#1210

[@andrewlecouteurbisson7217]

The scale factor input is not designed for division (it probably has lousy bandwidth and is used to scale the output for low voltage inputs.) Division is done by sticking the multiplier in a feedback loop to invert the function. These things are great for generating the chaotic solutions to non-linear differential equations when combined with 2 or 3 integrators. Quite a nice topic for a future video perhaps.

[@jj74qformerlyjailbreak3]

Thank you for more info than provided here.
I’m in love with this chip.

[@bearchow1929]

Someone didn't watch the video or download the data sheet to see what the bandwidth was.

[@bearchow1929]

I used to support the laser trimming of these devices back in the early 80's. It was done on manual laser trim at the time. It was like trying to balance a bowling ball on a razor blade. Nowadays it is all automated laser trim. Nowadays digitizing, then multiplying in the digital domain, the digital to analog can easily outperform these devices at far less cost.

[@LydellAaron]

I get a bit sad when some really good ICs go out of production or stop being manufactured (in general). Electronics are building blocks of technology and it feels like sources are drying up.

[@iblesbosuok]

don't worry, there's AD633 still in production.

[@jensknudsen4222]

I know that part! I actually just got two of them for a project I'm working on. It's actually not that easy to find a decent analog multiplier on a hobbyist's budget.

[@boonedockjourneyman7979]

I’m stuck watching an injured dog for several days. Your video library beats anything else I can find. What a treasure.

[@ke9tv]

Low cost is a relative thing. These things are $20 parts nowadays. The 4-quadrant jellybeans look to be AD533, AD633 and HA3-2557-9, plus RC4000, which is a current-mode device that I've never tried. That last one looks as if it's fast enough and clean enough to use in place of a diode ring as a sideband modulator/detector.
If you limit your search to 4-quadrant multipliers in active production that Digi-Key stocks themselves rather than acting as the middleman for an eBay supplier, you're left with AD633 ($13 or so), AD835 ($30 or so, down to sub $20 if you're buying a whole reel of 750) AD834 ($50+) and the discontinued MPY100 - plus a bunch of $100+ laser-trimmed parts that they keep around in onesie-twosies (and then you'll be shocked at how long the lead times are and how much they cost).
Cheap Gilbert cells are getting hard to find. Gone are the days when you could just slap down a few bucks and get a LM1495.

[@maeanderdev]

Fortunately matched pair bjts can still be bought inexpensively. Building analog multipliers with DMMT3904 and DMMT3906 pairs is drastically cheaper than those integrated ones.
Just use the circuit from Analog Devices "Multiplier Application Guide" Figure 63. The right half is an opamp, just use a generic ic for that. The biasing circuit on the left may well be replaced by something easier and some resistors can simply be omitted. The resulting multiplier will have some offset voltage here and there if no trimming is done, but for many applications the precision obtained that way is more than enough with fixed resistors only

[@joeteejoetee]

Agree that Analog Devices are better performance and price, but then I don't have drawers full of NOS legacy chips, and want to make a modular PCB for them. Retro-Tech videos first, then this century videos.

[@jensknudsen4222]

I found some on eBay for about $10 each (and no, they're not from China).

[@maeanderdev]

​@@jensknudsen4222 I just wish there were really cheap multiplier ICs.
With less precision, no internal trimming and such it'd be possible to build multiplier ICs for a fraction of their cost.
I think having tens of them at a time would be great, but not as much if it costs hundreds of dollars

[@woosix7735]

NOT at all low cost, what a scam =(

[@fredmitchel1236]

I love those BB analog multipler
chips...they made a bunch..
Some originally probably control system...missiles for Hughes Aircraft ...eventually formed signals to the servo amp and motor for the fins..
I am glad that person's harvested cache had this chip. This chip and other similar older versions..are on my bench BB 4302..analog fuel injection for a dirt bike. But probably since I can tune the carburetor good enough...it sits gathering dust...there are signs of life...
Your MPY634 looks to be much more versatile

[@Godzilla941]

I remember as an experiment in laziness many years ago breadboarding a headphone amplifier with a couple of these expressly for the purpose of using a single pot between 0 and Vcc for a common volume control. They worked really well. No L-R tracking issues that you commonly get with a stereo pot, and you can also put a capacitor on the control voltage line to eliminate wiper noise...
At one point I was going to try a mini AM transmitter with one of these and a wien bridge op-amp oscillator around 1MHz (grain of wheat bulbs are fun), but never got around to trying that.

[@Manf-ft6zk]

The CA3080 discussed in” #1203 DIY Analog Synthesizer (part 6 of )” is a 2-quadrant multiplier, as the Voltage at the input is multiplied with the current at the bias input resulting in the product provided as the output current.
Two of those circuits combined with the same input voltage and the inverted bias current (OpAmp as inverter for the bias signal) can provide a 4-quadrant multiplier by just adding the output currents. (Some gain adjustment for the inverted bias signal might be required)
Nice experiment, as the CA3080 is really a cheap chip.

[@danielmantione]

Interresting! I have a few LM3080 in my parts box and just thought they were normal opamps. But it looks like LM3080 and CA3080 are the same thing; at least it has the same pinout and same bias input as the CA3080. So I just add the multiplicator at the bias input and that's it?

