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???
08/10/07 21:55
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 		 #143074 - That's not what the bible states...
Responding to: ???'s previous message
Richard said:
I'm not at all sure what you mean by "slow or "stumbled" power-ups" since "the bible" clearly states that Vcc must have a rise-time of 1 ms or less. Are you suggesting, by this statement, that "the bible" is incorrect, that it is irrelevant, or that it doesn't apply to ATMEL components?

No, "stumbling" means, that bouncing can occur, when you want to switch-on a battery powered micro. "Slow" means, that it can take about one mains half-period (which is up to 10msec) to fully charge-up the storage cap in front of 7805, which is way beyond your 1msec limit.

By the way, the "bible" does not state that "Vcc must have a rise time of 1msec or less". Read carefully:




This means, that a time constant or 10µF times 8.2kOhm is enough, if the Vcc rise time does not exceed 1 millisecond. That's something totally different.

Kai

List of 29 messages in thread
TopicAuthorDate
reset supervisors            01/01/70 00:00      
   two purposes of the IC (at least)            01/01/70 00:00      
      Unfortunately, they seem to fail at one of them            01/01/70 00:00      
         you are talking about the RC resets, I assume            01/01/70 00:00      
            No, I'm referring to the DS and Max 1232            01/01/70 00:00      
               and what            01/01/70 00:00      
                  It's just not that simple ...            01/01/70 00:00      
                     I am getting tired            01/01/70 00:00      
                        Reset chips do work properly and prevent damage!            01/01/70 00:00      
                           I never doubted that, Kai            01/01/70 00:00      
                              can you please be more precise...            01/01/70 00:00      
                                 Yes            01/01/70 00:00      
                              It is a black box and you will never find out...            01/01/70 00:00      
                                 It\'s the power supply, and probably not the reset.            01/01/70 00:00      
                                    That's not what the bible states...            01/01/70 00:00      
                                       Isn't that the same thing with different syntax?            01/01/70 00:00      
                                          No, is not. Look at INTEL's original C51 manual!            01/01/70 00:00      
                                             Vcc rise time            01/01/70 00:00      
                                                It can, I believe, be done simply.            01/01/70 00:00      
                                             Brown-out Bug Chasing            01/01/70 00:00      
                                                Seems reasonable            01/01/70 00:00      
                                             There's been nothing specific enough to test.            01/01/70 00:00      
                                                Some hints            01/01/70 00:00      
                                                   it's a thorny problem            01/01/70 00:00      
                                                      Add a monoflop            01/01/70 00:00      
                                                         I\'ve got to be careful ...            01/01/70 00:00      
                        Jan, you\'re missing my point!            01/01/70 00:00      
                           that's too easy to answer            01/01/70 00:00      
                              You have stories, but no specifics            01/01/70 00:00      

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