Buck-Boost Converter

[Vicneesh]

Hello guys. I am a final year student doing a project on buck-boost converter with input of 9V-22V to produce output of 12V. My circuit needs to include power switching device and pwm. Any idea how can I construct my circuit on proteus to simulate? Thank you.

 

[Vbase]

You can't get what you want with one converter. There are 2 options; 1. With step up converter convert the input to say 30V and then a step down converter to 12V. 2. Step down converter to 5V and then step up to to 12V.
Option 1 is likely to be more efficient.

 

[BradtheRad]

In case this helps, here's an example drawn in another simulator:

The scope traces portray waveforms as the switch opens & closes.
Notice the output voltage is inverted polarity, a characteristic of buck-boost type.

For supply=9V duty cycle could be 65%.
For supply=22V it might be 38%.

 

[KlausST]

Hi,

Look for SEPIC.
LT has ready to buy controllers. Read the datasheets and application notes to understand the working principle.

Klaus

 

[Vicneesh]

Thank you for giving me ideas. Will attempt it and get back if there is any problem. Thank you.