[juliyet]

Hey guys, I bought some chips from eBay lately, but some of them blow out during using, some works fine, especially the lm338, how to test it to know if its fake, or how do I know if it's broke?
Btw, does this introduction to lm338 accurate? https://www.apogeeweb.net/circuitry/...regulator.html
Thanks in advance

[CitizenOfDreams]

My guess is that most chips you buy on eBay/AliExpress are of suspicious origin. That's not to say they are "fake" or "bad" - they are usually legitimate products that work perfectly fine.

How exactly are you using those LM338s? What is your input voltage, output voltage and load current? What are the values of the input/output capacitors? Are there voltage spikes in your circuit? Do the chips get adequate cooling? Those are linear regulators, so they dissipate ALL "unused" V*I as heat.

The introduction on that website pretty much just quotes the manufacturer's datasheet, so it is accurate.