Digital Logic Families

Comparison of Logic Families: The following are the Comparison of Logic Families are 1. RTL and DTL families have become obsolete because of their low speed, high power dissipation, and low fan-out. 2. TTL is the most popular general purpose logic family. It is available in seven different series with a wide range of operating […]

TTL Characteristics and other TTL Series: The first time standard TTL ICs were introduced by Taxas Instruments Corporation. They introduced 54 and 74 series, which were widely used as IC logic families. The major difference in these two series is that 54 series can operate over a wider range of temperatures and power-supply voltages. Many

What is Tristate Logic or Three State Logic Circuit? Tristate Logic or Three State Logic Circuit – In normal logic circuits there are two states of output, either low or high. But in complex digital systems like microcomputers and microprocessors, a number of gate outputs may be required to be connected to a common line

Integrated Injection Logic (IIL or I2L) Circuit: It is the latest entry into the bipolar saturated logic field. It uses no biasing and loading resistors at all. Resistors require lot of power and space on an IC chip. Hence, their elimination results in higher density circuits operating at much reduced power. Because of its high

What is Emitter Coupled Logic (ECL) Circuit? Emitter coupled logic (ECL) is the fastest of all logic families and, therefore, is employed in applications where very high speed is essential. High speeds have become possible in ECL because the transistors are used in differential amplifier configuration, in which they are never driven into saturation and

What is Transistor Transistor Logic (TTL) Circuit? Texas instruments introduced transistor transistor logic (TTL), a widely used family of digital devices in 1964. It is fast, inexpensive and easy to use. Transistor Transistor Logic family consists of variety of SSI and MSI chips, with the help of that all kinds of digital circuits and systems

What is Diode Transistor Logic (DTL) Circuit? Diode Transistor Logic (DTL) is also a saturated logic and uses diodes, resistors and transis­tors. The circuit diagram is shown in Fig. 47.2. The ba­sic DTL logic circuit is the NAND gate. When inputs to all the three diodes are high, neither diode conducts and the tran­sistor is

What is Resistor Transistor Logic (RTL) Circuit? Resistor Transistor Logic (RTL) is a saturated logic and makes use of only transistors and resistors as circuit elements and also of resistors in the input to each base. This family is based on the NOR circuit. Its circuit diagram is shown in Fig. 47.1. Assuming both transistors