>> The requirements are vague and the implementation even >> vaguer. I thought the scaled down AC was centered on >> Vdd/2 with the peaks within the A/D range. > Conceptually "scaled down full AC range" is not quite perfect > approach. Better one would be to scale down the _measured_ range. Circuit PLEASE Russell -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist