Help identifying some ICs - Page 1
Forum section: electronics / repair

author: W1ngs
author_rank: Contributor
timestamp: May 10, 2023, 05:47:36 am
content: I've got a few interesting ones here, one of which looks quite interesting. I've been able to find little about these, but I'm sure some will recognize them. Any ideas?

author: retiredfeline
author_rank: Frequent Contributor
timestamp: May 10, 2023, 07:53:05 am
content: That Motorola IC at the top right with the rounded corners and cute dimple on pin1 looks like the DTL chips I have and if 74 is the year, could be a fit. But the ID isn't familiar. Could be a custom or OEM ID. It could also be a non-logic IC too I guess.

author: W1ngs
author_rank: Contributor
timestamp: May 10, 2023, 08:25:57 am
content: Interesting! I do have a bunch of DTL (including MDTL) here but none of them look like this one. I've got other Motorola chips of that age for linear stuff.Quote from: retiredfeline on May 10, 2023, 07:53:05 am

author: wasedadoc
author_rank: Super Contributor
timestamp: May 10, 2023, 10:36:05 am
content: The one marked 710 might be a uA710 (mu A) comparator.

author: RES
author_rank: Regular Contributor
timestamp: May 10, 2023, 12:13:15 pm
content: (Motorola) M 7850 442-62 is a heathkit part number code. (442-62 not in this list:http://www.d8apro.com/heath3.htm)

author: retiredfeline
author_rank: Frequent Contributor
timestamp: May 10, 2023, 12:35:52 pm
content: Quote from: RES on May 10, 2023, 12:13:15 pmHa, MC1358P if this document is to be believed:https://www.yumpu.com/en/document/view/27722705/heathkit-cross-reference-italy

author: Haenk
author_rank: Super Contributor
timestamp: May 10, 2023, 01:57:18 pm
content: The 50210 look like Precision Monolithics (PMI).Edit: The printing might confirm this:https://www.ebay.com/itm/333850317674Edit2: PMI only did have a handful of chips in 1972, unfortunately, none of these resemble the part# of the ones shown. Maybe crack one open to confirm if it's an OPAMP or DAC.Edit3: 29011 found here as well:https://physicsmuseum.uq.edu.au/cross-section-display-transistors-and-ics

author: W1ngs
author_rank: Contributor
timestamp: May 10, 2023, 05:53:32 pm
content: I saw that site in my search for 29011; sadly no info though and I'm definitely not willing to open it.Quote from: Haenk on May 10, 2023, 01:57:18 pm

author: factory
author_rank: Super Contributor
timestamp: May 10, 2023, 06:02:35 pm
content: 29011 is the custom counter IC used in the Advance DMM2 multimeter, I have one here that has two defective outputs.David

author: W1ngs
author_rank: Contributor
timestamp: May 10, 2023, 06:04:10 pm
content: Ah! That explains why I have these; I parted out three of those Advance DMM2 multimeters! Are you needing another chip for yours?EDIT: I remember this chip now; it was pulled out (and mangled) and stuck to a piece of paper with a note saying it was bad and was expensive to replace. I'll keep an eye out if I saved any from the ones I tore apart.Quote from: factory on May 10, 2023, 06:02:35 pm

author: W1ngs
author_rank: Contributor
timestamp: May 10, 2023, 06:16:28 pm
content: Found this other thread and a mention GI MicroElectronics (General Instrument). This explains the GIM marking. Apparently it might be an AY-5-4057. Just a BDC counter. I'll breadboard this up and see if it does anything. Here's the thread mentioning the chiphttps://www.eevblog.com/forum/repair/faulty-yet-irreplacable-ic/

author: factory
author_rank: Super Contributor
timestamp: May 10, 2023, 06:26:42 pm
content: It's not the same as the as AY-5-4057, pinout is different, it more than just a counter, it does the latching & display multiplexing, I've got about 90% of the function with a board full of 74 series.https://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/msg4615303/#msg4615303P.S. since then I've found out my DMM2 does not match the circuit diagram in the manual.David

author: W1ngs
author_rank: Contributor
timestamp: May 10, 2023, 06:29:33 pm
content: Taking a second look at things, the PMI chips say CMP-01 on the bottom.... That is a well-known PMI comparator, but normally appears in an eight lead DIP or TO-5 style package... I dismissed the possibility of a DIP-14 package CMP-01 and shouldn't have. I found a 1976 databook from PMI depicting a DIP-14 version athttp://www.bitsavers.org/components/pmi/_dataBooks/1976_PMI_Linear_and_Data_Conversion_IC_Products.pdf! (Page 7-1 [PDF page 106]).I think I have some PMI DACs here... perhaps I shall waste some time and implement a vintage SAR ADC.

author: W1ngs
author_rank: Contributor
timestamp: May 10, 2023, 06:31:44 pm
content: The 4057 does latching and display MUX though? I see that the pinouts are different, so they must be different chips, but in the 4057 datasheet it does indeed provide multiplex outputs for four digits of display.Quote from: factory on May 10, 2023, 06:26:42 pm

author: W1ngs
author_rank: Contributor
timestamp: May 10, 2023, 06:36:02 pm
content: I think you're right. Amusingly, the datasheet I found for the 50210 (CMP-01 on the bottom) mentions 710s!Quote from: wasedadoc on May 10, 2023, 10:36:05 am

author: factory
author_rank: Super Contributor
timestamp: May 10, 2023, 06:56:29 pm
content: Quote from: W1ngs on May 10, 2023, 06:31:44 pmYes they both have latch & mux, but the 29011 isn't quite a full 4 decade counter though, max count is 1999 for the DMM2 and once it exceeds that it uses the 2 from the 2000 count for the overload indicator lamp.David