Author Topic: Replacement for LM3915  (Read 24412 times)

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Offline ebclr

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Re: Replacement for LM3915
« Reply #25 on: May 25, 2017, 08:40:53 pm »
OK, I understand you want controversy, not the component to be used in your circuit
 

Offline Ian.M

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Re: Replacement for LM3915
« Reply #26 on: May 25, 2017, 08:48:35 pm »
How many pieces do you want?

Who cares about TI
It doesn't matter how many. I want to know they work, haven't been stored in a damp cardboard box for five years, and weren't removed from some old PCB with a blowtorch and the edge of a table.
Who uses blowtorches?  I thought the 3rd world favourite was desoldering over an open brazier fueled by some unholy mix of low grade coal, dung, chopped up PCBs and plastic case parts.   Then after the table slam manoeuvre,  washed in the nearest river just downstream of the sewer outfall and dried on the pavement with rats pissing on them and trucks belching diesel soot over them, before sorting by child labour dressed in shoddy synthetics guaranteed to produce >10KV ESD on any day it isn't actually raining through the workshop roof.
 

Offline Monkeh

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Re: Replacement for LM3915
« Reply #27 on: May 25, 2017, 09:40:49 pm »
OK, I understand you want controversy, not the component to be used in your circuit

If I actually wanted an LM3915 (I don't, presently), I'd want a real one. Sorry, but shady shenzhen dealers don't work for most of us.
 

Offline Bruce Abbott

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Re: Replacement for LM3915
« Reply #28 on: May 25, 2017, 10:14:14 pm »
Who uses blowtorches?  I thought the 3rd world favourite was desoldering over an open brazier fueled by some unholy mix of low grade coal, dung, chopped up PCBs and plastic case parts.   Then after the table slam manoeuvre,  washed in the nearest river just downstream of the sewer outfall and dried on the pavement with rats pissing on them and trucks belching diesel soot over them, before sorting by child labour dressed in shoddy synthetics guaranteed to produce >10KV ESD on any day it isn't actually raining through the workshop roof.
And after all that, they still work fine.

I have bought a fair number of 'vintage' computer chips off various eBay vendors, and none have failed so far. The only problem I had was mislabeled parts (a couple of '20MHz' Z80's that were actually 4MHz NMOS parts, and a bunch of 2114 '1k static RAM' chips that turned out to be LED drivers with an almost identical part number). Most of the chips I have received lately are genuine pulls or unused parts which have not been tampered with - and they all work perfectly!

You may joke about it, but I for one appreciate the efforts of the 'Third World' to recycle components that otherwise would be wasted. I also do it myself, but modern electronic devices yield very few useful parts. It is a shame that our 'advanced' economies have to be based on the ever-increasing production of junk that just ends up in landfills or worse.
 
 

Offline Ian.M

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Re: Replacement for LM3915
« Reply #29 on: May 25, 2017, 10:24:35 pm »
I've done the blowtorch and slam method of recycling myself way back when I couldn't afford new TTL, (real 74xx not this newfangled LS stuff) and hotplate and slam is good for quick stripping SMD stuff, but I always put a heavy cloth down in the target area to avoid impact damage, and never felt the need to wash the salvaged parts in contaminated water.
 

Offline Richard CrowleyTopic starter

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Re: Replacement for LM3915
« Reply #30 on: May 25, 2017, 10:50:50 pm »
You cannot rely on gray-market parts if your product's (and you company's) reputation is on the line.  Of course if you are talking about casual hobby stuff, then go for it.  Sometimes, the lack of vision around here is astounding.
 

Offline ebclr

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Re: Replacement for LM3915
« Reply #31 on: May 25, 2017, 11:09:46 pm »
If you want to use LM3915 on your 30 year old project you have no other option than buying the component where they are available.

If you believe that they aren't reliable instead of solving your problem quick and in a cheap way, Maintain your xenophobic criteria and remake your 30 year old project with some fresh technology. But this is not necessary for a simple Led bargraph .

If you need only a few units you can buy easily online just go to aliexpress and type LM3915, if you wana buy directly from TI, put your project on the trash can and try something else.

If you can think outside the box make a try

https://www.aliexpress.com/wholesale?ltype=wholesale&d=y&origin=y&isViewCP=y&catId=0&initiative_id=SB_20170525150742&SearchText=lm3915&blanktest=0&tc=af




 

Offline technix

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Re: Replacement for LM3915
« Reply #32 on: May 26, 2017, 12:07:11 am »
You can maintain a test bed (especially if you are using DIP chips) and test all chips you received before using them.
 

