BJT vs MOSFET DC-DC SMPS Circuit

Status
Not open for further replies.
A

asking

Full Member level 5
Joined
Sep 21, 2010
Messages
279
Helped
6
Reputation
12
Reaction score
6
Trophy points
1,298
Visit site
Activity points
3,377
Hello,

I have been trying to make DC-DC Buck Converter but now actually after knowing more about its complications, i would like to know how to get maximum switching frequency of any Bipolar Transistor or MOSFET ? Because in datasheet its maximum switching frequency is not written. What is Transition Frequency given in the datasheet ?

Can i use Power Transistors like TIP35C for switching DC-DC buck converter ? Because it would be easy for me to drive it using PIC Microcontroller. For MOSFET i need to use Logic Level mosfet or mosfet drivers to use with microcontroller. So Please guide me how can i know the maximum switching frequency of any BJT ? ir MOSFET ?

Thanks
 

well i think that the constraint in frequency is mainly imposed by the switching losses you will have. generally switching losses, are lower in a mosfet so you can use a higher frequency. note that bjt is current controlled so it has higher losses at base.
 

MOSFETs are overall much easier to operate at high frequencies. Darlington BJTs are a very poor choice.
 

Thanks for information

- - - Updated - - -

Thanks for information
 

Status
Not open for further replies.

Similar threads

Menu
Log in
Register
Cookies are required to use this site. You must accept them to continue using the site. Learn more…