LMT70A: Response time

Danilo A.

Part Number: LMT70A
Other Parts Discussed in Thread: LMT70, TMP236-Q1

Hi Team,

Our customer would like to know the response time of the LMT70AYFQT. Please see the details of his inquiry below.

From the data sheet, it is not clear what is the actual temperature response time of this sensor component. Can you provide the measurement method used in the data sheet and provide a design example of how to use this sensor to accurately measure real time temperature change. Thank you.

Regards,

Danilo

over 2 years ago

0 Josh Wyatt over 2 years ago

TI__Guru* 91206 points

Danilo -

please see page 4 of the datasheet

https://www.ti.com/lit/ds/symlink/lmt70.pdf?ts=1678800015821&ref_url=https%253A%252F%252Fwww.ti.com%252Fproduct%252FLMT70

0 Danilo A. over 2 years ago in reply to Josh Wyatt

TI__Mastermind 28680 points

Hi Josh,

Thank you for your response. It seems that the customer's inquiry is about the response time of the device to send the temperature from one level to another. For example, the time it takes to reach 25C to 26C, from 30C to 50C and soon. Do we have this information?

Regards,

Danilo

0 Josh Wyatt over 2 years ago in reply to Danilo A.

TI__Guru* 91206 points

Danilo -

The LMT70 is an analog temperature sensor - the observed result would be as fast as the ADC conversions (in or connected to the MCU/MPU) were possible to be made as the temperature was changing.

0 Danilo A. over 2 years ago in reply to Josh Wyatt

TI__Mastermind 28680 points

Hi Josh,

Do we have a thermal response graph for LMT70 similar to the Figure 6-8 of the TMP236-Q1 shown below?

https://www.ti.com/lit/ds/symlink/tmp236-q1.pdf#page=7

Regards,

Danilo

0 Josh Wyatt over 2 years ago in reply to Danilo A.

TI__Guru* 91206 points

Danilo -

No, not for one degree - the datasheet EC table entries (that I referenced previously) represents same as you are requesting both for oil bath and still air.

0 Danilo A. over 2 years ago in reply to Josh Wyatt

TI__Mastermind 28680 points

Hi Josh,

After checking the forum and looking at the datasheets of other analog temperature sensors, I understand that the standard process is to measure the time it takes fo the device to reach 63% of 125C from 25C. For LMT70, it is 1.5 sec in when submerged in oil (constantly stirred) and 73 sec in still air.

https://e2e.ti.com/support/sensors-group/sensors---internal/f/sensors---internal-forum/1109569/tmp61-q1-thermal-response/4111704
https://e2e.ti.com/support/sensors-group/sensors/f/sensors-forum/1112072/tmp235-thermal-response

Thank you very much for your help.

Regards,

Danilo

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LMT70A: Response time