USB charger with over rated input spec'

[geko]

I just received this USB 5 volt charger from Banggood and popped it open to see what was inside. Not withstanding the fact it is just floating inside the case and the inductor is hanging by its leads.

It's supposed to be rated for 12-24 volt input, however to my mind the switcher IC is an MP1482DS, and is only rated to 20V DC input max. https://www.monolithicpower.com/Products/Product-Detail?ProductID=181

The circuit appears to be pretty much as the reference design in the datasheet and the switching frequency is ~350KHz. So unless I'm mistaken in identifying the IC would it be fair to say this should not be operated from a 24 volt supply?

 

[audioguru]

You bought a cheap Chinese product that has the wrong input voltage spec and has a heavy part simply hanging by its wires. What did you expect?

 

[geko]

You bought a cheap Chinese product that has the wrong input voltage spec and has a heavy part simply hanging by its wires. What did you expect?

That's not what I'm asking but is why I opened it in the first place.

 

[tronitech]

The label hints at a 12V or 24v input? Maybe somebody got carried away with their felt tip pen?

Can you provide a link to the actual product?

 

[Tony Stewart]

The diode gives a 1 volt extra margin and chip performance may tolerate more than absolute rating but not last as long. ... By an unknown amount. Quality products would use a dab of PU adhesive on the coil. What u expect for wun dallah ?

I remember when Made in Japan in the 60's meant unreliable cheap products. Now their reliability is best. Swiss are better but also most expensive.

 

[audioguru]

When I was young many years ago my AM radio was made in Japan and had 6 transistors. My friend's radio had molded into its case "12 Transistors". Inside 6 of them were connected together in a circle but were not connected to the radio circuit.

The excellent hearing aids I have as a demo are Swiss (Phonak). I tried some Danish ones (Widex) but I didn't like their sound.

 

[ChrisP58]

It's apparent to me that whoever designed this product didn't really understand the ic they were using. The MP1482 is a synchronous buck regulator, meaning that it doesn't need a freewheeling diode. And though I can't be certain without closer examination of the board, it sure looks to me that D1 is in that position.

 

[geko]

It's apparent to me that whoever designed this product didn't really understand the ic they were using. The MP1482 is a synchronous buck regulator, meaning that it doesn't need a freewheeling diode. And though I can't be certain without closer examination of the board, it sure looks to me that D1 is in that position.

See page 7 of the datasheet, under the section headed 'Optional Schottky diode'

 

[geko]

It's apparent to me that whoever designed this product didn't really understand the ic they were using. The MP1482 is a synchronous buck regulator, meaning that it doesn't need a freewheeling diode. And though I can't be certain without closer examination of the board, it sure looks to me that D1 is in that position.

See page 7 of the datasheet, under the section headed 'Optional Schottky diode'

The label hints at a 12V or 24v input? Maybe somebody got carried away with their felt tip pen?

Can you provide a link to the actual product?

https://www.banggood.com/12V-Dual-U...or-Motorcycle-Phone-Android-GPS-p-964408.html