DIP-8 Semi Conductor CR949N

[envelope]

DIP-8 IC labelled CR949N

 

[analogguru]

CR949N could be the date code - anything else written on it ?

 

[Gene Pink]

beside the CR949N,  there is only the "S" signetics logo and 7723 (I believe 7723 is the date code)

It is not in the Signetics '85 or '89 linear chip catalogs, IC master '96, or any of the replacement cross references NTE, ECG, RCA, GE, Motorola, or Radio Shack.

Gene

 

[benb]

I have Signetics Analog Applications Manual from 1979. Looking through Table Of Products and Ordering Information, I don't see a part that starts with CR, nor a string of digits in a part number that starts with 9. This is surely a house number, (almost) surely for a standard production chip, likely only printed for Midas, and no one has asked online about this chip in this device before now.

Is this board broke? Are you trying to fix it, or just it info, or what?

Do you have or can you get a schematic of the board this chip is in? If not, trace out out and draw the schematic around the chip. If pin 4 goes to ground or the negative power rail and pin 7 goes to the positive power rail, there's a good chance it's the standard pinout for a single opamp in an 8-pin package. If Pin 8 (instead of pin 7) goes to V+, it could be a dual opamp.

Presuming you have one or more working channel strips, power one up and measure the voltage at each pin of the chip. This will also give clues to its function.

 

[moamps]

If not, trace out out and draw the schematic around the chip. If pin 4 goes to ground or the negative power rail and pin 7 goes to the positive power rail, there's a good chance it's the standard pinout for a single opamp in an 8-pin package. If Pin 8 (instead of pin 7) goes to V+, it could be a dual opamp.

Yes, it is most probably a single opamp (as LM301).
https://www.gearslutz.com/board/high-end/1071036-old-midas-page-ranking-001-schematics-needed.html