SBOS441I September   2009  – October 2019 TMP431 , TMP432

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Typical Application Schematics
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
    1.     Pin Functions
  6. 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 Timing Requirements
    7. 6.7 Typical Characteristics
  7. 7 Parameter Measurement Information
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Temperature Measurement Data
      2. 8.3.2 Beta Compensation
      3. 8.3.3 Series Resistance Cancellation
      4. 8.3.4 Differential Input Capacitance
      5. 8.3.5 Filtering
      6. 8.3.6 Sensor Fault
      7. 8.3.7 THERM and ALERT/THERM2
    4. 8.4 Device Functional Modes
      1. 8.4.1 Shutdown Mode (SD)
      2. 8.4.2 One-Shot Mode
    5. 8.5 Programming
      1. 8.5.1  Serial Interface
      2. 8.5.2  Bus Overview
      3. 8.5.3  Timing Diagrams
      4. 8.5.4  Serial Bus Address
      5. 8.5.5  Read and Write Operations
      6. 8.5.6  Undervoltage Lockout
      7. 8.5.7  Timeout Function
      8. 8.5.8  High-Speed Mode
      9. 8.5.9  General Call Reset
      10. 8.5.10 SMBus Alert Function
    6. 8.6 Register Maps
      1. 8.6.1  Pointer Register
      2. 8.6.2  Temperature Registers
      3. 8.6.3  Limit Registers
      4. 8.6.4  Status Registers
        1. 8.6.4.1 TMP431 Status Register
        2. 8.6.4.2 TMP432 Status Register
      5. 8.6.5  Configuration Register 1
      6. 8.6.6  Configuration Register 2
      7. 8.6.7  Conversion Rate Register
      8. 8.6.8  Beta Compensation Configuration Register
      9. 8.6.9  η-Factor Correction Register
      10. 8.6.10 Software Reset
      11. 8.6.11 Consecutive Alert Register
      12. 8.6.12 Therm Hysteresis Register
      13. 8.6.13 Identification Registers
      14. 8.6.14 Open Status Register
      15. 8.6.15 Channel Mask Register
      16. 8.6.16 High Limit Status Register
      17. 8.6.17 Low Limit Status Register
      18. 8.6.18 THERM Limit Status Register
  9. 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
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Examples
  12. 12Device and Documentation Support
    1. 12.1 Related Links
    2. 12.2 Community Resources
    3. 12.3 Trademarks
    4. 12.4 Electrostatic Discharge Caution
    5. 12.5 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

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

8.6.9 η-Factor Correction Register

The TMP43x allow for a different η-factor value to be used for converting remote channel measurements to temperature. The remote channel uses sequential current excitation to extract a differential VBE voltage measurement to determine the temperature of the remote transistor. Equation 1 relates this voltage and temperature.

Equation 1. TMP431 TMP432 q_vbe_bos441.gif

The value η in Equation 1 is a characteristic of the particular transistor used for the remote channel. When the beta compensation configuration is set to 0111 (beta compensation disabled) or the sensor is diode-connected (base shorted to collector), the η-factor used by the TMP43x is 1.008. When the beta compensation configuration is set to 1000 (beta compensation enabled) and the sensor is GND collector-connected (PNP collector to ground), the η-factor used by the TMP43x is 1. If the η-factor used for the temperature conversion does not match the characteristic of the sensor, then temperature offset is observed. The value in the η-Factor Correction Register can be used to adjust the effective η-factor according to Equation 2 and Equation 3 for disabled beta compensation or a diode-connected sensor. Equation 4 and Equation 5 can be used for enabled beta compensation and a GND collector-connected sensor.

Equation 2. TMP431 TMP432 q_neff_1008_bos425.gif
Equation 3. TMP431 TMP432 q_nadjust_1008_bos425.gif
Equation 4. TMP431 TMP432 q_neff_1000_bos425.gif
Equation 5. TMP431 TMP432 q_nadjust_1000_bos425.gif

The η-correction value must be stored in twos-complement format, yielding an effective data range from –128 to 127. Table 11 shows the η-factor range for both 1.008 and 1. For the TMP431, the η-correction value can be written to and read from pointer address 18h. For the TMP432, the η-correction value can be written to and read from pointer address 27h. The η-correction value for the second remote channel is read to and written from pointer address 28h. The register power-on reset value is 00h, thus having no effect unless written to.

Table 11. η-Factor Range

NADJUST η = 1.008 η = 1.000
BINARY HEX DECIMAL
01111111 7F 127 1.747977 1.734104
00001010 0A 10 1.042759 1.034483
00001000 08 8 1.035616 1.027397
00000110 06 6 1.028571 1.020408
00000100 04 4 1.021622 1.013514
00000010 02 2 1.014765 1.006711
00000001 01 1 1.011371 1.003344
00000000 00 0 1.008 1
11111111 FF –1 1.004651 0.996678
11111110 FE –2 1.001325 0.993377
11111100 FC –4 0.994737 0.986842
11111010 FA –6 0.988235 0.980392
11111000 F8 –8 0.981818 0.974026
11110110 F6 –10 0.975484 0.967742
10000000 80 –128 0.706542 0.700935