Chip ID...

[Cursitor Doom]

Hi all,

Anyone seen one of these before? The IC itself has four bjts on a
single die according to the schematic, but - again according to the
schematic - there\'s no connection for whatever this thing mounted on
top is, which resembles a very thin button cell. The board it comes
from is dated 1970, so unless you\'re an old geezer, you won\'t
recognize it anyway.

https://disk.yandex.com/i/N1dGB_EIUYbf6A

 

[Cursitor Doom]

On Sun, 21 May 2023 11:07:38 +0100, Cursitor Doom <cd@notformail.com>
wrote:

Hi all,

Anyone seen one of these before? The IC itself has four bjts

Correction! Apparantly there are *5* BJTs on this chip (U973 on the
schematic) - and being as this is a 14 pin chip, there\'s a pin short!
Weird.

Here\'s the section of the schematic:

https://disk.yandex.com/i/DZTlhbFA0XTE1w

 

[Chuck]

On Sun, 21 May 2023 11:07:38 +0100, Cursitor Doom <cd@notformail.com>
wrote:

Hi all,

Anyone seen one of these before? The IC itself has four bjts on a
single die according to the schematic, but - again according to the
schematic - there\'s no connection for whatever this thing mounted on
top is, which resembles a very thin button cell. The board it comes
from is dated 1970, so unless you\'re an old geezer, you won\'t
recognize it anyway.

https://disk.yandex.com/i/N1dGB_EIUYbf6A

This will probably replace it. https://www.ebay.com/itm/125671758106

 

[Cursitor Doom]

On Sun, 21 May 2023 11:31:52 -0500, Chuck <chuck23@dejanews.net>
wrote:

On Sun, 21 May 2023 11:07:38 +0100, Cursitor Doom <cd@notformail.com
wrote:

Hi all,

Anyone seen one of these before? The IC itself has four bjts on a
single die according to the schematic, but - again according to the
schematic - there\'s no connection for whatever this thing mounted on
top is, which resembles a very thin button cell. The board it comes
from is dated 1970, so unless you\'re an old geezer, you won\'t
recognize it anyway.

https://disk.yandex.com/i/N1dGB_EIUYbf6A
This will probably replace it. https://www.ebay.com/itm/125671758106

Well, you\'ve had more luck than I did with that part number. My
searches threw up nothing at all.
The IC you\'ve linked to may well be a suitable replacement, but that\'s
not really what I was curious about. The encapsulation is white and
has something mounted on top of it. I\'d be interested to know why it\'s
white and what the disc-shaped object on the top is. As far as I can
tell, this white chip is not the original. The original resembles the
one you linked to. So.... what\'s the deal with the white encapsulation
and the disc thing on top of this usurper?

 

[Steve Goldstein]

On Sun, 21 May 2023 17:44:26 +0100, Cursitor Doom <cd@notformail.com>
wrote:

On Sun, 21 May 2023 11:31:52 -0500, Chuck <chuck23@dejanews.net
wrote:

On Sun, 21 May 2023 11:07:38 +0100, Cursitor Doom <cd@notformail.com
wrote:

Hi all,

Anyone seen one of these before? The IC itself has four bjts on a
single die according to the schematic, but - again according to the
schematic - there\'s no connection for whatever this thing mounted on
top is, which resembles a very thin button cell. The board it comes
from is dated 1970, so unless you\'re an old geezer, you won\'t
recognize it anyway.

https://disk.yandex.com/i/N1dGB_EIUYbf6A
This will probably replace it. https://www.ebay.com/itm/125671758106

Well, you\'ve had more luck than I did with that part number. My
searches threw up nothing at all.
The IC you\'ve linked to may well be a suitable replacement, but that\'s
not really what I was curious about. The encapsulation is white and
has something mounted on top of it. I\'d be interested to know why it\'s
white and what the disc-shaped object on the top is. As far as I can
tell, this white chip is not the original. The original resembles the
one you linked to. So.... what\'s the deal with the white encapsulation
and the disc thing on top of this usurper?

It could be a hermetically-sealed ceramic package. The die would have
been mounted inside a cavity, wire-bonded to the leads, and then the
lid soldered or weled on in an inert atmosphere. Back in the day
plastic packages were notoriously bad in terms of moisture resistance
and hermetic packages ruled where reliability was needed.

