The Chandler-based semiconductor and microcontroller manufacturer reported income of $99.4 million, or 45 cents per share, on revenue of $543.2 million for its fourth quarter that ended March 31. That compares with income of $111.5 million, or 50 cents per share, on revenue of $493.4 million for the same quarter a year ago. Microchip also reported its fiscal year 2015 financials of income of $369 million, or $1.65 a share, on revenue of $2.15 billion.