SLVUBB4B November   2017  – February 2023

 

  1.   Abstract
  2.   Trademarks
  3. 1 Topologies Window
  4. 2 FET Losses Calculator
  5. 3 Load Step Calculator
  6. 4 Capacitor Current Sharing Calculator
  7. 5 AC/DC Bulk Capacitor Calculator
  8. 6 RCD-Snubber Calculator for Flyback Converters
  9. 7 RC-Snubber Calculator
  10. 8 Output Voltage Resistor Divider
  11. 9 Dynamic Analog Output Voltage Scaling
  12. 10Dynamic Digital Output Voltage Scaling
  13. 11Unit Converter
  14. 12Loop Calculator
    1. 12.1 Inputs
    2. 12.2 Transfer Functions
      1. 12.2.1  Output Impedance Transfer Function
      2. 12.2.2  Transfer Function VMC Buck Power Stage
      3. 12.2.3  Transfer Function CMC Buck Power Stage
      4. 12.2.4  Transfer Function CMC Boost Power Stage
      5. 12.2.5  Transfer Function CMC Inverting Buck-Boost Power Stage
      6. 12.2.6  Transfer Function CMC Forward Power Stage
      7. 12.2.7  Transfer Function CMC Flyback Power Stage
      8. 12.2.8  Transfer Function Closed Loop
        1. 12.2.8.1 Transfer Function Type II Compensation Network
        2. 12.2.8.2 Transfer Function Type II Transconductance Compensation Network
        3. 12.2.8.3 Transfer Function Type III Compensation Network
      9. 12.2.9  Transfer Function Isolated Type II Compensation Network With a Zener Clamp
      10. 12.2.10 Transfer Function Isolated Type II Compensation Network Without a Zener Clamp
  15. 13Filter Designer
    1. 13.1 Impedances
    2. 13.2 Transfer Functions
    3. 13.3 Filter Output Impedance
    4. 13.4 Damping Factor
  16. 14Additional Information
  17. 15Revision History

8 Output Voltage Resistor Divider

The Output Voltage Resistor Divider Tool calculates the closest resistor values of the chosen E-Series to match the specified output voltage based on the entered reference voltage, reference voltage tolerance, and desired resistance value. The resistance value can be entered for the high-side (HS) or the low-side (LS) resistor. It is also possible to parallel two resistors to get more precise results. The following equations calculate the resulting output voltage while respecting resistor tolerances and reference voltage tolerances. However, because effects caused by the bias current are not considered for the calculations, these values are estimates.

#T5147377-24 shows the Output Voltage Resistor Divider Calculator window.

GUID-636C2E97-AD41-4158-A4CF-4BD761C1EB8B-low.pngFigure 8-1 Output Voltage Resistor Divider Calculator Window

Effective output voltage with chosen resistance values (see #T5147377-25):

V o u t , r e a l = V r e f × R H S + R L S R L S
Equation 22. ∆ V o u t = V o u t , r e a l - V o u t V o u t

Bias current:

Equation 23. I b i a s = V o u t , r e a l R H S + R L S

Worst-case minimum output voltage:

V o u t , m i n = V r e f , m i n × R H S , m i n + R L S , m a x R L S , m a x
Equation 24. ∆ V o u t , m i n = V o u t , m i n - V o u t V o u t

Worst-case maximum output voltage:

V o u t , m a x = V r e f , m a x × R H S , m a x + R L S , m i n R L S , m i n
Equation 25. ∆ V o u t , m a x = V o u t , m a x - V o u t V o u t