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7B21 Datasheet, PDF (1/8 Pages) Analog Devices – Isolated High Level Voltage Input
Isolated High Level Voltage Input
FEATURES
Unity gain single-channel signal conditioning module that
interfaces, filters, and isolates a +10 Volt input signal.
Features a nonlinearity of +0.02% maximum and an
accuracy of +0.1% maximum.
All 7B21 series modules are mix-and-match and Hot
Swappable.
APPLICATIONS
Industrial signal conditioning
Industrial signal isolation
Industrial signal filtering
PRODUCT OVERVIEW
The 7B Series of signal conditioners feature small size, low cost
and a wide output voltage range for a variety of applications
including process control and factory-floor environments. The
single-channel 7B modules accept inputs from a range of
transducers and are fully rated over the extended -40oC to
+85oC industrial temperature range.
All 7B Series modules are rated for a nominal power supply
input of +24 VDC; and, for maximum flexibility, they will
accept supply voltages in the +14 VDC to +35 VDC range. The
input modules, with the exception of the 7B21, provide a high-
level output voltage that is factory configured for either the +1
V to +5 V or 0 V to +10 V range. The 7B21 is a unity gain,
isolated input module with an input/output range of +10V.
Output modules are available that provide either isolated
process current or isolated bipolar voltage output. Model 7B39
converts either a +1 V to +5 V input to a 4 to 20 mA output or a
0 V to +10 V input to a 0-20 mA output. The input/output
ranges of the 7B39 are factory configured. The 7B22 is a unity
gain module that provides an isolated +10V output signal. All
modules have a universal pin-out and may be readily hot-
swapped under full power without disrupting field wiring.
Each module accepts analog transducer signals and transfers
them to a process control or factory data collection system
without the inherent noise, non-linearity, drift and extraneous
voltages which frequently accompany the signals.
7B21
FUNCTIONAL BLOCK DIAGRAM
Figure 1. 7B21 Functional Block Diagram
The modules feature a maximum nonlinearity of +0.02% and
are factory calibrated to guarantee a maximum accuracy
specification of +0.1%.
The 7B Series offers up to 1500 V rms continuous common
mode voltage isolation and 120 V rms of field wiring input
protection. The power supplies necessary to drive each of the
individual module’s input circuitry are internally isolated,
enabling the 7B Series modules to offer true channel-to-channel
isolation of the input signals.
The modules directly accept analog signals from
thermocouples, RTDs, current loop powered transmitters, and
other process control signals. The 7B Series modules amplify,
linearize, isolate, protect and convert the transducer output
signals to standardized analog inputs for high-level analog I/O
subsystems. The 7B Series Subsystem consists of 19-inch rack-
compatible hardware (model AC 1363), with universal
mounting backplane and a family of plug-in (up to 16 per
backplane) input and output signal conditioning modules. Four-
, eight-, and sixteen-channel backplanes are available. Each
backplane incorporates screw terminals for easy power
connections and field wiring, and includes a 25-pin D-type
connector for interfacing the high-level single-ended voltage
outputs to the user’s equipment. Gold-plated sockets are
provided on each channel of the backplane to ensure the
reliability of each module’s electrical connection.
Rev. 0
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