Buck-boost design calculation

Thread Starter

rvicneesh

Joined Nov 15, 2016
2
Hello good day friends. I am a final year student from Malaysia currently doing a project regarding Buck-boost converter. I am using arduino uno as my pwm generator. As for the circuit design I am stuck at determining the clock frequency for the Inductor calculation. Can you help teach me on the clock frequency for my project. Thank you.
 

AlbertHall

Joined Jun 4, 2014
12,338
Probably the fastest speed the arduino can produce the PWM will be best - that needs the lowest inductor and capacitor values.
 

Kermit2

Joined Feb 5, 2010
4,162
When switching speeds get to fast overall conversion efficiency falls. As the on time gets shorter the on and off transition time becomes a larger percentage of the conduction time of the mosfets. Try to keep the on time at least 10x longer than the off to on transition time to maintain good conversion efficiency.
 

crutschow

Joined Mar 14, 2008
34,201
As Kermit2 noted, the switch's transition times are usually the limiting factor.
If you use a MOSFET for a switch, then you need to design that part of the circuit first, since MOSFETs require a high current gate drive to switch rapidly.
Once you determine what the MOSFET's switching (rise and fall) times from that, then you can determine the maximum practical switching frequency.
 
Top