7B21

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 7B21 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 @ 300 Hz), a buffer amplifier and a power oscillator. The two-pole output filter and subsequent buffer ensures that a low noise, low impedance (<1) signal is available at the output to drive loads to 2 k minimum.