5B36 AD [Analog Devices], 5B36 Datasheet - Page 2

• Manufacturer Part Number: 5B36
• Description: Isolated, Potentiometer Input
• Manufacturer: AD [Analog Devices]

GENERAL DESCRIPTION
The 5B36 is a single-channel signal conditioning module that
amplifies, isolates, filters, buffers a wide variety of three-wire
potentiometers and two-wire rheostats (slidewires). The module
provides an accurately scaled, low-noise low-impedance output
of 0 to +5V.
Accurate and Stable Performance – The 5B36 supplies
protected potentiometer / slidewire excitation from a pair of
closely matched precision current sources designed to cancel
errors due to lead resistances. A low-drift chopper-stabilized
differential amplifier allows use of a very low excitation current
to minimize error due to potentiometer self-heating. The
amplifiers low input offset drift (+0.004 Ω /
30 ppm/
range.
True Three-Port Isolation – The floating, differential input
circuit on the field side eliminates the need for any input
grounding. Signal and power isolation by transformer coupling
uses a proprietary modulation technique for linear, stable and
reliable performance. A demodulator on the computer side of
the signal transformer recovers the original signal, which is then
filtered and buffered to provide a low-noise, low-impedance
output signal. True three-port isolation (Input-Output-Power)
includes common-mode rating of : 1500V rms between input-
.
o
C assure accuracy over the full operating temperature
o
C) and gain drift of
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Figure 2
output and input-power; 250V rms between power and output
– no return path is required between the power and signal
output commons.
Filtering and Protection – An optimized five-pole Butterworth
filter (with a 4-Hz bandwidth) provides 116 dB of normal-mode
rejection (noise on signal) at 60 Hz and 108 dB at 50. Output
noise is an exceptionally low 0.3 mV pk-pk in a 100 kHz
bandwidth and 6 mV pk-pk in a 5 MHz bandwidth.
The 5B36 protects the computer side from damage due to field-
side over-voltage faults. The module withstands 240V rms at the
input terminals without damage, thereby shielding the internal
computer-side circuitry from field-side over-voltage conditions.
In addition, the 5B36 is mix-and-match and hot swappable with
all other 5B Series modules, so can be inserted or removed from
any socket in the same backplane without disrupting system
power.
A series output switch eliminates the need for external
multiplexing in many applications. The switch is turned on by
an active-low enable input. If the switch is to be on at all times,
the enable-input should be grounded to power common as it is
on the 5B01 and 5B08 backplanes..
.
5B36