Tool/software:
Hi,
We are working on a project that involves the PCM6140-Q1.
Unfortunately, we are experiencing a weird behavior, where the ADC would quite frequently send (from 10% to 50% of the time) extremely high values in a sporadic manner, unrelated to what kind of signal is on the input.
More precisely, the ADC would do the signal conversion and send values that are related to the input signal, but with these high values spread across the stream. High values are values where the first couple of bits are high. MSB is always high when these values appear.
- IOVDD and AVDD are running from 3V3. I can measure 1V8 on AREG and 1V5 on DREG. VREF is 2V7.
- ADC is in Target mode (ASI_CFG0 = 0x20; ASI_CFG1 = 0x02), it is getting MCLK (on GPIO1, so GPIO_CFG0 = 0xA2), FSYNC, BCLK from the MCU that receives the data.
- PWR_CFG = 0x60
- ASI_STS shows the correct ratios.
- Inputs are AC coupled, and the ADC side has around 1V5 DC voltage
- There are 4 inputs connected to the ADC in a differential manner, but only Channel 1 is enabled. Both the input and the slot 0 in TDM.
May I ask for your advice regarding the above mentioned issue?
Best regards,
Bálint Nagy
