SBOSA41A May   2023  – September 2023 TMP4718

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Revision History
  6. 5 Device Comparison
  7. 6 Pin Configuration and Functions
  8. 7 Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 ESD Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information
    5. 7.5 Electrical Characteristics
    6. 7.6 I2C Interface Timing
    7. 7.7 Timing Diagrams
    8. 7.8 Typical Characteristics
  9. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 1.2-V Logic Compatible Inputs
      2. 8.3.2 Series Resistance Cancellation
      3. 8.3.3 Device Initialization, Resistor Decoding, and Default Temperature Conversion
      4. 8.3.4 Adjustable Default T_CRIT High-Temperature Limit
      5. 8.3.5 ALERT and T_CRIT Output
      6. 8.3.6 Fault Queue
      7. 8.3.7 Filtering
      8. 8.3.8 One-Shot Conversions
    4. 8.4 Device Functional Modes
      1. 8.4.1 Interrupt and Comparator Mode
        1. 8.4.1.1 Interrupt Mode
        2. 8.4.1.2 Comparator Mode
        3. 8.4.1.3 T_CRIT Output
      2. 8.4.2 Shutdown Mode
      3. 8.4.3 Continuous Conversion Mode
    5. 8.5 Programming
      1. 8.5.1 Temperature Data Format
      2. 8.5.2 I2C and SMBus Interface
      3. 8.5.3 Device Address
      4. 8.5.4 Bus Transactions
        1. 8.5.4.1 Writes
        2. 8.5.4.2 Reads
      5. 8.5.5 SMBus Alert Mode
    6. 8.6 Register Map
  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 Curves
    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 Documentation Support
      1. 10.1.1 Related Documentation
    2. 10.2 Receiving Notification of Documentation Updates
    3. 10.3 Support Resources
    4. 10.4 Trademarks
    5. 10.5 Electrostatic Discharge Caution
    6. 10.6 Glossary
  12. 11Mechanical, Packaging, and Orderable Information

Package Options

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

9.4.1 Layout Guidelines

Remote temperature sensing on the TMP4718 device measures very small voltages using very low currents, therefore noise at the device inputs must be minimized. Most applications using the TMP4718 have high digital content, with several clocks and logic-level transitions that create a noisy environment. The layout must adhere to the following guidelines:

  1. Place the TMP4718 device as close to the remote junction sensor as possible.
  2. Route the DP and DN traces next to each other and shield them from adjacent signals through the use of ground guard traces. If a multilayer PCB is used, bury these traces between the ground or V+ planes to shield them from extrinsic noise sources. 5-mil (0.127 mm) PCB traces are recommended.
  3. Minimize additional thermocouple junction induced offset voltage caused by copper-to-solder connections. If these junctions are used, make the same number and approximate locations of copper-to-solder connections in both the DP and DN connections to cancel any thermocouple effects.
  4. Use a 0.1-μF local bypass capacitor directly between the VDD and GND of the TMP4718 device. For optimum measurement performance, minimize filter capacitance between DP and DN to 3 nF or less. This capacitance includes any cable capacitance between the remote temperature sensor and the TMP4718 device. The external capacitor shall be placed as close to the DP and DN pin as possible.
  5. If the connection between the remote temperature sensor and the TMP4718 device is less than 8-in (20.32 cm) long, use a twisted-wire pair connection. For lengths greater than 8 inches, use a twisted, shielded pair with the shield grounded as close to the TMP4718 device as possible. Leave the remote sensor connection end of the shield wire open to avoid ground loops and 60-Hz pickup.
  6. Thoroughly clean and remove all flux residue in and around the pins of the TMP4718 device to avoid any leakage induced temperature measurement error.
  7. If series resistors are added, equal value shall be used for the DP and DN connections and the value shall not be greater than 1 kΩ. Place the resistors as closed to the DP and DN pins as possible.