Xnor gate pass transistor logic pdf

Gate is static a lowimpedance path exists to both supply rails under all circumstances. This circuits truth table, then, is equivalent to that of the nor gate. And, or, not, nand not and, nor not or, xor, and xnor not xor later building functions. A design of 3 input xnor gate using new 2t xnor gates. Pdf a novel 1bit full adder design using dcvsl xorxnor. Xorxnor ptl cell with 16 transistors is reported in 4. Transmission gate inverting multiplexer a m 2 m 1 b s s s f v dd gnd v dd in 1 s s in 2 s s. The design has been compared with earlier proposed 4t and 6t xor gates and a. Full adder design with 10 transistors using xor xnor gates is also reported in 6. Accordingly, neither of the two transistors will conduct and the transmission gate turns off. Indicates correct number of logic stages and transistor sizes. The passtransistor logic ptl is a better way to implement circuits designed for low power applications.

Single bit full adder design using 8 transistors with. An electronic xor exclusive or gate performs the digital logic xor function. The input to a ttl circuit is always through the emitters of the input transistor, which exhibits a. In pass transistor logic, the transistors are used as voltage controlled switches to implement the logic. For both or and xor, the output is high when either of the two inputs are high, and when both inputs are low, the.

Comparative performance analysis of xor xnor function based. Cmpen 411 vlsi digital circuits spring 2012 lecture 07. Ornor, and xorxnor in three conventional passtransistor techniques. A novel 1bit full adder design using dcvsl xor xnor gate and pass transistor multiplexers 143. In this paper, we propose an efficient selfchecking adder. Cmos vlsi is thedigital implementation technology of choice for the foreseeable future next 1020 years excellent energy versus delay characteristics high density of wires and transistors monolithic manufacturing of devices and interconnect, cheap. Watch this video to learn more and see the interesting practical. A novel 1bit full adder design using dcvsl xorxnor gate and pass transistor multiplexers 143 the static cmos consists of pullup and pulldown networks.

This technique uses the complementary properties of nmos and pmos transistors. Nikolic double passtransistor logic dpl dpl a b b b a c c o q qb n1 p1 n2 p2 n1 p1. The switching tree of a dpl gate consist of both nmos and pmos pass transistors, in contrast to the. A new 5 transistor xor xnor circuit based on the pass transistor logic. The xnor gate sometimes xornt, enor, exnor or nxor and pronounced as exclusive nor is a digital logic gate whose function is the logical complement of the exclusive or gate. Then, obviously, xnor is the inverse of xor so just stick an inverter on the output of xor exclusive or operator. Lowpower and fast full adder by exploring new xor and. Used to build logic functions there are seven basic logic gates. Logic gates a b out 0 0 0 0 1 1 1 0 1 1 1 1 a b out 0 0 0 0 1 0 1 0 0. Xor gate sometimes eor, or exor and pronounced as exclusive or is a digital logic gate that gives a true 1 or high output when the number of true inputs is odd. In this lecture, we will talk about another way to implement logic functions using transistors. Topology of 2 input subnanowatt xor gate in 65nm cmos. In this paper, an attempt has been made to generalize a.

In order to turn this nor gate circuit into an or gate, we would have to invert the output logic level with another transistor stage, just like we did with the nandtoand gate example. In contrast to static cmos primary inputs drive gate terminals. Logical effort is ratio of logic gates input 2 2 2. Hybrid pass transistor logic with dualgate ambipolar cntfets. Many circuits have been proposed to implement xorxnor gate, which a few examples of the most efficient ones are shown in fig. A novel 1bit full adder design using dcvsl xor xnor gate and pass transistor multiplexers. Comparative performance analysis of xorxnor function based. Among these, passtransistor logic is one of the most appealing design.

A high output 1 results if both of the inputs to the. This is owing to the fact that pmos transistor is inherently slow and an inverted signal was passed through a pmos transistor adding to the delay. Nikolic announcements l projects proposals due today by 5pm. Implementation of low power cmos full adders using pass transistor logic r. Dual gate ambipolar carbon nanotube transistors dgacntfets have two independent gates that enable polarity switching between electron and hole conduction see fig. The example transistor xor gate circuit is implemented here using pn2222a npn transistors a variant of the 2n2222a but many common npn bipolar junction transistors. Pdf a new 5transistor xorxnor circuit based on the pass. V s will initially charge up quickly, but the tail end of the transient is slow. The current drive of the transistor gatetosource voltage is reduce significantly as v. In 2 a 16 transistors full adder cell with xorxnor, pass transistor logic ptl and transmission gate is reported.

