A big deal in some cases is a wide voltage tolerance. For ram circuits you may need 2v to 5v.
On Tuesday, January 29, 2019, Mike Stein <[email protected]> wrote: > Thanks, Frank! HC is my choice unless I need to interface with TTL and it > seems to be easier to find; the higher speed of AC isn't really relevant > here. > > But it seems that there's a new 'TTL' family every month ... ;-) > > ----- Original Message ----- > From: "Francesco Messineo" <[email protected]> > To: <[email protected]> > Sent: Tuesday, January 29, 2019 11:08 AM > Subject: Re: [M100] Installing 8K modules in M100 > > > > Hi Mike, > > I use HC, sometimes I've used AHC when I needed some single gate ICs. > > 74AC logic has a low standby current, but current surges during the > > fast edges make a lot of additional noise and power rail bouncing. May > > be or maybe not a problem, but why taking chances? > > 8K modules with only HC/AHC logic and suitable RAM chip usually end up > > in the 0.1 to 3 uA standby current @3.3V. > > My setup lower current limit is 0.1uA, so many modules I've checked > > may have been better than that. > > > > On Tue, Jan 29, 2019 at 4:53 PM Mike Stein <[email protected]> wrote: > >> > >> > >> ----- Original Message ----- > >> From: "Francesco Messineo" <[email protected]> > >> To: <[email protected]> > >> Sent: Tuesday, January 29, 2019 2:50 AM > >> Subject: Re: [M100] Installing 8K modules in M100 > >> > >> > >> > ...HCT logic should not be used for M100 hardware (it works > correctly, but power needed is unnecessarily higher) > >> > >> > Frank IZ8DWF > >> ---------- > >> > >> Thanks for the tip; which logic family do you recommend instead? > >> > >> m >
