Qwhen I power up AD7367, the BUSY signal is always high and the part does not
work. I connect one RC circuit with the “range” pin and he pull up the range
pin to high and pull down low again after power up. This solution can help to
solve the power-up problem.
Whether this kind of operation is acceptable for AD7367 or not.
AI should have explained that there is a hardware reset for this device. If you
bring the two range pins and the ADDR pin high together it will reset the part.
I am not sure why we did not include the reset information on the datasheet but
it does work well. It is important to note that this reset operation is a logic
level function so the three pins must be returned to their functional state
post the reset in order for the conversions to commence.
You should hold the ADDR pin and the range pins high for 100ns to guarantee a
correct reset operation. There is no special requirements about coming out of a
reset operation, but you will need to configure the part for the correct mode
of operation and then allow at least the acquisition time for the analog input
to settle and the mux to switch before taking CS low to intiate a conversions
by taking CONVST low.