In negative logic, the logic state 1 corresponds to Lower voltage level.

The two logical states are usually represented by two different voltages, but two different currents are used in some logic families. High and low thresholds are specified for each logic family. When below the low threshold, the signal is "low". When above the high threshold, the signal is "high". Intermediate levels are undefined, resulting in highly implementation-specific circuit behavior.

A logic level is one of several states that a digital signal can possess, expressed as a DC (direct-current) voltage with respect to electrical ground. Usually, the term refers to binary logic in which two levels, or states, can exist: logic 1 (also called the high state) and logic 0 (also called the low state).

In digital circuits, a logic level is one of a finite number of states that a digital signal can inhabit. Logic levels are usually represented by the voltage difference between the signal and ground, although other standards exist. The range of voltage levels that represents each state depends on the logic family being used.

Logic gates are the building blocks of all the circuits in a computer.

Logic Gates are the basic building blocks of digital circuits. The computer/smartphone you are using now is made-up on these logic gates. Logics is made of diodes and transistors, these constitutes to registers, multiplexers, memory units, logical units and arithmetic units of your CPU/Microprocessors.

Of the two the NAND gate is the most widely seen. OR / NOR : OR gates and NOR gates are another form of logic gate that form one of the basic building blocks of digital technology. The OR gate gives a logical "1" when one of the other input (or both inputs) is high.

Half adder is the name of the logic circuit which can add two binary digits.

An adder is a digital circuit that performs addition of numbers. The half adder adds two binary digits called as augend and addend and produces two outputs as sum and carry; XOR is applied to both inputs to produce sum and AND gate is applied to both inputs to produce carry.

An adder is a digital logic circuit in electronics that implements addition of numbers. In many computers and other types of processors, adders are used to calculate addresses, similar operations and table indices in the ALU and also in other parts of the processors. These can be built for many numerical representations like excess-3 or binary coded decimal. Adders are classified into two types: half adder and full adder. The half adder circuit has two inputs: A and B, which add two input digits and generate a carry and sum. The full adder circuit has three inputs: A and C, which add the three input numbers and generate a carry and sum. This article gives brief information about half adder and full adder in tabular forms and circuit diagrams.

When an input electrical signal A=10100 is applied to a NOT gate, its output signal is 01011.

Electrical Transducers are used to convert energy of one kind into energy of another kind, so for example, a microphone (input device) converts sound waves into electrical signals for the amplifier to amplify (a process), and a loudspeaker (output device) converts these electrical signals back into sound waves and an.

When the maximum clock rate is quoted for a logic family, it applies to a shift register.

The Shift Register is another type of sequential logic circuit that can be used for the storage or the transfer of binary data.

Application(s) of flip-flop:-

1) Bounce elimination switch:- Switch bouncing is another real-world problem that happens too quickly for human perception but which can doom an electronics project. When a switch is toggled, contacts have to physically move from one position to another.

2) Latch:- Latch is a circuit that has two stable states and can be used to store state information. The circuit can be made to change state by signals applied to one or more control inputs and will have one or two outputs. It is the basic storage element in sequential logic.

3) Counters:- Counters are widely used in digital electronics and digital systems. They are used to count the number of events occurred in a specific interval of time. Mostly, a counter is used for counting the number of pulses entering at the input of a circuit in a specific time period.

Excitation table helps in representing the previous and next e of the sequential circuit prior to and after the clock pulse respectively.

Excitation table:- An excitation table shows the minimum inputs that are necessary to generate a particular next state. When the current state is known. They are similar to truth tables and state tables, but rearrange the data so that the current state and next state are next to each other on the left-hand side of the table, and the inputs needed to make that state change happen are shown on the right side of the table.

Sequential circuit:- A Sequential logic circuits is a form of binary circuit; its design employs one or more inputs and one or more outputs, whose states are related to some definite rules that depends on previous states. Both the inputs and outputs can reach either of the two states: logic 0 (low) or logic 1 (high).

A digital gate can respond to an input signal in A few billionth of a sec.

A logic gate is an electronic component that can be used to conduct electricity based on a rule. The output of the gate is the result of applying this rule to one or more "inputs". These inputs may be two wires or the output of other logic gates.

Logic gates are digital components. They normally work at only two levels of voltage, a positive level and a zero level. Commonly they work based on two states: On and Off. In the On state, voltage is present. In the Off state, the voltage is at zero.

Sequential circuit type is based upon time or clock pulse.

Combinational circuits and systems produce an output based on input variables only. Sequential circuits use current input variables and previous input variables by storing the information and putting back into the circuit on the next clock (activation) cycle.

For the clocked sequential circuits, the output pulse is the same duration as the clock pulse. A level output refers to an output that changes state at the start of an input pulse or clock pulse and remains in that state until the next input or clock pulse.

In J-K flip-flop the function K==J is used to realize T-flip-flop.

The JK flip-flop is basically a gated SR flip-flop with the addition of a clock input circuitry that prevents the illegal or invalid output condition that can occur when both inputs S and R are equal to logic level “1”. With the addition of a clock input circuitry that prevents the illegal or invalid output condition that can occur when both inputs S and R are equal to logic level “1”.

The "toggle" flip-flop changes its output on each clock edge, giving an output which is half the frequency of the signal to the T input. It is useful for constructing binary counters, frequency dividers, and general binary addition devices. It can be made from a J-K flip-flop by tying both of its inputs high.

Master slave flip-flop is also referred to as the-pulse triggered flip-flop.

Master-slave flip-flop:-A type of clocked flip-flop consisting of master and slave elements that are clocked on complementary transitions of the clock signal. Data is only transferred from the master to the slave, and hence to the output, after the master-device outputs have stabilized.

