Our customer is evaluating AD7134 for their seismic equipment
They use power supply AVDD5,DVDD5 - 5.04V
LDOIN,AVDD1V8,DVDD1V8,IOVDD - 1.81V external.
Pin 48,49 - 1.8V
Control via SPI from the microcontroller with using a 3.3 / 1.8V level converter
After the first power-up, the ADC is controlled well and behaves as described in the Datasheet.
But after about a week, the potential of pin4 (SDI) becomes equal to 0 and the IC can't be controlled. During this the ADC is working well - there is an output signal on pin10 (DOUT0). On pin12 (ODR) there is a 374KHz signal.
I also recommended the to look at the SPI Interface Lock/Unlock section in the datasheet however they can't write any symbols to the ADC.
What they do wrong?
Are they able to read any SPI registers? ask them to try reading address 0x03 and see if they read 0x07.
Also ask them probe the Voltage levels on Pins PIN/SPI, MODE, DCLKIO,DCLKMODE and let me know.
Here it is a feedback from the engineer:
so it seems the part is set right. can you share the schematic?
is only SPI using the 3.3V to 1.8V translator? Have they tried replacing the level translator?