SLVAFP0 December   2023 LMR51610

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
  5. 2Specifications
    1. 2.1 Input Voltage Range
    2. 2.2 Output Current Range
  6. 3External Component Selection
    1. 3.1 Duty Cycle Calculation
    2. 3.2 Output Voltage Calculation
    3. 3.3 Inductor Selection
    4. 3.4 Input and Output Capacitor
    5. 3.5 Enable Level Shift
    6. 3.6 Output Clamp Diode
  7. 4Evaluation Results
    1. 4.1 Typical Performance
    2. 4.2 Loop Response Bench Verification
  8. 5Conclusion
  9. 6References
  10. 7LMR50410 Design Example
    1. 7.1 LMR50410 Output Current Range
    2. 7.2 LMR50410 Efficiency

3.2 Output Voltage Calculation

The output voltage of the LMR51610 device is same as buck design, Equation 6 is used to determine the output voltage of the converter. Choose the value of RFBB to be 22.1 kΩ. With the desired output voltage set to -12V and the VREF = 0.8 V, the RFBT value can then be calculated using Equation Equation 6. The formula yields to a value 309kΩ .

Equation 6. GUID-862CE62C-32FB-492C-9FA9-424907B33AA6-low.gif
Table 3-2 Output Voltage Set Table
VO (V) RFBT (kΩ) RFBT (kΩ)
-3.3 69.8 22.1
-5 118 22.1
-12 309 22.1
-15 392 22.1