I need a reference voltage of 2.5V I need in my circuit. Would it be advisable to get a 7802 regulator or is there something better in the market. My ac dc converter doesnt have much current rating. only 333mA. will two regulators on the board be bad and take up too much power?

 

Get a reference diode - http://www.national.com/mpf/LM/LM336-2.5.html#Overview

That one is one of many.