I decided on a whim to take apart an old smoke detector that desperately needed replacing, and after some ripping, I got to the guts of the thing.

smoke detector guts

Neat stuff.

Clearly the brains of the detector is that DIP IC on the right of the board: Motorola XC370696P. Here's a closeup of the part.

Motorola XC370696P

The internet is surprisingly quiet about this IC. Any insight on what this part is, or where the datasheet lives?

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    \$\begingroup\$ With Motorola, the "XC" prefix means "Engineering sample." MC would have meant a fully qualified part. Don't know if that helps any, though. \$\endgroup\$ – jonk Sep 8 '16 at 6:27
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    \$\begingroup\$ looks pretty old 1998 , if it had a radioactive sensor, its probably clogged with dust. \$\endgroup\$ – Tony Stewart Sunnyskyguy EE75 Sep 8 '16 at 6:59
  • \$\begingroup\$ @Tony: 1998 is spot on. \$\endgroup\$ – TRISAbits Sep 8 '16 at 15:16
  • \$\begingroup\$ @jonk: I never knew about the XC/MC distinction. I guess the "engineering samples" were good enough for production. \$\endgroup\$ – TRISAbits Sep 8 '16 at 15:17

Have a look at the RE46C120, a similar device made by Microchip.

Its datasheet claims compatiblity with MC145017 and MC14467. I think it may very well be pin-compatible to your device too (pin15=detect).

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  • \$\begingroup\$ Peter, this is a fantastic find! Thanks for sharing! \$\endgroup\$ – TRISAbits Oct 12 '16 at 5:16

I believe it was designed by Freescale which had Motorola roots and manufacturing agreements with Mot but is now owned by NXP.

I also believe this is a proprietary part exclusive to those who paid for a license to build with these parts which is covered by an NDA.

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  • \$\begingroup\$ That's what I feared. \$\endgroup\$ – TRISAbits Sep 8 '16 at 15:18
  • \$\begingroup\$ feel free to reverse engineer the transfer functions on each pin \$\endgroup\$ – Tony Stewart Sunnyskyguy EE75 Sep 8 '16 at 16:08
  • \$\begingroup\$ Nice way to pass a sunday afternoon. \$\endgroup\$ – TRISAbits Sep 9 '16 at 4:47

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