I have found Wiki to be wrong MOST of the time on technical matters. --Bob On Sun, May 10, 2009 at 4:28 PM, John Coppens wrote: > On Sun, 10 May 2009 15:42:19 -0700 > "Vitaliy" wrote: > >> "Totem pole" and "push-pull" both mean the same thing. > > Not necessarily. CMOS outputs are generally push-pull. They have a > P-channel FET above and an N-channel fet below. Both are in digital model > (on/off). 'Totem-pole' will never apply to a CMOS output. > > TTL and such have above and below NPN transistors. The lower is really > working in digital mode. The upper NPN is in linear mode, and mainly > serves as an active resistor. There's almost always a diode between both > transistors, which is part of the totem pole output, to protect the upper > transistor, which doesn't even like to go all the way to VCC. > > Wikipedia is wrong there... That happens. > > John > -- > http://www.piclist.com PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist