MAX232 over heating, even without any connection to controller

[burrow]

Both are running on common power supply.

And yea when i was googling about my problem, some where i found that this problem is profound in max232. and some people seems to have fixed this problem by placing a series resistor in supply pin. Seems like that will prevent latching up. Yet to try that

 

[paulfjujo]

Are you sure about Max reference
if you have Max3232 instead of MAX232 you need to use 0.1µF instead of 1.0µF, else overheating...

 

[burrow]

Yea its max232 itself,

Also let me remind again, its working sometimes, when its working, it works as long as power is up, but when it restarts, it stops working..

 

[paulfjujo]

so, we can suspect also software !
did you manage Frame error and Overrun error in UART software ?
if UART detect this kind of error , receive part is blocked if no treatment applied for.

 

[burrow]

Iam not familiar with these terms. ..
my code works really well in proteus.
Also it doesn't send high amount of data or anything, I just need to get info on status of 5 pins, so iam encoding it to single byte and sending the byte over..


and i noticed some thing today, my cable length is 12m long, but communication seems to be working without max232 also. So is it going to work well all the time.. or i will run into noise problems anytime ?

 

[burrow]

in one of the forums i saw that adding a resistor in series with vcc might solve the problem, and i did that, and seems like problem is solved.

now latch becomes unstable so it doesnt heatup.