my customer is using ADAS3022 in their project, he found crosstalk between the channels,when he added 5V signal in the channel 1, he also can read data from channel 2 which is floating, what do you think cause the problem?
To clarify: is the 5V signal applied to Ch1 a DC voltage?
What is the level of the crosstalk showing when applying the 5V signal to channel one while then reading channel 2?
you mention that ch 2 is floating - advice would be to drive a signal to both channel 1 and channel 2.
Your customer could begin by setting the input on the second channel to zero volts.
As you can see from the cross talk spec and figure 29 the test used to determine the performance was to apply -0.5dB FS signal at 10kHz to each input of the mux apart from channel 4 and measure channel 4. This gave 120dB rejection of the signals from the other channels.
Start by setting up a similar test - Ch1 apply the 5V sine wave 1kHz. Ch2 set input to ground. Read channel 2 to determine signal strength at 1kHz in FFT.
Other tips for dealing with cross talk are in coupling between amplifiers in the stage prior to the inputs to the ADC.