We've been trying to test our ADC by interfacing it with a PIC32 microcontroller (PIC32MX795F512L) through the native SPI Channels.
We've connected everything as /CS mode 3 wire without busy indicator (digital side) and as the reference design with a AD4941 driver (analog side) but are unable to get anything other than a 0 result on the SDI in the microcontroller.
Vdd = 2.5V (regulated)
Vref = 5V
Vio/SDI = 3.3 V (digital logic, regulated)
SCK = SPI clock on MCU
SDO = SDI on MCU
CNV we've tried connecting it to SS on the chip or a pin controlled by us using the timing diagram in the 7982 datasheet.
Right now we have a 1V offset Sine wave in an attempt to test the chip but as mentioned before have been unsuccesful. The microcontroller is acting as a SPI master and have tested the SPI side functionality in a loopback succesfully so we know its not the microcontroller.
Any help will be MUCH appreciated.