Message	Date	From	Subject
12724	2016-04-23 10:13:54	Dana Myers	Measured output impedance of 74AHC74 vs 74AHC04
As if I haven't caused enough trouble lately, I figured it was easy enough to measure a TI SN74AHC74 output impedance. I wired-up a simple divider and did the same test using the Q output. Here's the inverter data: Part #, MFG Zout SN74AHC04N, TI 26.5 SN74AHC14N, TI 26.6 SN74AHCU04N, TI 28.0 and here's the flip-flop data: SN74AHC74, TI 43.4 So how about that? I probably didn't emphasize the variability of this value enough given that it's not specified in any datasheet. 73, Dana K6JQ

As if I haven't caused enough trouble lately, I figured it
was easy enough to measure a TI SN74AHC74 output impedance.
I wired-up a simple divider and did the same test using the
Q output.

Here's the inverter data:

Part #, MFG Zout
SN74AHC04N, TI 26.5
SN74AHC14N, TI 26.6
SN74AHCU04N, TI 28.0

and here's the flip-flop data:

SN74AHC74, TI 43.4

So how about that? I probably didn't emphasize the variability
of this value enough given that it's not specified in any
datasheet.

73,
Dana K6JQ