design of a boost converter

[vineetharavindran5]

Hello
First of all let me tell you that i am just beginner.
i have to design a boost converter 12-36v. i thought of using mosfet ic irf540 and i know driver ic for mosfet is tlp250. i have made pwm output of 50%duty cycle from 8051.But doesnt know how to interconnect all these threeeeee. pls could you help me ............

 

[sapna.dudani@gmail.com]

a very good link for beginners

courses.engr.illinois.edu/ece445/projects/.../project63_final_paper.doc

 

[thelukuntla]

Re: purpose of a resistor between gate and source of a switch in inverters

i have to design a boost converter 12-36v. i thought of using mosfet ic irf540 and i know driver ic for mosfet is tlp250. i have made pwm output of 50%duty cycle from 8051.But doesnt know how to interconnect all these threeeeee. pls could you help me ............

You can see application notes and datasheets of TLP250, also search related posts like

https://www.edaboard.com/threads/185739/

hope this may be helpful

 

[FvM]

Re: purpose of a resistor between gate and source of a switch in inverters

A boost converter would be usually implemented with a grounded switch and don't need an isolated driver. Non-isolated gate drivers are available as well.

 

[Tahmid]

You don't need to use TLP250 as isolation is not needed. You can use low-side driver such as TC427. Since you used TLP250, your frequency is less than 20kHz. So, you could also make your own driver with a few transistors. However, if you decide to use TLP250, you can find the connection in above provided link.

 

[vineetharavindran5]

You don't need to use TLP250 as isolation is not needed. You can use low-side driver such as TC427. Since you used TLP250, your frequency is less than 20kHz. So, you could also make your own driver with a few transistors. However, if you decide to use TLP250, you can find the connection in above provided link.

thanking you for ur valid suggestion. let me give you the entire details of design because i think you can help me out in this regard. as i have told you i am just a beginner so if am asking some thing stupid plsssss forgive me.
Vin=12v,Vout=36v,f=20khz, designed L=500uh,C=100uF and R=130ohm. mosfet ic selected is irf540 bcoz its peak voltage is 100v and current 22A. 50% duty cycle from 8051. and now regarding isolation and driver ic for mosfet. Isnt isolation manidatory even if there is one mosfet(boost converter)?isolation is actually between 8051 controller and mosfet board na? so why cant i go for Tlp250 ?but when i reffered its ic pins , two pins are given as output? so does it mean that either of it can be used to give connection to gate of mosfet?and also which diode can i use for boost coverter? will in5400 series be enough or any schotky diode should be used? plsssssssssss do reply me. i am anxiously waiting..........

 

[Tahmid]

Hi,
How do you plan to isolate it? Since the input voltage is 12v, the microcontroller and MOSFET will have to have same ground. If you try to isolate it, you'll need to make an auxiliary isolated power supply, and it's not worth the hassle. Plus, the output is only 36v, so, isolation is not required. Boost topology, is, by nature, non-isolated, so it can stay like that. You can use TLP250, but nothing much to be gained.

You can use either pin, but I would take connection from pin 6. For boost converter, you have to use an ultrafast diode or a schottky diode. What is your required output current? This will determine which diode you need to use. You can't use a standard diode such as the 1N540x as they have too high a reverse recovery time.

Hope this helps.
Tahmid.