7b40-08-2 Analog Devices, Inc., 7b40-08-2 Datasheet - Page 2

• Manufacturer Part Number: 7b40-08-2
• Description: Isolated Voltage Or Current Input
• Manufacturer: Analog Devices, Inc.

GENERAL DESCRIPTION
The 7B40 is a single-channel signal conditioning module that
interfaces, amplifies and filters unipolar and bipolar millivolt
and voltage inputs and provides a protected precision output of
either +1 V to +5 V or 0 V to +10 V. Model 7B40 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 110 dB @50/60 Hz and a normal mode
rejection (NMR) of 100 dB @50/60 Hz are provided. Rated to
operate with a nominal +24 VDC supply, Model 7B40 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 differential input of Model 7B40 is fully protected
up to 240 V rms line voltage. A one-pole 10 KHz filter
preconditions the input signal prior to amplification by a low
drift input amplifier. Amplitude modulation is used to
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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 four-pole low
pass filter (-3 dB @ 10KHz), a buffer amplifier and a power
oscillator. The four-pole output filter and subsequent buffer
ensures that a low noise, low impedance (<1Ω) signal is
available at the output to drive loads of 2 kΩ minimum.
7B40