 

[whit3rd]

On Sunday, May 21, 2023 at 3:09:37 AM UTC-7, Cursitor Doom wrote:

Hi all,

Anyone seen one of these before? The IC itself has four bjts on a
single die according to the schematic, but - again according to the
schematic - there\'s no connection for whatever this thing mounted on
top is, which resembles a very thin button cell. The board it comes
from is dated 1970, so unless you\'re an old geezer, you won\'t
recognize it anyway.

RCA made transistor arrays in DIP packages; the white ceramic dates it
from the early days, but plastic DIPs might still be in production.

https://disk.yandex.com/i/N1dGB_EIUYbf6A

the schematic section (pin numbers) is consistent with CA3046 and CA3045.
The CA3045 was the ceramic-package variant, but specifications are very similar
(CA3045F was the brown-ceramic frit seal package, you\'ve got the CA3045 with white ceramic).
The IC has five, not just four, transistors.

 

[whit3rd]

On Sunday, May 21, 2023 at 11:33:23 PM UTC-7, whit3rd wrote:

On Sunday, May 21, 2023 at 3:09:37 AM UTC-7, Cursitor Doom wrote:
Hi all,

Anyone seen one of these before? The IC itself has four bjts on a
single die according to the schematic, but - again according to the
schematic - there\'s no connection for whatever this thing mounted on
top is, which resembles a very thin button cell

Oh, the thing on top is the lid; it\'s grounded (to pin #13, which is to be
held non-positive with respect to other connections, it\'s the IC substrate)..

 

[Cursitor Doom]

On Sun, 21 May 2023 23:38:56 -0700 (PDT), whit3rd <whit3rd@gmail.com>
wrote:

On Sunday, May 21, 2023 at 11:33:23?PM UTC-7, whit3rd wrote:
On Sunday, May 21, 2023 at 3:09:37?AM UTC-7, Cursitor Doom wrote:
Hi all,

Anyone seen one of these before? The IC itself has four bjts on a
single die according to the schematic, but - again according to the
schematic - there\'s no connection for whatever this thing mounted on
top is, which resembles a very thin button cell

Oh, the thing on top is the lid; it\'s grounded (to pin #13, which is to be
held non-positive with respect to other connections, it\'s the IC substrate).

So it\'s possible to pop it off? Wow. Never come across one of those
before. Be interesting to take a look inside....

 

[Cursitor Doom]

On Sun, 21 May 2023 23:33:20 -0700 (PDT), whit3rd <whit3rd@gmail.com>
wrote:

On Sunday, May 21, 2023 at 3:09:37?AM UTC-7, Cursitor Doom wrote:
Hi all,

Anyone seen one of these before? The IC itself has four bjts on a
single die according to the schematic, but - again according to the
schematic - there\'s no connection for whatever this thing mounted on
top is, which resembles a very thin button cell. The board it comes
from is dated 1970, so unless you\'re an old geezer, you won\'t
recognize it anyway.

RCA made transistor arrays in DIP packages; the white ceramic dates it
from the early days, but plastic DIPs might still be in production.


https://disk.yandex.com/i/N1dGB_EIUYbf6A

the schematic section (pin numbers) is consistent with CA3046 and CA3045.
The CA3045 was the ceramic-package variant, but specifications are very similar
(CA3045F was the brown-ceramic frit seal package, you\'ve got the CA3045 with white ceramic).
The IC has five, not just four, transistors.

Yes, it has five transistors (I did correct myself earlier on up the
thread). However, it\'s a 14 pin package and 5 BJTs require 15
connections!

 

[Cursitor Doom]

On Mon, 22 May 2023 10:08:12 +0100, Cursitor Doom <cd@notformail.com>
wrote:

On Sun, 21 May 2023 23:33:20 -0700 (PDT), whit3rd <whit3rd@gmail.com
wrote:

On Sunday, May 21, 2023 at 3:09:37?AM UTC-7, Cursitor Doom wrote:
Hi all,

Anyone seen one of these before? The IC itself has four bjts on a
single die according to the schematic, but - again according to the
schematic - there\'s no connection for whatever this thing mounted on
top is, which resembles a very thin button cell. The board it comes
from is dated 1970, so unless you\'re an old geezer, you won\'t
recognize it anyway.

