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Associate II
January 8, 2025
Question

reference voltage in STM32H743 for Calibration values TSCAL2 & TSCAL1 ?

  • January 8, 2025
  • 7 replies
  • 2189 views

What is the reference voltage did ST set in STM743 micro controller for temperature sensor for acquiring the Calibrated value TSCAL2 & TSCAL1 for 130*C and 30*C. Since during factory set How do ST Know What external voltage is going to come from design side ?

 

For Example If you set reference voltage 1.2V for 130*c then How do i scale it that if i give 2.5V external voltage for Vref ? Then calibrated value i am getting from internal is different from what i am expecting so it will throw error in calculation ? How do i know the information about factory set Ref voltage for TSCAL2 and TSCAL1 for maximum and minimum temperature ?

 

Is there any application note for calculating the temperature as per the reference voltage to get to know the internal calibrated value for TSCAL2 & TSCAL1 ?

7 replies

SaranrajAuthor
Associate II
January 8, 2025

Merging of two thread for the same subject.

what is the maximum temperature did set in STM743 micro controller during factory set for TS_CAL2 Calibrated value? Is it 110*c or 130*C for maximum temperature Calibrated value ?

 

Since STM743 Production Datasheet Rev 7, Table 191 shows for 110*C but in Rev10 shows 130*c for TS_CAL2. The given memory address is same for both revisions so i will get only one data under that

 

Rev7 STM743 Reference Document RM0433 in Section 25.4.33

 

Temperature (in °C) = 110 °C – 30 °C

-------------------------- × (TS_DATA – TS_CAL1) + 30 °C

TS_CAL2 - TS_CAL1

 

Rev8 STM743 Reference Document RM0433 in Section 25.4.33

 

Temperature (in °C) = TS_CAL2_TEMP – TS_CAL1_TEMP

------------------------------------------------------- × (TS_DATA – TS_CAL1) + 30 °C

TS_CAL2 - TS_CAL1

 

so I want to know that whether it is for 110*c or 130*c for max temperature Calibrated value.

SaranrajAuthor
Associate II
January 8, 2025

What is the reference voltage for the internal temperature sensor this ti connected with internal ADC ?

 

TDK
January 8, 2025

The reference voltage for these readings is 3.3V +/- 10 mA.

TDK_3-1736349731638.png

 

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TDK
January 8, 2025

The datasheet says it's 110 C for rev Y and 130 C for rev V. Presumably, the RM was changed due to it varying between revisions.

TDK_0-1736349545534.png

 

 

TDK_1-1736349581942.png

TDK_2-1736349588169.png

 

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SaranrajAuthor
Associate II
January 9, 2025

Hi TDK,

 

 Thank You for your reply. Yes I agree with you. But in my design i am giving 2.5V externally to the Vref pin of the IC. SO will it give wrong values for calculating the temperature since internally temp sensor  it is set(Calibrated) for 3.3V ?

How do i map it for 3.3V values  to 2.5V  ? 

 

Regards

Saranraj

SaranrajAuthor
Associate II
January 9, 2025

Ok Thank you. What is the meaning of RM ?  may i Know ?

TDK
January 9, 2025

Reference Manual.

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SaranrajAuthor
Associate II
January 9, 2025

So What is the max temperature did set in for the controller for TSCAL2 during calibration? 110* c or 130*c ?

 

TDK
January 9, 2025

> So What is the max temperature did set in for the controller for TSCAL2 during calibration? 110* c or 130*c ?

As I said before:

> The datasheet says it's 110 C for rev Y and 130 C for rev V.

To find out what chip revision you have, connect to it with STM32CubeProgrammer and look in the bottom right. Typically, you will have the newer revision (V).

TDK_0-1736436644905.png

 

TDK_1-1736436801118.png

 

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SaranrajAuthor
Associate II
January 9, 2025

Hi TDK,

 

 Thank You for your reply. How do i know the revision number if my system is closed and what if its production board ???

Christian N
ST Employee
January 9, 2025

This post has been escalated to the ST Online Support Team for additional assistance. We'll contact you directly.

SaranrajAuthor
Associate II
January 22, 2025

Hi TDK,

 

  I Got it. I agree with your points. I can map the value to 2.5V. But Both Rev 7 and Rev10 ST uC Datasheet shows different temperature in Rev V ?

In Rev 10

Saranraj_0-1737545861044.png

 

In Rev 7 DS

Saranraj_1-1737545925402.png

So While doing calculation which temperature should i consider for TSCAL2 when using below formula whether is it 110* or 130*C ? Please Calrify

Saranraj_2-1737546130322.png

And Addition to this One more query ?

How to read the internal temperature sensor output value converted by ADC (TSDATA) ? ?

 

Thanks 

Saranraj

 

   

SaranrajAuthor
Associate II
January 22, 2025

Could you please tell me the memory address where ADC converted data(TSDATA) is Stored ?? How to read the ADC Converted data ? I have closed system so i am reading all the data through RS485 .

 

Regards

Saranraj

TDK
January 24, 2025

> Please Calrify

Datasheets are revised to correct information. Use the latest one.

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