5B30 / 5B31

Rev. 0 | Page 2 of 8

GENERAL DESCRIPTION

The 5B30 and 5B31 are single-channel signal conditioning

modules that amplify, protect, filter and isolate analog input

voltages.

The 5B30 and 5B31 protect the computer side from damage due

to field-side over voltage faults. All models withstand 240V rms

at their input terminals without damage thereby shielding

computer side circuitry from field-side over voltage conditions.

In addition, 5B30 and 5B31 Series modules are mix-and-match

and hot swappable, so can be inserted or removed from any

socket in the same backplane without disrupting system power.

A chopper-stabilized input amplifier provides low drift and

stable gain. At the amplifier input, a stable, laser-trimmed zero-

scale input voltage is subtracted from the input signal to set the

zero scale value. For user convenience, the zero can be

optionally factory-set to meet custom needs. This allows

suppression of a zero-scale input value many times larger that

the total span for precise expanded-scale measurements.

Internal multi-pole low-pass filtering with a four-Hz cutoff (-

3dB) enhances normal-mode (noise on signal) and common-

mode (nosie on signal return) rejection at 50/60 Hz, enabling

accurate measurement of small signals in high electrical noise.

Signal isolation by transformer coupling uses a proprietary

modulation technique for linear, stable and reliable

performance. The differential input circuit on the field side is

fully floating, eliminating the need for any input grounding. 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. The

output common must be kept within +3 V of power common.

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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Figure2