Obsolete parts?

What was their function ?

Rene

They are a synthesiser and prescaler respectively.

Yes they are. If they obsoloete, I'd like to try something similar. The MC145158P is a Paralell Input PLL Frequency synth. and the MC12017 is a Divide x 64 / x 65 Dual Mod Prescaler.

Greg

I was clarifying your post for Rene's benefit.

AFAIK they are no longer produced,a lthough there may be residual stock around.

If you want them for a new design, I'd look elsewhere in the /\\/\\oto-OnSemi range for starters.

If you need one or two, there are a pair of surface mount 158's and a pair of (also SMD) 12018's on feebay at the moment - item 120105811897. Knowing a bit about the seller, I wouldn't be surprised if he had some 017's on the shelf.

(No, I'm not connected with the seller, but I have exchanged a few emails with him in the past).

I'm redoing a 10+ year old design, that used a 80C30 / 8051 and 27C64 IC combo for the micro. It's in a radio transceiver project for the 3 to 30 MHz frequency range.

Greg