EEVblog Electronics Community Forum

Electronics => Manufacturing & Assembly => Topic started by: CyberPK on April 18, 2016, 12:56:43 am

Title: This SN74HC00N looks genuine to you?
Post by: CyberPK on April 18, 2016, 12:56:43 am

I've buyed from a chinese seller a couple of 74hc00.
I think they are fake. What do you think about? How can I check it works as expected?

Thank you!

P.S. I know, I know, never buy from untrusted seller....

Title: Re: This SN74HC00N looks genuine to you?
Post by: T3sl4co1l on April 18, 2016, 01:34:25 am

We (by reading and typing) have already wasted more than enough time to render the question moot.

If you have to ask, the answer is most likely: no.

Offhand, I don't see any TI parts in my collection with that exact font width, and all the date codes start with one or two numbers, never letters.  The plastic and laser etching look good.

Tim

Title: Re: This SN74HC00N looks genuine to you?
Post by: amyk on April 18, 2016, 03:18:54 am

It's four NAND gates... I'd say fake or not, their operation is going to be pretty easy to check and this is basically a cheap "jellybean" part where the die costs almost nothing.

Title: Re: This SN74HC00N looks genuine to you?
Post by: mij59 on April 18, 2016, 03:47:17 am

From the limited components I ordered from China, I say there's most of the time something wrong with it.
Measure the properties of the chips and compare them  with the data sheet.

You could check the supply current as function of the logical states, output drive capability,  rise time, propagation delay.

 

Title: Re: This SN74HC00N looks genuine to you?
Post by: bson on April 23, 2016, 06:22:42 am

It's hard to tell, but the pins look like they might be tinned.  They look too shiny.  If so, it's likely recycled.

Title: Re: This SN74HC00N looks genuine to you?
Post by: wraper on April 23, 2016, 07:00:30 am

Looks fake, wrong font, too large marking, TI logo is wrong, no proper space around "i", Texas state has changed it's shape :), character count in the first row is 8 VS 7 that normally should be. Lead shape and finish seem to be wrong too. Genuine IC should look like this:
(http://cdn3.bigcommerce.com/s-vt19phz/products/2167/images/5812/Texas_Instruments_74AHCT125_Quad_Level_Shifter_3V_to_5V_from_Tronixlabs_Australia__65425.1425434475.1280.1280.jpg?c=2)
(http://tronixstuff.com/wp-content/uploads/2010/06/hello4541small.jpg?w=300&h=173)
(http://sigma.octopart.com/44714041/image/Texas-Instruments-SN74HC14N.jpg)