SLVAFJ8 may   2023 TPS7H5001-SP

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
  5. 2System Design Theory
    1. 2.1  Switching Frequency
    2. 2.2  Leading Edge Blanking
    3. 2.3  Dead Time
    4. 2.4  Enable and UVLO
    5. 2.5  Output Voltage Programing
    6. 2.6  Soft Start
    7. 2.7  Sensing Circuit
    8. 2.8  FAULT Mode
    9. 2.9  HICCUP Mode
    10. 2.10 Slope Compensation
    11. 2.11 Output Capacitance
    12. 2.12 Compensation
  6. 3Test Results
  7. 4Bill of Materials
  8. 5Schematics
  9. 6PCB Layouts
  10. 7References

2.4 Enable and UVLO

The TPS7H5001-SP EVM uses two resistors to program the controller to enable the device when VIN surpasses a user determined threshold. The two resistors are configured as a divider, with one between VIN and EN and the other between EN and AVSS. Using Equation 5, the user can calculate the value for a chosen value of . Once the resistor values are determined, Equation 6 can be used to determine the minimum startup voltage.

Equation 5. RUVLO_TOP= RUVLO_Bottom  VStart_Max  VEN_Rising_Max-1=10 V0.65 V-1= 71.9 kΩ 
Equation 6. VSTART,MIN= VEN_FALLING_MIN  RUVLO_TOP  RUVLO_BOT+1=75 kΩ 5 kΩ+1= 16 V