SNIA042 November   2021 TMP114 , TMP126 , TMP126-Q1

 

  1.   Abstract
  2.   Trademarks
  3. 1Introduction
  4. 2Concept
  5. 3Design Considerations
    1. 3.1 Conversion Period Impact
    2. 3.2 Impact of Conversion Period Error
  6. 4Design Example
    1. 4.1 Design Requirements
    2. 4.2 Detailed Design Procedure
  7. 5Summary
  8. 6Temperature Slew Rate Warning Device List

Design Requirements

In this example a power FET driving a brushless DC motor cannot operate above 125 °C, and it is known that there is a potential issue with the FET if the temperature rises faster than 20 °C/s. This rapid change in temperature will lead to a runaway thermal condition unless the current is reduced.

The accuracy of the temperature sensor should remain within 1 °C throughout its temperature range. And the temperature sensor has a conversion period error of 15 %. A timing error of 15 % would indicate that for a given conversion period setting, the conversion period can be ±15 % of the setting.