[@aduedc]

Thanks,
Real nice chip with lots of potential applications.
I can use it to measure phase in Wheatstone bridge, easily.
Also lots of control system applications.
Add a good opamp differentiator and opamp integrator, then sky is the limit for its applications.

[@InssiAjaton]

My interest was picked by the speed specification. The one other limitation in general on all the analog multipliers is the dynamic range (as well as no 4-quadrant operation) in certain applications. I have had my battles with two applications requiring an analog divide. The two designs were more than 20 years apart. This part could potentially have made both designs a bit easier.

[@teslakovalaborator]

You could make a mains wattmeter with it. Not a low cost part though, even AD633, that is considered low-cost is absolutely over my budget (costs around 400 CZK, compared to jellybean ICs that cost around 20CZK)

[@absurdengineering]

At least a squarer/square-rooter is just a couple matched diodes in an ULN2003 and some simple circuitry around it to close the loop. There’s a US patent on it, I forget the number. They use BE diodes on a die, but the less ideal single-junction diodes work quite well too.

[@simonkormendy849]

Experimenting with one of these piqued my interest a lot so I went and downloaded the datasheet for it, there's an interesting VCA circuit in the datasheet.

[@SanthoshRamaraj]

Interesting part, never thought such a thing would exist.

[@ats89117]

Great video on an Incredible chip, but it's not cheap. About $20...

[@danielmantione]

Super interresting IC, but eh... low cost?? €26.58 at Mouser, that's similar to the price of a big FPGA.

[@andrewlecouteurbisson7217]

The AD633 is somewhat cheaper but beware cheap Chinese chips (I speak from experience)

[@simonkormendy849]

What you basically have there going is commonly called a Ring Modulator circuit.

[@chupathingy5862]

Some of your videos, like this and the light to pulse chip, I'd love to have as synthesizer modules. I was actually investigating building that light pulse one into a circuit. Please do something with it! I'd buy it!

[@krish2nasa]

We are not far away from Analog based computing as it's highly energy efficient.

[@simonkormendy849]

Analog computers have been around for a long time, they were used a lot in the 60's to do artillery trajectory calculations and simulations.

[@gordonspond]

Would be nice if you could have explained the multiplier core. I remember getting that circuit on a test in college. It is really ingenious.

[@espenbgh2540]

An older model is the XR2208

[@tsusec]

Analog multipliers that you have mentioned coast more than my cheap chinese multimeter. Its sad that ill have to wait for some alternative.

[@icollided]

Great video. Too bad these chips are so expensive. The least expensive 4 quadrant that I know of is the AD633. Even that is $18! yikes! I'm glad that I have a couple for breadboarding, but I'm looking into making my own out of jellybean parts. I don't need insanely accurate results. I don't plan on using this of Automotive, Aerospace or Medical use. Just DIY audio do dads.

[@dalesmith8015]

For audio I would think this does something similar to, for example, the Befaco AB+C module

[@simonkormendy849]

I wonder if it is at all possible to use one of these MPY634 ICs configured as a scale-factor circuit to convert a linear Hz/Volt VCO IC like the Yamaha IG00153 VCO IC to a Log V/Oct response?

[@user-hn5qi9pw4z]

Good morning. Mr professor.
Sorry, japanese language.
これは、正弦波の搬送波を「矩形波」の信号波(入力信号)で「振幅変調 」した波形ですね。
従来の振幅変調より、帯域幅は どの位 変わりますか？ 気に成ります。
ー 今後も研究に御健闘下さい(^_^) ー

[@IMSAIGuy]

this is the same as 100% AM modulation

[@joecolchic1620]

A quick search on ebay for analog multiplier ICs has led me to believe that they are difficult to come by lately. Is there any modern IC in DIP8 packaging that is both available and affordable?

[@IMSAIGuy]

ad633

[@AnalogDude_]

cool device, thanks for enlighten us about it, but ... 26,58 €
"Expected 07/31/2023"
what about analog devices AD633 as someone else already mentioned?
Befaco AB+C schematic and others.

[@IMSAIGuy]

the ad633 is good, I've used them.

[@AnalogDude_]

@@IMSAIGuy i forgot about them in my last order, whilst knowing in the back of head.
: )

[@petersage5157]

So this basically takes an integral of the input?

[@drstrangelove09]

low cost?

[@t1d100]

Cool.

[@supercompooper]

synthesizer ring mod !

[@mufeedco]

But it is very expensive chip.

[@Chris-vr8cd]

i wanna hear how this sounds hah

[@jj74qformerlyjailbreak3]

I need to buy some, I’d like to purchase them from you, if possible. Where has this been all my life?
Probably in IMSAI Guys Drawer.
Looks like Unobtainium to me.

[@jj74qformerlyjailbreak3]

Thanks for introducing me to that little friend.

[@maeanderdev]

@@jj74qformerlyjailbreak3 Maybe the AD633 will be an option for you. Discrete Multipliers work well too and were much cheaper

[@jj74qformerlyjailbreak3]

@@maeanderdev Hey thanks. I think it was mentioned in the Analog Discovery 2 Parts Kit I need to order anyway. If not it will get added. Thank you very much for the feedback. some things just don’t work without it.
God Bless