Weighted Non-Weighted Coding
The digital circuitry you see inside computers and other electronic devices can only communicate via two concepts: on and off. These concepts are represented to us in the form of…
Axioms – Laws of Boolean Algebra
Boolean algebra is the algebra of propositions.Propositions are denoted by letters, such as A, B, x or y, etc.In the following axioms and theorems (laws of boolean algebra), the '+' or 'V' signs represent…
Hazards in Combinational Logic
If the input of a combinational circuit changes, unwanted switching variations may appear in the output. These variations occur when different paths from the input to output have different delays.…
NMOS Logic and PMOS Logic
Logic families discussed so far are the ones that are commonly used for implementing discrete logic functions such as logic gates, flip flops, counters, multiplexers, demultiplexers etc., in relatively less complex digital ICs belonging to…
CMOS Gate Circuitry
Up until this point, our analysis of transistor logic circuits has been limited to the TTL design paradigm, whereby bipolar transistors are used, and the general strategy of floating inputs being equivalent…
Transistor-Transistor Logic (TTL)
Introduction to Logic Families: Logic Gates like NAND, NOR are used in daily applications for performing logic operations. The Gates are manufactured using semiconductor devices like BJT, Diodes or FETs. Different Gate’s…
Digital Logic Families
In Digital Designs, our primary aim is to create an Integrated Circuit (IC). A Circuit configuration or arrangement of the circuit elements in a special manner will result in a…
Decoder: Decoding the Input
A decoder is a combinational logic circuit that turns one of several outputs ON (High) based on the logic of the inputs. Figure 7 represents a decoder in terms of…
Selecting Output Signals with a Multiplexer
A multiplexer is a signal switcher that selects an output signal from among multiple input signals. Its operation resembles that of a vending machine: press one of many available buttons,…
The Significance of Fan-Out
When connecting standard logic ICs, care must be taken to avoid connecting too many ICs to a given output. With TTL ICs, the output current limits the number of IC…
