
Apple iPhone charger teardown on Ken Shirriffs blog:
Disassembling Apples diminutive inch-cube iPhone charger reveals a technologically advanced flyback switching power supply that goes beyond the typical charger. It simply takes AC input (anything between 100 and 240 volts) and produce 5 watts of smooth 5 volt power, but the circuit to do this is surprisingly complex and innovative.

Printable catalog (PDF)
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Cool! can you reverse engineer a circuit diagram out of that puppy? How many layers are in the PCB? Does it have a wound transformer – how does it achieve the voltage step down? Are there any chip / coding devices that mark the charger as being “Apple only?”
Comment by Richard — May 20, 2012 @ 8:51 pm
PS. Link to the original article?
http://www.arcfn.com/2012/05/apple-iphone-charger-teardown-quality.html
Comment by Richard — May 20, 2012 @ 8:53 pm
Whoops, fixed!
Comment by Becky Stern — May 20, 2012 @ 9:52 pm
I wonder how much of this super-filtered design is because they had issues with the touchscreen on the 1st gen not being stable with normal supplies. I know that some of my laptops don’t deal well with 1st gen iPad charging (the touchscreen jitters around and on one registers phantom touches).
Comment by AMS — May 21, 2012 @ 12:43 am
Richard: I included a circuit diagram in the original article. The PCBs (two of them) are two-layer. Yes, it has a flyback transformer – the article includes a complete transformer teardown. It uses the same Apple-proprietary D+/D- resistors to indicate that it’s an Apple charger that Adafruit discovered earlier.
Comment by Ken Shirriff — May 21, 2012 @ 2:22 am