Offline westfw

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Re: Replacement for LM3915
« Reply #33 on: May 27, 2017, 09:18:42 am »
Quote
If I actually wanted an LM3915 (I don't, presently), I'd want a real one. Sorry, but shady shenzhen dealers don't work for most of us.
Why?  You don't think you can trust China to produce a working version of a 30-year old chip, whose main function is a visual indicator?  Or do you have some alternate reality where properly operation and exactly identical behavior of blinky lights is a mission-critical function?
 ;)
 

Offline ebclr

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Re: Replacement for LM3915
« Reply #34 on: May 28, 2017, 05:42:54 am »
Those people believe on "gnomes" they only buy from Digikey paying 3 times China price, just because they love to be ripped off, believing that Digikey is a "reliable" supplier and that  Schensen market isn't. They refuse to accept that the real electronic component market is in China. And China for sure have 1st class suppliers ( majority) and also several 3rd class who sell fake, used, copied ( minority). Just because you can buy a Fake Rolex in Times Square does not mean that all Rolex in USA is fake.

Wakeup



 

Offline Monkeh

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Re: Replacement for LM3915
« Reply #35 on: May 28, 2017, 01:08:02 pm »
Those people believe on "gnomes" they only buy from Digikey paying 3 times China price, just because they love to be ripped off, believing that Digikey is a "reliable" supplier and that  Schensen market isn't. They refuse to accept that the real electronic component market is in China. And China for sure have 1st class suppliers ( majority) and also several 3rd class who sell fake, used, copied ( minority). Just because you can buy a Fake Rolex in Times Square does not mean that all Rolex in USA is fake.

Wakeup

I can wait weeks to get an item from China, with a moderate to high chance of it being inappropriately packaged, salvaged, scrap which didn't meet testing criteria, or outright fake, or any combination of the above, plus the threat of having to deal with it going through customs pushing the price up by up to a factor of two, or I can just get it tomorrow with an extremely low chance of any of the above and a fixed price.

Nah, I'm asleep, China's the best way to buy things. So easy to search for things on Aliexpress, too, why would I want a nice parametric engine?

I buy all sorts of stuff out of China to save money here and there, over a quarter of it never turns up, isn't what was advertised, doesn't perform correctly, is dead, or is fake. For some stuff that's fine, most of the time I do not want to deal with that.
« Last Edit: May 28, 2017, 01:09:38 pm by Monkeh »
 

Offline ebclr

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Re: Replacement for LM3915
« Reply #36 on: May 28, 2017, 05:03:12 pm »
I beat 80% of all thing surrounding you came from China, including your chairs, dishes, carpet windows, Ipdas, phones, ligths, car parts with few exceptions.

The point to pay more to get a quick component locally is totally valid, But  pointed the finger that everything in China is fake or not tested or bad quality or gray market isn't true,  Have parts for all flavors from a simple Atmega fake Arduino to a developed and made in China Infrared grid array to be used on missiles. Don't label China as grays market, There you can get full spectrum, you get what you paid for.

 

Offline Monkeh

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Re: Replacement for LM3915
« Reply #37 on: May 28, 2017, 05:21:04 pm »
I beat 80% of all thing surrounding you came from China, including your chairs, dishes, carpet windows, Ipdas, phones, ligths, car parts with few exceptions.

Well, I don't have an iPad, but yes, there's a lot of Chinese produce. Almost all of which is produced to specification and supplied by a more local company, or at the least one more versed in dealing with the western world, so I don't have to filter the garbage. Unlike random online sellers, they're held to quality and safety standards.

The windows fitted more recently are manufactured in the UK, though. The glass was made 10 minutes down the road from me.

Quote
The point to pay more to get a quick component locally is totally valid, But  pointed the finger that everything in China is fake or not tested or bad quality or gray market isn't true,  Have parts for all flavors from a simple Atmega fake Arduino to a developed and made in China Infrared grid array to be used on missiles. Don't label China as grays market, There you can get full spectrum, you get what you paid for.

I'm not labeling China as a grey market, just the companies (which is often a generous term) who do small-scale business with the western world. Buying parts off Aliexpress is an extremely dodgy game, especially when it comes to parts no longer manufactured, triply so for parts never available in small quantity to begin with. And the trouble is, you don't know what you paid for, because pricing over there is so utterly alien, and what we'd consider lying is standard practice.

Now, if there's a legitimate, reasonably well known company in China manufacturing LM3915s, whether it be a direct die copy or a functional equivalent (without copy and pasted specs and graphs), I'm all ears. It'd be great to hear someone is producing them. But, like other famous chips before it (XR-2206 springs to mind), I sincerely doubt anyone is - they're selling old stock if you're lucky, salvaged parts if you're not too unlucky, and outright fakes.
 

Offline ebclr

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Re: Replacement for LM3915
« Reply #38 on: May 28, 2017, 05:38:26 pm »
Did you note that you have a no question full refund on those so-called "bad business", is simple 0 risk
 

Offline Monkeh

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Re: Replacement for LM3915
« Reply #39 on: May 28, 2017, 05:40:24 pm »
Did you note that you have a no question full refund on those so-called "bad business", is simple 0 risk

Other than lost time (and if this is for a business, this can mean lost business) and potential for damage to other components...

