Matrix user forums

Hi,
The EB023 internet E-Block used a dc-dc buck regulator (national 'simpleswitcher' LM2575S) to create the required 3.3v for the WIZ810MJ

Is there any reason I can't use a simple linear reg , when implementing a WIZ810MJ in a custom PCB?
I know Linears are not as efficient and may need a bit more heatsinking on the PCB, but they are super simple to implement.
I've used DC-DC IC's before and they have been bit of a pain to setup.
Is there some high current demand from the WIZ810MJ that I am missing that makes an efficient 3.3V regulation the sensible route?
Cheers, J.

Hi J,
Wiznet are quoting max 185mA, so as you say if you use a linear you will need to calculate your heatsink requirements based on your input voltage.

Ok Thanks Leigh, I'll run with a Linear and see how we go. I suspect the EB023 E-Block designer wanted to use the 12V DC supply so as to not load up the upstream EB006 Linears's 5V supply.
When dropping from 12-16V to 3.3V..I guess the efficiency of the DC-DC make it a good choice. J.