Highperformance multiplexerbased logic synthesis using. Spl singlerail passtransistor logic is one of the most promising logic. Free download cmos logic circuit design ebook circuitmix. The pins are aligned in two straight lines, one on each side of the ic. For some types of functions, this can lead to much more efficient implementations than using gates. The pass transistor logic is required to reduce the transistors for implementing logic by using the primary inputs to drive gate terminals, source and drain terminals. Hybrid pass transistor logic with dualgate ambipolar cntfets. Vlsi design pass transistor logicpass transistor logic. In the configuration above, the transistor is referred to as a pass transistor. Actually, there are many different ttl families, with a range of speed, power consumption, and other characteristics. Implementation using pass transistor logic cell library once the boolean functions are represented by bdd trees, we can easily realize the logic functions by replacing each node in the bdd trees with a 2to1 multiplexer designed using pass transistor logic, such as cpl or dpl.
Digital integrated circuits combinational logic prentice hall 1995 combinational logic. Then leap which is singlerail passtransistor logic then differential. Problems design 4 to 1 multiplexor using transmissiongates. Slide set 3 pass transistor logic transmission gates. Pdf this paper introduces pass transistor logic design with dual threshold voltages. Section 3 describes a general method to synthesize basic twoinput and threeinput logic gates andnand, ornor, and xorxnor in each of. Evaluation kit dual, 300ma, lownoise linear regulator. Conventional static cmos logic ratioed logic pass transistor transmission gate logic. The dual mode comparator examines the set voltage and selects the feedback path. V s will initially charge up quickly, but the tail end of the transient is slow. Vlsi digital circuits design, chapter 4 oklobdzija, yano filename.
Vlsi design pass transistor logicpass transistor logic adapted from rabaeys digital integrated circuits, 2002, j. Cmos, lowvoltage lowpower logic styles, passtransistor. Implementation using passtransistor logic cell library once the boolean functions are represented by bdd trees, we can easily realize the logic functions by replacing each node in the bdd trees with a 2to1 multiplexer designed using passtransistor logic, such as cpl or dpl. Thus a minimal surface area is required for each logic input. Implementation of low power cmos full adders using pass. A general method in synthesis of passtransistor circuits. 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. Select lines and complements choose between available inputs at each stage. Highperformance multiplexerbased logic synthesis using pass. Interfacing reversible passtransistor cmos chips with. A static cmos gate is a combination of two networks, called the pullup network pun.
Hello and welcome original pdf to todays lecture on pass transistor logic circuits this is the page replacement policies pdf second. Passtransistor logic has been considered as a lowpower alternative to cmos logic 37. As with the nchannel example, a logic signal from the system power management control circuitry turns the load switch on and off via a smallsignal nmos transistor, q1. In this paper, we present a selfchecking full adder based on the double pass transistor technology. Evaluation kit dual, 300ma, lownoise linear regulator with.
In particular, nmos transistors pass 0s well but pass 1s poorly. Pass transistor is wellsuited to circuits that contain large proportions of xor gates and arithmetic units, because ptl based. The input to a ttl circuit is always through the emitters of the input transistor, which exhibits a. Transistors are used as switches to pass logic levels between nodes of a circuit, instead of as switches connected directly to supply voltages. Pass transistor logic families complementary pass transistor logic family dual pass transistor logic family swing restored pass transistor logic family 31. Ttl logic family digital logic families electronics. The line in the mosfet symbol between the drain d and source s connections represents the transistors semiconductive channel. One way to simplify the circuit for manual analysis is to open the feedback loop. Sense amplifierbased pass transistor logic university of. Section 3 describes a general method to synthesize basic twoinput and threeinput logic gates andnand, ornor, and xorxnor in each of these families, and discusses balancing input loads of the gates. In this paper, we propose an efficient selfchecking adder.
