[SOLVED] System power supply 3.3v vs 3.0v

[JuniorEE]

Hello,

What are the considerations for choosing system power supply voltage 3.0v or 3.3v ?
For example :
If i have ICs that can operate at both voltages but a power supply of 5v - Which LDO output voltage will be better ? and why ?
Or it doesn't matter at all ?

Many thanks

 

[schmitt trigger]

It depends on the voltage rating of the ICs in your system, whether they require 3 or 3.3V.

Having said that, most modern ICs that I've looked up lately, are fully characterized at both 3 and 3.3 volt.
Personally, if my design has an analog path, I like the extra headroom of 3.3 volt.

With respect to LDOs....there are dozens and dozens of them from many vendors. The decision is whether you want a simple 3-terminal device, or a full featured one which has external shutdown, error flags, noise reduction, trimming, power-on-delays, etc.

Again, I personally like the LP2987 in the latter case.

 

[KlausST]

Hi,

it doesn´t matter much. I´d prefer 3.3V because it is more common.
Using 3.0V may reduce power consumption a little.

Klaus

 

[ads-ee]

Using a 3.0V/3.3V part at the 3.0V will usually mean the part is slower. uC commonly have this issue and have graphs that show MHz vs. V.