Author Topic: Small review of LCSC  (Read 29856 times)

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Offline sokoloff

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Re: Small review of LCSC
« Reply #25 on: October 31, 2018, 01:36:39 pm »
If you run it at 5A rds on is 0.234mohm. It would be dissipating 5.85W, and a temperature of 2,100C.
If you go based off of the rds spec and 350mW max dissipation, absolute max current is more like 1.2A. So saying 5A is BS.
Power = I*I*R = 5 * 5 * 0.000234 = 0.00585 W, right?
234mR is 0.234R
Ah, prior post above had the resistance listed as 0.234mOhm, not 234mOhm, a factor of 1000 error.
 

Offline janekm

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Re: Small review of LCSC
« Reply #26 on: November 01, 2018, 07:01:55 am »
How about a part such as this

https://lcsc.com/product-detail/MOSFET_HL-1H05_C237256.html

its specs for the price don't seem authentic. Vacant also is a safe operating area - a part rated to the values which its rated to should have it specified.

That one is more suspicious.
If you run it at 5A rds on is 0.234mohm. It would be dissipating 5.85W, and a temperature of 2,100C.
If you go based off of the rds spec and 350mW max dissipation, absolute max current is more like 1.2A. So saying 5A is BS.

There are "fat" SOT23 packages which may be more suitable if you need higher currents as well.

AO3400 would be a more suitable choice for anyone needing to switch that kind of current, as it has only about 0.35mOhm on-resistance (and it's from a fairly reputable brand). It does cost about 50% more of course! The horror!  :-DD

Of course I meant 35mOhm...  |O
 

Offline LaserTazerPhaser

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Re: Small review of LCSC
« Reply #27 on: November 02, 2018, 01:52:06 am »
How about a part such as this

https://lcsc.com/product-detail/MOSFET_HL-1H05_C237256.html

its specs for the price don't seem authentic. Vacant also is a safe operating area - a part rated to the values which its rated to should have it specified.

That one is more suspicious.
If you run it at 5A rds on is 0.234mohm. It would be dissipating 5.85W, and a temperature of 2,100C.
If you go based off of the rds spec and 350mW max dissipation, absolute max current is more like 1.2A. So saying 5A is BS.

There are "fat" SOT23 packages which may be more suitable if you need higher currents as well.

AO3400 would be a more suitable choice for anyone needing to switch that kind of current, as it has only about 0.35mOhm on-resistance (and it's from a fairly reputable brand). It does cost about 50% more of course! The horror!  :-DD

There is an enormous difference in price

https://lcsc.com/product-detail/MOSFET_AOS_AO3400A_AO3400A_C20917.html

https://www.digikey.com/products/en?keywords=AO3400A
 

Offline thm_w

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Re: Small review of LCSC
« Reply #28 on: November 02, 2018, 08:08:32 pm »
There is an enormous difference in price

https://lcsc.com/product-detail/MOSFET_AOS_AO3400A_AO3400A_C20917.html

https://www.digikey.com/products/en?keywords=AO3400A

The LCSC prices are 50% more is what they mean (ok its more like 60-90% more), but the actual cost of 6c is quite low..
1H05 3.3c for 5,000
AO3400A 6.3c for 5,000

Digikey price is inflated, due to tariffs and usual markup.
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Offline rsjsouza

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Re: Small review of LCSC
« Reply #29 on: November 03, 2018, 06:29:50 pm »
At least here, a few parts I found more expensive than Mouser (ADS1240E, OPA2232AIDGKT, for example) and others were about 10~15% cheaper (ADS1232IPW).

For hobby I don't think it would make much difference, but perhaps their delivery and freight may make up for the difference.
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Offline mrpackethead

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Re: Small review of LCSC
« Reply #30 on: November 03, 2018, 07:35:24 pm »
At least here, a few parts I found more expensive than Mouser (ADS1240E, OPA2232AIDGKT, for example) and others were about 10~15% cheaper (ADS1232IPW).

For hobby I don't think it would make much difference, but perhaps their delivery and freight may make up for the difference.

There are parts that are definately more expensive on LCSC than elsewhere.   You would probably not buy microprocessors from TI, or Microchip etc from them, becuase they are more expensive.   But they do have a lot of bargins elsewhere.
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Offline Axk

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Re: Small review of LCSC
« Reply #31 on: December 02, 2018, 08:49:07 pm »
Trying to use Easy EDA and they have a handy feature where they have parts from LCSC in the component library.
I've just tried with a couple of parts, but looks very handy. At least for hobby use.
And there's apparently an option to ship parts and PCBs in one shipment.
So one can order parts while designing and have them shipped with the boards.
Haven't ordered yet, but at least in theory very convenient.
 

Online bd139

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Re: Small review of LCSC
« Reply #32 on: December 02, 2018, 09:29:01 pm »
To note the parts and the boards are ordered at the same time but don't necessarily turn up at the same time... as I found out. 4 days between them.
 

