7B21 Analog Devices Inc, 7B21 Datasheet - Page 2

• Manufacturer Part Number: 7B21
• Manufacturer: Analog Devices Inc

Specifications of 7B21

• Lead Free Status / RoHS Status: Not Compliant

GENERAL DESCRIPTION
The 7B21 is a unity gain single-channel signal conditioning
module that interfaces, filters and isolates a +10 Volt input
signal and provides a protected precision output of +10 Volt.
Model 7B21 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 100 dB @ 50/60 Hz is
provided. Rated to operate with a nominal +24 VDC supply,
Model 7B21 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 7B21 is fully protected
up to 120 V rms line voltage. A one-pole 300 Hz filter
preconditions the input signal prior to a low drift differential
input amplifier. Amplitude modulation is used to implement
transformer isolation (1500 V rms input-to-output and power).
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Figure 2
Isolated front-end circuitry power is supplied by a DC/DC
converter. The output section contains a two-pole low pass filter
(-3 dB @ 300 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.
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7B21