RNRLOGDEVICES fRX-ON-DEHRND HOTLINE
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-. ANALOG
W DEVICES
I
HighPerfonnance,Isolated
Voltage-to-CurrentConverter
. 2822 I
FEATURES
WideInput Range: 0 to +1Vto 0 to +10V
..~tandard Output Range:4 to 2OmA
HighCMVInput/Output Isolation: 1500Vde Continuous
Low Nonlinearity: 0.05%max, 2B22L
LowSpan Drift: o.OO5%fCmax, 2B22L
SingleSupply: +14V to +32V
MeetsIEEESui 472: Transient Protection (SWC)
MeetsISAS1II60.1: Isolated Current Loop Transmitters
APPLICATIONS
Industrial Instrumentation and ProcessControl
Ground Loop Elimination
HighVoltageTransient Protaction
D/A Convertar -Current Loop Interface
AnelogT...nsmittan and Controllers
Remote Da1aAcquisition Systems
GENERAL DESCRIPTION
Model 2B22 is a high performance, compact voltagc-to-cur-
rent converter offering 1500Y dc input to output isolation in
interfacing standard process signals. The input stage of the
model 2B22 is single resistor programmable to accept voltage
ranges from 0 to +lV to 0 to +10Y. The isolated output cur-
rent range is 4 to 20mA, and the 2B22 can be operated with
0 to 100011 grounded or floating loads.
Using modulation techniques with transformer isolation for
reliable performance, the 2B22 is available in three accuracy
selections offering guaranteed nonlinearity error (2B22L:
fO.OS%max, 2B22K: :to. 1%max, and 2822J: :to.2% max)
and guaranteed low span drift: :i:O.OOS%/oCmax, :to.Ol %tc
max, and :to.01S%I'C max, respectively. The internally trim-
med span and offset errors are :to.1% max for the 2822L and
:to.2S" max for the 2B22}/2B22K. Both span and offset are
adjustable by the optional external potentiometers.
Featuring a wide ransc. single supply operation (+14Y to
+32Y), the 2B22 provides isolated +28Y loop power and is
capable of delivering rated current into an external 0 to 100011
load resistance. The unique output stage configuration also al-
lows the user to urilize an optional cxremalloop power supply
to interface systems desjgncd for a two-wire operation.
APPUCATIONS
Model 2B22 has been specifically designed for high accuracy
applications in process control and monitoring systems to offer
compkte galvanic isolation and protection against damage
from transientS and fault voltages in transmitting information
between subsystems or $Cparated system clementS. The 2B22
FUNCTIONAL BLOCK DIAGRAM
RE' OUT
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meets the requirements of the Instrument Society of America
Std. 50.1 "Compatibility of Analog Signals for Electronic
Industrial Process InstrumentS" for Type 4, Class U isolated
current loop transmitters.
In the industrial environment, model 2B22 can serve as a
transmission link between such system elements as transmit-
ters, indicators, controllers, recorders, computers, actuators
and signal conditioners. In data acquisition and control sys-
tems, the 2822 may act as an isolated interface between the
D/A converter output of a microcomputer and standard 4 to
'2OmA analog loops.
DESIGN FEATURES AND USER BENEFITS
High Reliability: Model 2B22 is a conservatively designed,
compact module capable of reliable operation in harsh
environments. To assure high reliability, the 2822 has a
calculated MT8F of over 270,000 hours and has been de-
signed to meet the IEEE Standard for Transient Voltage
Protection (472-1974: Surge Withstand Capability).
Process Signal Compatibility: The versatile input stage design
with a single resistor gain adjustment enables the 2822 to ac-
cept anyone of tbe standard inputs-o-IV. O-IOY, 1-5Y; or
I-SmA,4-20mA, la-SOmA; and provide standard, isolated
4-20mA output.
Isolated Loop Power. Internal28Y dc loop supply, completely
isolated from the input power terminals (:t1500V dc isolation),
provides the capability to drive 0 to 1000111oads and elimi-
nates the need for an external dc/dc converter.
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OBSOLETE
