The calibration ad4111

Hi, 

Can you read back the gain calibration register? For example readback the gain register before calibration and then read it back again after performing calibration to ensure that it is calibrated properly. 

Based from your previous post the error increases with the input voltage so it seems a gain error to me. But we need to confirm that, can you also share how to convert codes to voltage? I'm just confused with the above code and the voltage value. 

Thanks,

Jellenie

The values that I read back haven't changed,It should be a calibration error.

write ADCMODE_REG:0x8140

write ADCMODE_REG:0x8150

Isn't that right?

Hi, 

Apologies. I'm expecting that you will provide the 24 bit gain register value. Writing 0x8150 will initiate gain calibration, so before writing that just read first the default gain calibration register to see the default value and then after writing 0x8150 then read again the gain register to see if it was updated. Please make sure that the calibration was completed before accessing the gain register. Treat calibration as conversion, once the RDY signal goes low this means that calibration is completed and the ADC will revert to standby mode. 

Thanks,

Jellenie

delay 1ms...

delay 1ms...

Hi, 

The default gain register is 0x5XXXX0. Can you explain the attached scope shot please? 

To read the gain 0 register for example (i.e. if you are using Setup0). You have to write 0x38 to the communication register and then apply 24SCLKs for your gain register data. Here's the steps that will guide you through. 

1. Upon power up, read the gain0 register by writing 0x38 and then followed by 24SCLKs for the DOUT data. 

2. Configure the other device registers, (i.e. Channel0, Setup0, IF mode, etc.). Please make sure that you only enable one channel prior performing calibration. 

3. Perform internal gain calibration, by writing to the ADCMODE register. Please make sure that you enable internal reference in case that internal reference is your selected reference voltage. Wait for the RDY signal (you can either poll the ADC status register or monitor the DRDY pin with /CS low).

4. Once RDY signal goes low. Try to read again the gain0 register. See if it is different with the reading in step1. 

Regards,

Jellenie

OK, what you have said is clear. I will try later. Thank you.

Yes please. And if you see some issues just let me know. 

Thanks,

Jellenie

i have the same issues and hope you could help me.

When i read the default value of the offset and gain registers，i got the following two 24bit data: 0x008000（offset register），0x005A63（gain register）.

but the datasheet says the default values are: 0x800000 and 0x5XXXXX.

Thank you.

Hi, 

First, I would recommend next time to create a new related question shown below instead of commenting to an old thread. This will ensure that your question will be seen and responded in a timely manner. 

With regards to your question, can you share your full default register map settings readings? Is it only reading the gain and offset registers that have an issue? 

Can you also share a scope shot of your interface?

Thanks,

Jellenie

Hi, 

First, I would recommend next time to create a new related question shown below instead of commenting to an old thread. This will ensure that your question will be seen and responded in a timely manner. 

With regards to your question, can you share your full default register map settings readings? Is it only reading the gain and offset registers that have an issue? 

Can you also share a scope shot of your interface?

Thanks,

Jellenie