SBVS419B March   2022  – March 2026 TPS3760-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 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
  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 Undervoltage Lockout (VPOR < VDD < UVLO)
        2. 7.3.1.2 Power-On Reset (VDD < VPOR )
      2. 7.3.2 SENSE
        1. 7.3.2.1 SENSE Hysteresis
      3. 7.3.3 Output Logic Configurations
        1. 7.3.3.1 Open-Drain
        2. 7.3.3.2 Push-Pull
        3. 7.3.3.3 Active-High (RESET)
        4. 7.3.3.4 Active-Low (RESET)
      4. 7.3.4 User-Programmable Reset Time Delay
        1. 7.3.4.1 Reset Time Delay Configuration
      5. 7.3.5 User-Programmable Sense Delay
        1. 7.3.5.1 Sense Time Delay Configuration
      6. 7.3.6 Manual RESET (CTR / MR) Input
      7. 7.3.7 RESET Latch Mode
    4. 7.4 Device Functional Modes
  9. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Adjustable Voltage Thresholds
    3. 8.3 Typical Application
      1. 8.3.1 Design 1: Off-Battery Monitoring
        1. 8.3.1.1 Design Requirements
        2. 8.3.1.2 Detailed Design Procedure
        3. 8.3.1.3 Application Curves
    4. 8.4 Power Supply Recommendations
      1. 8.4.1 Power Dissipation and Device Operation
    5. 8.5 Layout
      1. 8.5.1 Layout Guidelines
      2. 8.5.2 Layout Example
      3. 8.5.3 Creepage Distance
  10. 9 Device and Documentation Support
    1. 9.1 Device Nomenclature
    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

8.2 Adjustable Voltage Thresholds

Equation 7 illustrates an example of how to adjust the voltage threshold with external resistor dividers. The resistors can be calculated depending on the desired voltage threshold and device part number. TI recommends using the 0.8V voltage threshold device when using an adjustable voltage variant. This variant bypasses the internal resistor ladder.

For example, consider a 12V rail being monitored VMON for undervoltage (UV) using of the TPS3760A012DYYRQ1 variant. Using Equation 7 and shown in Equation 8, R1 is the top resistor of the resistor divider that is between VMON and VSENSE, R2 is the bottom resistor that is between VSENSE and GND, VMON is the voltage rail that is being monitored and VSENSE is the input threshold voltage. The monitored UV threshold, denoted as VMON-, where the device will assert a reset signal occurs when VSENSE = VIT-(UV) or, for this example, VMON- = 10.8V which is 90% from 12V. Using Equation 7 and assuming R2 = 10kΩ , R1 can be calculated shown in Equation 8 where IR1 is represented in Equation 9:

Equation 7. VSENSE = VMON- × (R2 ÷ (R1 + R2))
Equation 8. R1 = (VMON- - VSENSE) ÷ IR1
Equation 9. IR1 = IR2 = VSENSE ÷ R2

Substituting Equation 9 into Equation 8 and solving for R1 in Equation 7, R1 = 125kΩ. The TPS3760A012DYYRQ1 is typically meant to monitor a 0.8V rail with ±2% voltage threshold hysteresis. For the reset signal to become deasserted, VMON would need to go above VIT- + VHYS. For this example,
VMON = 11.016V when the reset signal becomes deasserted.

There are inaccuracies that must be taken into consideration while adjusting voltage thresholds. Aside from the tolerance of the resistor divider, there is an internal resistance of the SENSE pin that may affect the accuracy of the resistor divider. Although expected to be very high impedance, users are recommended to calculate the values for the design specifications. The internal SENSE resistance RSENSE can be calculated by the SENSE voltage VSENSE divided by the SENSE current ISENSE as shown in Equation 11. VSENSE can be calculated using Equation 7 depending on the resistor divider and monitored voltage. ISENSE can be calculated using Equation 10.

Equation 10. ISENSE = [(VMON - VSENSE) ÷ R1] - (VSENSE ÷ R2)
Equation 11. RSENSE = VSENSE ÷ ISENSE
TPS3760-Q1 Adjustable Voltage Threshold with External Resistor Dividers Figure 8-1 Adjustable Voltage Threshold with External Resistor Dividers