Oh for a world in which time can be refunded.
 

Offline thm_w

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Offline Monkeh

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Re: Replacement for LM3915
« Reply #41 on: May 31, 2017, 10:37:36 pm »
Lovely.

They'll dry up soon enough if people are using them.
 

Offline Richard CrowleyTopic starter

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Re: Replacement for LM3915
« Reply #42 on: June 01, 2017, 12:28:59 am »
You would think that people here would understand what End Of Life means.
Nobody makes them anymore.    :palm:

It doesn't matter how many "Can Ship Immediately".  It just went EOL a few months ago.
The question is how many can ship next year?  Very possibly zero.

The main issue here is what to use for a new design to replace the functionality of the chip.
The comparator ladder, log resistor array, plus display driver all in a single convenient package.
 

Offline Bruce Abbott

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Re: Replacement for LM3915
« Reply #43 on: June 01, 2017, 01:37:59 am »
Back on topic...

The main issue here is what to use for a new design to replace the functionality of the chip.
I would look at a 14 PIC such as the  PIC16F1503. You need 1 ADC input and 10 LED outputs. RA3/MCLR is input only and no ADC, so you have just enough I/O pins to do the job. Max. Vss current is 210mA industrial (95mA extended), so it should be able to drive 10 LEDs at <=10mA each. 5V Vdd so it can drive any color LED. Available in 3x3 QFN (though since the LM3915 was DIP you should have plenty of room for a larger package). Only downside I can think of is you will probably need resistors to stabilize LED current, but they can be pretty small.

But you could do so much more than just replacing the functionality of the original chip. In audio applications the LM39015 usually needed a peak detector, and while you could make it do other things like flash on overload, external components were required. All this and more could easily be put inside the MCU. Plus the RA3 input could be used to change modes etc.
 
     
« Last Edit: June 01, 2017, 01:39:39 am by Bruce Abbott »
 

Offline technix

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Re: Replacement for LM3915
« Reply #44 on: June 01, 2017, 01:53:54 am »
How about something slightly more modern: STM32F030F4P6. This is indeed a 32-bit micro and a 3.3V part but it is easily hand solderable and coding it with maximum optimization is completely free (as in speech and as in beer) if you are using the GNU toolchain and Eclipse IDE.

That chip only have 120mA maximum current sinking ability but you can multiplex them so each LED gets the full current. The internal ADC can operate in differential mode if your audio chain is balanced.
 

Offline ebclr

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Re: Replacement for LM3915
« Reply #45 on: June 01, 2017, 03:38:36 am »
Virtually any microprocessor in the market who have a 8 Bit ad and some  IO capable do drive some mA will replace a LM3915, with very few lines of code, you can choose from any brand.

This eBay product is an example ( proof of concept (http://www.ebay.com/itm/16-16-Audio-LED-Level-Meter-Display-Spectrum-Analyzer-mp3-for-Amplifier-Kits-/222353845465?hash=item33c5526cd9:g:n~0AAOSw5cNYW6eF)

If the component went EOL is for a reason, no demand.

I would love to know why a simple panel indicator need to be military grade,

 

Offline Richard CrowleyTopic starter

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Re: Replacement for LM3915
« Reply #46 on: June 01, 2017, 03:48:41 am »
If the component went EOL is for a reason, no demand.

Actually, it is EOL because when TI acquired National Semiconductor, they closed down the older factories like GFAB6 in Scotland that was running the process that the higher end audio and mixed-mode products were manufactured on.  In a way it is true the demand was likely lower than the "jelly-bean" stuff that TI is more comfortable selling.

There is a long list of 100s of ICs, many of them quite innovative and for which there are no replacements.  The high-end audio world is in mourning because some of the very best audio op-amps have disappeared with GFAB6.
 

Offline ebclr

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Re: Replacement for LM3915
« Reply #47 on: June 01, 2017, 03:50:39 am »
"You would think that people here would understand what End Of Life means. Nobody makes them anymore. "

Nobody isn't TI, nobody is much wider than TI

You mean this company will close the doors.

http://www.barmeter.com/cn/index.asp

If demand exist, on a very low-tech device like this one, the supply is warranted for decades


 

Offline Monkeh

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Re: Replacement for LM3915
« Reply #48 on: June 01, 2017, 03:53:13 am »
"You would think that people here would understand what End Of Life means. Nobody makes them anymore. "

Nobody isn't TI, nobody is much wider than TI

You mean this company will close the doors.

http://www.barmeter.com/cn/index.asp

If demand exist, on a very low-tech device like this one, the supply is warranted for decades

And uh, where's their LM3915?

Once again, show me someone manufacturing the chip in question.
 

Offline ebclr

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Re: Replacement for LM3915
« Reply #49 on: June 01, 2017, 03:59:18 am »
 


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