point is that: i have fixed Pulse width signal source. I need to make the ****ft in its level (step size 10mV upto 6V for a particular period of time). please advice.. -- Message posted using http://www.talkaboutelectronicequipment.com/group/sci.electronics.design/ More information at http://www.talkaboutelectronicequipment.com/faq.html