TTL serial max power

[Stuart]

ok Im working on something and I need to know how much power the TTL serial port can put out. basicly the question is weather or not I can run several (2+) microchips off of that +5v. but if I could get a # that would be great.

[karlcswanson]

I think the 5v on the RC can supply 1 amp, that is shared by all of the devices in or plugged in to the RC.

+5V Power Pin - The total combined current supplied from all 16 Analog and 18 Digital +5V Power header pins is 1 Amp. The 1 Amp max can come from a single +5V Power pin.

http://www.ifirobotics.com/rc.shtml#Specifications

[Stuart]

awesome!

[John Gutmann]

Yea but that doesn't mean you can safely pull an 1 amp through the chip. if the TTL serial port is connected to the uC then you can only source ( or sink ) as much current as a general IO pin because that is basically what the pin is.

-John

[whytheheckme]

I wouldn't worry too much about the safety of this....

For instance, if you short out a +5v pin and a gnd pin on a Digital I/O (for example), all that happens is the RC Hardware light comes on. It doesn't break anything. It just won't work.

My 2 cents.

Jacob

[Stuart]

no I was just looking for an answer over 100ma. I dont plan on running close to an amp.

[John Gutmann]

If you look in the data sheet look at the max sink/source per I/O and that is your answer.

-John

[Eldarion]

I think he is talking about the +5V that is available on that pin, not the actual TTL lines themselves. That +5V pin is tied directly into the 1A 5V bus in the RC.