Accuracy Estimate of LM20C with Single Point Calibration Over Narrow Temperature Range

Eric Lanoue

If I calibrate a LM20C sensor at T1=37°C and apply the offset to the 2^nd order transfer function, what can I say about the calculated temperature error at T2=25°C?

For the LM20C, the 2^nd order transfer function is

Vo = (–3.88 × 10–^6 × T^2) + (–1.15 × 10–^2 × T) + 1.8639 [V],

Thank you, E

over 11 years ago

0 Emmy Denton over 11 years ago

TI__Expert 4905 points

Hi Eric,

What accuracy can you calibrate the part to?

I can give you what you can typically expect but I need the calibration precision of your system. Currently we don't have data published that can give you a guarantee nor a method that you can use. We are looking at it though as this is a common request.

Take care,

0 Eric Lanoue over 11 years ago in reply to Emmy Denton

Prodigy 130 points

Hello Emmy,

With some averaging, we can get ±0.1°C.

0 Eric Lanoue over 11 years ago in reply to Emmy Denton

Prodigy 130 points

"I can give you what you can typically expect but I need the calibration precision of your system."

Do you have an a value?

0 Emmy Denton over 11 years ago in reply to Eric Lanoue

TI__Expert 4905 points

Hi Eric,

Sorry for the delay. Our characterization data shows that typically you would be within +/-0.12C at 25C after calibration at 37C. You would need to add the error of your calibration temperature to that so if you were to do an RMS sum you would get around 0.16C. Now that does not include the long term drift of the device. You would be safe in doubling the 0.12C so in reality you would get around 0.25C typical error.

Take care,

Sensors

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Accuracy Estimate of LM20C with Single Point Calibration Over Narrow Temperature Range