LM1875 Original or fake ?

Gold_xyz · 11th December 2006, 05:26 PM

Hallo !

I have purchased five tda1875 to build a Multichannel amplifier.
Today when I have gone to withdraw I have noticed them that the pins are folded up in different way.

these are the photos:

the original from datasheet :

Datasheet from factory :
http://www.national.com/ds/LM/LM1875.pdf

Original

or fake

?

tnx !

Leolabs · 12th December 2006, 01:42 AM

The topic title is misleading,it's LM1875 rather than TDA1875.

Well,the rear of the IC looks kind of weird to me.

Dxvideo · 12th December 2006, 07:02 AM

Hi Gold,

Most possible its FAKE... There are a lot of fake LM chips on market... Have a look to pin tips. I've never seen any like that.. And if its not a second hand IC, why has many scratchs on its case? I bought two LM1876 from a local market and they were look like your LM1875. Now they're in trash bin... Because they burned (from my fault, but probably they would burn even i made everything ok). I recommend; dont use them.

Stuey · 12th December 2006, 07:29 AM

Hi Gold,

The quality and precision of construction doesn't look as high as the proper National Semiconductor chips, I'm afraid. It does look like a fake.

Did you buy them from a store, or online?

Stuey

Gold_xyz · 12th December 2006, 01:16 PM

Quote:

Originally posted by Leolabs
The topic title is misleading,it's LM1875 rather than TDA1875.

Well,the rear of the IC looks kind of weird to me.

ehm.. I am sorry for the mistake..

I wanted to write LM1875

Gold_xyz · 12th December 2006, 01:34 PM

Hi

I have bought these ic in a shop for new. Five LM1875 for 10€
And the shopkeeper has ordered them from an Italian wholesaler.

Fake ? Ouch ! Grumble...

bye

jpg · 12th December 2006, 07:35 PM

I can only compare to my LM3875s, which are the only LM chips that I've ever closely examined.

1) The form of the pin tips of your (alleged) LM1875 look different both from my LM chips and from the specs.

2) As you can see in the specs, the pins should all be stepped, not only those in the front row. In your photo, it looks like the pins in the back row are straight!

3) The bend of the pins in the front row looks much sharper on my chips and in the specs.

4) It's hard to tell, but the metal back of your chip looks more coarsly machined then mine.

Gold_xyz · 13th December 2006, 12:25 PM

Hallo !

Now it is official, they are fake ...

This is the answer of National Semicon :
"Henry,
Based on the topmark of the device, the part was most likely not manufactured by National Semiconductor.
Thanks. "

I am desperate now I have to order from another supplier and to hope that he have the true ICs...

bye.

DJ Exprice · 17th December 2006, 04:18 PM

If you order samples from NS, are they always real?

jpg · 17th December 2006, 04:45 PM

Why wouldn't they be real? The sample programme isn't meant to provide hobbyists with free chips, it's meant to initiate business relations. I don't think National sends out fakes in order to ruin their reputation.

11th December 2006, 05:26 PM	#1
Gold_xyz diyAudio Member Join Date: Dec 2005 Location: Italy	TDA1875 Original or fake ? Hallo ! I have purchased five tda1875 to build a Multichannel amplifier. Today when I have gone to withdraw I have noticed them that the pins are folded up in different way. these are the photos: the original from datasheet : Datasheet from factory : http://www.national.com/ds/LM/LM1875.pdf Original or fake ? tnx ! __________________ My English originates from here

12th December 2006, 01:34 PM	#6
Gold_xyz diyAudio Member Join Date: Dec 2005 Location: Italy	Hi I have bought these ic in a shop for new. Five LM1875 for 10€ And the shopkeeper has ordered them from an Italian wholesaler. Fake ? Ouch ! Grumble... bye __________________ My English originates from here

13th December 2006, 12:25 PM	#8
Gold_xyz diyAudio Member Join Date: Dec 2005 Location: Italy	Hallo ! Now it is official, they are fake ... This is the answer of National Semicon : "Henry, Based on the topmark of the device, the part was most likely not manufactured by National Semiconductor. Thanks. " I am desperate now I have to order from another supplier and to hope that he have the true ICs... bye. __________________ My English originates from here

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12th December 2006, 01:42 AM	#2
Leolabs diyAudio Member Join Date: Dec 2004 Location: Bukit Mertajam	The topic title is misleading,it's LM1875 rather than TDA1875. Well,the rear of the IC looks kind of weird to me.

12th December 2006, 07:02 AM	#3
Dxvideo diyAudio Member Join Date: Nov 2003 Location: Turkey	Hi Gold, Most possible its FAKE... There are a lot of fake LM chips on market... Have a look to pin tips. I've never seen any like that.. And if its not a second hand IC, why has many scratchs on its case? I bought two LM1876 from a local market and they were look like your LM1875. Now they're in trash bin... Because they burned (from my fault, but probably they would burn even i made everything ok). I recommend; dont use them.

12th December 2006, 07:29 AM	#4
Stuey diyAudio Member Join Date: Mar 2006 Location: Perth, Western Australia	Hi Gold, The quality and precision of construction doesn't look as high as the proper National Semiconductor chips, I'm afraid. It does look like a fake. Did you buy them from a store, or online? Stuey

12th December 2006, 07:35 PM	#7
jpg diyAudio Member Join Date: Mar 2003 Location: Germany	I can only compare to my LM3875s, which are the only LM chips that I've ever closely examined. 1) The form of the pin tips of your (alleged) LM1875 look different both from my LM chips and from the specs. 2) As you can see in the specs, the pins should all be stepped, not only those in the front row. In your photo, it looks like the pins in the back row are straight! 3) The bend of the pins in the front row looks much sharper on my chips and in the specs. 4) It's hard to tell, but the metal back of your chip looks more coarsly machined then mine.

17th December 2006, 04:18 PM	#9
DJ Exprice diyAudio Member Join Date: Mar 2006 Location: San Francisco, California	If you order samples from NS, are they always real?

17th December 2006, 04:45 PM	#10
jpg diyAudio Member Join Date: Mar 2003 Location: Germany	Why wouldn't they be real? The sample programme isn't meant to provide hobbyists with free chips, it's meant to initiate business relations. I don't think National sends out fakes in order to ruin their reputation.

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