What is this IC? - Page 1
Forum section: electronics / beginners

author: pe1dnn
author_rank: Contributor
timestamp: March 03, 2023, 11:31:42 pm
content: Does anyone recognize the component in the picture? What is it?

author: Benta
author_rank: Super Contributor
timestamp: March 03, 2023, 11:36:47 pm
content: Well, it's a CA3183E. RCA/Harris/Intersil. Data sheet can be found on the interwebs.

author: pe1dnn
author_rank: Contributor
timestamp: March 03, 2023, 11:39:58 pm
content: Yes, that's a 5 NPN transistor pack. I highlighted the other one from Philips with codes 000146 and 13705EC if I read that correctly... That's the mystery chip...

author: BillyO
author_rank: Super Contributor
timestamp: March 04, 2023, 12:50:12 am
content: It's an OQ0146. No idea what it does though.Maybe in some of the schematics in this thread it's shown. Look at the last picture in post #102.https://www.eevblog.com/forum/repair/repairing-an-old-pm3320a/msg1327121/#msg1327121

author: coromonadalix
author_rank: Super Contributor
timestamp: March 04, 2023, 03:06:08 am
content: page 315 pm3320 service manual ??https://ia800200.us.archive.org/35/items/philips_pm3320_service_manual/pm3320_service_manual.pdfvertical amplifier processor board A44boards A38 A39 ...

author: coromonadalix
author_rank: Super Contributor
timestamp: March 04, 2023, 03:14:50 am
content: and please avoid double posting or variations ??https://www.eevblog.com/forum/beginners/help-with-philips-pm5139-synthesized-function-generator/

author: pe1dnn
author_rank: Contributor
timestamp: March 04, 2023, 09:21:15 am
content: Thanks or the pointers, I will investigate it further, very helpful indeed.About double posting noticed by coromonadalix, you are right but this is a very specific question about one detailed part. I don't think this stands out in the original topic because most people will not read that much if they are not interested in that topic, while asking for one part is much more common and straight to the point. Sorry if I violated some rule, I will remove the question about this part from the other topic so it will be a single posting once again.

author: Terry Bites
author_rank: Super Contributor
timestamp: March 04, 2023, 11:28:51 am
content: Its an array of 5 NPN transistors.

author: pe1dnn
author_rank: Contributor
timestamp: March 04, 2023, 03:13:37 pm
content: I meant the other IC... The one which I highlighted. Maybe next time I have to put a big red circle around it. The CA3183 is not a mystery chip as it can be easily found with no effort at all. The other one is apparently an OQ0146 according to other reactions. Thanks for taking the time anyway.

author: pe1dnn
author_rank: Contributor
timestamp: March 04, 2023, 03:28:58 pm
content: Does somebody have a data sheet for the OQ0146? The schematics for the PM3320 show the device and numbers the pins but the pin out is clearly wrong because it mentions pin 19 while the package has only 18 legs. Pin 11 is missing in the schematic, something got mixed up or pins are counted differently?When looking at the PCB the PM3320 in the service manual is using different package, wider. There is one picture in the PM3320 thread where the OQ0146 is in a socket and that one is 18 pin. But on the PCB in the service manual they are 20 pin devices. Looks like the service manual is for an other revision that used a other style OQ0146.

author: BillyO
author_rank: Super Contributor
timestamp: March 04, 2023, 04:00:23 pm
content: Philips were/are famous for making custom chips that were not released to the public. The only people that might have a datasheet are those that commissioned the part or Philips themselves. I'm not saying that is definitely the case here, but it's unfortunately a distinct possibility.Perhaps trying to contact them directly may get some results.They do say they are a technology compnay that cares about people. You could tell them that not knowing is causing you negative stress.

