I was wondering what type of circuit components mobile power banks (like this "http://www.bazaared.net/wp-content/uploads/2013/07/universal-2600-mah-mobile-power-bank-black-1.jpg") generally use. I know the inside is a single lithium battery charger and a boost converter, what I want to know is do they use basic components to make the charger and boost converter or they use ICs from TI, STMicroelectronics, Maxim etc. I assume the driving factor will be cost and these ICs cost seems to be on quite lower side (0.50-1.00 $ for 1Amp charger and DC-Dc converter). I cant find any similar thread, was wondering if someone have made anything similar or have the diagram.

Any help in this regard is highly appreciated.
Regards

 

Some designs might use off the shelf components and some could be done with custom IC's or whatever.. Like you said..for everything in the world, cost is the driving factor.. along with availability,etc...