Design of reversible logic circuits using standard cells. Though efficient and simple, dynamic cmos also brings certain problems and risks associated with its use. Dynamic pass transistor logic ptl, which combines pass transistor logic with dynamic logic, is proposed for highperformance vlsi circuit design. Esign of d reversible multiplexer we design the reversible circuit using dual line passtransistor logic 1. Among these, pass transistor logic is one of the most appealing design. Indeed, designing highspeed lowpower circuits with. Double passtransistor logic dpl the basic difference of pass transistor logic compared to the cmos logic style is that the source side of the logic transistor networks is connected to some input signals instead of the power lines. Double passtransistor logic and its characteristics are dis at reduced supply.
It is noted that in our designed pass transistor configuration dualv th domino dynamic logic circuits, the pass transistor xnor gate in fig. Us6222788b1 vertical gate transistors in pass transistor. In this paper, we propose an improved asynchronous logic dual rail saptl approach over the reported saptl. Basic pass transistor logic model f sum of products control signals pass signals v i p i 1 1 2 2 n n f p v p v p v. So, when the nmos is charging up the load capacitance, the source is. The novel decode circuits of the present invention include an address. Similarly, pmos transistors pass 1s well but 0s poorly. Improved asynchronouslogic dualrail sense amplifier. When en is low, q1 is off and the gate is pulled up to vin. Transistortransistorlogic topics the most commonly used bipolar logic family is transistortransistor logic.
This comes because in pass transistor logic the source and drain nodes are not fixed. Systems and methods are provided for vertical gate transistors in static pass transistor decode circuits. Transistor transistor logic dual in line packaging dip dual in line package dip is the most common pin layout for integrated circuits. When en is high, q1 turns on, the pass transistor gate is pulled to ground, and the. Disadvantage that output levels are always lower than the input level. Improved asynchronouslogic dualrail sense amplifierbased. Logic network employs input signals at both gate and drain terminals. Oct 09, 2012 in electronics pass transistor logic ptl describes several logic families used in the design of integrated circuits. Specifically, when the gate of an nmos transistor is at v dd, the drain will only swing between 0 and v dd. A set of singlerail, fully restored, pass transistor gates are. However, we will see that it is possible to build logic gates that use transistors only in their good mode. Esign of d reversible multiplexer we design the reversible circuit using dual line passtransistor logic 1 and monotone circuit. This paper introduces passtransistor logic design with dual. The output node charges from 0 v ddv tn, and the energy drawn from the power supply for charging the output of a pass transistor is given by c l.
Double pass transistor logic dpl the basic difference of pass transistor logic compared to the cmos logic style is that the source side of the logic transistor networks is connected to some input signals instead of the power lines. For example, the diode in the dtl can be replaced by a transistor whose collector is pulled up to the power supply. Transistor transistor logic topics the most commonly used bipolar logic family is transistor transistor logic. In electronics, pass transistor logic ptl describes several logic families used in the design of integrated circuits. Internal pchannel pass transistor the max8559 features two 0. Double pass technology and these circuit techniques 18. Pass transistor logic has been considered a low power logic 14,15. Regenerative passtransistor logic rpl, a modular dualrail circuit technique for high speed logic design that gives reasonably low power consumption, was developed. Its name signifies that transistors perform both the logic function the first transistor and the amplifying function the second transistor. A selfchecking cmos full adder in double pass transistor. The pins are aligned in two straight lines, one on each side of. Dualgate ambipolar carbon nanotube transistors dgacntfets have two independent gates that enable polarity switching between electron and hole conduction see fig.
