Cours ttl et cmos pdf

Used to be that cmos was low power, ttl was high speed. Basic operational characteristics and parameters dc supply. A voltage transfer curve is a graph of the input voltage to a gate versus its output voltage. Vitesse dexecution, consommation etc, je trouve des infos sur le bicmos et encore, mais pas sur ce qui me concerne. For this course, we need to study only ttl and cmos mostly ttl. Roux ediscience suite du precedent, memes remarques cours et problemes delectronique numerique par j. Each of the nais latest generation ttlcmos modules are used on our rugged cots multifunction embedded io boards, single board computers sbcs, and configurable systems offered in openvpx, cpci, vme, and pcipcie configurations the ttlcmos modules are offered in two versions. Cmos allows a much higher density of logic functions in a single chip compared to ttl. Chapter 2 digital circuits ttl and cmos based on chapter 3. Tout le cours en fiches iut licence ecoles dingenieurs. Cmos hex voltagelevel shifter for ttltocmos or cmosto. Aboushady university of paris vi carriers always flow from the source to drain nmos. Technologie ttl et cmos electronique tutoriels robot maker.

Using cmos ic in a ttl circuit electrical engineering. A diodes iv characteristic is shown in figure 6 below. Technologie ttl et cmos electronique tutoriels robot. The circuit schematic symbol of a diode is shown in figure 5. Cuales son las principales diferencias entre las senales. Ttl circuits consumes more power compared to cmos circuits at rest. With some care, you can interface them together and there are families with them, such as 74hctxx, that are specifically designed to be mixed hct highspeed cmos with ttl comptatible i. Cmos complementary metaloxide semiconductor devices are. Niveaux logiques pour une famille donnee, les niveaux logiques 0 ou l low et 1 ou h high ne correspondent pas a une. Telechargez comme pdf, txt ou lisez en ligne sur scribd. You can constrain your design to allow the use of any of them. Ce cours va donc comparer les familles ttl et cmos en donnant leurs principales caracteristiques. There is also the 74hct family, which is compatible with ttl. Used to be that cmos was more susceptible to electrostatic damage, ttl less so.

Ttl and cmos characteristics purpose logic gates are classified not only by their logical functions, but also by their logical families. Chapitre 1 caracteristiques electriques dune porte logique ttlstandard. This page covers ttl to cmos ic interfacing and cmos to ttl ic interfacing. To shift ttl signals to cmos logic levels, the select input is at the v cc high logic state. Figure1 depicts ttl to cmos interfacing and cmos to ttl interfacing circuits. Variante ttl low pwer schottky ou ttlls, variantes ttl avancee as et als, variante ttlf ou ttl fast. There are cmos chips that have ttl logic and are meant as replacements for ttl chips. Problem is worse if more than 2 ttl circuits are connected 5. The output of a ttl device sinks current when it is low and sources current when it. In any implementation of a digital system, an understanding of a logic elements physical capabilities and limitations, determined by its logic family, are critical to proper operation. Cmos transistor theory cmos vlsi design slide 2 outline qintroduction qmos capacitor qnmos iv characteristics qpmos iv characteristics qgate and diffusion capacitance qpass transistors qrc delay models.

Tl1, our standard functionality sf module with variants tl3, tl5, and tl7, and tl2. Digital circuits and systems 5 digital circuitry page of 31 ttl defines i olmax 16ma, so wiredanded ttl current would be more than allowed. Cmos transistor theory cmos vlsi design slide 3 introduction qso far, we have treated transistors as ideal switches qan on transistor passes a finite amount of current depends on terminal voltages derive currentvoltage iv relationships qtransistor gate, source, drain all have capacitance i c. Oxide growth doping diffusion, ion implantation deposition metal, polysilicon etching epitaxy silicon wafer. Interfacage cmosttl et ttlcmos une sortie cmos peut commander sans probleme une entree ttl. Instead of a cd4000 series device i would use a function and pin compatible 74hct4017.

In general, no, you cannot mix them together because their drive capabilities and requirements are not well matched. For example, a part that might be used is a 573 latch. When 5v supply is given to ttl and cmos ics, logic levels of ttl and cmos are different. Further down in the course we will use the same transistors to design other blocks such as flipflops or memories ideally, a transistor behaves like a switch. Basic cmos concepts we will now see the use of transistor for designing logic gates. The ttl low sink current ioj is the limiting factor when interfacing to mul tiple ttl inputs. Ttl transistor transistor logic circuit digital logic families tech gurukul by dinesh arya duration. Cmosttl power requirements ttl power essentially constant no frequency dependence cmos power scales as. Cmos chips are a lot more susceptible to static discharge compared to ttl chips. Basic operational characteristics and parameters dc supply voltage.

Never confuse the 74hc or 74hct cmos families with other families such as 74, 74s, 74l, 74ls and 74f ttl families. Digital circuits and systems electronic engineering. For nmos transistors, if the input is a 1 the switch is on, otherwise it is off. Cmos transistor theory david harris harvey mudd college spring 2004. Cmos hex voltagelevel shifter for ttltocmos or cmostocmos operation. A ttl output can drive up to 10 standard ttl inputs or up to 40. Anyway, if you use 74hc cmos you can probably find pincompatible parts in cmos, ls ttl and more modern logic families such as vhc cmos. Piv is the peakinversevoltage of the diode forward bias occurs when the ptype block is connected to the positive terminal of the battery and the ntype is connected to the negative terminal of the battery, as shown below. Ttl to cmos converter and cmos to ttl converters are useful for converting 3v system to 5v system and viceversa. Razavi, design of analog cmos integrated circuits, mc. These converters normally use buffers at the input and output pins and level converter at the middle. Ttl low level outputs are no problem, but the high level may be as low as 2.

Controlled baseline input signals can exceed both v cc and v dd one assemblytest site up and down levelshifting capability one fabrication site. Cmos vs ttl ttl stands for transistortransistor logic. The name is derived from the use of two bipolar junction transistors or bjts in the design of each logic gate. Interfacage cmos ttl et ttl cmos une sortie cmos peut commander sans probleme une entree ttl. Nowadays, cmos used for a lot more stuff, using one vs the other more a matter of what. Cmos hex voltagelevel shifter for ttltocmos or cmostocmos operation independence of powersupply sequence and medical applications considerations v cc can exceed v dd. When the select input is at a low logic state, each circuit translates signals from one cmos level to another. Cours, exercices corriges, examens alloschool, votre ecole sur internet. Hence comparing the schematic symbol to the pn junction in figure 4, we see the anode is the ptype semiconductor and the cathode is the ntype semiconductor. Cmos less power hungry than ttl, with cmos power needs based on switching speeds, with ttl power usage more steady state. Diode schematic symbol and actual picture of a common 1n914 diode the black stripe in the picture is the cathode. With some care, you can interface them together and there are families with them, such as 74hctxx, that are specifically designed to be mixed hct highspeed cmos with ttlcomptatible i.