Wednesday, August 27, 2014


Due to the rapid growth in technology there is need of high speed, low power consumption and higher noise immunity.
CMOS is the abbreviation of complementary metal oxide semiconductor. CMOS is the combination of PMOS and NMOS. Classical CMOS is represented as shown below.


Working of cmos

At one time only one transistor will be ON and other one wil be in OFF state. When input given is low or logic 0 PMOS becomes ON and NMOS will be in cut off region so there is vdd at output.
Similarily when input is logic high NMOS and PMOS will be ON and OFF respectively therefore output will be connected to ground directly and output will become zero.

Significant properties of CMOS in vlsi design

·         Low static power dissipation
Because at one time only one transistor is ON in static state so power consumption is low.   

High noise immunity

Noise tolerance capability of CMOS circuits is good enough so output is correct uptil a particular noise level.

Classification of cmos circuit.

Classification of CMOS circuit

Application of CMOS technology

               For high performance computing and engineering applications.

              CMOS circuits are highly used to developed RAM chips, microprocessor chips, DSP chips.

              CMOS logic is also used to design  different kind of  logic circuits like  gate, flipflops  etc.

Tags : HDL      VHDL        CMOS            FPGA          ASIC          SPICE              HSPICE


 Author- Jyotishna Bansal
(Intern at Silicon Mentor)