I am currently working on a project where I need to read an analog voltage ranging from 0-5V on a PC through USB. The ADC I have chosen for this project is the AD4000, because the requirements needed are 16 bits of resolution, 1MSps, and the SPI-USB interface I am using has a max SPI clock frequency of 40 MHz.
The issue is that for the AD4000 and other SAR ADCs, it seems like CNV needs to be set to high for a certain time after 16 bits have been sent over. For the FT4222HQ chip, which uses hi-speed USB frames (125us) to communicate between the PC and the ADC, CNV could only be switched every 125 us.
Is there any way that the CNV pin of the AD4000 or any other SAR ADC that fit my requirements can be set to low for 125us, where data is sent over continuously?
I have also tried to use an ESP32, where I manually set CNV to low, read 16 bits of data, and set CNV to high. The issue is with the overhead associated with the SPI read on the ESP32, where the time between each SPI read function call is too long for the 1MSps requirement. Are there any other applications where an AD4000 can be hooked up to some digital device that can communicate via USB to PC at 1MSps?
