SLVA372D November   2009  – November 2022 LM2577 , LM2585 , LM2586 , LM2587 , LM2588 , LMR61428 , LMR62014 , LMR62421 , LMR64010 , TL1451A , TL5001 , TL5001A , TLV61220 , TPS40210 , TPS40211 , TPS43000 , TPS61000 , TPS61002 , TPS61005 , TPS61006 , TPS61007 , TPS61010 , TPS61012 , TPS61013 , TPS61014 , TPS61015 , TPS61016 , TPS61020 , TPS61021A , TPS61024 , TPS61025 , TPS61026 , TPS61027 , TPS61028 , TPS61029 , TPS61029-Q1 , TPS61030 , TPS61031 , TPS61032 , TPS61046 , TPS61070 , TPS61071 , TPS61072 , TPS61073 , TPS61085 , TPS61086 , TPS61087 , TPS61088 , TPS61089 , TPS61090 , TPS61091 , TPS61092 , TPS61093 , TPS61093-Q1 , TPS61097-33 , TPS61100 , TPS61107 , TPS61120 , TPS61121 , TPS61122 , TPS61130 , TPS61131 , TPS61170 , TPS61175 , TPS61175-Q1 , TPS61200 , TPS61201 , TPS61202 , TPS61220 , TPS61221 , TPS61222 , TPS61230A , TPS61235P , TPS61236P , TPS61240 , TPS61241 , TPS61253 , TPS61254 , TPS61256 , TPS61258 , TPS61259 , TPS612592 , TPS61291 , TPS65070 , TPS65072 , TPS65073 , TPS65100 , TPS65100-Q1 , TPS65101 , TPS65105 , TPS65130 , TPS65131 , TPS65131-Q1 , TPS65132 , TPS65132S , TPS65133 , TPS65137 , TPS65140 , TPS65140-Q1 , TPS65141 , TPS65142 , TPS65145 , TPS65145-Q1 , TPS65150 , TPS65150-Q1 , TPS65154 , TPS65155 , TPS65160 , TPS65160A , TPS65161 , TPS65161A , TPS65161B , TPS65162 , TPS65163 , TPS65167A , TPS65170 , TPS65175 , TPS65175B , TPS65175C , TPS65176 , TPS65177 , TPS65177A , TPS65178 , TPS65631 , TPS65631W , TPS65632 , TPS65632A , TPS65640 , TPS65642 , TPS65642A , UCC39411

 

  1.   Basic Calculation of a Boost Converter's Power Stage
  2. Basic Configuration of a Boost Converter
    1. 1.1 Necessary Parameters of the Power Stage
  3. Calculate the Maximum Switch Current
  4. Inductor Selection
  5. Rectifier Diode Selection
  6. Output Voltage Setting
  7. Input Capacitor Selection
  8. Output Capacitor Selection
  9. Equations to Calculate the Power Stage of a Boost Converter
  10. References
  11. 10Revision History

Equations to Calculate the Power Stage of a Boost Converter

Equation 14. GUID-E5175946-DD3B-4709-B10C-94A169004185-low.gif

VIN(min) = minimum input voltage
VOUT = desired output voltage
η = efficiency of the converter, e.g. estimated 85%

Equation 15. GUID-63AEFCB6-9E30-4B7F-99D9-BFBC62F6B84F-low.gif

VIN(min) = minimum input voltage
D = duty cycle calculated in Equation 14
fS = minimum switching frequency of the converter
L = selected inductor value

Equation 16. GUID-FB375935-D084-4D04-B705-68A11889AC44-low.gif

ILIM(min) = minimum value of the current limit of the integrated witch (given in the data sheet)
ΔIL = inductor ripple current calculated in Equation 15
D = duty cycle calculated in Equation 14

Equation 17. GUID-FF0619EF-D851-4DD2-84A7-83B4485F1E73-low.gif

ΔIL = inductor ripple current calculated in Equation 15
IOUT(max) = maximum output current necessary in the application
D = duty cycle calculated in Equation 14

Equation 18. GUID-FD7FB7AC-35C3-474E-AACF-BF71F0667D26-low.gif

VIN = typical input voltage
VOUT = desired output voltage
fS = minimum switching frequency of the converter
ΔIL= estimated inductor ripple current, see Equation 19

Equation 19. GUID-B1BFC618-AABB-4362-803F-4DDA244CD0DB-low.gif

ΔIL = estimated inductor ripple current
IOUT(max) = maximum output current necessary in the application

Equation 20. GUID-D7C39E59-2ADB-4AA0-BEA3-23E7DCDAA4EF-low.gif

IOUT(max) = maximum output current necessary in the application

Equation 21. GUID-0EC7D45D-F04A-4894-B574-EB618031D98B-low.gif

IF = average forward current of the rectifier diode
VF = forward voltage of the rectifier diode

Equation 22. GUID-176BBE65-249B-4B3C-8D0D-587015546D81-low.gif

IFB = feedback bias current from data sheet

Equation 23. GUID-701B36EA-DE03-4EB5-8895-F0263F577D42-low.gif
Equation 24. GUID-26686A42-1220-4116-8325-BCE16B935430-low.gif

VFB = feedback voltage from the data sheet
IR1/2 = current through the resistive divider to GND, calculated in Equation 22
VOUT = desired output voltage

Equation 25. GUID-2FB7A449-FB74-4D37-8DC8-F6F2845BCFFD-low.gif

IOUT(max) = maximum output current of the application
D = duty cycle calculated in Equation 14
fS = minimum switching frequency of the converter
ΔVOUT = desired output voltage ripple

Equation 26. GUID-4F80D4F9-9E85-4335-AE2E-554D9C3F9EDD-low.gif

ESR = equivalent series resistance of the used output capacitor
IOUT(max) = maximum output current of the application
D = duty cycle calculated in Equation 14
ΔIL = inductor ripple current from Equation 15 or Equation 19