2 to 1 multiplexer using nmos transistors pdf

A pmos transistor acts as an inverse switch that is on when the controlling signal is low and off when the controlling signal is high. Instead of a dc input, we use a sinusoidal input as power clock pck input. So it would be a total of 8 gates times 2 for the amount of transistors, this would be 16 total transistors correct. Solved how many transistors do i need to design a cmos. From what i understand from another thread is if its implemented into a cmos i would need 1 pmos transistor and 1 nmos transistor so 2 transistors per 1 gate. Thus this paper analyzes 2 to1 multiplexer using complementary cmos, dynamic and passtransistor logic styles.

Common n well requires single supply to the circuit and reduces the power consumption in the 2 to 1 multiplexer circuit. Cmos design of area and power efficient multiplexer using tree topology. A transmission gate tg is a complementary cmos switch. I have a circuit using 3 not gates, 4 and gates, and 1 or gate. Implementing multiplexers with passtransistor logic. Metal oxide semiconductor field effect transistors nmos and pmos mosfets voltage applied to insulated gate controls current between source and drain low power allows very high integration. This gate selects either input a or b on the basis of the value of the control signal c. Figure 6 2to1 multiplexer realized using a nmos pass transistors only, b using cmos transmission gates, c platch inverter, d aspect ratio of. Vaijayanti panse research scholar, nagpur university. Efficient layout design and simulation of cmos multiplexer. Figure 1b shows the cmos transistor schematic configuration of 16 to 1 multiplexer. Transistors are used as switches to pass logic levels between. When i used muxes as shown in the diagram, my book said that i will be using 16 transistors.

We can confirm this in the following boolean expression. This is the adiabatic diode discharge logic addl which consumes very less power as compared to pfal logic. All functions are implemented using nmos only, and pmos transistors serve only as the pullup devices. Theprimary eason for this choice is that nmos transistors producer strong zeros, and pmos devices generate strong ones. Whats the minimum number of transistors we can use to build. Latest cmos technology 45 nanometre library has been used in cadence virtuoso tool simulations. A report on 2 to 1 mux using tg linkedin slideshare. The power is optimized and explored using the multiplexer. Design the 2x1 mux with 2t logic and comparing the. Instead of connecting the sources of nmos and pmos to ground and vdd respectively as for the inverter, we. A multiplexer or mux is a combinational circuits that selects several analog or digital input signals and forwards the selected input into a single output line.

I am using pmos and nmos to implement complement a, means that i am not using complement directly into the circuit. In this logic, we use 10 nmos transistors and 2 pmos transistors. When i used the nand, or, and not gates, i got 48 transistors. Realizing constructing a cmos pass gate cmos transmission gate from transistors.

Cmos pass gate, transmission gate, wl ratio, on resistance. A multiplexer of 2 n inputs has n selected lines, are used to select. As we only have one control line, a then we can only switch 2 1 inputs and in this simple example, the 2 input multiplexer connects one of two 1 bit sources to a common output, producing a 2 to 1 line multiplexer. This design uses seven pv gates producing 14 garbage outputs. When control signal c is logic low the output is equal to the input a and when control signal c is logic high the output is equal to the input b. Implementation of low power cmos full adders using pass. At times, designers find it convenient to use an ideal switch that can pass both 0 and 1 well. Characteristics of a mos transistor using this model are shown in.

In the late 70s as the era of lsi and vlsi began, nmos became the fabrication technology of choice. When c1, both mosfets are on, allowing the signal to pass through the gate. Convert the 2to1 mux without enable to a time division multiplexer tdm replace the slide switch select input s with a pulse module. Highperformance multiplexerbased logic synthesis using pass. Sep 17, 2016 cmos pass gate, transmission gate, wl ratio, on resistance. Pass transistor multiplexers can be built using transmission gates or the lone nmos type of switch. In nmos logic six nmos transistors are used to design 4. Nmos transistors are connected together for strong output. Nand gates are composed 160 pmos and nmos transistors, 16 inputs of nand gates are composed from 32 pmos and nmos transistor, and a cascade inverter is composed from four pmos and nmos transistors. This paper shows the contrast between conventional mux and mux using nmos transistors and accentuates the advantages of the latter. The threshold voltage of both passtransistors of single unit of 2. Conclusion gate diffusion input gdi technique is used for implementing 2. Lecture 2 circuits and layout university of pittsburgh.

