Replacement for LM3915

[Richard Crowley]

I knew it was coming, but was nevertheless shocked when I went to the Texas Instruments website and they didn't acknowledge that the very popular classic National Semi "bar graph driver" series (LM3914, 3915, 3916) had ever even existed. "Page not found" was all they replied with.  What a sad end.   

So I am soliciting help in identifying a microcontroller (or FPGA?) with these characteristics

• One analog input.  8-bit resolution is plenty good enough
• Ten outputs that can drive LED (10-20mA)
• Bonus: very tiny package (BGA?)

The LM391x series had 10 outputs, and there are hundreds of LED bar graph displays which have 10 elements.  That makes them awkward to use with things like LM339 quad comparators (not to mention that this is the 21st century).  I would like to find a single-chip solution. There are many options if I have to devolve by replacing an integrated chip with a bunch of discrete semis and passives.

So, what are my options?  I have some projects (perhaps small-scale commercial products) in mind that could use something like this.  Or are there perhaps (unauthorized) "counterfeit" LM391x chips still available from the Far East?

[BravoV]

  Or are there perhaps (unauthorized) "counterfeit" LM391x chips still available from the Far East?

There are tons of sellers from Aliexpress, friend bought them once while ago and they work as spec.

No particular selection, just randomly search and with high rating from the buyers feedback -> https://goo.gl/dqzq2R or you can search for your self.

[Monkeh]

So.. basically any ADC equipped micro on the market? Most of them can handle sourcing or sinking ~10mA per pin..

[ebclr]

Any processor line that have one AD will fit, foir this and much more than this

PIC16F
C8051F350
MEGA328
STM32F101   
and another thousands models

http://www.ebay.com/itm/LED-Music-Spectrum-Display-Analyzer-MP3-PC-Amplifier-Audio-Level-Indicator-kits-/331734664602?var=&hash=item4d3ced459a:m:mFAX1kyBnHbrqhWlMoYY3fQ

LM3915 still widely available

https://world.taobao.com/search/search.htm?_ksTS=1481264894814_313&spm=a21bp.7806943.20151106.1&_input_charset=utf-8&navigator=all&json=on&q=LM3915&callback=__jsonp_cb&cna=Fb46ECHjIXICAbrne69e0gIM&abtest=_AB-LR517-LR854-LR895-PR517-PR854-PR895

[Kjelt]

Stm8 series, widely used in China for the Led Voltage / Current indicators.
Built in oscillator,  8 or 10 bit adc, cheap.

[Kleinstein]

Many small µC can do the job. For 10 LEDs one will need a µC with something like 14-16 Pins if one does not use a kind of multiplexing. A modern LEDs usually don't need 10 mA any more - one could well use multiplexing to do something like 2 channels from one chip.

With so few pins I would not want BGA, more like tssop, MLF or QFN. The LEDs have certain size anyway. You may not want a tight tolerance process for such a board, maybe even wave soldering.

[forrestc]

I knew it was coming, but was nevertheless shocked when I went to the Texas Instruments website and they didn't acknowledge that the very popular classic National Semi "bar graph driver" series (LM3914, 3915, 3916) had ever even existed. "Page not found" was all they replied with.  What a sad end.   

So I am soliciting help in identifying a microcontroller (or FPGA?) with these characteristics

• One analog input.  8-bit resolution is plenty good enough
• Ten outputs that can drive LED (10-20mA)
• Bonus: very tiny package (BGA?)

The LM391x series had 10 outputs, and there are hundreds of LED bar graph displays which have 10 elements.  That makes them awkward to use with things like LM339 quad comparators (not to mention that this is the 21st century).  I would like to find a single-chip solution. There are many options if I have to devolve by replacing an integrated chip with a bunch of discrete semis and passives.

So, what are my options?  I have some projects (perhaps small-scale commercial products) in mind that could use something like this.  Or are there perhaps (unauthorized) "counterfeit" LM391x chips still available from the Far East?

16F506 in QFN package?  3x3mm.  Under $1.

Actually scratch that... A PIC16F1503 is the same size and the same price, and might open up some interesting applications for you.

[technix]

STC15F401AS in SO-16 or DIP-16? That chip is 20-30 US cents each, 1-cycle 8051 architecture, internal calibrated oscillator and POR, and comes with a 8-bit ADC.

