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???
02/18/05 20:05
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 		 #87918 - just a zener - naah
Responding to: ???'s previous message
The inputs are also 5v tolerant. so not too much of an issue migrating. just a zener, on the VCC?
I am using a LM2937-3.3 LDO ($0.67 from DigiKey) to drop the 5V to 3.3. I would not go with a zener though it might very well work in some cases (no Vdd load for sink only) but definitely not if you configure the ports for push-pull.

Erik

A little trick schematicwise for mixed voltage lables. My Vcc is 5V, my Vdd is 3.3 it works well for me and I have parts such as HC7400D and HC7400C with the + terminal conneted respectively defined in ORCAD.





List of 37 messages in thread
TopicAuthorDate
P89LPC922 vs AT89C2051            01/01/70 00:00      
   Sheer price            01/01/70 00:00      
      LPC price            01/01/70 00:00      
   no chance at 5V !            01/01/70 00:00      
      But requirement is for 51 series MCU            01/01/70 00:00      
         whats your problem ?            01/01/70 00:00      
            3.3 and 5            01/01/70 00:00      
            why?            01/01/70 00:00      
               money, money...            01/01/70 00:00      
                  not agree            01/01/70 00:00      
                     your choice(s)            01/01/70 00:00      
                  a concern and a yes            01/01/70 00:00      
                     5 V tolerant I/O LPC900 family            01/01/70 00:00      
                        2051 pin compatibility            01/01/70 00:00      
                           compatibility            01/01/70 00:00      
                           2051 compatibility            01/01/70 00:00      
                              pity...            01/01/70 00:00      
                                 nbot a pity            01/01/70 00:00      
                                    more details            01/01/70 00:00      
                                       Pin compatibility            01/01/70 00:00      
                                          it's nice            01/01/70 00:00      
                                             2nd source and pin kompatibility            01/01/70 00:00      
                                                second source always            01/01/70 00:00      
         51 Architecture            01/01/70 00:00      
            just a zener - naah            01/01/70 00:00      
               power nomenclature            01/01/70 00:00      
      MCU51 side            01/01/70 00:00      
         These are the options            01/01/70 00:00      
            doubt            01/01/70 00:00      
               Mr. Peter - Its not my problem            01/01/70 00:00      
   We us both 2051's and LPC's            01/01/70 00:00      
   good news            01/01/70 00:00      
      What a misery!            01/01/70 00:00      
         Atmel innovating ?            01/01/70 00:00      
            2nd source and pin kompatibility revisit            01/01/70 00:00      
               what's the fuzz            01/01/70 00:00      
                  Word is not only new products            01/01/70 00:00      

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