I notice many TI/ADI's ADCs/OPAs can work under a wide power range, e.g. 1.4V~5.5V, which would bring big difficulty to the design. Is there any need for a wide power supply range in the application? What is the most original intention of doing this, I think most system should have a relatively fixed power supply.
Yes wider supply range make it easy to use, but also make it difficulte to design/fabricate such a chip. I'm a noob IC designer, don't know much about the application, so I wonder what applications need wide power supply range..
If you want IC design answers please post in IC design section.
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So answer the question in reverse:
Why do IC manufacturers design their ICs for a wider supply voltage range?
--> Because they want to sell them. As much as possible. So they design them to fit as many applications as possible.
If you design for one dedicated application, then you may focus on one dedicated power supply voltage.
Klaus
Added:
For sure if you design something for running from a 12V battery you may consider a supply voltage range of 10V ... 15V at least.