Various minor corrections for Powering Alternatives for Arduino Boards

[kevinjwalters]

Powering Alternatives for Arduino Boards fills a gap that's been around for a while, it's very useful document. I've been researching how much power the 5V pin on an Arduino UNO R3 can supply and I've only just discovered it.

A few questions:

• For VIN Pin section the table has UNO Rev3 as 7-12V range, the datasheet says 6-20V
• For 3V3/5V Pin section the table has UNO Rev3 as 1A from 5V and 0.150 from 3V3. Are these numbers based on just the regulators? They look misleading as
  • the 3V3 is documented as "MAXIMUM current per +3.3V pin is 50mA" (not 150mA) in the pinout;
  • the 5V current is going to be more like 1000mA - board-use-including-3V3-regulator - current-that-cannot-be-used-due-to-over-heating - it will also be limited to 500mA (or a lower conservative value) for USB powering due to the polyfuse.

I'll mention @futureshocked in case he's interested as he's written an article in this area.

[kevinjwalters]

BTW, where's best place to ask about UNO R3 datasheet?

• The table in 2.2 Power Consumption only has an xx entry for Maximum Power Consumption
• Perhaps the Description column entries should lose the word "Maximum" as there's already a Max column and it doesn't make sense for Min and Typ?
• The value for Min voltage for Maximum input voltage from USB connector is blank.