As described hereinabove, an xor gate and xnor gate are formed by the pass transistor logic circuit, and the comparator is formed by combining these with a differential sense amplifier. Comparative performance analysis of xor xnor function. Transmissiongate digitalcmosdesign electronics tutorial. For low power applications pass transistor logic ptl is best suitable technique and explanation was given in. Complementary pass transistor logic a general method of karnaugh map coverage and mapping into circuit realizations is applied to design logic andnand, ornor, and xor xnor gates in cpl. The truth table and equivalent gate circuit an invertedoutput nor gate are shown. Simulation results of 6transistor xorxnor gate the xorxnor gate is simulated using spectre cadence in the voltage range of 0. The hybrid adder is designed using dcvsl gates because these can produce both complementary and true outputs using single gate architecture. The advantage of pass transistor logic ptl is that. Ttl nor and or gates logic gates electronics textbook. The current work proposes the design of a 6t full adder using a novel 2t xnor gate. Andnand, ornor, and xorxnor in each of these families.

Combinational logic gates in cmos purdue engineering. A general method in synthesis of passtransistor circuits people. The advantage of ptl is that only one ptl network either nmos or pmos is. This paper compares the use of complementary passtransistor logic cpl as more powerefficient than conventional cmos design. Ratio gate counttransistor count is roughly 110 ic logic gates fall under ssi, combinational. Full adder design with 10 transistors using xorxnor gates is also reported in 6. This circuit design uses a concept of pass transistor and mos inverter. The transmission gate logic is used to solve the voltage drop problem of the pass transistor logic. Pass transistor logic xor gate using pass transistor logic. A new design 6t full adder circuit using novel 2t xnor gates. The logic gate design presents a systematic implementa. Logic gates digital circuit that either allows a signal to pass through it or not. The thesis comparison of cmos xor and xnor gate design by makara tang has been examined and approved by the following examination committee.

The proposed adder cell has 16 transistors and is mainly based up on low power xorxnor pass transistor logic and transmission gates. Pass transistor logic ptl, double pass transistor logic dpl and transmission gate tg logic to enhance performance of time synchronised. Though it has high speed due to low input capacitance, it has limited capacity to drive a load. Comparative performance analysis of xorxnor function. The pass transistor logic ptl is a better way to implement circuits designed for low power applications. Xor and xnor outputs has been improved to overcome the switching delay problem. Single bit full adder design using 8 transistors with novel 3. Transistortransistor logic ttl transistortransistor logic, or ttl, refers to the technology for designing and fabricating digital integrated circuits that employ logic gates consisting primarily of bipolar transistors. Dpl gate compensate for the speed degradation due to the fig. The twoinput version implements logical equality, behaving according to the truth table to the right, and hence the gate is sometimes called an equivalence gate. Novel design methodology for highperformance xorxnor. A novel 1bit full adder design using dcvsl xorxnor gate. Note that the caret does not denote logical conjunction and in these languages, despite the similarity of symbol. Complementary passtransistor logic cpl with 32 transistors having high power dissipation and better driving capability is reported in 4.

Cmos exnor xnor gate using gates as well as transistors. The method consists of the implementation of the gates. Analysis of conventional cmos and finfet based 6t xorxnor. And, or, not, nandnot and, nornot or, xor xnor not xor 9 did you know.

In this paper, we proposed the new design 2t xnor gate circuit is based on the pass transistor logic. Analysis of conventional cmos and finfet based 6t xor. Transmission gate logic circuits adapted from cmos logic circuit design by john p. A hybrid cmos logic style adder with 22 transistors is reported 7. A general method in synthesis of passtransistor circuits. Diode logic dl resistor transistor logic rtl diode transistor logic dtl emitter coupled logic ecl logic families can be classified broadly according to the technologies they are built with transistor transistor logic ttl cmos logic ttl and cmos logic family is most widely used ic technologies. When the control input is a logic one, the gate terminal of the nchannel mosfets is located at a positive supply voltage potential. The low power pass transistor logic and its design and analysis procedures were reported in 16. Transmission gate logic conditional sum adder conditional cell 2way muxes rothermel, jssc 89. Pdf a new 5transistor xorxnor circuit based on the. This function is generally similar to the standard or function with one critical difference.

Many circuits have been proposed to implement xor xnor gate, which a few examples of the most efficient ones are shown in fig. The truth table of xor gate is as shown in table below. Sep 19, 2016 cmos exnor xnor gate using gates as well as transistors. Digital logic gates nand and nor are called universal logic gate because we can construct. Pass transistor logic adapted from rabaeys digital integrated circuits, second edition, 2003 j.

