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Semiconductor Components Industries, LLC, 2002
January, 2002 – Rev. 0
1 Publication Order Number:
TND306/D
TND306
High-Speed CMOS Product
Designation Definitions
Prepared by: Steve West
ON Semiconductor
HC vs. HCT
ON Semiconductor’s High–Speed CMOS product family,
intended to give the designer an alternative to LSTTL.
HSCMOS, with the faster speed advantage over
metal–gate CMOS (MC14000 series) and the lower power
consumption advantage over LSTTL, is an optimum choice
for midrange designs. With the availability of high–speed
CMOS microprocessors and memories, the ability to design
a 100% CMOS system is possible.
HCT devices offer a short–term solution to the TTL/
NMOS–to–CMOS interface problem. To achieve this
interface capability, some CMOS advantages had to be
compromised. These compromises include power
consumption, operating voltage range, and noise immunity.
In most cases HCT devices are drop–in replacements of
TTL devices with significant advantages over the TTL
devices. However, in some cases, an equivalent HCT
device may not replace a TTL device without some form of
circuit modification.
Designers can use HCT devices to perform logic level
conversions only. In newer designs, the designer wants all
the advantages of a true CMOS system and designs using
only HC devices.
“A” versus “Non–A”
“A” Versus “Non–A” — ON Semiconductor has a
device performance enhancement program for the
High–Speed CMOS family. This is indicated by an “A” suffix
on the device identification. Some of the characteristics of
this “A” enhancement program are improved design, a
better quality process, faster performing AC propagation
delays and enhancements to various DC characteristics.
The old “Non–A” process was a 5 micron process that
was modified to run a 3.5 micron family. The new “A”
process is a true 3 micron process and gives better process
control, with improved performance and quality.
Please see the specific device data sheet for “A”
designation parameters.
http://onsemi.com
TECHNICAL NOTE
