SLVSGE8A november   2022  – june 2023 TPS35-Q1

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Revision History
  6. 5 Device Comparison
  7. 6 Pin Configuration and Functions
  8. 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
    6. 7.6 Timing Requirements
    7. 7.7 Switching Characteristics
    8. 7.8 Timing Diagrams
    9. 7.9 Typical Characteristics
  9. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagrams
    3. 8.3 Feature Description
      1. 8.3.1 Voltage Supervisor
      2. 8.3.2 Timeout Watchdog Timer
        1. 8.3.2.1 tWD Timer
        2. 8.3.2.2 Watchdog Enable Disable Operation
        3. 8.3.2.3 tSD Watchdog Start Up Delay
        4. 8.3.2.4 SET Pin Behavior
      3. 8.3.3 Manual RESET
      4. 8.3.4 RESET and WDO Output
    4. 8.4 Device Functional Modes
  10. 9 Application and Implementation
    1. 9.1 Application Information
      1. 9.1.1 CRST Delay
        1. 9.1.1.1 Factory-Programmed watchdog Timing
        2. 9.1.1.2 Adjustable Capacitor Timing
      2. 9.1.2 Watchdog Timer Functionality
        1. 9.1.2.1 Factory-Programmed watchdog Timing
        2. 9.1.2.2 Adjustable Capacitor Timings
    2. 9.2 Typical Applications
      1. 9.2.1 Design 1: Monitoring a Microcontroller Supply Voltage and Watchdog Timer
        1. 9.2.1.1 Design Requirements
        2. 9.2.1.2 Detailed Design Procedure
          1. 9.2.1.2.1 Setting the Voltage Threshold
          2. 9.2.1.2.2 Meeting the Watchdog Timeout Period
          3. 9.2.1.2.3 Setting the Reset Delay
          4. 9.2.1.2.4 Setting the Startup Delay and Output Topology
          5. 9.2.1.2.5 Calculating the RESET Pullup Resistor
  11. 10Power Supply Recommendations
  12. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  13. 12Device and Documentation Support
    1. 12.1 Receiving Notification of Documentation Updates
    2. 12.2 Support Resources
    3. 12.3 Trademarks
    4. 12.4 Electrostatic Discharge Caution
    5. 12.5 Glossary
  14. 13Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information
9.2.1.2.1 Setting the Voltage Threshold

The negative-going threshold voltage, VIT-, is set by the device variant. Equation 4 shows how to calculate the "Threshold Voltage" section of the orderable part number.

Equation 4. OPN "Threshold Voltage" number = (VIT- - 1) / 0.05

In this example, the nominal supply voltage for the microcontroller is 1.8 V. The minimum supply voltage is 10% lower than the nominal supply voltage, or 1.62 V. Setting a 1.65 V threshold ensures that the device will be reset just before the supply voltage reaches the minimum allowed. Thus a 1.65 V threshold is chosen and, using Equation 4, the part number is reduced to TPS35xx13xxxxxxxQ1. Since the hysteresis is 5% typical, the positive-going threshold voltage, VIT+, is 1.73 V.