SNVSCP5A April   2025  – August 2025 TPS7H3024-SP

PRODMIX  

  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 Quality Conformance Inspection
    8. 6.8 Typical Characteristics
  8. 7 Parameter Measurement Information
  9. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Input Voltage (IN), VLDO and REFCAP
        1. 8.3.1.1 Undervoltage Lockout (VPOR_IN < VIN < UVLO)
        2. 8.3.1.2 Power-On Reset (VIN < VPOR_IN )
      2. 8.3.2 SR_UVLO
      3. 8.3.3 SENSEx Inputs
        1. 8.3.3.1 VTH_SENSEX and VOUTx_RISE
        2. 8.3.3.2 IHYS_SENSEx and VOUTx_FALL
        3. 8.3.3.3 Input to Output Time Diagrams
        4. 8.3.3.4 Top and Bottom Resistive Divider Design Equations
      4. 8.3.4 MODE
      5. 8.3.5 Output Stages (RESETx, PWRGD, WDO, PULL_UP1 and PULL_UP2)
        1. 8.3.5.1 Push-Pull Outputs
      6. 8.3.6 WDI
      7. 8.3.7 User-Programmable TIMERS
        1. 8.3.7.1 DLY_TMR
        2. 8.3.7.2 WD_TMR
    4. 8.4 Device Functional Modes
  10. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Window Voltage Monitoring
        1. 9.2.1.1 Design Requirements
        2. 9.2.1.2 Detailed Design Procedure
          1. 9.2.1.2.1 Input Power Supplies and Decoupling Capacitors
          2. 9.2.1.2.2 SR_UVLO Threshold
          3. 9.2.1.2.3 SENSEx Thresholds
        3. 9.2.1.3 Application Curves
    3. 9.3 Power Supply Recommendations
    4. 9.4 Layout
      1. 9.4.1 Layout Guidelines
      2. 9.4.2 Layout Example
  11. 10Device and Documentation Support
    1. 10.1 Documentation Support
      1. 10.1.1 Related Documentation
    2. 10.2 Receiving Notification of Documentation Updates
    3. 10.3 Support Resources
    4. 10.4 Trademarks
    5. 10.5 Electrostatic Discharge Caution
    6. 10.6 Glossary
  12. 11Revision History
  13. 12Mechanical, Packaging, and Orderable Information
9.2.1.2.3 SENSEx Thresholds

The SENSEx inputs are used to monitor the voltage rails against system level bounds (or limits). For this design the output voltages to be monitored are:

  1. VOUT1 = 3.3V
  2. VOUT2 = 1.8V

The design VOUTx_RISE and VOUTx_FALL for each rail is specified in Table 9-2

Table 9-2 Rise and Fall Design Requirement by Channel
Channel # Channel
Type		 VOUTx_NOM (V) VONx_RISE (%) VONx_RISE (V) VONx_FALL (%) VONx_FALL (V)
1 UV 3.3 98 3.23 95 3.14
2 OV 105 3.47 102 3.37
3 UV 1.8 98 1.76 97 1.75
4 OV 103 1.85 102 1.84

Using Equation 21 and Equation 22 we can calculate the top and bottom reference resistors and select the closest resistor values using 0.1% resistor values. Table 9-3 shows the reference (or calculated) top and bottom resistors. Table 9-4 shows the selected resistors for the application.

Table 9-3 SENSEx Reference Nominal Resistors
Channel # RTOP (kΩ) RBOTTOM (kΩ)
1 4.13 0.94
2 0.86
3 0.75 0.39
4 0.36

An calculation example for channel 1 (or SENSE1) top and bottom resistor is shown below:

Equation 32. 3.23   V -   3.14   V 24   μ A   =   4.13 k Ω  
Equation 33. 4.13   k Ω × 0.60   V 3.23   V   -   0.60   V   =   0.94 k Ω
Table 9-4 SENSEx Selected Resistors Using 0.1 % Tolerance Resistors
Channel # RTOP (kΩ) RBOTTOM (kΩ)
1 4.12 0.931
2 0.866
3 0.75 0.383
4 0.357

Now that the actual resistors are known, we can calculate the actual on and off nominal voltages and the error voltages by using Equation 9, Equation 10, Equation 11, Equation 14, Equation 15, and Equation 20. Using the errors, we can calculate the upper and lower voltages and normalize the values with respect to the nominal output voltage.

Table 9-5 VOUTx_RISE Nominal Values With Statistics in Volts and Percentage
Channel # VOUTx_RISE_NOMINAL (V) VOUTx_RISE_NOMINAL(1) (%)
1 3.25 98.48
2 3.45 104.51
3 1.77 98.44
4 1.86 103.19
(1) Values are normalized to the nominal output voltage for that rail.
Table 9-6 VOUTx_FALL Nominal Values with Statistics in Volts and Percentage
Channel # VOUTx_FALL_NOMINAL (V) VOUTx_FALL_NOMINAL (%)(1)
1 3.15 95.48
2 3.35 104.51
3 1.75 98.88
4 1.84 103.19
(1) Values are normalized to the nominal output voltage for that rail.