typical ripple of switch mode regulator

[senmeis]

Hi,

What’s the typical ripple value of 12V switch mode regulator for laptops?

 

[cupoftea]

Probably about 1% or so.
You can measure it with DIY Coaxial probe.
But they are usually about 19V or so.

 

[dick_freebird]

This is a system, BOM call. Better inductor interwinding C goes to the HF noise blow-through against filter-C ESL; more bulk C tamps down baseband and low-order-harmonic ripple amplitude. But all that then gets thrown to "ground" and HF return currents go where they will (so you care about that too).

 

[senmeis]

Is it rms or max value? What about linear power supply?

 

[KlausST]

Hi,

I personally don´t think one can speak of a "typical" ripple.
It depends on a lot of parameters (switching frequency, load current, operation mode...) and design goals (efficiency, cost... )

Still unclear where you expect this 12V SMPS expect to be (in a circuit) and what it is expected to power, and the power rating at all.

Is it rms or max value?

You - as the OP - should ask for what you are interested in.

What about linear power supply?

Yes, what about it? What do you want to know?
Your headline focusses on SMPS. SMPS is switching with (usually) a fixed frequency. Thus you get ripple by design.

A linear regulator does not switch. There is no frequency involved, thus there is no ripple generated by the regulator. Noise, yes.
But ripple may be caused by the load. But we don´t know nothing about the connected laod. (neither SMPS nor linear)


Klaus