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Jim Granville
08/01/13 20:30
  08/01/13 20:43

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Msg Score: +1
 +1 Good Answer/Helpful
#189993 - Try Logic level power FETS
Responding to: Erik Malund's previous message
Erik Malund said:
.. but what else but ludditeism requires 5V Vcc

Err, do you never use Logic level power FETS, of the Milli-Ohm kind ?
Plenty of other designers do.

Your 3v3 (or 1.8V) fails abysmally at driving one of those, and the fix of 'just add more parts' simply (again) proves my point.

Even in the subset of cases, where an added pullup might 'get by', on a '5V tolerant' device, you then hit this fish-hook :
Absolute Maximum Ratings: [VDD < 3.3 V] : VIN <= (VDD+2.5)

Yes, that '5V tolerant' is only really universally 2.5V tolerant, and now power cycling matters.

List of 9 messages in thread
New SiLabs F85x/6x      Jan Waclawek      08/01/13 03:42      
   A good addition       Jim Granville      08/01/13 04:53      
      you may, as well, get used to 3V3      Erik Malund      08/01/13 08:42      
         1.8-5.5V :: is the new game in town.      Jim Granville      08/01/13 14:10      
            if i need a 3V3 chip ....      Erik Malund      08/01/13 19:48      
               Try Logic level power FETS        Jim Granville      08/01/13 20:30      
               USB 5V      Andy Peters      08/12/13 14:23      
                  .. or multiple onboard regulators      Jim Granville      08/12/13 19:15      
                     lots of chips these days have that      Erik Malund      08/13/13 08:43      

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