Arduino Forum

Development => Other Hardware Development => Topic started by: pchelper4 on Aug 14, 2012, 06:45 pm

Title: Which variation of the ATMega168 should I choose?
Post by: pchelper4 on Aug 14, 2012, 06:45 pm
I am searching digikey for a chip and there are so many variations I don't know what the difference is! I tried looking through Atmel's site but not much luck. I am looking at the ATMega168 chip and these variations came up:

ATMEGA168A-PU-ND
http://www.digikey.com/product-detail/en/ATMEGA168A-PU/ATMEGA168A-PU-ND/2271215 (http://www.digikey.com/product-detail/en/ATMEGA168A-PU/ATMEGA168A-PU-ND/2271215)

ATMEGA168PA-PU-ND
http://www.digikey.com/product-detail/en/ATMEGA168PA-PU/ATMEGA168PA-PU-ND/1914551 (http://www.digikey.com/product-detail/en/ATMEGA168PA-PU/ATMEGA168PA-PU-ND/1914551)

ATMEGA168PA-PN-ND
http://www.digikey.com/product-detail/en/ATMEGA168PA-PN/ATMEGA168PA-PN-ND/2522746 (http://www.digikey.com/product-detail/en/ATMEGA168PA-PN/ATMEGA168PA-PN-ND/2522746)

ATMEGA168-20PU-ND
http://www.digikey.com/product-detail/en/ATMEGA168-20PU/ATMEGA168-20PU-ND/735446 (http://www.digikey.com/product-detail/en/ATMEGA168-20PU/ATMEGA168-20PU-ND/735446)

ATMEGA168P-20PU-ND
http://www.digikey.com/product-detail/en/ATMEGA168P-20PU/ATMEGA168P-20PU-ND/1914548 (http://www.digikey.com/product-detail/en/ATMEGA168P-20PU/ATMEGA168P-20PU-ND/1914548)

What does the P/A/PA/PU/PN/ND suffixes mean? Any ideas how that will effect design/programming/bootloading?
Title: Re: Which variation of the ATMega168 should I choose?
Post by: CrossRoads on Aug 14, 2012, 07:44 pm
The differences will show up in device signature bytes, causing you a little grief when its time to bootload/program, which can be worked around.
ATmega168     0x1E   0x94   0x06
ATmega168     0x1E   0x94   0x06
ATmega168A   0x1E   0x94   0x06
ATmega168PA 0x1E   0x94   0x0B

So I guess not really too different.
Functionally they are similar, with subtle differences you are not likely to notice.
P for picopower.
-PU vs -PN is a temperature rating. -PN has higher upper temp than -PU.
-ND is a Digikey thing for how it is packaged for sale (individually, tube, whatever)

I used to know what the A meant, need to look it up again.
You can find all their datasheets here
http://www.atmel.com/products/microcontrollers/avr/megaAVR.aspx
Title: Re: Which variation of the ATMega168 should I choose?
Post by: PaulS on Aug 15, 2012, 03:26 pm
Quote
Which variation of the ATMega168 should I choose?

Given that the price of the 328 is generally just about the same, and the 328 has twice the memory, why would you choose any version of the 168?
Title: Re: Which variation of the ATMega168 should I choose?
Post by: Chagrin on Aug 16, 2012, 12:08 am

Quote
Which variation of the ATMega168 should I choose?

Given that the price of the 328 is generally just about the same, and the 328 has twice the memory, why would you choose any version of the 168?

The 328 is cheaper, actually.

http://octopart.com/atmega328p-pu-atmel-10454248
http://octopart.com/atmega168p-20pu-atmel-5825898
Title: Re: Which variation of the ATMega168 should I choose?
Post by: CrossRoads on Aug 16, 2012, 06:54 am
Wow, down to $2.24 qty 1 Newark.  Wow.

Atmel AVR ISP MKii still $34 tho.
Title: Re: Which variation of the ATMega168 should I choose?
Post by: skyjumper on Sep 08, 2012, 03:00 am

Atmel AVR ISP MKii still $34 tho.


Yeah but you only need one for a whole line of processors. I noticed the 1284P is down to about $8.50 quantity one! That's my favorite AVR.
Title: Re: Which variation of the ATMega168 should I choose?
Post by: CrossRoads on Sep 09, 2012, 12:39 am
I think $8.40 is actually an increase.
Still my favorite AVR too tho.
Might make a dual '328 board make sense!

I ordered some boards Thursday night.
Title: Re: Which variation of the ATMega168 should I choose?
Post by: skyjumper on Sep 09, 2012, 12:44 am
Thats cool!