SBOS835C May   2017  – October 2019 TMP464

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Typical Application Schematic
  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 Two-Wire Timing Requirements
    7. 6.7 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 Temperature Measurement Data
      2. 7.3.2 Series Resistance Cancellation
      3. 7.3.3 Differential Input Capacitance
      4. 7.3.4 Sensor Fault
      5. 7.3.5 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
          1. 7.5.1.4.1 Single Register Reads
          2. 7.5.1.4.2 Block Register Reads
        5. 7.5.1.5 Timeout Function
        6. 7.5.1.6 High-Speed Mode
      2. 7.5.2 TMP464 Register Reset
      3. 7.5.3 Lock Register
    6. 7.6 Register Maps
      1. 7.6.1 Register Information
        1. 7.6.1.1  Pointer Register
        2. 7.6.1.2  Local and Remote Temperature Value Registers
        3. 7.6.1.3  Software Reset Register
        4. 7.6.1.4  THERM Status Register
        5. 7.6.1.5  THERM2 Status Register
        6. 7.6.1.6  Remote Channel Open Status Register
        7. 7.6.1.7  Configuration Register
        8. 7.6.1.8  η-Factor Correction Register
        9. 7.6.1.9  Remote Temperature Offset Register
        10. 7.6.1.10 THERM Hysteresis Register
        11. 7.6.1.11 Local and Remote THERM and THERM2 Limit Registers
        12. 7.6.1.12 Block Read - Auto Increment Pointer
        13. 7.6.1.13 Lock Register
        14. 7.6.1.14 Manufacturer and Device Identification Plus Revision Registers
  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 Curve
  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 Receiving Notification of Documentation Updates
    2. 11.2 Community Resources
    3. 11.3 Trademarks
    4. 11.4 Electrostatic Discharge Caution
    5. 11.5 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

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

7.6.1.8 η-Factor Correction Register

The TMP464 device allows for a different η-factor value to be used for converting remote channel measurements to temperature for each temperature channel. There are four η-Factor Correction registers assigned: one to each of the remote input channels (addresses 41h, 49h, 51h, and 59h). Each remote channel uses sequential current excitation to extract a differential VBE voltage measurement to determine the temperature of the remote transistor. Equation 1 shows this voltage and temperature.

Equation 1. TMP464 q_vbe_bos762.gif

The value η in Equation 1 is a characteristic of the particular transistor used for the remote channel. The POR value for the TMP464 device is η = 1.008. The value in the η-Factor Correction register can be used to adjust the effective η-factor, according to Equation 2 and Equation 3.

Equation 2. TMP464 q_neff_bos686.gif
Equation 3. TMP464 q_nadjust_bos686.gif

The η-factor correction value must be stored in a two's-complement format, which yields an effective data range from –128 to +127. The POR value for each register is 0000h, which does not affect register values unless a different value is written to the register. The resolution of the η-factor register changes linearly as the code changes and has a range from 0.0004292 to 0.0005476, with an average of 0.0004848.

Table 12. η-Factor Range

NADJUST ONLY BITS 15 TO 8 IN THE REGISTER ARE SHOWN η
BINARY HEX DECIMAL
0111 1111 7F 127 0.950205
0000 1010 0A 10 1.003195
0000 1000 08 8 1.004153
0000 0110 06 6 1.005112
0000 0100 04 4 1.006073
0000 0010 02 2 1.007035
0000 0001 01 1 1.007517
0000 0000 00 0 1.008
1111 1111 FF –1 1.008483
1111 1110 FE –2 1.008966
1111 1100 FC –4 1.009935
1111 1010 FA –6 1.010905
1111 1000 F8 –8 1.011877
1111 0110 F6 –10 1.012851
1000 0000 80 –128 1.073829