TPS659037: Current monitoring using GPADC ch11

Shota Mago

Expert 8130 points

Part Number: TPS659037
Other Parts Discussed in Thread: AM5728, INA260

Hi team,

My customer considers to use TPS659037 for powering AM5728 and provided a question.

He measured IL of SMPS12 by using internal GPADC ch11 and result was as follows.

GPADC_SW_CONV0_LSB->0x17

GPADC_SW_CONV0_MSB->0x03

Then he calculated IL in accordance with eq(1) in the datasheet with substituting following values and its result was 225mA.

・Ifs0=3.958A

・Ios0=0.652A

・K=2

・GPADC code = 0x317

Meanwhile, he measured IL of SMPS12 by using external INA260 and it showed 1073mA.

What is the cause of this contradiction?

Best regards,

Shota Mago

over 5 years ago

0 Layne J over 5 years ago

TI__Genius 12735 points

Hi Mago-san,

The expert for this part is currently out of office and will return tomorrow. I will reach out with an answer tomorrow.

Best regards,

Layne J

0 Layne J over 5 years ago in reply to Layne J

TI__Genius 12735 points

Hi Mago-san,

Has the GPADC been calibrated before this measurement? This document contains a section about calibrating the GPADC to correct for any offset and/or gain error. Please attempt this calibration and let me know what the result is.

Best regards,

Layne J

0 Shota Mago over 5 years ago in reply to Layne J

TI__Expert 8130 points

Hi Layne-san

Thanks for your reply.

I will ask customer to try the calibration.

Just FYI, this post is follow up for below question.

https://e2e.ti.com/support/power-management/f/196/t/704363

Best regards,
Shota Mago

0 Layne J over 5 years ago in reply to Shota Mago

TI__Genius 12735 points

Hi Mago-san,

I am going to close this thread now. If you have any further questions feel free to create another thread.

Best regards,

Layne J

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TPS659037: Current monitoring using GPADC ch11