What is CMOS and how does it work?


Do you know what is CMOS (What is CMOS in Hindi)? If not, then today’s article is going to be very beneficial for you. By the way, whenever it comes to Integrated Circuit, then how can anyone forget CMOS. This is because the two biggest advantages of CMOS that no one else can provide are its high noise immunity and low static power consumption. CMOS circuits use a combination of P-Type and N-Type MOSFETs, so that they can easily implement logic gates and other digital circuits.

If seen, there are many such features and advantages of CMOS, due to which it is often given a place in all modern integrated circuits. That’s why today I thought that why should not all of you be provided complete information about what is the meaning of CMOS so that you too can get in touch with this great technology. Then without delay let’s start and know about what is CMOS in Hindi. It has always been my endeavor to provide you complete information as much as possible, so that you will not need to go anywhere else.

what is CMOS

The full form of CMOS is “Complementary Metal Oxide Semiconductor”. CMOS technology is a very popular technology in the computer chip design industry and is widely used today in the form of Integrated Circuits. in many applications. This technology is used in computer memories, CPUs and cell phones of the present times, due to its many advantages. In this technology, both P channel and N channel of semiconductor devices are used.

One of the very popular MOSFET technologies available today is Complementary MOS or CMOS technology. It is a dominant semiconductor technology of microprocessors, microcontroller chips, memories such as RAM, ROM, EEPROM and application specific integrated circuits (ASICs).

The main advantage of CMOS compared to NMOS and BIPOLAR technology is its smaller power dissipation. Unlike NMOS and BIPOLAR circuits, almost no static power dissipation is found in a Complementary MOS circuit. Power dissipates only when the circuit actually switches. As a result of this, more quantity of CMOS gates can be integrated in one IC than NMOS and Bipolar technology which can provide much better performance. Complementary Metal Oxide Semiconductor transistors have two types of MOS circuits, P-channel MOS (PMOS) and N-channel MOS (NMOS). Let us know about both these types.

What is NMOS

NMOS is built into a p-type substrate in which the n-type source and drain are diffused. In NMOS, the majority carriers are electrons. When a high voltage is applied in the gate then the NMOS starts conducting. Similarly, when a low voltage is applied in the gate, then NMOS starts conducting. NMOS are considered to be much faster than PMOS, since NMOS are carriers of electrons, and they travel at twice the speed as compared to holes.

what is PMOS

P-channel MOSFETs have a P-type source and the drain is diffused into an N-type substrate. Majority carriers in this have holes. When a high voltage is applied to the gate, then the PMOS starts conducting. Whereas when a low voltage is applied in the gate, then the PMOS starts conducting. By the way, these PMOS devices are more immune to noise than NMOS devices.

Who was the first to discover CMOS?

In 1963, Frank Wanlass was the first to discover CMOS. He also made a patent on it when he was doing some experiments in Fairchild Semiconductor.

What is the meaning of CMOS in computer?

CMOS Battery in English
CMOS (complementary metal-oxide-semiconductor) This technical term usually refers to the small amount of memory in a computer motherboard that stores BIOS settings. Talking about some BIOS settings, then it comes to system time and date, as well as hardware settings.

You must have heard the terms like Clearing CMOS many times, but you may not have understood it, then it means resetting the BIOS settings to its default levels. This is a very easy task, but it solves many problems of the computer.

What is another name for CMOS?

CMOS is referred to by many names such as Real-Time Clock (RTC), CMOS RAM, Non-Volatile RAM (NVRAM), Non-Volatile BIOS memory, and complementary-symmetry metal-oxide-semiconductor (COS-MOS). ). All have the same meaning which is CMOS.

How BIOS and CMOS work together

This BIOS is also a computer chip on top of the motherboard such as CMOS, while its function is slightly different, which is to communicate with the processor and other hardware components such as hard drives, USB ports, sound cards, video cards, and other hardwares. with. Whereas a computer without a BIOS cannot understand how these pieces of computer will work together.

CMOS is also a computer chip in the motherboard, or we can also call it more specifically a RAM chip, which means that it can normally lose its settings which are stored when the computer starts shutting down. . But this CMOS battery is used to provide constant power to the chip.
When the computer boots up for the first time, the BIOS pulls all the necessary information from the CMOS chip, so that it can understand all the hardware settings, times, and different settings and work accordingly.

What is CMOS Battery?

CMOS is usually powered by the use of a CR2032 cell battery. This battery is called CMOS battery.

Most CMOS batteries have a lifetime, which is roughly the same as the lifetime of the motherboard in which they are used. 10 years in most cases, but it may have to be replaced sometimes. If you see some major signs like incorrect or slow system date and time, and loss in BIOS settings, then it shows that your CMOS battery is dead or going to be dead.

To fix this, you have to replace them. Together it is very easy to do, you just have to remove the dead battery and make a new fit.

About CMOS and CMOS Batteries
While most motherboards have a spot for the CMOS battery, some smaller computers, such as tablets and laptops, have a small external compartment for the CMOS battery that is connected to the motherboard via two small wires.

Some devices that use CMOS are microprocessors, microcontrollers, and static RAM (SRAM). It is very important to understand that both CMOS and BIOS are not interchangeable terms. Although these two work together for a specific function within a computer, but both of them are completely different components.

When we start the computer, then we have an option to boot from within the BIOS and CMOS. By opening the CMOS setup, you can easily change the settings that it stores, such as date and time, how the different components of the computer will start. You can also disable/enable some hardware devices using these CMOS setup.

CMOS chips are most needed in battery-powered devices such as laptops because they use very little power and others use other types of chips. Although they use both negative polarity circuits and positive polarity circuits (NMOS and PMOS), only one circuit type can be powered at a time.

Note The Mac equivalent of CMOS is called PRAM, whose full form is Parameter RAM.

What are the applications of CMOS

Complementary MOS or CMOS processes are very widely implemented and have fundamentally replaced all NMOS and bipolar processes with all digital logic applications. This CMOS technology is used in the digital IC designs shown below.

Computer memories, in CPUs.
Microprocessor designs
In designing flash memory chip.
Together they are used to design application specific integrated circuits (ASICs).
These devices are used with analog circuits in many range of applications such as image sensors, data converters, etc.

Advantages of CMOS
Let us know about the advantages of CMOS as compared to NMOS:-

It has very low static power consumption
It reduces the complexity of the circuit.
It provides high density of logic functions in the chip.
It has low static power consumption.
It has high noise immunity.


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