MCU-PLUS-SDK-AM243X: Equation method to Calculate VTM temperature

Arunkumar Sundaram

Tool/software:

Hello

Due to memory limitations, we are using the equation method as described in Section 5.2.2.1.5.2.1.1 to calculate the VTM temperature instead of using the SDL_VTM_tsConvADCToTemp API in ti\sdk\sdl\vtm\v0\sdl_vtm_pvt_sensor.c. When doing so, we observed that there is notable difference in temperature values between using this equation vs SDL_VTM_tsConvADCToTemp API. After some debugging, we came to know that the equation method matches the gSDL_pvt_poly_golden table, but the API is using the gSDL_pvt_poly table that factors in some workaround.

Could you clarify whether gSDL_pvt_poly is the correct poly table to be used? If so, could you share the corresponding equation that should be used for the equation method?

Thanks

Arunkumar

11 months ago

0 Christopher Roberts 11 months ago

TI__Genius 9450 points

Arunkumar,

Apologies for the delay in response. I am looping in our SW team to review this query.

Thanks,

Chris

0 Arunkumar Sundaram 11 months ago in reply to Christopher Roberts

Prodigy 15 points

Thank you. This is blocking couple of our diagnostics; any help would be greatly appreciated.

0 Nihar Potturu 11 months ago in reply to Arunkumar Sundaram

TI__Mastermind 20376 points

Hello Arunkumar,

I am checking on this with the internally development team. on this. The concerned person is out of office this week. I will get an answer by EOD Monday next week.

Regards,

Nihar Potturu.

0 Nihar Potturu 10 months ago in reply to Nihar Potturu

TI__Mastermind 20376 points

Hello Arunkumar,

I have checked on this topic.

Arunkumar Sundaram said:
Could you clarify whether gSDL_pvt_poly is the correct poly table to be used? If so, could you share the corresponding equation that should be used for the equation method?

No, gSDL_pvt_poly_golden is the correct polynomial and even SDL has to use that. This has to be fixed in the SDL code. I have raised an internal JIRA for this issue.

Regards,

Nihar Potturu.

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MCU-PLUS-SDK-AM243X: Equation method to Calculate VTM temperature