ADC081C027: question about ADC081C027

Jimmy Huang

Expert 2965 points

Part Number: ADC081C027

Tool/software:

Hello：

Now debug the ADC081C027 chip, connect an external 10K resistor to AIN and pull it to 3.3V for debugging:

1. Read the 0x00 register, the first two readings are 1, and the subsequent readings are both 0.

2. Set the 0x02 register to 0xe8, and then read the 0x00 register again. The read value keeps changing and the difference is significant. The values fluctuate around 246 and 56. Can you please take a look，Thanks！！！

At present, VDD is connected to 3.3V, and an external 10K resistor is connected to AIN and pulled up to 3.3V for debugging

3 months ago

0 Joel Meraz 3 months ago

TI__Expert 6620 points

Hi Jimmy,

Is this reading fluctuation observed with an external measurement device, such as an oscilloscope or multimeter?

It would also be useful to observe the actual I2C transactions that are taking place. Are you able to provide a logic capture of the I2C bus during a period of a few conversion reads?

Regards,
Joel

0 Jimmy Huang 2 months ago in reply to Joel Meraz

Expert 2965 points

Hi Joel：

As shown in the above figure, read the value of I2C through software commands

0 Joel Meraz 2 months ago in reply to Jimmy Huang

TI__Expert 6620 points

Hi Jimmy,

It's easier to take a look a the actual logic that the ADC is outputting since I don't have insight into the software's operation. Are you able to provide this so I can further debug? It would only require probing SDA and SCL.

Regards,
Joel

Data converters

Data converters forum

ADC081C027: question about ADC081C027