Market share of linear vs. switching chargers in phones and tablets

[NiHaoMike]

A few years ago, Kelly Wu designed a USB host enabled microcontroller board. (It was based on a PIC24FJ64GB002 plus some regulator circuits, so it's really more of a breakout board.) It never got popular enough to make it to mass production (originally intended for some USB datalogger application), but it did have a very interesting feature: the 5V USB supply could be margined from about 4.5V to 5.3V by turning a trimpot. The theory was that when using a USB Flash drive that ran all its internals from a LDO (nearly all of them nowadays), reducing the voltage would theoretically save a little power, or the voltage could be boosted to compensate for long cables.

I have managed to build a DIY clone of the Kelly Wu and got it connected to various Android devices, which got me thinking: what's the rough percentage of devices that use switching chargers as opposed to linear chargers nowadays? In that case, a somewhat lower voltage would work great for keeping linear chargers cooler, but would slow down charging on a switching charger. Am I correct that almost every Android device made nowadays uses a switching charger?

[Wuerstchenhund]

I have managed to build a DIY clone of the Kelly Wu and got it connected to various Android devices, which got me thinking: what's the rough percentage of devices that use switching chargers as opposed to linear chargers nowadays?

The last time I saw a device which still came with a linear wall wart was maybe 6 years ago. Everything else, no matter how cheap, is switch-mode these days.

[NiHaoMike]

I'm talking about the actual charger chip inside the device, not the wall wart.

[free_electron]

Inside the device? 100%. Nobody uses linear chargers.

[SeanB]

I would guess anything other than the simplest non feature phone ( it makes calls and might do text but nothing more) would use a switching supply, simply to get the charge time down. Especially any phone that charges via USB will be using a switching supply, as they have limits on current draw and voltage on the port.

[Sionyn]

only seen switching

[vlf3]

SMPSU are nasty little Buggers... wide QRM spectrum noise, and short lived too; the worst idea ever created for AM radio or short-wave reception.   

[tom66]

I'm guessing OP means the IC that actually charges the li-po/li-ion, the vast majority below 0.5A charge current are typically linear, above that are switching mostly. I would guess e.g. in a smartphone real estate would be limited so they would use a switcher (probably on the main power management IC too), but a tablet would  not be as critical space wise so may use a linear IC.

[BravoV]

what's the rough percentage of devices that use switching chargers as opposed to linear chargers nowadays?

99.999999 % switcher

Am I correct that almost every Android device made nowadays uses a switching charger?

Yes

I have managed to build a DIY clone of the Kelly Wu and got it connected to various Android devices....

Wow .. can you really do that nowdays at home ? Really-really curious what is your plan to do with her while she is connected, running some certain fun apps ?  ... j/k  (sorry, just couldn't help it) 

[FenderBender]

I just bought a pair of Altec Lansing speakers and it had a linear wall wart. Thank goodness! I don't need any cheap and crappy smps residue on the output!