topic Re: lpc553x Temperature sensor function constants in LPC Microcontrollers

lpc553x Temperature sensor function constants

podema — Thu, 23 Feb 2023 14:48:16 GMT

Hello,

I'm trying to read the temperature from the internal temperature sensor on the LPC5334.

I'm following the steps described on 47.3.7 Temperature sensor on the reference manual.

I have search throughly for the constants A (slope factor), B(offset factor) and alpha (bandgap coefficient) on the datasheet and i have not been able to find them.

Which is the value of the constants ?

Re: lpc553x Temperature sensor function constants

xiangjun_rong — Mon, 27 Feb 2023 02:09:51 GMT

Hi,

I have checked the data sheet Rev2.0 of LPC553x, it appears that the parameters(A,B, alpha) are not defined in DS.

I will ask AE team for the parameters, I will notify you after I get feedback.

Sorry for the inconvenience.

XiangJun Rong

Re: lpc553x Temperature sensor function constants

xiangjun_rong — Mon, 27 Feb 2023 02:45:36 GMT

Hi,

The temperature sensor parameters are defined in section 39.7.6 Temperature sensor in UM11424.pdf.

I copy it here:

3. An equation can be used to convert from these results into the final temperature
sensor reading: A*[alpha*(Vbe8-Vbe1)/(Vbe8 + alpha*(Vbe8-Vbe1))] - B.
4. Following Alpha, A and B values are needed to achieve +/- 4 C temperature accuracy:Alpha = 8.5, A = 804 and B = 280.

Hope it can help you

XiangJun Rong

Re: lpc553x Temperature sensor function constants

podema — Thu, 02 Mar 2023 11:01:12 GMT

After following the steps described in the user manual and using those constants i have been able to correctly read the internal temperature sensor.

Thank you very much XiangJun