SBVS301B October   2016  – September 2021 TPS3850

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Pin Configuration and 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 Timing Diagrams
    8. 6.8 Typical Characteristics
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagrams
    3. 7.3 Feature Description
      1. 7.3.1 CRST
      2. 7.3.2 RESET
      3. 7.3.3 Over- and Undervoltage Fault Detection
      4. 7.3.4 Adjustable Operation Using the TPS3850H01
      5. 7.3.5 Window Watchdog
        1. 7.3.5.1 SET0 and SET1
          1. 7.3.5.1.1 Enabling the Window Watchdog
          2. 7.3.5.1.2 Disabling the Watchdog Timer When Using the CRST Capacitor
          3. 7.3.5.1.3 SET0 and SET1 During Normal Watchdog Operation
      6. 7.3.6 Window Watchdog Timer
        1. 7.3.6.1 CWD
        2. 7.3.6.2 WDI Functionality
        3. 7.3.6.3 WDO Functionality
    4. 7.4 Device Functional Modes
      1. 7.4.1 VDD is Below VPOR ( VDD < VPOR)
      2. 7.4.2 Above Power-On-Reset But Less Than UVLO (VPOR ≤ VDD < VUVLO)
      3. 7.4.3 Above UVLO But Less Than VDD (min) (VUVLO ≤ VDD < VDD (min))
      4. 7.4.4 Normal Operation (VDD ≥ VDD (min))
  8. 8 Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1 CRST Delay
        1. 8.1.1.1 Factory-Programmed Reset Delay Timing
        2. 8.1.1.2 Programmable Reset Delay-Timing
      2. 8.1.2 CWD Functionality
        1. 8.1.2.1 Factory-Programmed Timing Options
        2. 8.1.2.2 Adjustable Capacitor Timing
      3. 8.1.3 Adjustable SENSE Configuration
      4. 8.1.4 Overdrive on the SENSE Pin
    2. 8.2 Typical Applications
      1. 8.2.1 Design 1: Monitoring a 1.2-V Rail with Factory-Programmable Watchdog Timing
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
          1. 8.2.1.2.1 Monitoring the 1.2-V Rail
          2. 8.2.1.2.2 Meeting the Minimum Reset Delay
          3. 8.2.1.2.3 Setting the Watchdog Window
          4. 8.2.1.2.4 Calculating the RESET and WDO Pullup Resistor
        3. 8.2.1.3 Application Curves
      2. 8.2.2 Design 2: Using TPS3850H01 to monitor a 0.7-V Rail With an Adjustable Window Watchdog Timing
        1. 8.2.2.1 Design Requirements
        2. 8.2.2.2 Detailed Design Procedure
          1. 8.2.2.2.1 Meeting the Minimum Reset Delay
          2. 8.2.2.2.2 Setting the Window Watchdog
          3. 8.2.2.2.3 Watchdog Disabled During the Initialization Period
          4. 8.2.2.2.4 Calculating the Sense Resistor
        3. 8.2.2.3 Application Curves
  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 Device Support
      1. 11.1.1 Device Nomenclature
    2. 11.2 Documentation Support
      1. 11.2.1 Related Documentation
    3. 11.3 Receiving Notification of Documentation Updates
    4. 11.4 Support Resources
    5. 11.5 Trademarks
    6. 11.6 Electrostatic Discharge Caution
    7. 11.7 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

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

7.3.6.3 WDO Functionality

The TPS3850 features a window watchdog timer with an independent watchdog output ( WDO). The independent watchdog output provides the flexibility to flag a fault in the watchdog timing without performing an entire system reset. When RESET is not asserted (high), the WDO signal maintains normal operation. When asserted, WDO remains down for tRST. When the RESET signal is asserted (low), the WDO pin goes to a high-impedance state. When RESET is unasserted, the window watchdog timer resumes normal operation and WDO can be used again.