3B39_15 Datasheet, PDF (2/8 Pages) Analog Devices – Isolated Process Current Output

GENERAL DESCRIPTION
The 3B39 is a single-channel signal conditioning current output
module that interfaces, isolates and filters a 0 to +10V or -10V
to +10V input signal and provides an isolated process current
output across loads of 0 to 850Ω. The output current appears at
the 3B Series backplane current output screw terminal block. It
is intended for high-accuracy process control and monitoring
applications requiring complete galvanic isolation and
protection against damage from transients and faults between
systems or separated system elements. Either of the two input
voltage ranges can be converted to either of the two output
current ranges via programming jumpers provided on the
bottom of the module. Model 3B39 features a nonlinearity of
+0.01% and an accuracy of +0.1%. Providing +1500V peak of
galvanic transformer based isolation output-to-input and power,
the 3B39 offers a common mode rejection (CMR) of 90 dB @
50/60 Hz to preserve the integrity of low level signals in noisy
environments. The 3B39 is mix-and-match and hot-swappable
with other 3B Series modules, so it can be inserted or removed
from any socket in the same backplane without disturbing
system power.
Signal isolation by transformer coupling uses a proprietary
3B39
modulation technique for linear, stable and reliable
performance. A demodulator on the output side of the signal
transformer recovers the original signal, which is then filtered
and converted to an accurate current output by a current (V-to-
I) converter output stage. Output protection enables the 3B39 to
withstand accidental connection to 220V rms power lines
without damage, isolating computer-side circuitry. The 3B39
provides total ground isolation and transient protection when
interfacing DACs to standard 4-20 mA current loops, common
requirement in microcomputer based control system.
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