7B32

Rev. 0 | Page 2 of 8

GENERAL DESCRIPTION

The 7B32 is a single-channel signal conditioning module that

interfaces, amplifies and filters a process-current input and

provides a protected precision output voltage of either +1V to

+5 V or 0 V to +10 V. Process-current input signals are

measured by reading the voltage across an internal 200Ω

protected resistor. Model 7B32 features a nonlinearity of +0.02%

maximum and an accuracy of +0.1% maximum (+0.01%

typical). To accurately measure low level signals in electrically

noisy environments, 1500 V rms of galvanic transformer-based

isolation with a common mode rejection (CMR) of 105 dB @

50/60 Hz is provided. Rated to operate with a nominal +24

VDC supply, Model 7B32 is mix-and-match and hot-swappable

with other 7B Series input modules, so it can be inserted or

removed from any socket in the same backplane without

disturbing system power.

The floating current input of Model 7B32 is fully protected up

to 120 V rms line voltage. A one-pole 100 Hz filter

preconditions the voltage signal across the 200W protected

input resistor prior to amplification by a low drift amplifier.

Amplitude modulation is used to implement transformer

isolation(1500 V rms input-to-output and power). Isolated

front-end circuitry power is supplied by a DC/DC converter.

The output section contains a two-pole low pass filter (-3 dB @

100 Hz), a buffer amplifier and a power oscillator. The two-pole

output filter and subsequent buffer ensures that a low noise, low

impedance (<1Ω) signal is available at the output to drive loads

to 2 kΩ minimum

Figure 2