Which variation of the ATMega168 should I choose?

[pchelper4]

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

ATMEGA168PA-PU-ND
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

ATMEGA168-20PU-ND
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

What does the P/A/PA/PU/PN/ND suffixes mean? Any ideas how that will effect design/programming/bootloading?

[CrossRoads]

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

[PaulS]

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?

[Chagrin]

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

[CrossRoads]

Wow, down to $2.24 qty 1 Newark.  Wow.

Atmel AVR ISP MKii still $34 tho.

[skyjumper]

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.

[CrossRoads]

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.

[skyjumper]

Thats cool!