SLUU180B January   2022  – February 2022 TPS40070 , TPS40071

 

  1.   Trademarks
  2. 1Introduction
  3. 2Description
  4. 3Schematic
    1. 3.1 Output Filter Components
    2. 3.2 MOSFET Selection
    3. 3.3 Frequency Feedforward Resistor Selection
    4. 3.4 Output Voltage Setpoint
    5. 3.5 Short Circuit Protection Resistor Selection
    6. 3.6 Miscellaneous Parts
    7. 3.7 Control Loop Compensation
  5. 4Test Setup
  6. 5Results
    1. 5.1 Control Loop Characteristics
  7. 6Assembly Drawing and PCB Layout
  8. 7List of Materials
  9. 8Reference
  10. 9Revision History

3.4 Output Voltage Setpoint

The output voltage can be easily adjusted from 1.2 V to 3.3 V by changing the value of R3 from its nominal value. Equation 4 is derived from the output voltage divider R7 and R3, and the internal reference of 0.7 V.

Equation 4. R3=(0.7 V ×R7VOUT-0.7)

The following table specifies the value of R3 for VOUT ranging from 1.2 V to 3.3 V.

VOUT R3 VALUE (Ω)
1.2 V 35.7 k
1.8 V 16.2 k
3.3 V 6.81 k