[Monkeh]

LM3915 still widely available

https://world.taobao.com/search/search.htm?_ksTS=1481264894814_313&spm=a21bp.7806943.20151106.1&_input_charset=utf-8&navigator=all&json=on&q=LM3915&callback=__jsonp_cb&cna=Fb46ECHjIXICAbrne69e0gIM&abtest=_AB-LR517-LR854-LR895-PR517-PR854-PR895

Via back alley sellers, yes. The fab which made it is being (has been?) closed.

[Richard Crowley]

Via back alley sellers, yes. The fab which made it is being (has been?) closed.

Has been.  As I mentioned in the original question.
So the only source now is questionable stock from unauthorized, 3rd party sellers.
And of limited and finite supply since they are not being made anymore.
Hence my search for a functional replacement.

[Ian.M]

There are two problems with this idea:
1.  LED current limiting:  Most MCUs will require external resistors for each LED.
2. Supply voltage: A LM3914/5/6 has a max supply voltage of 25V, but most MCUs Vdd <5.5V.

Probably the best solution is to use two chips - a SPI LED driver + a small MCU to do the ADC conversion and control the LED driver.   If the LED driver has a regulated output <5.5V or add an external regulator you've got a lot of options for an 8 pin MCU, but if you choose one that doesn't its far more restrictive.   Microchip's PIC12HV615 has an internal shunt regulator + the required ADC, and is available in a 3x3mm DFN package, and can run from any fixed supply voltage >5V with only an external dropper resistor + a decoupling cap.

[wraper]

I knew it was coming, but was nevertheless shocked when I went to the Texas Instruments website and they didn't acknowledge that the very popular classic National Semi "bar graph driver" series (LM3914, 3915, 3916) had ever even existed. "Page not found" was all they replied with.  What a sad end.   
[/list]

LM3914 is active product. But I won't use it. Except you would need external resistors (I would go for cheap SMD resistor networks), $ 0.5 MCU can do the same or better and will be more flexible and provide additional functionality.

[wraper]

http://eu.mouser.com/ProductDetail/Silicon-Labs/EFM8BB10F2G-A-QFN20/?qs=sGAEpiMZZMu6TJb8E8CjrwBsgQXTdCLERcnzQKHvN68%3d
Extremely small as you asked (3x3 mm), $0.41 @ quantity of 1. 16 I/O (5V tolerant and can drive leds powered from 5V power rail), 12 bit ADC. Precision internal oscillator, don't need any crystal. Max VDD is 3.6V so may be somewhat limiting.
But you can go to a little bit more expensive EFM8UB1 series which have internal 5V->3.3V LDO, and even have USB on top of that, LOL. Could upgrade your bar graph firmware via USB with no other parts that connector needed.
P.S. Check reference manual as datasheet is quiet limited.

[David Hess]

I knew it was coming, but was nevertheless shocked when I went to the Texas Instruments website and they didn't acknowledge that the very popular classic National Semi "bar graph driver" series (LM3914, 3915, 3916) had ever even existed. "Page not found" was all they replied with.  What a sad end.   

TI also ignores older less expensive products which are still active in their selection guides so unless you know exactly what part you are looking for, it often cannot be found.

[MarcusS]

I too have the same problem.  My application that I have has been using LM3915s for an audio power meter display on a production audio amplifier.

I haven't yet found a solution to this.  I'm surprised TI haven't released a replacement for the LM3915 even if the replacement was an SMD package.  Certainly I need to be on a scrounge to build up some stock of these until I have a simple redesign method.  I don't want to go the microcontroller option when it is an IC that is quite simple.  Nor do I want to fill my board up with quad op amps and more discrete resistors when to date I have been able to do what I needed to do with 1 simple IC.

[ElektroQuark]

TI has the LM3914 as an active part in production: CLICK!

[MarcusS]

TI has the LM3914 as an active part in production: CLICK!

I know that.  Not sure how much longer for but besides that its not really suitable for an audio power meter as it is not logarithmic.

[ElektroQuark]

Sorry, the info was for the OP.

EDIT:

Ouch! The original post is from 2016!

