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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Material is molded plastic, epoxy, resin, or silicone. Asymmetrical Square wave generator.

Transistor-Transistor Logic TTL In transistor-transistor logic, the logic gates are constructed around the transistors.

Sometimes an extra transistor is needed to re-amplify the signal. The disadvantage of Diodes is that they tend to degrade the signals quickly. ICs of different families can sometimes also be directly connected together, but may require some extra circuitry at the interface of the two IC families to maintain compatibility.

In this logic, input signals are combined with the use of transistors. It could be used both ci logic devices which used 3. Early transistorized computers were implemented using discrete transistors, resistors, diodes and capacitors.

But the switching speed of the transistor is limited due to the input resistor to transistor. The first diode—transistor logic family of integrated circuits was introduced by Signetics in A fanout of 10 means that 10 unit loads can be driven by the gate while still maintaining the output voltage within specifications for logic levels 0 and 1.


Diode logic was used with vacuum tubes in the earliest electronic computers in famiiles s including ENIAC. TTL Logic has the following sub-families: In Emitter coupled logic, the transistors are prevented from going into deep saturation so that there are no storage delays. Finite State Machines Reduced energy implies less heat dissipation.

Digital Logic Design: IC Families Explained

Toggle speed dcl the fastest speed at which a J-K flip flop could operate. As the diodes can perform AND and OR operations but along with a transistor the output signal can be amplified. Fa,ilies used if higher thermal dissipation capabilities required. 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.

SR Flip-flop Electronics Tutorial. Resistor-Transistor Logic RTL In resistor-transistor logic, all the logic is implemented with the use of transistors and resistors. Separately Excited DC Motor.

Fanilies Phase Full Bridge Inverter. Comparator as a function generator. Archived from the original on Texas Instruments introduced the series TTL family in This logic is used in applications with high speed environment. Online tutorials designed are mainly intended to understand the basic concepts of electronics engineering.

Introduction In Digital Electronicsa logic family refers to digital integrated circuit devices which are constructed witha combination of electronic gates. Non-Saturated type Precision Half wave Rectifier. Static Dynamic Domino logic Four-phase logic.


Logic Families – Power, Speed and Compatibility

The input transistor conducts when the emitter-base junction becomes forward biased. Another advantage of DTL is that the OR operation can be performed by the diodes instead of resistors. Resistor Transistor Logic In RTL resistor transistor logicall the logic are implemented using resistors and transistors. This is the maximum current which the gate can sink in 0 level.

Digital Logic Design: IC Families Explained

Several early transistorized computers e. Chip designers therefore had to try and reconcile the fact ccmos higher speeds meant more power consumption, and so some families developed, using optimum speed whilst others were developed to use the minimum of power.

IC packaging Protect the chip from mechanical damage and chemical contamination. In computer engineeringa logic family may refer to one of two related concepts. The PMOS and I 2 L logic families were used for relatively familifs periods, mostly in special purpose custom large-scale integration circuits devices and are generally considered obsolete.

These devices only work with a 5V power supply. From Wikipedia, the free encyclopedia. These input signals are then inverted and amplified. All the TTL families above have three configurations namely: Some families were also introduced as individual components efl were used to design integrated circuits and also to interconnect them.