides Gain for Signal Conditioning and High
Throughput Rate
Gain Ratio Error: :1:0.02%FS max
GENERAL DESCRIPTION
The DAS1150 and DAS1151 are two data acquisition modules
designed, built and tested to meet system data acquisition re-
quirements. Each device comprises an instrumentation ampli-
fier, sample-hold amplifier and 12-bit successive approximation
AID converter. These products are used on Analog Devices
Real Time Interface boards as data acquisition systems to
interface with microcomputer boards.
With the DAS1150 and DAS1151, users can apply gain to the
instrumentation amplifier for signal conditioning and still
achieve high speed data conversion. The difference between
to :l:10V with the DAS1150 or any of 4 input voltage ranges
with the DAS1151. The instrumentation amplifier drives a
sample-hold amplifier, whose function is to hold the selected
analog input signal at a constant level while the AID converter
is making a conversion.
The AID converter is a high speed 12-bit successive approxi-
mation device that has been designed using Analog Devices
AD562 IC DI A converter with a precision reference source, a
models is how the gain is controlled. With the DAS 1150, the
high speed comparator and successive approximation logic.
designer sets the gain from 1 to 1000 V/V with a resistor, RG.
The DAS1151 has gains of 1-2-4-8 that are software-program-
mable.
ADDRESS Ao
DESIGN FEATURES AND USER BENEFITS
ADDRESSA,
The DAS1150 and DAS1151 offer true high-speed 12-bit per-
formancewith maximum overall error at unity gain of :1:1least
significant bit (LSB). This performance is guaranteed at a
25kHz throughput rate. There is very little performance lost at'
high gains. For example, at gain of 1000, the DAS1l50 has a
throughput of 13kHz and an overall accuracy of :l:2LSB. The
DAS1151 with its software-programmable gain provides dy-
namic range expansion as well as the flexibility of using differ-
ent gain settings to accommodate different input signal levels.
The resistor-programmable-gain DAS 1150 may be used for in-
put ranges from 1OmV full scale to :l:10V full scale with very.
little loss of speed and no degradation of linearity at high gain.
THEORY OF OPERATION
'SV 0
GDRIGOITUANlD ⁰
R"'RENCE
OUT
O>FSET ADJ
SUMMING
POINT
+
CONTROl
IN
R"'RENCE
IN
BIPOlAR Df'SET
'OV"'AN
'"V SPAN
Block diagrams of the DAS 1150 and DAS 1151 are shown in
Figures 1 and 2. Analog input signals are applied to the input
Figure 1. DAS1151 Block Diagramand Pin Designations
of the instrumentation amplifier. The instrumentation ampli-
. fier is gain-programmable by the user via a resistor (DAS1150)
or TTL/CMOS logic (DAS1151). This featUre permits the user
to operate the module on any input voltage range from :l:10mV
Information furnished by Analog Devices is believed to be accurate
and reliable. However, no responsibility is assumed by Analog Devices
for its use; nor for any infringements of patents or other rights of third
parties which may result from its use. No license is granted by implica-
tion or otherwise under any patent or patent rights of Analog Devices.
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