Help identifying chip

Trying to identify SMD part U5. It is a 16 pin VQFN with marking ALX on top and BAC on the bottom. This is a DC to DC converter 3mm X 3mm



Hello, welcome to the TechForum!

Unfortunately, I was unable to find any information on this part for a possible alternative, do you have any information on the electrical specifications for it?

Hi Rob,

I only know that it is an adjustable regulator from 3v to 5v with a 12v input


I too was not able to verify the original item.
The below link shows the options I had found for options that can handle the voltage spec you gave.
Voltage Regulators - DC DC Switching Regulators | Power Management (PMIC) | Electronic Components Distributor DigiKey

Hi Nathan,

Here is a partial schematic of the circuit. Maybe this will help

16 pin VQFN DC to DC converter.pdf (29.2 KB)

Where is this chip installed? Laptop, router, hub? Specify the model.


Hi, I took a crack at this as well, and given your schematic its closest match in our stock would likely be one of the parts in the list I’ve linked here: 16-VQFN DC DC Regulators

I took a look at some of the datasheets and I wasn’t able to find a chip that’s going to be a direct replacement for the original from what I can tell. The main thing that I ran into was that these each seem to have a different pinout from yours based on the schematic you provided.

At this point, I’d simply second Adam7’s question.

Power supply section for weighing scale.

Link did not work!