Rihanna's Obsessed Fan -- I'm No Burglar!!

The man who allegedly tried to break in to Rihanna's L.A. home back in February has plead not guilty to burglary charges ... TMZ has learned.

As we previously reported, cops believe the man broke into the home next to Rihanna's property believing it was RiRi's crib. He was arrested when neighbors noticed him acting suspicious.

The man has since been ordered to stay at least 1,000 yards away from Rihanna's home.

The judge also told the guy he's not allowed to possess any dangerous or deadly weapons (guns or knives).