Q: about the NEW Uno R3- and it's LP2985

I am sorry if this is in the wrong place, but I was not sure where to put this.

OK I read the UNO R3 page >> http://www.arduino.cc/en/Main/arduinoBoardUno and it said "Maximum current draw for 3.3V is 50 mA." But I thought the LP2985 regulator max current was 150mA @3.3V?

I know in the old days when the Arduino used the FTDI chip, it's internal 3.3v regulator could only supply 50 mA. But that's why they put on the board the 3.3V LP2985 regulator.

Is it just things have not been totally updated? or have I missed something?

It might be thermal issues. The regulator can handle 150mA peaks, but prolonged operation above 50mA under certain conditions might cause it to overheat.

from the ftdi 232 datasheet - the 3.3v out should only be used if the current consumption its less than 5mA otherwise an external regulator should be used

BlackLab1: I know in the old days when the Arduino used the FTDI chip, it's internal 3.3v regulator could only supply 50 mA. But that's why they put on the board the 3.3V LP2985 regulator.

One school of thought was that the 50mA specification was used so that shields using 3V3 will remain compatible with pre-Uno boards.

I've done some minor tests, with resistors, and have been able to get draw 100mA from the LP2985 on the Uno.

Is it just things have not been totally updated? or have I missed something?

What your missing is that if any shield device draws more then 50 ma from the 3.3 volt pin it can then not be used with any arduino board made prior to the Uno design without damaging the FTDI chip. The added current capacity of 3.3vdc on the Uno is only useful for ones personal designs not to be shared or duplicated unless clearly stating the possible 3.3vdc problem other users may have. It's kind of a trap waiting to snap.

Lefty