Highperformance multiplexerbased logic synthesis using. Low power multiplexer design using modified dcvsl logic. Should i use nmos or pmos in cmos demultiplexer circuit. Vddand gnd rails are strongest 1 and 0 nmos pass strong 0 but degraded or weak 1 pmos pass strong 1. The pdn is constructed using nmos devices, while pmos transistors are used in the pun. Examples of solved problems for chapter3,5,6,7,and8. Combining them we get a good 0 and a good 1 passed in both directions. An nmos switch is on when the controlling signal is high and is off when the controlling signal is low. Finally a 16 bit arithmetic logic unit is designed using mixed logic families such as cmos for basic logic functions, pseudo nmos for and logic and pass transistor logic for multiplexers, in order. The small transistor size and low power dissipation of cmos.

Sizing the transistors in a cmos transmission gate. L14 combinational logic building blocks and bus structure. Ece 410 homework 2 solution spring 2008 problem 1 using the rules given in lecture notes, find vg2 and vo required for both transistors to be on in the twotransistor circuit shown below. Efficient layout design and simulation of cmos multiplexer by. Design of mux using different logic styles a logic style is the way how a logic function is implemented using a set of transistors. Transmission gate an overview sciencedirect topics. While accurate modeling of the output conductance is essential for linear design, the. In terms of pure logic functionality, these are interchangeablethey both pass or block an input signal based on the state of a control signal. Mar 16, 20 the cmos transmission gate logic tgl is used to design a new 4. Vlsi1 class notes signal strength strengthof signal how close it approximates ideal voltage source vddand gnd rails are strongest 1 and 0 nmos pass strong 0 but degraded or weak 1 pmos pass strong 1 but degraded or weak 0 thus nmos are best for pulldown network 91118 page 15. The field of electronics is trending with miniaturization and reduction in the threshold voltage. Later the design flexibility and other advantages of the cmos were realized, cmos technology then replaced nmos at all level of integration. Solved how many transistors do i need to design a cmos xor. You will then have what is commonly known as time division multiplexing or tdm for short.

Pass transistor logic ptl describes several designs of circuits. Assume that only the uncomplemented inputs w1, w2, w3,andw4 are available. Efficient layout design and simulation of cmos multiplexer by using different technologies. The cmos transmission gate logic tgl is used to design a new 4. By contrast, conventional cmos logic switches transistors so the output.

Adiabatic diode discharge logic based nibble multiplexer. Cmos design of area and power efficient multiplexer using. Whats the minimum number of transistors we can use to. The aim of this experiment is to design and plot the characteristics of a 4x1 digital multiplexer using pass transistor and transmission gate logic introduction. Performance analysis of multiplexer using low power techniques indian j. Recall that nmos transistors are good at passing 0 and pmos transistors are good at passing 1, so the parallel combination of the two passes both values well. All the results of this paper are simulated on cadence virtuoso tool realized in 45nm technology with reduction of 4. The input a of this simple 21 line multiplexer circuit constructed from standard nand gates acts to control which input i 0 or i 1 gets passed to the output at q from the truth table above, we can see that when the data select input, a is low at logic 0, input i 1 passes its data through the nand gate multiplexer circuit to the output, while input i 0 is blocked. Sep 29, 2012 i have a circuit using 3 not gates, 4 and gates, and 1 or gate. Based on tgl, it removes the degraded output, the nmos and pmos are combined together for strong output level with the gain in area, which is a central result of proposed mux. To illustrate this, consider the examples shown in figure 6. So the number of cmos transistors are 206 transistors. On the other hand, c0, places both transistors in cutoff, creating an open circuit between nodes a and b. Multiplexer is a circuit in which n select lines select one of input lines and.

Key word multiplexer, leakage power, nmos, pmos and transistor gating technique source voltage. The design of proposed 16to1 multiplexer has been nmos. Pdf this paper compares the use of complementary passtransistor logic cpl as more powerefficient than conventional cmos design. The multiplexer has been realized with stacking power gating leakage reduction technique in 45 nanometer technology 10 11.