crisp@uncecs.edu (Russ Crisp) (03/04/91)
Hello. I'm trying to cross reference a 74LS165 to an RCA SK device. While this specific device is not listed in the cross section of my replacement guide, I found two devices, a SK7C165, and a SK7CT165 that appear to be the same thing, as far as I can tell. Anyone know if either one of these devices would be a satisfactory replacement for a 74LS165? What is the difference between a 'C' device and a 'CT' device? Any insight would be appreciated. Thanks, Russ Crisp Western Carolina University
henry@zoo.toronto.edu (Henry Spencer) (03/06/91)
In article <1991Mar3.221144.6692@uncecs.edu> crisp@uncecs.edu (Russ Crisp) writes: >... I found two devices, a SK7C165, and a SK7CT165 >that appear to be the same thing, as far as I can tell. Anyone >know if either one of these devices would be a satisfactory >replacement for a 74LS165? What is the difference between a >'C' device and a 'CT' device? ... Unfortunately, the answer to the first question is "it depends". It sounds like the SK7C165 is what would normally be called a [74]HC165, and similarly for the CT. They are all pin-compatible, but the HC165 is CMOS, while the HCT165 is CMOS with voltage levels fiddled to be more TTL-compatible. These parts are rather similar to the LS165, and the CT one might be worth a try, but both speed and drive characteristics differ enough that a designer would substitute one for the other only after careful consideration. -- "But this *is* the simplified version | Henry Spencer @ U of Toronto Zoology for the general public." -S. Harris | henry@zoo.toronto.edu utzoo!henry