[time-nuts] 74AC logic differences between manufactures
stanley_reynolds at yahoo.com
Tue Jul 13 15:30:39 EDT 2010
Learning about the differences between families now know why a 74F is not a
substitute for 74AC.
But remembering something I read in Brooks Shera, W5OJM GPSDO notes "Take care
about which 4046 chips you use for U1 and U3. The Phillips 74HCT4046 chips
(formerly sold by Radio Shack) are fine. So are CD74HC4046 chips made by Harris
or T.I. Do not use chips made by Fairchild and do not use CD4046 chips; both
have a different design and will not work in this circuit."
Does anyone know about any differences in Fairchild and National Semiconductor
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