I'm making project with I2C communication and Serial interface(9600 baud) with PC. Right now I'm using internal oscillator of ATMega328p (running with 3.3V power) and serial communication with help of PL2301 module is working working pretty well.
What will happen if I will power it up with 5V? Will it blow or it will also work without problems? I'm also thinking about adding FT234XD chip instead of PL2301 module. Will it work as well?
The ATmega processor at 5 V works just fine with any oscillator speed up to its maximum specified rating. The limitation is that it will not necessarily function at 16 MHz on 3.3 V.
Another concern is whether the internal oscillator will operate sufficiently accurately to provide reliable serial communication.
And there is no advantage in an FTDI chip over a PL2301. FTDI is somewhat "on the nose" regarding past practices in any case.
Then I'll get into more details why I don't want to use external oscillator so maybe You'll help me.
That's my first product I would like to bring to the market and I'm a little worried about passing EMC tests. Thats why I don't want to use external oscillator, since internal one will generate less noise and wll be more immune in noisy enviroment.
Are my worries correct or I should worry at all and add external oscillator?
Kamool:
Then I'll get into more details why I don't want to use external oscillator so maybe You'll help me.
That's my first product I would like to bring to the market and I'm a little worried about passing EMC tests. Thats why I don't want to use external oscillator, since internal one will generate less noise and wll be more immune in noisy enviroment.
Are my worries correct or I should worry at all and add external oscillator?
Actually I've just read 328p datasheet agai ant it was my bad about immunity to noise. It referred to "Low power Crystal Oscillator" (Less immune to noise) and Full Swing Crystal Oscillator" (More immune to noise).
I don't remember where I read about less noise generated by internal oscillator.