Logic families

1. How many logic families are there?
2. What are digital logic families?
3. Which is fastest logic family?
4. Why CMOS logic family is better than bipolar family?
5. Which was the first logic family?
6. What is meant by logic family?
7. Why is interfacing of different logic families needed?
8. What are unipolar logic families?
9. What are the three basic logic gates?
10. What is unipolar and bipolar logic families?

How many logic families are there?

Four major logic families that predominated from the 1970's through the 1990's are Transistor-Transistor Logic (TTL), Complementary Metal-Oxide-Semiconductor Logic (CMOS, pronounced sea-moss), Low Voltage TTL Logic (LVTTL), and Low Voltage CMOS Logic (LVCMOS). Their logic levels are compared in Table 1.4.

What are digital logic families?

Digital logic family is a group of logic gates constructed using passive devices like a resistor, transistor, diodes, etc. Such devices have compatible logic levels and supply voltage with certain characteristics.

Which is fastest logic family?

Emitter-coupled logic (ECL) is a BJT-based logic family which is generally considered as the fastest logic available. ECL achieves its high-speed operation by employing a relatively small voltage swing and preventing the transistors from entering the saturation region.

Why CMOS logic family is better than bipolar family?

The main advantage of CMOS logic family is their extremely low power consumption. This is because there is no direct conducting path from Vdd to ground in either of input conditions. So there is practically zero power dissipation in STATIC conditioms.

Which was the first logic family?

The first, and oldest, family is TTL. TTL stands for 'transistor-transistor logic', this logic family having replaced the older (now obsolete) DTL—diode-transistor logic. The second logic family is CMOS (pronounced 'sea-moss') which stands for 'complementary metal oxide semiconductor'.

What is meant by logic family?

In computer engineering, a logic family is one of two related concepts: 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.

Why is interfacing of different logic families needed?

To achieve optimum performance in a digital system, devices from more than one logic family can be used, taking advantages of the superior characteristics of each family for different parts of the system. Therefore, it is necessary to examine the interface between CMOS and TTL devices. ...

What are unipolar logic families?

In unipolar logic families, unipolar devices are the key element. MOSFET (Metal Oxide Semiconductor Field Effect Transistor) is a unipolar device, in which the current flows because of only one type of charge carriers (that is, either electrons or holes). The examples of unipolar families include PMOS, NMOS, and CMOS.

What are the three basic logic gates?

All digital systems can be constructed by only three basic logic gates. These basic gates are called the AND gate, the OR gate, and the NOT gate. Some textbooks also include the NAND gate, the NOR gate and the EOR gate as the members of the family of basic logic gates.

What is unipolar and bipolar logic families?

The examples of unipolar families include. PMOS, NMOS, and CMOS.  Bipolar Logic Family: Transistors and diodes are bipolar. devices, in which the current flows because of both the. charge carriers (electrons and holes).