Tom Austin <taustin> wrote:
> Nicolas Alvarez wrote:
>> Tom Austin <taustin> wrote:
>>> One think to keep in mind, you are best off not trying to drive the LED
>>> directly from the chip.  Some chips can do it, but most cannot.  Lots of
>>> times you need to put a *switch* that the gate switches.
>> 
>> I have an electronics kit, with CMOS ICs, LEDs, and AA batteries adding
>> up to 9v. I have always connected LEDs directly at the output of gates.
>> With a resistor, of course (3.3k ohm), I mean without any kind of switch.
>> 
> 
> With TTL you should be able to drive a LED from the outputs.
> With CMOS you better check to be sure.

It's all CMOS. In very few places it actually uses an extra transistor or
switch to drive an output.

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