ADS8638: Temperature acquisition accuracy

Pascal Regache

Part Number: ADS8638

Tool/software:

Hello,

Referring to the previous thread, I have the exact same question and I fail to understand how figure 71 answers it.

The datasheet says the typical accuracy is 5% of FSR. There are no full scale range specified as there is no maximum temperature specifiied to and the 12-bit output code never saturates (does not reach 4095).

So I am left assuming that the max temperature is 125°C and 5% of it makes 6.25°C of typical error. Is that correct ? If not, then how can I compute the temperature acquisition accuracy ?

I also understand that the temperature LSB is 1/mREF (Vref = 2.5V) = 2.127 (temperature reading resolution). Is that correct ?

Thanks, best regards

Pascal

8 months ago

0 Tom Hendrick 8 months ago

TI__Guru**** 180981 points

Hi Pascal,

Towards the bottom of page 5 in the ADS8638 datasheet, the Temperature Range is specified as -40 to 125 - this is the range of the temperature sensor which maps to Figure 71. The span is 165 C which makes the typical error closer to 8.25°C. The error is linear, so it should be something you can calibrate. Your understanding of the Temp sensor LSB size is correct.

0 Pascal Regache 8 months ago in reply to Tom Hendrick

Prodigy 130 points

Hi Tom, thank you.

Pascal

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ADS8638: Temperature acquisition accuracy