author: jmelson
author_rank: Super Contributor
timestamp: March 04, 2023, 04:00:33 pm
content: Quote from: pe1dnn on March 04, 2023, 03:28:58 pmWell, it was made by Philips, before they morphed into NXP, and was made in 1990, so a replacement might be hard to find, or even a datasheet. It might also be a house-numbered part.Jon

author: pe1dnn
author_rank: Contributor
timestamp: March 04, 2023, 09:01:03 pm
content: Well, I guess I have to hope it is still okay. The PM3320 schematic shows at least what's inside although it uses a different package. By the way. looking more closely the 20 pin part used in the PM3320 is SMD while the 18 pin part I have in the PM5139 is through hole. Needs some reverse engineering what pins are where. But if the same die is inside the chip, which I would expect, I guess pins can only be shifted. Educated guess I have to verify.When I look at it using the pins for the SMD part I was already puzzled because the DAC312 I+ output is connected to pin 12 which is substrate ground which was weird. But if shifted then pin 11 might be substrate ground and then I+ connects to what is on the SMD part pin 13 and I- which is connected to pin 17 and becomes pin 18 on the SMD part and then it is at least symmetrical again what I would more or less expect.I also tried to find some other Philips service documents from that period, they also have OQxxxx components but with lower numbers. So pure luck if there is a service document for a device having the through hole version of the OQ0146; then I should be able to get the pin out from the schematic. The PM3320 is just slightly too new, having switched from through hole to SMD and the older PM3311 is through hole but is too old and does not have that part but some older OQxxxx numbered parts. I may get lucky with other Philips/Fluke digital/analog test equipment from around 1990 but not much service manuals are floating around.I guess the reason for these components, which are in fact simple transistor networks, is that by having them on the same die it makes all the transistors perfectly equal. This is nice for a differential pair and the reason why they are found in their test equipment. On the later model PM5193 I see they switched to using Op-amps instead which also has that characteristic of transistors inside being equal but are more elaborate than just a bunch of transistors in a package (and documented too...). After some research I see Philips used a lot of variants of these.By the way, not a bad word about Philips from me, I started my career at Philips Computers until it was acquired by Digital Equipment Corporation. Still have fond memories of that time, although Philips of today is just a shadow of what it once used to be (at least they are still there, what cannot be said about DEC unfortunately).A good day would be if Philips made their 12NC database accessible for searches. It contains every bit used in every device Philips ever produced.

author: macboy
author_rank: Super Contributor
timestamp: March 05, 2023, 02:19:55 pm
content: I recently parted out a PM3320. On the final amp board (A1) the service manual lists two ICs as OQ0012, but on the PCB they are actually OQ0146, in 18-pin PDIP package. Another board has several OQ0146Tin 20-pin SOIC package. The function of OQ0012 and OQ0146T (SOIC) appears to be very similar, but the pinout is very different, according to the internal diagrams shown in the schematics. Since my PCB matches exactly with the one shown in the service manual, I assume that the OQ0012 and OQ0146 (PDIP) should have the same pinout. This isn't the only IC different on my PCBs vs the service manual schematics. For example, all UA714 precision opamps in the SM were populated with OP77 instead.

author: tooki
author_rank: Super Contributor
timestamp: March 05, 2023, 02:29:46 pm
content: Quote from: pe1dnn on March 04, 2023, 03:13:37 pmYeah, your highlighting is practically invisible.Or you could just, ya know, crop off everything but the component in question. Or super luxury option: type out the markings.

author: pe1dnn
author_rank: Contributor
timestamp: March 05, 2023, 05:00:49 pm
content: Well I did, in my reply to the first poster that also mentioned the obvious component. The reason I didn't do it was because I had trouble reading it, it looked like the first number started with 3 zeros but that didn't make sense. That's why I unsure if the second line was the component number instead. To prevent to put anything in somebodies mouth I let the picture speak for itself instead.Anyway, the OQ0146 is working fine lucky enough, because I got the device containing it working again properly. Will post an update to the PM5139 issue I posted before; this thread was just a thread to get help looking up this component. I learned a, thank you all.