[Test-Equipment] Help Finding Chip = 4046 VCO and phase detector

[Sakari Mattila]

Folks,
4046 VCO and phase detector is a common 4000-series CMOS IC. However
there is also 74HCT4046 which is much faster TTL-logic compatible IC with
same functions and pin-outs. The frequencies (ca. 300 kHz) fit within 
4046, but
it may be better to try both types.  74HCT4046 goes up to 10 MHz.  4046s 
are
unique, there is nothing even nearly similar. The letters after 4046 are 
just
indicating ceramic or plastic types and maybe temperature range. I remember
this IC because I used it in several low speed modems in the 1970s. It 
can be
used alone in signal cleaning and with any divider as a PLL. It was 
still common
in the 1980s. The phase detectors are quite good. One is exclusive-OR type,
the other is more advanced phase and frequency difference detector. RCA, 
Philips
and Motorola made these ICs, fully compatible with each others. 4046 is an
easy IC to design around, no quirks like in some older 555 models with 
very high
current spikes.
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Sakari, VK2XIN / OH2AZG    Sakari.Mattila@canberra.edu.au
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