Precision bridge isolation amplifier composed of ISO101

As shown in the figure, this is a precision bridge isolation amplifier circuit. Bridge circuits are widely used in automatic control, detection, data acquisition and other systems to convert non-electrical quantities into electrical signals. Figure (a) shows a high-precision, high-gain bridge isolation amplifier circuit. The sensor R in the bridge can be a thermistor, photosensitive resistor or varistor, etc. The signal voltage output by the sampling bridge is a unipolar signal with a value of 0 to -10mV. This input signal is first amplified by the high-precision instrument amplifier INA101, which has a voltage amplification factor of 100. The internal circuit block diagram of INA101 is shown in Figures (b) and (c).