Digital Systems: Principles and Design

171Interfacing Circuits between the Logic Gates of Same Family, Different Families and Types

7.4 INTERFACING CMOS WITH CMOS GATES

What about a CMOS to CMOS interconnection? The current levels are too small in CMOS

so that the large number of interconnections does not pose any difficulty unless the

operating frequencies become higher than maximum limiting MHz.

Points to Remember when Interfacing

1. A + 5 V operated CMOS gate output can always be interfaced to a single LS TTL

gate.

2. In CMOS gates, the current ratio i

sink

/i

supply

from supply is negligible as the cur-

rents are in few mA only if the inputs are not floating but are kept at ...