SMPS BUCK CONV HELP

Thread Starter

hieveeyone

Joined May 17, 2024
2
Hi everyone

I designed a buck converter circuit that steps down from 12V to 6V. I tested the circuit in Proteus and it works. I'm using a Trudyo development board, which contains a PIC18F45K50 microcontroller. I set the PWM duty cycle to 50%. However, the circuit doesn't work in reality. I replaced the 1-ohm resistor with a 1k-ohm resistor. Can you tell me where my mistake might be?IMG_20240517_130722.jpg
 

ronsimpson

Joined Oct 7, 2019
3,215
I can see 8v from 12v
I don't understand. What is the G-S voltage? Is it 12V for off and 8V for on?
This is a P-FET? Source on +12V? That gate driver was designed for driving N-FETs. Try a "N".
You have the Gate driver connected from G to D not G to S. Mostfets are controlled by the voltage from G to S.
Do you need to ground the micro?

Either change to a different Gate Driver or use a N MOSFET.
 
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