SNVSCK4B April   2024  – October 2025 TPS3842-Q1

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Device Comparison
  6. 5 Pin Configuration and Functions
  7. 6 Specification
    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 Timing Diagram
    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 SENSE Input
        1. 7.3.1.1 SENSE Hysteresis
      2. 7.3.2 Selecting the SENSE Delay Time
      3. 7.3.3 Selecting the RESET Delay Time
      4. 7.3.4 RESET Output
    4. 7.4 Device Functional Modes
      1. 7.4.1 Normal Operation (VDD > VDD(min))
      2. 7.4.2 Above Power-On Reset but Less Than VDD(min) (VPOR < VDD < VDD(min))
      3. 7.4.3 Below Power-On Reset (VDD < VPOR)
  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
        1. 8.2.2.1 Meeting the Sense and Reset Delay
      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 Device Support
    2. 9.2 Documentation Support
    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

8.2.2 Detailed Design Procedure

The TPS3842-Q1 uses high-voltage SENSE and VDD inputs to monitor a 12V battery for undervoltage. In this design example TPS3842A011DRLRQ1 is used.

The negative-going threshold voltage, VITN, is set by the device variant. In this example, the nominal supply voltage from the battery is 12V. Setting a undervoltage threshold of 5.5V (6.5V under 12V) makes sure that the device resets before supply voltage violates the allowed boundary for the DC/DC and indicates the battery is discharged. The adjustable voltage variant is chosen and R1 and R2 are adjusted to meet the threshold. Assuming R2 equal to 10kΩ and R1 is calculated as 68.5kΩ. For additional information on selecting resistor values see Section 7.3.1. TPS3842-Q1 also supports fixed voltage threshold variants. Threshold voltage decoding can be found in Section 4.