SLVS331J December   2000  – August 2024 TPS3813

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Device Comparison Table
  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 Timing Requirements
    7. 6.7 Switching Characteristics
    8. 6.8 Dissipation Ratings
    9. 6.9 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 Input Voltage (VDD)
        1. 7.3.1.1 VDD Hysteresis
        2. 7.3.1.2 VDD Glitch Immunity
      2. 7.3.2 User-Programmable Watchdog Timer (WDI)
      3. 7.3.3 RESET Output
    4. 7.4 Device Functional Modes
      1. 7.4.1 Normal Operation (VDD > VIT)
      2. 7.4.2 Above Power-On Reset But Less Than Threshold (VPOR < VDD < VIT)
      3. 7.4.3 Below Power-On Reset (VDD < VPOR)
    5. 7.5 Programming
      1. 7.5.1 Implementing Window-Watchdog Settings
      2. 7.5.2 Programmable Window-Watchdog by Using an External Capacitor
      3. 7.5.3 Lower Boundary Calculation
      4. 7.5.4 Watchdog Software Considerations
      5. 7.5.5 Power-Up Considerations
  9. 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
    3. 8.3 Power Supply Recommendations
    4. 8.4 Layout
      1. 8.4.1 Layout Guidelines
      2. 8.4.2 Layout Example
  10. 9 Device and Documentation Support
    1. 9.1 Related Links
    2. 9.2 Receiving Notification of Documentation Updates
    3. 9.3 Support Resources
    4. 9.4 Trademarks
    5. 9.5 Electrostatic Discharge Caution
    6. 9.6 Glossary
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information

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

7.5.3 Lower Boundary Calculation

The lower boundary can be calculated based on the values given in Section 6.7. Additionally, facts must be considered to verify that the lower boundary is where it is expected. Because the internal oscillator of the window watchdog is running free, any rising edge at the WDI pin is considered at the next internal clock cycle. This happens regardless of the external source. Because the shift between internal and external clock is not known, it is best to consider the worst-case condition for calculating this value.

Table 7-4 Setting Lower Boundary Using External Cap
SELECTED OPERATION MODELOWER BOUNDARY OF FRAME
WDT = external capacitor C(ext)WDR = 0Vtboundary,max = twindow,max / 23.5
tboundary,typ = twindow,typ / 25.8
tboundary,min = twindow,min / 28.7
WDR = VDDtboundary,max = twindow,max / 51.6
tboundary,typ = twindow,typ / 64.5
tboundary,min = twindow,min / 92.7