Master flip-flop is triggered by the external clock pulse train while the slave is activated at its inversion that is if the master is positive edge-triggered, then the slave is negative-edge triggered. This means that the data enters into the flip flop at leading/trailing edge of the clock pulse while it is obtained at the output pins during trailing/leading edge of the clock pulse. Hence a master-slave flip-flop completes its operation only after the appearance of one full clock pulse for which they are known as pulse-triggered flip-flops.

The propagation delay for ECL IC family is approximately 2 ns.

It is an old technology and the speed is due to the fact that the transistors never enter saturation. So there is no time to wait for the transistor to come out of saturation. However, this logic works with negative power supplies and does dissipate more power than other logic families.

Emitter-coupled logic (ECL) is a high-speed integrated circuit bipolar transistor logic family.

A logic family of monolithic digital integrated circuit devices is a group of electronic logic gates constructed using one of several different designs, usually with compatible logic levels and power supply characteristics within a family.

Race condition occur in RS flip-flop.

When the S and R inputs of an SR flip flop is at logical 1 and then the input is changed to any other condition, then the output becomes unpredictable and this is called the race around condition.

RS flip flop:-

An SR Flip Flop is an arrangement of logic gates that maintains a stable output even after the inputs are turned off. This simple flip flop circuit has a set input (S) and a reset input (R). The set input causes the output of 0 (top output) and 1 (bottom output).

Enhancement mode is used in MOSFET.

In most circuits, this means pulling an enhancement-mode MOSFET's gate voltage towards its drain voltage turns it ON. In a depletion-mode MOSFET, the device is normally ON at zero gate–source voltage. Such devices are used as load "resistors" in logic circuits.

The MOSFET (Metal Oxide Semiconductor Field Effect Transistor) transistor is a semiconductor device which is widely used for switching and amplifying electronic signals in the electronic devices. The MOSFET is a three terminal device such as source, gate, and drain.

CMOS have highest fan out.

Fan-out is a term that defines the maximum number of digital inputs that the output of a single logic gate can feed. Most transistor-transistor logic ( TTL ) gates can feed up to 10 other digital gates or devices.

Fanout for CMOS gates, is the ratio of the load capacitance (the capacitance that it is driving) to the input gate capacitance. As capacitance is proportional to gate size, the fanout turns out to be the ratio of the size of the driven gate to the size of the driver gate.

Fanout of a CMOS gate depends upon the load capacitance and how fast the driving gate can charge and discharge the load capacitance. 

S=1, R=1 input combinations is not allowed in an SR flip-flop.

An SR flip Flop is an arrangement of logic gates that maintains a stable output even after the inputs are turned off. This simple flip flop circuit has a set input (S) and a reset input (R). The set input causes the output of 0 (top output) and 1 (bottom output).

S=1, R=1 is state forbidden in SR flip flop. The flip flop does not get damaged in forbidden state (S=R=1). It is called forbidden because there is no definitive gurantee of a fixed output.

An n stage ripple counter can count upto 2n-1.

All subsequent flip-flops are clocked by the output of the preceding flip-flop. Asynchronous counters are also called ripple-counters because of the way the clock pulse ripples it way through the flip-flops. The MOD of the ripple counter or asynchronous counter is 2ⁿ if n flip-flops are used.

The clock input or the information ripples through the consecutive flip flops in asynchronous counters that is the clock input to a flip flop is the output of the preceeding flip flop. Hence they are also termed as ripple counters.

A n-bit ripple counter can count up to 2ⁿ states. It is also known as MOD n counter. It is known as ripple counter because of the way the clock pulse ripples its way through the flip-flops.

A ripple counter is an asynchronous counter where only the first flip-flop is clocked by an external clock. All subsequent flip-flops are clocked by the output of the preceding flip-flop. Asynchronous counters are also called ripple-counters because of the way the clock pulse ripples it way through the flip-flops.

ECL logic family is well suited for high speed operation.

Emitter-coupled logic is a high-speed integrated circuit bipolar transistor logic family. A variation of ECL in which all signal paths and gate inputs are differential is known as differential current switch logic.

A logic family of monolithic digital integrated circuit devices is a group of electronic logic gates constructed using one of several different designs, usually with compatible logic levels and power supply characteristics within a family.

If both J and K input is same, then it works like T type flip-flop.

When both the J and K input are at logic “1” at the same time and the clock input is pulsed HIGH, the circuit toggle from its SET state to a RESET. When both the terminals are HIGH the JK flip-flop acts as a T type toggle flip-flop.

The JK flip flop is basically a gated SR flip-flop with the addition of a clock input circuitry that prevents the illegal or invalid output condition that can occur when both inputs S and R are equal to logic level “1”.

The T flip-flop changes its output on each clock edge, giving an output which is half the frequency of the signal to the T input. It is useful for constructing binary counters, frequency dividers, and general binary addition devices. It can be made from a J-K flip-flop by tying both of its inputs high.

In logic, a functionally complete set of logical connectives or Boolean operators is one which can be used to express all possible truth tables by combining members of the set into a Boolean expression. A well-known complete set of connectives is {AND, NOT}, consisting of binary conjunction and negation.

AND gate:-

The AND gate is an electronic circuit that gives a high output (1) only if all its inputs are high.  A dot (.) is used to show the AND operation i.e. A.B.

OR gate:-

The OR gate is an electronic circuit that gives a high output (1) if one or more of its inputs are high.

NOT gate:-

The NOT gate is an electronic circuit that produces an inverted version of the input at its output.

Minimum hardware required to construct a 3×83×8 decoder is using a Two 2×42×4 decoder and one 1×21×2 decoder.