SYMBiFACE II maximal values

[TFM]

Hi!

Which are the maximal values one can use for the power supply of the SF2 without any problems?

(I'm currently using 9 Volt and 350 mA).

What are YOU using?

[Bryce]

As far as I can remember, the SF2 uses an LM2574N-5 to regulate the 5V rail (correct me if I'm wrong, I don't own an SF2, but I've fixed a few). The LM2574N-5 can take up to 40V on the input, so anything below 40V should be safe, but of course the higher you go, the more heat it will need to disipate. So at 40V you'll need some serious cooling.
It's designed to supply 5V @ 500mA with an input voltage of around 10V, but according to the datasheet, it will work down to about 7.5V but the output voltage then drops to 4.99V. The supply you use should be able to deliver at least 500mA @ 10V for an absolutely perfect 5V @ 500mA output. As 12V supplies are very common, I'd suggest using a 12V supply.

Bryce.

[CraigsBar]

Mine is on the 12v of a pc powesupply.

[TFM]

Thanks for the informations.  What are other people using successful? 

[HAL6128]

12V out of an old ATX PSU.

[TFM]

Well, 210 mA at 10 Volt is probably not a good idea then...

[Bryce]

Well, 210 mA at 10 Volt is probably not a good idea then...

Simple maths will tell you that the most Amps you can get on the 5V side is 420mA (assuming the LM was completely lossless), so it's a bit weak for the job. Although I doubt the SF2 needs anything near 420mA, it's better to have some headroom.

Bryce.

[TFM]

Oh, I got a 15 Volt and 300 mA now, that should be just fine right?

[Bryce]

Oh, I got a 15 Volt and 300 mA now, that should be just fine right?

Yes, that should get you the full 500mA @ 5V.

Bryce.

[TFM]

Thanks Bryce.