Npn transistor xor gate circuit sully station technologies. Figure below shows the implementation of xor function using pass transistors. Analysis of conventional cmos and finfet based 6t xorxnor circuit at 45nm technology neha yadav. It overcomes the main problem associated with dtl, i.

As can be seen in the logic diagram below, the xor gate is built by combining three more simple gates, the or gate, the nand gate and the and gate to produce the desired result. Each pass element is a pair of complementary transistors, so this gate uses 2 nmos and 2 pmos. Passtransistor logic switch network a b b reduced number of transistors. Full adder circuit based on transmissiongates is shown in. By the inverter, the gate terminal of the pchannel mosfets is now at a negative supply voltage potential. Nmos devices passes a strong 0 but a weak 1 while pmos transistors pass a strong 1 but a weak 0. The sense amplifier and comparator are thus effectively integrated, and the readcomparison time can be shortened by performing both operations simultaneously.

Dualgate ambipolar carbon nanotube transistors dgacntfets have two independent gates that enable polarity switching between electron and hole conduction see fig. A comparative performance analysis of various cmos design. Complementary pass transistor logic cpl is used in 1. Some logical circuits using ptl pass transistor logic october 9, 2012 8 9. Single bit full adder design using 8 transistors with novel 3 arxiv.

In 2 a 16 transistors full adder cell with xor xnor, pass transistor logic ptl and transmission gate is reported. Passtransistorlogic xor gate using pass transistor logic. This video takes the viewers, step by step to four different derived gates, i. Section 3 describes a general method to synthesize basic twoinput and three input logic gates. Nmos devices passes a strong 0 but a weak 1 while pmos transistors pass a. Section 3 describes a general method to synthesize basic twoinput and threeinput logic gates andnand, ornor, and xor xnor in each of. Vlsi design pass transistor logicpass transistor logic. Slide set 3 pass transistor logic transmission gates. The xorxnor circuit based on pass transistor logic ptl using 6 transistor is described in 20 as. The multiplexers in the design are based on the pass transistor logic ptl because these are simple to construct and occupies less chip area per component.

This circuit has a nonfull voltage swing at the output. Lowpower and fast full adder by exploring new xor and xnor gates. A new design of xorxnor gates for low power application. Logic gates digital circuit that either allows signal to pass through it or not used to build logic functions seven basic logic gates. The proposed circuit has the minimum transistor count and there is no complementary input signal is. For some types of functions, this can lead to much more efficient implementations than using gates. Complementary pass transistor logic cpl with 32 transistors having high power dissipation and better driving capability is reported in 4. Nov 12, 2016 this video takes the viewers, step by step to four different derived gates, i. Vlsi design pass transistor logicpass transistor logic adapted from rabaeys digital integrated circuits, 2002, j. Comparative performance analysis of xorxnor function based highspeed cmos. From switches to transistors, logic gates and logic circuits. This paper proposes the novel design of 2t xnor gate using pass transistor logic.

Section 2 gives an overview of three conventional pass transistor logic families complementary pass transistor logic cpl, double pass transistor logic dpl, and dual value logic dvl. You can find circuits using 4, 6, 8, 9, 10 or 12 transistors, again with varied strengths for the inputs and the output. A design of 3 input xnor gate using new 2t xnor gates krishna chandra1 vishal ramola2. Cmos technology and logic gates mit opencourseware. Xor and xnorgate and use additional transistors to rectify the levels at specific inputs see fig. Logic gates in cmos indepth discussion of logic families in cmosstatic and dynamic, passtransistor, nonran tioed and ratioed logic n optimizing a logic gate for area, speed, energy, or robustness lowpower and highperformance circuitdesign techniques 6. For example, pass transistor logic transmission gates makes it pretty simple. The advantage in area is obtained since the pmos network of a dynamic cmos gate consists of only one transistor. Transmission gate logic circuit is based on special kind of passtransistor logic circuit 4,6. Implementation of low power cmos full adders using pass. Pass transistor logic adapted from rabaeys digital integrated circuits, second edition, 2003.

And, or, not, nandnot and, nornot or, xor xnornot xor 9 did you know. A novel 1bit full adder design using dcvsl xorxnor gate and. Xor xnor ptl cell with 16 transistors is reported in 4. The performances of this circuit have been compared to earlier designed xnor gate delay, power dissipation and power delay product pdp. He was born in lincoln, england and he was the son of a shoemaker. Section 3 describes a general method to synthesize basic twoinput and threeinput logic gates. Proposed xor xnor gate circuit in fig 7, the proposed circuit design of xor xnor gate using 6 transistors is displayed.