5B36

Rev. 0 | Page 2 of 8

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

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-

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..

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Figure 2