Offline Axk

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Re: Small review of LCSC
« Reply #33 on: December 02, 2018, 11:21:15 pm »
To note the parts and the boards are ordered at the same time but don't necessarily turn up at the same time... as I found out. 4 days between them.

Even when you check the checkbox to combine the orders? https://support.lcsc.com/article/24-do-you-offer-combine-shipment-with-pcbs
 

Online bd139

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Re: Small review of LCSC
« Reply #34 on: December 02, 2018, 11:25:44 pm »
Yep. Well once attempt from me failed miserably so far. I've heard other similar stories.

Still I have no complaints.
 
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Online HwAoRrDk

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Re: Small review of LCSC
« Reply #35 on: December 04, 2018, 12:58:41 am »
I did an order recently with LCSC where I combined shipping with a PCB order from JLC. Not impressed either with the way they handled it.

While mine did at least turn up together in one package, it was the rest I had trouble with. Firstly, I got a "your order was shipped" e-mail from JLC when according to the order progress on LCSC that half wasn't even ready for despatch yet. Second, the tracking number in that e-mail, while it was for my package, was linked to the wrong site (17track), which had no record of it (should have been 4PX, which did). And third, even though I have since received everything, my LCSC order status still says "waiting for pickup".

So, the accuracy of communication is terrible. Will probably not bother doing it again, and just pay the extra few pounds for separate shipping.
 
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Offline LaserTazerPhaser

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Re: Small review of LCSC
« Reply #36 on: December 13, 2018, 06:49:26 am »
Its not authentic

https://pasteboard.co/HRv92kV.png

no were to be found also

https://www.infineon.com/cms/en/product/where-to-buy/

Same goes for TI

http://www.ti.com/info-store/distributors.html

parts on the site are likely similar to those found on ebay and aliexpress but with different performance.
« Last Edit: December 13, 2018, 07:20:28 am by LaserTazerPhaser »
 

Online bd139

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Re: Small review of LCSC
« Reply #37 on: December 13, 2018, 07:44:28 am »
That doesn’t mean it’s not authentic just that they aren’t the first hop in the supply chain.

About a decade ago someone at Crucial didn’t know that they were selling micron products  :-//
 

Offline LaserTazerPhaser

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Re: Small review of LCSC
« Reply #38 on: December 13, 2018, 08:34:25 am »
The several orders I placed including PCBs were very well packaged very much like if not precisely the same as digikey does.
But you get antistatic baggies and transistor tubes from aliexpress and ebay also.

But digikey way overdoes it on paper wrapping. Mcmaster is a bit more overboard than both of them, they just go very far to prevent product damage in transit.

The parts inscription appear to be identical however the small circle indent is not identical
https://lcsc.com/product-detail/MOSFET_Infineon-Technologies_IRF4905PBF_Infineon-Technologies-IRF4905PBF_C2564.html?manu_id=330

https://www.newark.com/infineon/irf4905pbf/p-channel-mosfet-55v-74a-to-220ab/dp/63J7300?st=IRF4905PBF

LCSC photographs most of the parts they have which makes them seem more legitamate.
« Last Edit: December 13, 2018, 08:43:23 am by LaserTazerPhaser »
 

Offline mrpackethead

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Re: Small review of LCSC
« Reply #39 on: December 13, 2018, 08:45:08 am »
Its not authentic

https://pasteboard.co/HRv92kV.png

no were to be found also

https://www.infineon.com/cms/en/product/where-to-buy/

Same goes for TI

http://www.ti.com/info-store/distributors.html

parts on the site are likely similar to those found on ebay and aliexpress but with different performance.

LCSC is not the registered business name of the company either.   

I have found that TI parts are better priced from other distribution lines,  ( TI directly in fact is very good ).   I mostly buy passives from them, and have done a little bit of checking on them, and was able to verify that my electrolytic caps ( panasonic ) were in fact bonafide real parts.   My chinese manufacturing partners also use them a LOT and have had no problems, with fake parts, or re-reels.   If you look at prices at LCSC vs what is avaialbe out of the SEG for example, they are often 3x higher, as they just are not a grey-market reseller.
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Online ataradov

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Re: Small review of LCSC
« Reply #40 on: December 13, 2018, 08:48:48 am »
Its not authentic
Not being an authorized distributor does not mean they are not selling authentic parts. There are many ways parts can get on the market.
Alex
 
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Offline LaserTazerPhaser

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Re: Small review of LCSC
« Reply #41 on: December 13, 2018, 09:04:28 am »
Its not authentic

https://pasteboard.co/HRv92kV.png

no were to be found also

https://www.infineon.com/cms/en/product/where-to-buy/

Same goes for TI

http://www.ti.com/info-store/distributors.html

parts on the site are likely similar to those found on ebay and aliexpress but with different performance.

LCSC is not the registered business name of the company either.   

