Part Number: ADS8678EVM-PDK
Hi
we buy an ADS8678EVM-PDK Evaluation Module from IT. we followed the "ADS8678EVM-PDK Evaluation Module user's guide" , set all jumper as default configuration describled in Table 13,except we keep J17 open for generating HVDD and HVSS using an onboard switching regulator as saying in Table 10.
100KHz sinusoidal wave is the waveform that we need to be sampled in practical application. In theory, the board has 500ksps sampling rate, which can meet the demand. But according the test results in the experiment we do not know whether our operation is wrong or whether we bought a bad board.
when we begin our test, we stick ADS8678EVM and the simple capture card together, the simple capture card connect to PC using an usb line,5V is given to ADS8678EVM on J32 using an DC power supply, using singal source(Tektronix AFG3022C) generate waveform, connet positive electrode to AIN0+, connet negetive electrode to AIN0- , at the same time, an oscilloscope is connected to the input end of the signal. we have problems during the test.
case1: signal source:20kHz - sine wave, Vp-p=9V, problem: the amplitude showing on the GUI is obviously smaller than the actual signal
case2: signal source:100kHz - sine wave, Vp-p=8.5V, problem: the amplitude showing on the GUI is obviously smaller than the actual signal, seem to be limited
case3:signal source:10kHz - square wave, Vp-p=10V, problem: the waveform is seriously distorted. It doesn't look like a square wave, but rather like a sine wave.