EEVblog Electronics Community Forum

Products => Other Equipment & Products => Topic started by: Urs42 on December 03, 2018, 08:22:41 am

Title: Fake LM2596HV again?
Post by: Urs42 on December 03, 2018, 08:22:41 am
I guess you can't expect too much for $1.46. The linked modules did work with 30V but it didn't like 50V...

https://www.aliexpress.com/item/DC-DC-Converter-Adjustable-Power-Supply-DC-DC-Step-Down-3A-LM2596HVS-LM2596HV-DC-Step-Down/32485142548.html (https://www.aliexpress.com/item/DC-DC-Converter-Adjustable-Power-Supply-DC-DC-Step-Down-3A-LM2596HVS-LM2596HV-DC-Step-Down/32485142548.html)

Title: Re: Fake LM2596HV again?
Post by: thm_w on December 04, 2018, 10:50:32 pm
What output current?
Is there any chance it spiked above 50V, what is the source?

They seem to be re-made by some chinese manufacturers, guess the demand is high: http://hmsemi.com/downfile/LM2596HV.PDF (http://hmsemi.com/downfile/LM2596HV.PDF)

I had a boost board recently where I assumed the MT3608 was fake as the adjustment wasn't working initially, but oddly ended up being a layout issue.
Title: Re: Fake LM2596HV again?
Post by: tsman on December 04, 2018, 11:05:40 pm
Pretty sure all of those modules are counterfeit. They're all sold for less than the bulk pricing of the chip alone. The switching frequency is far lower and they've got a tendency to die with an input to output hard short so wave goodbye to anything downstream from this.

The logo is for NatSemi and they got bought out by TI in 2011. I can't even find a datasheet for a LM2596HVS. It is just endless listings for these modules and chip supplier databases.