I have about 150 of these 8 pin DIP chips still in their original Texas Instruments tubes. I probably got them in one of many surplus lots of parts I got at least 20 years ago. The parts are marked Ti 4130A2T and 321581. There is a circle on the back with TAIWAN across the middle, 16 above the TAIWAN and J3 below it.
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I can't find any evidence that the THS4130 was ever made in a DIP package. Anyone ever seen one? I'll try to wire one up according to the THS4130 data sheet to see what happens.
It is George asking. You don't need to teach a snake how to lie down.
I think his point is: if it doesn't pop right up as THS4130, what else should he try while the bench is hot?
I´m well aware of who he is, and I voiced my respect many times ... yet he´s asking here, so I offered MY answer.
Feel free to offer yours.
You know I am a Functionalist, as in "I don´t care WHAT is inside, only in how it behaves"
So again: what should a "150MHz, Fully Differential Input/Output Low Noise Amplifier" do?
It meets specs YES/NO
Take care Friend. 🙂
EDIT: about
Who knows? ... it´s a full unknown.
We don´t even know which are the power supply pins, go figure, so we can´t randomly apply , say, 5V between 2 of them and measure what appears on others.
And which would be the reference pin where all measurements must be related to?
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The mystery chip is beginning to get more mysterious.
I found 3 full sticks and one partially full stick in a box full of surplus semiconductors that I had packed long ago. Googling TI, Texas Instruments, 4130, 4130A2T, and 321581 in any combination returned no results associated with electronics. I'm surprised that it didn't return the THS4130 though.
I tried this and got an open which greatly lowers the probability that it is a THS4130.
I continued poking around the pins on the chip with a cheap DVM on several different ranges and found NO continuity between any two pins, but this meter uses a rather low (under 1 volt) test voltage.
My next step is to apply more voltage between random pins to see if there is anything semi conductive inside. I crushed one with a pair of Vice Grips and there is (was) a die inside that's about .050 X .080 inches in size.
I have about 150 of these chips, and they are going in the trash if I can't figure out what they are, or what they do, so I don't mind "testing" a few. I probably will get out a little white breadboard to try some typical opamp configurations, but that won't happen until after I have dug through three boxes of unsorted stuff from a house move 8 years ago. Most of my surplus parts hunting occurred over 20 years ago, so odds are that these chips are 20 to 40 years old.
The ground plane of a resin packaged device can often be found by digging at the ends of the package.
The resin part is made in two halves with the pins laid between them. The silicone is normally bonded to a metal ground plane with the pins arranged around it before wiring up with very fine wires.
The packages are sent for the resin tops to be added with an indexing link between them.
A continuity test between the indexing link located by digging at the end of the package and the pins will often find the signal ground.
An X-ray of a chip package is the best thing to look at.
https://www.sciencephoto.com/media/347815/view/x-ray-of-a-silicon-chip-from-a-teletext-board
The resin part is made in two halves with the pins laid between them. The silicone is normally bonded to a metal ground plane with the pins arranged around it before wiring up with very fine wires.
The packages are sent for the resin tops to be added with an indexing link between them.
A continuity test between the indexing link located by digging at the end of the package and the pins will often find the signal ground.
An X-ray of a chip package is the best thing to look at.
https://www.sciencephoto.com/media/347815/view/x-ray-of-a-silicon-chip-from-a-teletext-board
George, the 'A' in the number doesn't really look like an A to me.
Is it a clear A on another chip, or could it be some non-character symbol?
Jan
Is it a clear A on another chip, or could it be some non-character symbol?
Jan
I spent the last 12 years of my 41 year engineering career at Motorola working in a research group that designed custom CMOS RF chips for two way radios. We had the capability to go from finished wafer to packaged parts in house. We designed custom packages for some chips that had to work from low frequency up to 2 GHz. Most of my patents were for custom packages for RF power amp transistors and IC's. We might have had a secret lab with the capability to reverse engineer chips too. Plastic packages like these dissolve in a about an hour in boiling sulphuric acid. The die gets removed from the paddle with heat, then rebonded to a custom surface. The chip can then be dissected layer by layer. We did have X-ray equipment and an electron microscope with the capability to look at a powered up chip, and get voltage level estimates on the paths present on the top metal layer. If I was still working there, I could have likely gotten some attention from the TI sales engineer. Motorola used TI processors in the iDEN phones at that time and we built those phones in the plant.
I just noticed that. I also dumped out several chips from each tube for a look. It may or may not be an "A" as all of them look identical. I also discovered that two tubes of chips say A2T, but the other two say A1T. This leads me to believe that the top character string may be the date / lot code and the 321581 may be somebody's house number, since it is the same on all chips and is in a bolder font. I have set these aside for some breadboard testing at a later date.
How fast Google works: Googling '321581 chip' brings up your photo of the chip!
Jan
Jan
Time to pull a leaf out of Ken Shirriff's book, take a die shot, and start the reverse-engineering...