[sdiy] early history of motorola 4-quadrant multipliers?

[michael johnsen]

hi-
as a part of a recent restoration project, i’ve been working with
the versatile and very obsolete motorola mc1545. it was designed by
jim thompson around 1968 and intended primarily as a 2-channel rf multiplexer,
though it can be used quite well as a balanced multiplier, gate/vca,
etc. it even has a differential output.

i’ve corresponded with mr thompson about the ic and was curious
about its place in the development of ic multipliers. he couldn’t remember
the timeline well, but suggested that motorola part numbers were at least
“intended” to be chronological, which would make the mc1545 older than
its well-known cousins, the mc1594, mc1595, and mc1596. can anyone
verify this or elaborate with other examples of earlier ic multipliers?
the mullard tab101 used in the ems synthi dates from 1969 [datasheet],
and barrie gilbert first wrote about the gilbert cell in 1968 [for
analog devices].

finally, i’m also looking for the following motorola app note:
“an-491: gated video amplifier applications -- The mc 1545”
which dates from about ’68-’71 and about which motorola/freescale
can no longer be bothered. if anyone’s got it i’d be grateful.

thanks from pittsburgh,
-michael