ADS1261: IC being non-responsive some times after some time

Samyak Puri

Part Number: ADS1261
Other Parts Discussed in Thread: LM27762

Tool/software:

Hi,

We are in the final stage of finalizing the code for ADS1261 and it is going unresponsive after some time.

It is used in pulse conversion mode with single ended operation, with -2.5 to 2.5 power rails and internal reference. SINC1 filter and 1200 SPS.
After reading a single channel we select next channel to continue processing. The system is set to read from ADC after interrupt from DRDY pin/

During the selection of channel it fails, there is a while loop to continuously try.

while(ads1261SelectChannel(pdToChannel[current_pd]))

{

PRINTF("[ADS1261] Channel select failed .... retrying \n\r");

ads1261SendCommand(OPCODE_STOP);

ads1261SendCommand(OPCODE_RESET);

ads1261Init();

msDelay(50);

}

EnableIRQ(ADS1261_DATA_READY_IRQ);

What could be the possible reasons and a way to fix this?

Thank you and best regards
Samyak

4 months ago

0 Bryan Lizon86 4 months ago

TI__Mastermind 41771 points

Hi Samyak Puri,

Can you help us understand what is the failure mode you are seeing? Is the ADC completely unresponsive, or are you just missing conversion cycles? Can you send a RESET command to get the ADC out of this mode, or do you have to cycle the power?

-Bryan

0 Samyak Puri 4 months ago in reply to Bryan Lizon86

Prodigy 10 points

Hi Bryan,

There is a complete communication breakdown and soft RESET command does not help, a power cycle is required to recover.

Thanks
- Samyak

0 Bryan Lizon86 4 months ago in reply to Samyak Puri

TI__Mastermind 41771 points

Hi Samyak Puri,

If the ADC works fine for some time, and then randomly stops working and requires a complete power cycle to recover, then it sounds like you might have an issue with your power supply i.e. this is unlikely a code issue.

Can you provide a schematic of your system, including the power supply?

-Bryan

0 Samyak Puri 4 months ago in reply to Bryan Lizon86

Prodigy 10 points

Hi Bryan,

Here are the relevant schematics.

Thanks

Thanks
-Samyak

0 Bryan Lizon86 4 months ago in reply to Samyak Puri

TI__Mastermind 41771 points

Hi Samyak Puri,

Thanks for sharing the schematic

Is there any pattern to this behavior? You said that the ADC becomes "unresponsive after some time". Is that time consistent?

Does this issue always occur during that "while" loop?

Is the LM27762 power affected when this issue occurs? In other words, is the supply voltage to the ADC stable before and after the issue? Any indication that something went wrong with the PGOOD signal?

-Bryan

0 Samyak Puri 3 months ago in reply to Bryan Lizon86

Prodigy 10 points

Hi Bryan,

Thanks, the issue was resolved, the power supply for whole product couldn't provide enough current for stable supply with everything running,
upgrading it resolved the issue.

Thanks
-Samyak

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ADS1261: IC being non-responsive some times after some time