> Thanks for answering. This is very simple: There is basically > no change in > written specs between the 16C54 and 16F54 in this area. The > 16C54 (and a 16F84 I > also tested) withstands the use in this circuit perfectly, > with -7mA drained > from an input pin, the voltage is less than -0.6V and > everything is fine. With > 16F54 the voltage is higher although the current is lower. So > either I am > missing something very obvious OR something has indeed > changed and the datasheet > needs updating. Imho. If I understand you right: You used a chip outside its specs and it worked. You use the newer chip this way and it fails. And you are surprised? Wouter van Ooijen -- ------------------------------------------- Van Ooijen Technische Informatica: www.voti.nl consultancy, development, PICmicro products docent Hogeschool van Utrecht: www.voti.nl/hvu -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist