Each IC family has its own characteristics, limitations and advantages. There have been many improvements in logical families such as TTL and CMOS. Logic (DTL); Transistor-Transistor Logic (TTL); Emitter Coupled Logic (ECL). Evolution of TTL family. • ECL. • CMOS family and its evolution. • Overview. 2 Diode-Transistor Logic (DTL) . Scaling capabilities (large integration all MOS). Logic Families – TTL, CMOS, ECL. 10 January Basic Logic Families indicate the type of logic circuit used in the IC. The main types of logic families are.

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Saturating type Precision HWR. A family of simple resistor—transistor logic integrated circuits was developed at Fairchild Semiconductor for the Apollo Guidance Famllies in These are generally used “on-chip” and are not delivered as building-block medium-scale or small-scale integrated circuits.

The logic levels for ECL are normally From Wikipedia, the free encyclopedia. Diode Logic DL 2. Retrieved from ” https: They can also be used as an interface between digital and linear circuits. Three phase Half controlled rectifier. Comparator IC LM This page was last edited on 18 July dgital, at Ideally logic gates should be able to change state immediately and consume little or no power. The extremely small capacitance of the on-chip wiring caused an increase in performance by several orders of magnitude.

The output circuit has also been modified in recent years and the the configuration is called “Totem pole”. Analog Integrated Circuits Electrical Characteristics of the IC will be identical. Multivibrators Familids Square wave generator Bistable multivibrators Monostable multivibrator Sawtooth waveform generator Triangular waveform generator.


Many motherboards have a voltage regulator digita to provide the even lower power supply voltages required by many CPUs. Evolution of Digital IC Technologies.

Digital Logic Families | Electronics Tutorial

CMOS gates can also tolerate much wider voltage ranges than TTL gates because the logic thresholds are approximately proportional to power supply voltage, and not the fixed levels required by bipolar circuits. The diodes also cannot perform the NOT operation which limits their functionality.

CMOS logic gates use complementary arrangements of enhancement-mode N-channel and P-channel field effect transistor.

Maximum Power Transfer Theorem. These two logic families were not readily compatible; apart from the differences in supply voltage and speed, they were not particularly pin compatible, as illustrated in Fig.

Logic family

Not shown are some early obscure logic families from the early s such as DCTL direct-coupled transistor logicwhich did not become widely available. When the gate switches states, current is drawn from the power supply to charge the capacitance at the output of the gate. A “logic family” may also refer to a set of techniques used to implement logic within VLSI integrated circuits such as central idgitalmemories, or other complex functions.

Several early transistorized computers e. A short list of the most important family designators of these newer devices includes:.

Different types of logic gate families: Each logic family has its own basic electronic circuit upon which more complex digital circuits and functions are developed. Another advantage of DTL is that the OR operation can be performed by the diodes instead of resistors. Since the initial devices failies oxide-isolated metal gates, they were called CMOS complementary metal—oxide—semiconductor logic.


Logic Families – Power, Speed and Compatibility

The drawback in using RTL gates is that they draw a great amount of current from the power supply. Toggle speed represents the fastest speed at which a J-K flip flop could operate. Transistor—transistor logic uses bipolar transistors to form its integrated circuits.

A variant of DTL called “high-threshold logic” incorporated Zener diodes to create a large offset between logic 1 and logic 0 voltage levels. High-level output voltage, VOH: This is the maximum current which the gate can sink in 1 level. Less number of Transistors Disadvantage: Field Programmable Gate Array. Non-Saturated type Precision Half wave Rectifier. Programmable Logic Devices 7. Some families were also introduced as individual components which were used to design integrated circuits and also to interconnect them.

Comparator as a function generator.

Ceramic used if higher thermal dissipation capabilities required. DTL was used in early vacuum tube computers. The speed of a digital circuit is specified in terms of the propagation delay time.