RCA made transistor arrays in DIP packages; the white ceramic dates it
from the early days, but plastic DIPs might still be in production.


https://disk.yandex.com/i/N1dGB_EIUYbf6A

the schematic section (pin numbers) is consistent with CA3046 and CA3045.
The CA3045 was the ceramic-package variant, but specifications are very similar
(CA3045F was the brown-ceramic frit seal package, you\'ve got the CA3045 with white ceramic).
The IC has five, not just four, transistors.

Yes, it has five transistors (I did correct myself earlier on up the
thread). However, it\'s a 14 pin package and 5 BJTs require 15
connections!

Ignore that! I\'ve just spotted they\'ve internally tied together the
emitters.

 

[Jeff Liebermann]

On Mon, 22 May 2023 10:11:59 +0100, Cursitor Doom <cd@notformail.com>
wrote:

>>>> https://disk.yandex.com/i/N1dGB_EIUYbf6A

The full TEK part number is 156-0065-00
<https://4gte.com/products/tektronix-156-0065-00-transistor-array/>

If you don\'t care about reliability, you can probably just replace it
with 5 TO-92 transistors. Just shove the leads into the 14 pin
socket. If you want thermal tracking in the differential pair (U973A
and B), use matched TO-18 packaged devices and some insulating thermal
glue to hold them together.

This stuff should work for good insulation, high thermal conduction,
and moderate ease of removal is you screw it up:
<https://cht-silicones.com/products/adhesives/neutral-cure-rtvs-adhesives>
You could also use it to glue the transistor leads to the IC socket,
but it would be difficult to remove if you change your mind.

Good luck.
--
Jeff Liebermann jeffl@cruzio.com
PO Box 272 http://www.LearnByDestroying.com
Ben Lomond CA 95005-0272
Skype: JeffLiebermann AE6KS 831-336-2558

 

[Cursitor Doom]

On Mon, 22 May 2023 10:34:50 -0700, Jeff Liebermann <jeffl@cruzio.com>
wrote:

On Mon, 22 May 2023 10:11:59 +0100, Cursitor Doom <cd@notformail.com
wrote:

https://disk.yandex.com/i/N1dGB_EIUYbf6A

The full TEK part number is 156-0065-00
https://4gte.com/products/tektronix-156-0065-00-transistor-array/

If you don\'t care about reliability, you can probably just replace it
with 5 TO-92 transistors. Just shove the leads into the 14 pin
socket. If you want thermal tracking in the differential pair (U973A
and B), use matched TO-18 packaged devices and some insulating thermal
glue to hold them together.

This stuff should work for good insulation, high thermal conduction,
and moderate ease of removal is you screw it up:
https://cht-silicones.com/products/adhesives/neutral-cure-rtvs-adhesives
You could also use it to glue the transistor leads to the IC socket,
but it would be difficult to remove if you change your mind.

Good luck.

Thank you, Jeffrey, you\'re a credit to Usenet!

 

[legg]

On Mon, 22 May 2023 10:06:26 +0100, Cursitor Doom <cd@notformail.com>
wrote:

On Sun, 21 May 2023 23:38:56 -0700 (PDT), whit3rd <whit3rd@gmail.com
wrote:

On Sunday, May 21, 2023 at 11:33:23?PM UTC-7, whit3rd wrote:
On Sunday, May 21, 2023 at 3:09:37?AM UTC-7, Cursitor Doom wrote:
Hi all,

Anyone seen one of these before? The IC itself has four bjts on a
single die according to the schematic, but - again according to the
schematic - there\'s no connection for whatever this thing mounted on
top is, which resembles a very thin button cell

Oh, the thing on top is the lid; it\'s grounded (to pin #13, which is to be
held non-positive with respect to other connections, it\'s the IC substrate).

So it\'s possible to pop it off? Wow. Never come across one of those
before. Be interesting to take a look inside....

Also might be interesting to buy a CA3045 and fix the damn thing.

Are you even sure it\'s failed?

RL