Thick lines indicate the vt,l transistors of the logic circuitry and thin. Digital integrated circuits combinational logic prentice hall 1995 overview static cmos conventional static cmos logic ratioed logic pass transistor transmission. The pass transistor is driven by a periodic clock signal and acts as an access switch to either charge up or charge down the parasitic capacitance c x, depending on the input signal v in. Pdf a differential double pass transistor logic unit. Pass transistor logic f product term control signal pass signal v p if 1 if 0 v p z p f. Lowpower 1bit fulladder cell using modified pass transistor logic n. Passtransistor design was the work of lara oliver was supported in part by a semiconductor research corporation graduate fellowship permission to make digital or hard copies of all or part of this work for. Dualthreshold passtransistor logic design duke university. Hello and welcome original pdf to todays lecture on passtransistor logic circuits this is the page replacement policies pdf second. The circuit examples in this section are based on a representative ttl family, lowpower schottky ls or lsttl. This, however, raises new issues regarding the compatibility between this adiabatic logic implementation and conventional cmos logic. Complementary pass transistor logic a b a b b a b a b. Logic gates in conventional or complementary cmos also simply referred to as cmos in the sequel are built from an nmos pulldown and a dual pmos pullup logic network. Introduction conventional static cmos has been a technique of choice in most processor design 1.
It reduces the count of transistors used to make different logic gates, by eliminating redundant transistors. Max8863tsr lodropot 120a linear relators max8864tsr. Alternatively, static pass transistor circuits have also been suggested for lowpower applications 2. In this lecture, we will talk about another way to implement logic functions using transistors.
Power supply using power transistors university of north. Implement an xor gate using minimum number of transistors. In this paper, we propose an improved asynchronouslogic dualrail. The output voltage is fed back through either an internal resistor voltage divider connected to the out pin, or an external resistor network connected to the set pin. Dual gate ambipolar carbon nanotube transistors dgacntfets have two independent gates that enable polarity switching between electron and hole conduction see fig. The current drive of the transistor gatetosource voltage is reduce significantly as v. If this channel line is a solid unbroken line then it represents a depletion normallyon type mosfet as drain current can flow with zero gate biasing potential. Then leap which is singlerail pass transistor logic then differential. Transistortransistor logic ttl is a logic family built from bipolar junction transistors. Recent progress on the prototyping of reversible digital circuits, have shown that adiabatic reversible dual line passtransistor logic can be used for special purpose applications in reversible computation. The vertical gate transistors have multiple vertical gates which are edge defined such that only a single transistor is required for multiple logic inputs. A selfchecking cmos full adder in double pass transistor logic. Among them a general new toffoli gate, ntg 8, new gate, ng 5, 7, tks gate 18, tr gate 19 are discussed. The source and drain switch whenever the transistor is either charging or discharging the load capacitance.
Though it has high speed due to low input capacitance, it has limited capacity to drive a load. In complementary cmos logic primary inputs are allowed to drive only gate terminals. Dynamic passtransistor logic ptl, which combines passtransistor logic with dynamic logic, is proposed for highperformance vlsi circuit design. Using dynamic cmos combined with pass transistor logic yields one of the simplest and fastest implementation of the carry function and it has been widely used for implementing vlsi adders. Logic dpl style 33, 34, 35, both nmos and pmos logic networks are used in. It uses an inverted pass transistor logic ptl tree, which inherently. Thus, two possible operations when the clock signal is active ck 1 are the logic 1 transfer charging up the capacitance c x to a logic high level and. Pass transistor design was the work of lara oliver was supported in part by a semiconductor research corporation graduate fellowship permission to make digital or hard copies of all or part of this work for. 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. Regenerative pass transistor logic rpl, a modular dual rail circuit technique for high speed logic design that gives reasonably low power consumption, was developed.
Dynamic cmos circuits university of california, davis. 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. Ttl logic family the evolution from diode transistor logic to transistor transistor logic can be seen by observing the placement of pn junctions. However, if the nodes n were taken directly as outputs, thus driving the inputs of the next logic blocks, all of the subsequent blocks. Because of the current amplifying properties of the bjt in the ef ccconfiguration, the current through the zener diode may be small. It overcomes the main problem associated with dtl, i. Among these, passtransistor logic is one of the most appealing design. The output of the cpllike multiplexer, as shown in fig. Pass transistor logic has been considered as a lowpower alternative to cmos logic 37. Pass transistors require lower switching energy to charge up a node, due to the reduces voltage swing.
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