Sensing signal 8-digit digital display drive circuit

Most measurements must ultimately display the measurement results digitally, and
circuits such as A/D converters and decoding display drivers are indispensable for this part of the task. ICM7226 and ICL7106 are A/D converters of the same type and function, and are also decoding
display drivers, but the former can display 8 digits, while the latter only has 3 digits. The circuit shown in the figure is designed using ICM7226A and AD654, and the measurement results can be displayed
in 8- digit numbers , which greatly improves the display accuracy.     AD654 is a voltage-to-frequency conversion circuit. The input terminal can be connected to the 0~1-OV analog voltage output by the sensor . After conversion by AD654, it outputs a frequency of 0~100kHz. After the frequency signal is sent to ICM7226A for processing, it is finally converted into a digital signal. The words display the measurement results.