DC-DC converters worksheet with answers

Free printable DC-DC converters worksheet: 6 problems from easy to exam level, with an answer key. Print it or save it as a PDF.

New worksheetPractise online with hints

For teachers: free to print, copy and use in class. Every new worksheet has new values and its own answer key. A link to ExamProblems on your course page is appreciated.

Name: ____________________   Date: ____________

1.Easy
+−36 VD = ?LCR−+108 V

An ideal inverting buck-boost converter must produce −108 V from 36 V in continuous conduction. Find the duty cycle D.

Vin​ = 36 VVo​ = −108 V
D =
2.Easy
+−12 VLD = 0.2CR+−Vo​ = ?

An ideal boost converter runs from 12 V with a duty cycle D = 0.2 in continuous conduction. Find the output voltage Vo.

Vin​ = 12 VD = 0.2
Vo = V
3.Medium
tiL​Imax​Imin​ΔI = ?DTT2T

An ideal boost converter turns 9 V into 22.5 V at 40 kHz with L = 220 µH. Find the peak-to-peak inductor ripple current ΔIL.

Vin​ = 9 VVo​ = 22.5 Vf = 40 kHzL = 220 µH
ΔIL = A
4.Medium
+−48 VSL = ?CR+−12 V

An ideal buck converter turns 48 V into 12 V at a switching frequency of 25 kHz. Find the inductance L that keeps the peak-to-peak inductor ripple current at 0.6 A.

Vin​ = 48 VVo​ = 12 Vf = 25 kHzΔIL = 0.6 A
L = µH
5.Hard
tiL​Imax​IL​DTT2T

An ideal buck converter turns 36 V into 25.2 V for a 25 Ω load at 20 kHz. Find the smallest inductance Lcrit for continuous conduction.

Vin​ = 36 VVo​ = 25.2 Vf = 20 kHzR = 25 Ω
Lcrit = µH
6.Hard
tiL​Imax​Io​DTT2T

A buck converter turns 48 V into 36 V at 100 kHz with L = 10 µH. Find the smallest load current Io,min for which it stays in continuous conduction.

Vin​ = 48 VVo​ = 36 Vf = 100 kHzL = 10 µH
Io,min = A

Answer key

  1. 1. D = 0.75
  2. 2. Vo = 15 V
  3. 3. ΔIL = 0.6136 A
  4. 4. L = 600 µH
  5. 5. Lcrit = 187.5 µH
  6. 6. Io,min = 4.5 A

Full step-by-step solutions: practise this topic on examproblems.com.