Study of high-accuracy data acquisition in mixed-signal boundary scanning test system

A high-accuracy data acquisition system is required in mixed-signal boundary scanning test system. The paper illustrates one based on AD7862 to meet its demands. AD7862 collects 100 simulation signals and then stores the corresponding digital values in the RAM of STC before group sending them to serial port. Upper monitor software converts the collected digital values into instantaneous values of analog voltage signal and then shows the messages including signals' wave, frequency, maximum value, minimum value, sample rate, valid value, et al. It realizes the best perspective of analog voltage signal by controllable sampling rate. The test results show that the circuit's performance is very well and reliable. Meanwhile, it meets the requirements of the Mixed-signal boundary scanning test system.