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Microcontroller 18f4550 gets hot

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sprooch

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p18f4550 hot

Dear Forum,

I have a problem with the microcontroller 18f4550.
I use its PWM for controlling a driver mosfet (**broken link removed**), and it goes to the boost converter mosfet. The output of the PIC should be 5Volt DC 150kHz 70% Dutycycle. I tested the output (without connecting it to the driver and the boost converter) and it is running well..

I connect the converter with the microcontroller, it worked well and in a short time it became very hot, the driver did not give any output and offcourse the mosfet waas not switching. I dont know the reason for that.

Anyone knows something about this?
 

18f4550 pwm

microcontroller getting hot? rare case,either the chip is bad by itself.
but here you say it works well without the converter..huh?
 

measurement - sprooch

Something is wrong in your driver/mosfet circuit
try ti use this circuit with simple logic
 

sprooch said:
Dear Forum,

I have a problem with the microcontroller 18f4550.
I use its PWM for controlling a driver mosfet (**broken link removed**), and it goes to the boost converter mosfet. The output of the PIC should be 5Volt DC 150kHz 70% Dutycycle. I tested the output (without connecting it to the driver and the boost converter) and it is running well..

I connect the converter with the microcontroller, it worked well and in a short time it became very hot, the driver did not give any output and offcourse the mosfet waas not switching. I dont know the reason for that.

Anyone knows something about this?
Click to expand...
your schematic and actual implementation may have to be cross checked with the datasheet for comments. Why not post it and check at your level also by any third person, as you yourself likely to miss the observation, afterall human .
 

I have solved the problem.

The problem is on the input of the micro which read the boost converter input using LEM current transducer.
If I disconnect that current measurement, everything is fine.

I checked the LEM and finally I found the connection is not good.
finally...

thanks...
 

Basically it has gone in the problem of isolation.
Put optocoupler isolation.
Once pic gets hot it means that it is to through out.
 

Hi Sprooch,

I need your help. I'm designing buck/boost converter. Can I know what type of inductor u get for ur cct? Also the mosfet driver connection is the typical connection shown in the link of the datasheet IR2301? By apply PWM, the mosfet will work?
 

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