car usb charger not durable

Some of the chargers that I have use 34063 chips. A few others use what appears to be a AD84064Q (certainly not Analog Devices). I didn't spend much time searching, but the only reference I found describes it as a

Thanks. I'll keep digging. I found some photos of the insides of other USB car chargers, but they're mostly MC34063 chips.

I couldn't resist tearing apart the "better" USB charger: I like the part where they "upgraded" the specs from 3.1A to 4.2A. I wonder if only the spec was change, not the circuitry.

See photos at: There are two chips labeled MK2347 and MK2348 which are nowhere to be found on the internet. The board construction is creatinly better than the $3 variety. It seems like far too much work to reverse engineer the schematic. No LTspice model without the chip numbers. Dead end, I guess.

Just a FYI, given the non-standard USB of Apple products, I don't think you can make a device that is capable of high current for both Apple and normal USB devices. Probably that device works well for normal USB but not the odd Apple type.

Your best bet to getting a good charger is to buy OEM devices. Since a real company (say Samsung, HTC) has a name to protect, they are less likely put their name on a junky device. Now you can go on ebay and get real branded OEM chargers at a good price. I see OEM Samsung car chargers on ebay now.

My last deal, though not for car use, was OEM 1.8A Blackberry branded charger for $2 each in a quantity of three. Ebay item 221391879004. Blackberry follows the USB standard, so it will charge any phone, well other than Apple. Now I can leave a charger at all times in my suitcase, one in the notebook bag, and one in the car. The microusb charger standard is command economics at it's finest. People will junk a phone but not the chargers because they can always use a spare charger. Anything Blackberry is enterprise grade, kind of like Lenovo. It will work.

They should be using this:

-or-

but it's waaaaay too expensive.

MP1410 - 2A Step Down DC to DC Converter

Please google for the data sheet. Best regards, Piotr

Really bad, 16V max input in an automotive app? No wonder they pop.

Actually 16v is a common spec for such chips. The problem with going much higher is either the chip gets very complicated, process wise, or has to be made on a very old high voltage process. It is cheaper to make a 16V chip and protect it externally.

Of course it is really cheap not to protect it at all, especially if you are some Chinese company that can just do a name change if the product is unreliable.

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I'm not sure about that, all the major semis have automotive grade chips, a ble to withstand that 60V 500ms load dump, which keeps getting worse every time you turn around. Someone has to be buying their stuff maybe out of nec essity to meet safety regulations.