This is a sour experience I wish to share with everyone. The lesson learned: do not buy ICs from Aliexpress/Banggood etc.
On my VFD tube driver design, everything runs off 12V. Everything except an ATTINY13 that generates a 5V square wave. I therefore needed a tiny 12V to 5V drop out voltage to feed the microcontroller. I chose the LP2985 because it fits this design purpose perfectly: 150mA, SOT23 sized LDO voltage regulator. Easy to fit in the design.
While waiting for the PCB from Oshpark, I ordered a bunch of LP2985s from Aliexpress because I thought I could afford to wait and as I didn’t have anything else to buy from my traditional retailers (Mouser and Farnell to name them); I did not want to be hit by hefty shipping charges.
The first thing I did when I got the PCB: solder in the regulator. First test: 12.2V in… 11.5V out?… Wait a minute… Let’s try another one… Same result?
By the end of this counterfeit LP2985 fiasco, I’ll have lost a whole month. This small side project is now waiting for an order at Farnell for a dozen of LP2985s and a few other things like power inductors to reach the free shipping threshold.
It was my first and last time buying ICs from online Chinese sellers. In my experience passive components such as resistors and ceramic capacitors are still OK.