On 20 Aug 97 at 20:57, Jim Ham wrote: > I know of two generic methods to solve the problem. One is a > transistor and resistors or a zener as shown in the data sheet. This > is the least expensive (from component cost point of view) method. > The other is to use a power supply supervisor. Check out Maxim and > Dallas. This is a more expensive solution (US$1 to US$2), but they > have features that might be worth the cost: Low power, smaller > footprint, more precise, and turn-on delay. I believe that you will > find that you will need to handle reset in some way. I have a > product that I am recalling because of this. Believe me, it's better > to do it right the first time. > > The watchdog does _NOT_ work reliable after broun-out. I have no > explaination for this, only experience with 16F84s. The 'F84s will > wake up "sort of" working, and the watchdog will not do a proper > reset. Ports wake up in a funny mode (not documented) and there is a > good possibility that the EEPROM is corrupted. Reset doesn't always seem to remedy some of the problems, either. How about a 'snap' action on the Vdd pin? (so any voltage below, say 4 volts give 0 v output, then turns on quickly at above 4 volts) MikeS === For PICLIST help (including "unsubscribe" instructions), === send an e-mail containing the single phrase "help piclist" === to: listserv@mitvma.mit.edu