SNIS241 September   2025 TMP461-EP

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Device Information
  6. 5 Pin Configuration and Functions
  7. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics
    6. 6.6 Two-Wire Timing Requirements
    7. 6.7 Timing Diagrams
    8. 6.8 Typical Characteristics
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Temperature Measurement Data
        1. 7.3.1.1 Decoding Temperature Data
      2. 7.3.2 Series Resistance Cancellation
      3. 7.3.3 Differential Input Capacitance
      4. 7.3.4 Filtering
      5. 7.3.5 Sensor Fault
      6. 7.3.6 ALERT and THERM Functions
    4. 7.4 Device Functional Modes
      1. 7.4.1 Shutdown Mode (SD)
    5. 7.5 Programming
      1. 7.5.1 Serial Interface
        1. 7.5.1.1 Bus Overview
        2. 7.5.1.2 Bus Definitions
        3. 7.5.1.3 Serial Bus Address
        4. 7.5.1.4 Read and Write Operations
        5. 7.5.1.5 Timeout Function
        6. 7.5.1.6 High-Speed Mode
      2. 7.5.2 General-Call Reset
  9. 8 Register Map
    1. 8.1 Register Information
      1. 8.1.1  Pointer Register
      2. 8.1.2  Local and Remote Temperature Registers
      3. 8.1.3  Status Register
      4. 8.1.4  Configuration Register
      5. 8.1.5  Conversion Rate Register
      6. 8.1.6  One-Shot Start Register
      7. 8.1.7  Channel Enable Register
      8. 8.1.8  Consecutive ALERT Register
      9. 8.1.9  η-Factor Correction Register
      10. 8.1.10 Remote Temperature Offset Register
      11. 8.1.11 Manufacturer Identification Register
  10. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
      3. 9.2.3 Application Curve
    3. 9.3 Power Supply Recommendations
    4. 9.4 Layout
      1. 9.4.1 Layout Guidelines
      2. 9.4.2 Layout Example
  11. 10Device and Documentation Support
    1. 10.1 Receiving Notification of Documentation Updates
    2. 10.2 Related Documentation
    3. 10.3 Support Resources
    4. 10.4 Trademarks
    5. 10.5 Electrostatic Discharge Caution
    6. 10.6 Glossary
  12. 11Revision History
  13. 12Mechanical, Packaging, and Orderable Information

Package Options

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

9.2.2 Detailed Design Procedure

The local temperature sensor inside the TMP461-EP device monitors the ambient air around the device. The thermal time constant for the TMP461-EP device is approximately 1.1 seconds. This constant implies that if the ambient air changes quickly by 100°C, then the TMP461-EP device takes approximately 5.5 seconds (that is, five thermal time constants) to settle to within 1°C of the final value. In most applications, the TMP461-EP package is in electrical, and therefore thermal, contact with the printed circuit board (PCB), as well as subjected to forced airflow. The accuracy of the measured temperature directly depends on how accurately the PCB and forced airflow temperatures represent the temperature that the TMP461-EP is measuring. Additionally, the internal power dissipation of the TMP461-EP can cause the temperature to rise above the ambient or PCB temperature. The internal power dissipated as a result of exciting the remote temperature sensor is negligible because of the small currents used. Equation 6 can be used to calculate the average conversion current for power dissipation and self-heating based on the number of conversions per second and the temperature sensor channel enabled. Equation 7 shows an example with local and remote sensor channels enabled and 16 conversions per second; see the Section 6.5 table for typical values required for these calculations. For a 3.3V supply and a conversion rate of 16 conversions per second, the TMP461-EP device dissipates 0.531mW (PDIQ = 3.3V × 161μA) when both the remote and local channels are enabled.

Equation 6. TMP461-EP
Equation 7. TMP461-EP

The temperature measurement accuracy of the TMP461-EP device depends on the remote and local temperature sensor being at the same temperature as the system point being monitored. If the temperature sensor is not in good thermal contact with the part of the system being monitored, then there is a delay between the sensor response and the system changing temperature. This delay is typically not a concern for remote temperature-sensing applications that use a substrate transistor (or a small, SOT23 transistor) placed close to the device being monitored.