Charactoristics of an LED flash circuit

[raptor1956]

I'm curious about the kind of circuits used to power the LED's as flash units in smartphones etc.  These are obviously a lot different than Zenon flash units and I understand that among the differences is that the peak voltage is MUCH less.  I would surmise a capacitor is used to store a charge and that a similar control circuit is used to fire and cutoff the current but, again, I'm not real clear on this.  The LED's used would likely be an optimized type but I'd guess many other LED's could be used though at lower power and with lower output.  So, looking at a typical smartphone that has an LED for autofocus, general illumination for video, as well as flash for stills what would be the typical values for charge, max/average current and voltage?  Assuming a 5600K LED that would operate continuously at about 3.2V or there abouts I'd have to guess that the voltage would need to be somewhat higher but within the breakdown voltage. 

I'd like to test this out with some 4000K LED's I have but knowing a bit more before hand would be desirable.


Brian

[StillTrying]

There quite a few phone LED driver ICs and circuits out there, I don't think they're all that special, mostly what they're doing is creating enough voltage.

http://www.electroschematics.com/12394/camera-white-led-flash-illumination

[raptor1956]

There quite a few phone LED driver ICs and circuits out there, I don't think they're all that special, mostly what they're doing is creating enough voltage.

http://www.electroschematics.com/12394/camera-white-led-flash-illumination

Thanks, that's what I was looking for.   The article is mostly related to the LED flash systems in smartphones with three or fewer LED's, but my application will have many more LED's so I should not have to drive them as hard. 


Brian