SBAA705 August   2025 ISOTMP35-Q1

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
  5. 2ISOTMP35-Q1 Key Information for Design
    1. 2.1 Simplified Design Schematic to Sense Temperature
    2. 2.2 Temperature Transfer Table
  6. 3PWM Controller UCC28C43-Q1 Key Information for Design
    1. 3.1 UCC28C43-Q1 Internal Block Diagram
    2. 3.2 UCC28C43-Q1 Voltage Mode Setting
    3. 3.3 UCC28C43-Q1 Heating Frequency Setting
  7. 4OPA333-Q1 Key Information
  8. 5Air Heater Circuitry Design Sample
    1. 5.1 Working Mechanism Explanation
    2. 5.2 Air Heater Schematic Design
      1. 5.2.1 Working Condition
      2. 5.2.2 Design Procedure
  9. 6Typical Heater Schematic
  10. 7References

Abstract

In EV (Electric Vehicle) system, to have a better working circumstance for electronic equipment in EV cockpit at extreme low temperature condition, such as -40℃, there can be a need for a air-heater unit to meet this target, this document provides PWM heating design for this requirement. This can make heater running automatically according to ambient temperature change without MCU control. Besides ISOTMP35-Q1, such as PWM controller UCC28C43-Q1, operation amplifier OPA333-Q1 are used as well to form closed temperature control loop in this design