Resolution Relationship with Inputs, Outputs and Word Length.

[Combinu]

Hi i know that for some this is a very alimentary question, but i cannot figure out what i should actually write on this question. I searched for the net and i know what resolution actually is. I have uploaded an image explaining my knowledge about these two things (resolution and word length).

N.B. Download the image and enlarge it on your PC sorry but that is just a photo from my iPhone but you should see everything.

My problem is how to explain their relationship and here below is the actual question.

Describe the resolution between analogue inputs and outputs and word length.

With the aid of a typical interface for example an ADC e.g. ADC 0804 and any other device e.g. temperature sensor, describe what is meant by the term 'resolution' and the the relationship between analogue inputs and outputs and word length.

I have found the datasheet of the ADC0804 and found that the resolution is 8bits on the other hand that of the LM35 tells nothing about its resolution.

Can you help me figure out this question and perhaps if available any links that explain in detail word length and resolution and their relationship?

Image: **broken link removed**

Uploaded with ImageShack.us

Thanks & Regards
Combinu

 

[ark5230]

The image is not clear but resolution is defined there. The point that concerns is that while using a sensor like LM35, the input to ADC has to be such that the results are representative of the input. With 8 bit ADC the best resolution is achieved with all the 8 bits used. If the input from LM35 is so small that it requires only 3 bits then inspite of using 8 bit ADC you are utilising only 3 bits and your resolution is 1 part in 8. Thus choice of suitable ADC with desirable Vref and a sensor with amplifier / signal conditioner would allow for optimum utilisation of the resolution capabilities of the ADC.