[danadak]

Use a PSOC -

For me what stands out is -

1) Routability
2) Fast 12 bit SAR A/D and slow 20 bit DelSig
3) DFB (Digital Filter Block) that is dual channel, handle FIR or IIR filters, or DFB
can be used as a GP fast processor block, similar to RISC block
4) MSI logic elements GUI based and/or the UDB Verilog capability. Eg. the FPGA
like capability
5) Onboard Vref
6) IDAC, VDAC, OpAmps (up to 4), comparator, mixer, switch cap, analog mux....
7) LCD,  COM, UART, I2C, I2S, One Wire, SPI, Parallel, LIN, CAN, BLE, USB
9) Custom components capability, create with schematic capture or Verilog
10) DMA to offload processes like filters, COM, Display
11) ARM M0 (PSOC 4) or M3 (PSOC  5LP) or 8051 core(PSOC 3)
12) Extensive clock generation capabilities
13) All components supported by extensive prewritten APIs

https://www.element14.com/community/thread/23736/l/100-projects-in-100-days?displayFullThread=true

http://www.cypress.com/documentation/code-examples/psoc-345-code-examples

Great video library

Attached component list.  A component is an on chip HW resource.

Free GUI design tool with schematic capture, "Creator". Components have rich API library attached
to each component. Compilers free as well.

PSOC 4 is low end of family, consider 5LP parts as well. PSOC 4 also has arduino footprint boards (pioneer) as well

https://www.elektormagazine.com/labs/robot-build-with-cypress-psoc

http://www.cypress.com/products/32-bit-arm-cortex-m-psoc





Regards, Dana.

[technix]

I am very suspicious of the Cypress PSoC promotional posts here... For tasks like this I would think something like a STM32F030F4P6 is the highest grade processor I would consider using.

[ebclr]

LM3915 still widely available, no needs for replacements

[Richard Crowley]

LM3915 still widely available, no needs for replacements 

It is still on the "Withdrawal of the Select Devices Sourced in GFAB6 " list from Texas Instruments.
Perhaps it is in "zombie" status.  (walking dead).

Furthermore Texas Instruments is selling off the entire Greenock, Scotland site:
http://atreg.com/available-for-sale-ti-200mm-150mm-fab-greenock-scotland/

[Monkeh]

LM3915 still widely available, no needs for replacements

We're all aware your definition of available is a little skewed, but be serious, they're no longer manufacturing the things.

[ebclr]

How many pieces do you want?

Who cares about TI

[Monkeh]

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.

[ebclr]

OK, I understand you want controversy, not the component to be used in your circuit

[Ian.M]

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.

[Monkeh]

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.

[Bruce Abbott]

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.
 

[Ian.M]

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.

[Richard Crowley]

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.

[ebclr]

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

[technix]

You can maintain a test bed (especially if you are using DIP chips) and test all chips you received before using them.

[westfw]

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?
 

[ebclr]

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

[Monkeh]

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.

[ebclr]

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.

[Monkeh]

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.

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.

[ebclr]

Did you note that you have a no question full refund on those so-called "bad business", is simple 0 risk

[Monkeh]

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.

[thm_w]

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.

"Real Time Availability Stock: 39,398 Can Ship Immediately"

http://www.kynix.com/Detail/707212/LM3915N-1.html
http://www.jameco.com/webapp/wcs/stores/servlet/ProductDisplay?langId=-1&storeId=10001&catalogId=10001&pa=901061&productId=901061&CID=octopart#
http://www.win-source.net/en/pmic-display-drivers-lm3915n-1nopb.html (china)
http://www.chip1exchange.com/inventory.php?part=lm3915n

[Monkeh]

Lovely.

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

[Richard Crowley]

You would think that people here would understand what End Of Life means.
Nobody makes them anymore.   

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.

[Bruce Abbott]

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.
 
     

[technix]

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.

[ebclr]

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,

[Richard Crowley]

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.

[ebclr]

"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

[Monkeh]

"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.

[ebclr]

One example on this aplication PIC

http://www.electronics-lab.com/project/bargraph-voltmeter-0-5v-dc-range-pic16f686/

[ruffrecords]

There are lots of companies making small mixers contains several LED bargraph VU meters. What do they use instead of the LM3916?

Cheers

Ian

[Yansi]

Resistor strings and sets of LM339s used in most mixing desks. It is way cheaper than the overpriced "LM391x" and you can get whatever response you want.

//EDIT: Like for example this: