Hi
Today I purchased Olimex sam7-p64 board.
It says 6V DC power supply required, but I’ve got only 9V PSU.
The question is may I power the board with 9V?
I think it’s possible because they use lm1117 (according to schematik) stabilizer which can accept up to 15V. But I’d rather listen to your opinions.
Thanks, andrew
To start with and for development the simplest soultion is power by usb.
Just plug in an USB cable.
I have one of theese boards and it works very nice.This is useable even if you do not use USB for debugging or anything else,
I started working on this board with serial flash downloading, SAM-BA, and USB power.
Nowadays I use USB power and jtag/OpenOCD for flash programming and debugging.
The power connector should work nicely with anything from 6-12 V AC or DC.
Regards
Magnus
Thanks for respond
andrew
After reading the datasheet for LM1117, if the input voltage is high you must
keep the total current draw low in order to not overheat the regulator.
Some simple calcluations shows that with no extra cooling, a fan or a small heatsink on the regulator, the total current should be limited about as follows
Input voltage Max current
5V 600mA
6V 400mA
9V 200mA
12V 125mA
15V 100mA
My estimate is that the processor at 50MHz and other onboard components uses max 50mA. So the current limits are only a problem if you add external power hungry components to the board.
Regards
Magnus
mlu, thanks
I’ll keep it in mind
andrew