JAJSAR0B March   2007  – October 2017 LM95214

PRODUCTION DATA.  

  1. 1 特長
  2. 2 アプリケーション
  3. 3 概要
    1.     リモート1温度エラー、TA＝TD
  4. 4 改訂履歴
  5. 5 概要（続き）
  6. 6 Pin Configuration and Functions
    1.     Pin Functions
  7. 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: Temperature-to-Digital Converter
    6. 7.6 Logic Electrical Characteristics: Digital DC Characteristics
    7. 7.7 Switching Characteristics: SMBus Digital
    8. 7.8 Typical Characteristics
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Conversion Sequence
      2. 8.3.2 Power-On-Default States
      3. 8.3.3 SMBus Interface
      4. 8.3.4 Temperature Conversion Sequence
        1. 8.3.4.1 Digital Filter
      5. 8.3.5 Fault Queue
      6. 8.3.6 Temperature Data Format
      7. 8.3.7 SMBDAT Open-Drain Output
      8. 8.3.8 TCRIT1, TCRIT2, and TCRIT3 Outputs
      9. 8.3.9 TCRIT Limits and TCRIT Outputs
    4. 8.4 Device Functional Modes
      1. 8.4.1 Diode Fault Detection
      2. 8.4.2 Communicating With the LM95214
      3. 8.4.3 Serial Interface Reset
      4. 8.4.4 One-Shot Conversion
    5. 8.5 Register Maps
      1. 8.5.1 LM95214 Registers
        1. 8.5.1.1 Value Registers
          1. 8.5.1.1.1 Local Value Registers
          2. 8.5.1.1.2 Remote Temperature Value Registers With Signed Format
          3. 8.5.1.1.3 Remote Temperature Value Registers With Unsigned Format
        2. 8.5.1.2 Diode Configuration Register
          1. 8.5.1.2.1 Remote 1-4 Offset
        3. 8.5.1.3 Configuration Registers
          1. 8.5.1.3.1 Main Configuration Register
          2. 8.5.1.3.2 Conversion Rate Register
          3. 8.5.1.3.3 Channel Conversion Enable
          4. 8.5.1.3.4 Filter Setting
          5. 8.5.1.3.5 1-Shot
        4. 8.5.1.4 Status Registers
          1. 8.5.1.4.1 Common Status Register
          2. 8.5.1.4.2 Status 1 Register (Diode Fault)
          3. 8.5.1.4.3 Status 2 (TCRIT1)
          4. 8.5.1.4.4 Status 3 (TCRIT2)
          5. 8.5.1.4.5 Status 4 (TCRIT3)
        5. 8.5.1.5 Mask Registers
          1. 8.5.1.5.1 TCRIT1 Mask Register
          2. 8.5.1.5.2 TCRIT2 Mask Registers
          3. 8.5.1.5.3 TCRIT3 Mask Register
        6. 8.5.1.6 Limit Registers
          1. 8.5.1.6.1 Local Limit Register
          2. 8.5.1.6.2 Remote Limit Registers
          3. 8.5.1.6.3 Common Tcrit Hysteresis Register
        7. 8.5.1.7 Identification Registers
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
    3. 9.3 Diode Non-Ideality
      1. 9.3.1 Diode Non-Ideality Factor Effect on Accuracy
      2. 9.3.2 Calculating Total System Accuracy
      3. 9.3.3 Compensating for Different Non-Ideality
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12デバイスおよびドキュメントのサポート
    1. 12.1 ドキュメントの更新通知を受け取る方法
    2. 12.2 コミュニティ・リソース
    3. 12.3 商標
    4. 12.4 静電気放電に関する注意事項
    5. 12.5 Glossary
  13. 13メカニカル、パッケージ、および注文情報

パッケージ・オプション

メカニカル・データ（パッケージ｜ピン）
サーマルパッド・メカニカル・データ
発注情報

9.3.1 Diode Non-Ideality Factor Effect on Accuracy

When a transistor is connected as a diode, the following relationship holds for variables VBE, T and IF:

Equation 1. LM95214 30006132.gif

where

  • LM95214 30006133.gif
  • q = 1.6 × 10−19 Coulombs (the electron charge)
  • T = Absolute Temperature in Kelvin
  • k = 1.38 × 10−23 joules/K (Boltzmann's constant)
  • η is the non-ideality factor of the process the diode is manufactured on
  • IS = Saturation Current and is process dependent
  • If = Forward Current through the base-emitter junction
  • VBE = Base-Emitter Voltage drop

In the active region, the –1 term is negligible and may be eliminated, yielding Equation 2

Equation 2. LM95214 30006134.gif

In Equation 2,  η and IS are dependant upon the process that was used in the fabrication of the particular diode. By forcing two currents with a very controlled ratio(IF2 / IF1) and measuring the resulting voltage difference, it is possible to eliminate the IS term. Solving for the forward voltage difference yields the relationship:

Equation 3. LM95214 30006135.gif

Solving Equation 3 for temperature yields:

Equation 4. LM95214 30006136.gif

Equation 4 holds true when a diode connected transistor such as the MMBT3904 is used. When this diode equation is applied to an integrated diode such as a processor transistor with its collector tied to GND as shown in Figure 26 it will yield a wide non-ideality spread. This wide non-ideality spread is not due to true process variation but due to the fact that Equation 4 is an approximation.

Texas Instruments invented TruTherm beta cancellation technology that uses the transistor equation, Equation 5, which is a more accurate representation of the topology of the thermal diode found in some sub-micron FPGAs or processors.

Equation 5. LM95214 30006137.gif
LM95214 30006115.gifFigure 26. Thermal Diode Current Paths

TruTherm technology can be found in the LM95234 four channel remote diode sensor that is pin and register compatible with the LM95214. The LM95214 does not support this technology.