Hi Steve I was wondering how you solved the problem with the variable Vcore? Which of the following possebilities do you prefer? 1.) Two or three FET's 2.) With a 10bit DAC like the LTC1663 or Ti's dac5741 cheers Juergen sunrise ADSL: Jetzt drei Monate testen! http://www.sunrise.ch/home/proint/proint_ads-2.htm