Single 12v and +-12v needed, What options?

[sarathssca]

You definitely need some filtering after the convertor. There are many options. An R/C/R/C can work well. Every implementation is unique depending on what device you use. You always need to confirm with real measurements on a scope

Thanks Mooly..
I am also looking to use laptop power supply to power both main amp (19.5v and works well with SNMPS) and pre amp (+/- 9 to 10v , needs better low noise power supply). So the way forward is only to analysis the output in a oscilloscope to decide on the type of filter to be used.
In general what would be level of nose or switching ripple after filtering would be ok for a audio preamplifier?

thanks and regards
S Sarath

 

[Mooly]

Noise should always be as low as possible, and that's not easy with SMPS supplies. There are no hard a fast rules. If I said 10mv pk/pk someone else will say its to high and should be nearer 1mv... and so it goes on. For test purposes I've used pretty noisy supplies for opamp circuitry and not heard any ill effects in the overall result.

Grounding and layout become hugely important where there is lots of high frequency energy and charging pulses flying around. And shunt regulators are probably the best option too, even if its just a simple zener arrangement.

 

[sarathssca]

These are a good option if space is tight and current requirements modest,
Your Search Results | CPC

Or a 15 volts one that allows you to add further regulation if you want,
Your Search Results | CPC

Hi Mooly,

Could you please tell the part name/no. of the above? the above links are not showing anything....

thanks and regards
S Sarath

 

[Mooly]

These should be universally available from many manufacturers.

Isolated Board Mount | CPC UK

- - JCA02-03 Series