SBOS707B April   2014  – August 2014 TMP75C

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
  6. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 Handling Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics
    6. 6.6 Typical Characteristics
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Digital Temperature Output
      2. 7.3.2 Temperature Limits and Alert
      3. 7.3.3 Serial Interface
        1. 7.3.3.1 Bus Overview
        2. 7.3.3.2 Serial Bus Address
        3. 7.3.3.3 Writing and Reading Operation
        4. 7.3.3.4 Slave Mode Operations
          1. 7.3.3.4.1 Slave Receiver Mode:
          2. 7.3.3.4.2 Slave Transmitter Mode:
        5. 7.3.3.5 High-Speed (Hs) Mode
        6. 7.3.3.6 Timeout Function
        7. 7.3.3.7 Two-Wire Timing
        8. 7.3.3.8 Two-Wire Timing Diagrams
    4. 7.4 Device Functional Modes
      1. 7.4.1 Continuous-Conversion Mode
      2. 7.4.2 Shutdown Mode
      3. 7.4.3 One-Shot Mode
    5. 7.5 Programming
    6. 7.6 Register Map
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
      3. 8.2.3 Application Curves
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Documentation Support
      1. 11.1.1 Related Documentation
    2. 11.2 Trademarks
    3. 11.3 Electrostatic Discharge Caution
    4. 11.4 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information

8 Application and Implementation

8.1 Application Information

The TMP75C is used to measure the PCB temperature of the location it is mounted. The programmable address options allow up to eight locations on the board to be monitored on a single serial bus. Connecting the ALERT pins together and programming the temperature limit registers to desired values allows for a temperature watchdog operation of all devices, interrupting the host controller only if the temperature exceeds the limits.

8.2 Typical Application

ai_typ_app_sbos707.gifFigure 18. Temperature Monitoring of Multiple Locations on a PCB

8.2.1 Design Requirements

The TMP75C only requires pull-up resistors on SDA and ALERT, although a pull-up resistor is typically present on the SCL as well. A 0.01-μF bypass capacitor on the supply is recommended, as shown in Figure 18. The SCL, SDA, and ALERT lines can be pulled up to a supply that is equal to or higher than VS through the pull-up resistors. To configure one of eight different addresses on the bus, connect A0, A1, and A2 to either VS or GND.

8.2.2 Detailed Design Procedure

The TMP75C should be placed in close proximity to the heat source to be monitored, with a proper layout for good thermal coupling. This ensures that temperature changes are captured within the shortest possible time interval.

8.2.3 Application Curves

Figure 19 shows the step response of the TMP75C to a submersion in an oil bath of 100°C from room temperature (27°C). The time-constant, or the time for the output to reach 63% of the input step, is 1.5 seconds.

C007_SBOS706.png
Figure 19. Temperature Step Response