Question 1.8v line

[bentomo]

Does anyone know how much the 1.8v line draws from the LDO regulator? And how much current does the LDO regulator draw from the 3.3v line? And I'm talking about revisions 4 and up obviously.

I need to know for power memes.

 

[Shank]

Current draw on the 1.8v line is 350ma. Its a linear regulator so the current in and current out are the same. Power waste is about .5 watts.

Input: 3.3v @ 350ma
Output: 1.8v @ 350ma
Waste: 1.5v @ 350ma

 

[bentomo]

Documented

 

[ShockSlayer]

Denied!

bentomath

 

[Shank]

Nice! These are some very elaborate tests, much more so than mine.

Mine was simply done on the sysmenu. I ran a stock board on stock regs, but desoldered the 1.8v LDO and powered it off of my regulated benchtop linear supply instead. Thanks for taking the time to get more detailed numbers!

 

[ShockSlayer]

I wouldn't call these elaborate, but basic requirements to form a reliable conclusion. Science is what's repeatable, so multiple circumstances are required in order to determine the truth.

Even more important than that is since bentomo is making power memes, it's extremely important to get some real numbers instead of eyeball values; as a good setup is designed to compensate for any potential draw spikes. Assuming he had went with a 1.8v 400ma(max) regulator to compensate for any spikes at a 350ma rated line, the results would be disastrous: the Wii would appear to function properly in the Sysmenu and Priiloader, but would be unable to function past that point. Similar to how a single PTH08080 functions on a combined 1.15v and 1.1v line.

 

[bentomo]

Awesome, thank you for finding that out. And yes originally I had picked out a 400mA buck regulator for the 1.8v line. I will adjust accordingly!

 

[ShockSlayer]

helped tomo