I have found that TI parts are better priced from other distribution lines,  ( TI directly in fact is very good ).   I mostly buy passives from them, and have done a little bit of checking on them, and was able to verify that my electrolytic caps ( panasonic ) were in fact bonafide real parts.   My chinese manufacturing partners also use them a LOT and have had no problems, with fake parts, or re-reels.   If you look at prices at LCSC vs what is avaialbe out of the SEG for example, they are often 3x higher, as they just are not a grey-market reseller.

I recently placed orders with LCSC for passives along with a few other things well over 180 items and largely went with companies which I did not hear of - particularly Guangdong Fenghua Advanced Tech going off their website

http://www.fenghua-advanced.com

which is very decent and they have patents https://patents.google.com/?assignee=Guangdong+Fenghua+Advanced+Tech+Holding+Co+Ltd make them legitimate. Another company makes mosfets which is http://en.sinoictest.com.cn/newsinfor/p7_59.html?&pageid=7&_id=59 I noted another company Wuxi NCE Power Semiconductor participates in IEEE events https://ieeexplore.ieee.org/search/searchresult.jsp?newsearch=true&queryText=Wuxi%20NCE%20Power%20Semiconductor the important object about these companies is they stand by their products and provide datasheets for them right off their websites. This is a great indicator for authentic parts.
« Last Edit: December 13, 2018, 09:30:43 am by LaserTazerPhaser »
 
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Offline mrpackethead

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Re: Small review of LCSC
« Reply #42 on: December 13, 2018, 09:20:50 am »
I've been buying a lot of large inductors for Buck Regulators, and had great results from them. More than happy.  And saving 60% over a 'name' brand.  IN essense its a coil of wire on a ferrite former.  theres not that much that can go wrong with it.

Electrolytics are possibly my most likely to fail part, so I typically will run with more know brands there.   
On a quest to find increasingly complicated ways to blink things
 
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Offline cdev

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Re: Small review of LCSC
« Reply #43 on: December 16, 2018, 02:45:14 pm »
I'm looking for small RF parts- saving a lot of money on parts would be very nice. If I just knew which parts were the ones I wanted.

I've been buying a lot of large inductors for Buck Regulators, and had great results from them. More than happy.  And saving 60% over a 'name' brand.  IN essense its a coil of wire on a ferrite former.  theres not that much that can go wrong with it.


Certain RF applications are technically challenging for manufacturers. For example, making an RF choke that has a low internal capacitance and high self-resonant frequency requires very thin wire and use of materials that don't degrade performance but offer adequate support to the coil at the same time.
« Last Edit: December 16, 2018, 02:48:42 pm by cdev »
"What the large print giveth, the small print taketh away."
 

Offline wraper

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Re: Small review of LCSC
« Reply #44 on: December 21, 2018, 12:40:02 am »
The mosfets dont appear to be identical
Package itself looks exactly the same and marking does not look like Chinesium counterfeits have with low laser resolution. No signs of sanding surface with marking. I'm pretty sure it's genuine.
 

Offline LaserTazerPhaser

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Re: Small review of LCSC
« Reply #45 on: December 21, 2018, 12:42:38 am »
The mosfets dont appear to be identical
Package itself looks exactly the same and marking does not look like Chinesium counterfeits have with low laser resolution. No signs of sanding surface with marking. I'm pretty sure it's genuine.

Is there a chemical free way to get to the die?
 

Offline wraper

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Re: Small review of LCSC
« Reply #46 on: December 21, 2018, 12:46:55 am »
You can break plastic from the tab. Die will break but you still will be able to estimate it's area. IMHO just measuring RDS(on) is enough in this case.
« Last Edit: December 21, 2018, 12:48:38 am by wraper »
 

Offline LaserTazerPhaser

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Re: Small review of LCSC
« Reply #47 on: December 21, 2018, 12:53:15 am »
« Last Edit: December 21, 2018, 08:37:48 am by LaserTazerPhaser »
 

Offline LaserTazerPhaser

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Re: Small review of LCSC
« Reply #48 on: December 21, 2018, 01:57:28 am »
You can break plastic from the tab. Die will break but you still will be able to estimate it's area. IMHO just measuring RDS(on) is enough in this case.

I did measurements varying Vgs putting 4amps thru drain to source and both parts were not close to be identical. The die packages do look identical.

https://pasteboard.co/HSGGk9m.jpg
« Last Edit: January 10, 2019, 09:54:44 am by LaserTazerPhaser »
 
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Offline 1276-2449-1-ND

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Re: Small review of LCSC
« Reply #49 on: December 27, 2018, 10:22:33 pm »
Trying to spot fakes by looks isn't going to work. ICs are made in batches, often years apart, sometimes by completely different fabs in different countries.

Most counterfeits (especially from Asia) are done by the same contract manufacturer that made the originals. Since they have all the machines and workers set up, they'll just run them a few days longer to make a batch for themselves.

In short, even if it looks and functions 100% identical it could still be counterfeit. Yet it could look different and the specs be a bit off and be completely authentic.
 


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