TMP102: accuracy vs supply calculation

Dylan

Other Parts Discussed in Thread: TMP102

Hey Team,

The TMP102 is being considered for a camera design but there are some questions on how to calculate accuracy vs supply.
After reviewing the datasheet, worst-case accuracy due to temperature alone would be +/-3 C. I also know that higher supply voltage will result in lower accuracy error due to supply. On the datasheed, Tables 6.3 and 6.5, it provides a range of 1.4V to 3.6V but they don’t provide a reference VDD from where to add the 0.5C/V parameter, I am not sure how to calculate that additional accuracy error. Specifically, how to calculate accuracy at 1.8V and 3.3V Vcc.

Thanks!
Dylan Ashley

over 10 years ago

0 Guang Zhou over 10 years ago

TI__Mastermind 34240 points

Hi Dylan,

As indicated by the note at the beginning of the spec table, 3⁰C applies for the entire supply range, 1.4V to 3.6V. You don’t have to added PSR error on top of the 3⁰C.

Regard, Guang

Apps-Sensing Products

0 Dylan over 10 years ago in reply to Guang Zhou

TI__Intellectual 1255 points

Guang,
Thanks for the response. In Figure 5 (page 6 of the datasheet) the graph shows the Temp Error vs Temperature but does not state at what fixed supply voltage these measurements were taken.
Is it possible to get the same Temp Error vs Temperature graph but for the fixed voltage at 1.8V and a second graph for 3.3V ?
Thanks,
Dylan

0 Guang Zhou over 10 years ago in reply to Dylan

TI__Mastermind 34240 points

Hi Dylan,

All the typical curves were taken with 3.3V supply unless otherwise noted.

To infer the typical curve under a different supply, simply shift the curve down if going lower in supply magnitude; otherwise shift the curve up when going higher. And please note that this is not a universal rule, it applies to TMP102 because of its designed characteristics. The amount to shift is calculated like this:

The 3σ guard band curves follow the same shift.

Thank you for your interest in our device, please let us know when you have any questions, we are here to help in any way we can.

Regard, Guang

Apps-Sensing Products

0 cafain over 9 years ago in reply to Guang Zhou

Mastermind 6755 points

It is the same content should be, but to question.TMP102

During Conversion (26ms), if the Vcc is varied rapidly, does it give affect the accuracy?

For example, Vcc (3.3V) is during the conversion, if 5ms change to 1.8V (but then I go back to 3.3V).

Best regards

0 Aaron Heng over 9 years ago in reply to cafain

TI__Mastermind 37370 points

Hi Cafain,

Let me check, and get back to you.

Aaron

0 cafain over 9 years ago in reply to Aaron Heng

Mastermind 6755 points

Hi Aaron-san

We have to organize the information.
(Once again, I re-test)

When the question was more, we will inquire again.
Thank I need your help.

0 Dylan over 9 years ago in reply to Guang Zhou

TI__Intellectual 1255 points

Thanks Guang!

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TMP102: accuracy vs supply calculation