Atmel atmega 8-bit devices include the analog comparator. I'm trying to find out what is the input voltage range for it when the chip is powered +5V. Thx.

 

It should be 0 to +5V, but you need to pull up the datasheet to verify this. All the answers to you question will be in the datasheet and supporting materials.

 

I tried to find but I wasn't successful.

 

Do you mean you could not find the information in the datasheet, or do you mean that you cannot find the datasheet? Show us where you have looked.

 

Please check the pages 366 and 399.
ATMega328/P datasheet.

 

Let me share my looking procedure:
1st. step/
getting the datasheet from atmel website:
https://www.google.com/search?q=atmega328p+datasheet+complete+site:atmel.com

2nd. step/
Go to chapter 32. Electrical characteristic on page 365.
Find keyword: comparator
These params. found:
Analog Comparator Input Offset Voltage
Analog Comparator Input Leakage Current
Analog Comparator Propagation Delay
Analog Comparator Current vs. VCC

Still I'm not able to get the information what is the input voltage range for this comparator. For instance the LM393 datasheet contains the information: Input Common Mode Voltage Range: 0V min.; VCC-1.5V max.

 

It appears that Atmel does not provide this information in the datasheet. I found this chart in an old AT90S1200 datasheet. I am pretty sure that the process for the ATMEGA328 is better than the old AT90S parts but this might give you some confidence.

With 442 pages through which to search, it might be there but only indirectly mentioned. One I had a similar question about the comparator (maybe this same question) a very long time ago for a different AVR and was able to get an answer from the forum at http://www.avrfreaks.net/

 

... the ATMEGA328 is better than the old AT90S parts but this might give you some confidence...
View attachment 125418

Thank you

 

It's in the datasheet, multiple places-- fairly obvious. ADC input is same as Vcc. You said your Vcc is 5VDC, so ADC is 5VDC input.

 

@BobaMosfet , where in the datasheet did you see that fairly obvious information?

 

pg. 205
http://ww1.microchip.com/downloads/...ive-Microcontrollers-ATmega328P_Datasheet.pdf


23.1 Features
0 to VCC ADC input voltage range

 

Four years and three months to get an answer! This proves that the information is not in an obvious place! Just kidding. Thank you @Thomas Swan , better late than never, I’ll check it out as soon as I can get to a data sheet.

 

Referenced section of the datasheet:


Thanks @Thomas Swan. Welcome to AAC!

 

To recap, the original question related to Analog Comparator input voltage range.

I found it in table 28.2, DC Characteristics.


23.1 relates to the Analog to Digital Converter rather than the Analog Comparator.

However we got here, I am glad we eventually made it.

Yes, Welcome to All About Circuits, @Thomas Swan , and thank you for kicking this loose.

Note: in the Table, 10 mv and 40 mv refer to the typical offset voltage and maximum offset voltage respectively.

 

Any IC that has a 442 page data sheet is way more than I ever want to wade through.
My eyes would completely glaze over at about the 10th page.
Suppose that's why I stick with analog or small digital circuits.