Logic Families
183
ECL – to –TTL
Translator
(MC10125)
TTL
(b)
O/P
I/P
TTL – to –ECL
Translator
(MC10124)
TTL
ECL
(a)
O/P
I/P
ECL
Figure 5.64 TTL-to-ECL and ECL-to-TTL interfaces.
5.12.4 CMOS-to-ECL and ECL-to-CMOS Interfaces
CMOS-to-ECL and ECL-to-CMOS interfaces are similar to the TTL-to-ECL and ECL-to-TTL
interfaces described. Again, dedicated level translators are available. MC10352, for instance, is a quad
CMOS-to-ECL level translator chip. A CMOS-to-ECL interface is also possible by having firstly
a CMOS-to-TTL interface followed by a TTL-to-ECL interface using MC10124 or a similar chip.
Figure 5.65(a) shows the arrangement. Similarly, an ECL-to-CMOS interface is possible by having
an ECL-to-TTL interface using MC10125 or a similar chip followed by a TTL-to-CMOS interface.
Figure 5.65(b) shows a typical interface schematic.
5.13 Classification of Digital ICs
We are all familiar with terms like SSI, MSI, LSI, VLSI and ULSI being used with reference to digital
integrated circuits. These terms refer to groups in which digital ICs are divided on the basis of the
complexity of the circuitry integrated on the chip. It is common practice to consider the complexity of