Table of Contents
What is DCTL in digital electronics?
Direct-coupled transistor logic (DCTL) is similar to resistor–transistor logic (RTL) but the input transistor bases are connected directly to the collector outputs without any base resistors.
What is current hogging?
A condition in which the largest fraction of a current passes through one of several parallel logic circuits because it has a lower resistance than the others. It is an undesirable condition and can result in damage to the transistor. Current Hogging exists in Direct Coupled transistor logic family.
What are the basic gates in MOS family?
They are: P-type MOS (PMOS) Logic. N-type MOS (NMOS) logic. Complementary MOS (CMOS) logic.
How many types of logic families are there?
Four major logic families that predominated from the 1970’s through the 1990’s are Transistor-Transistor Logic (TTL), Complementary Metal-Oxide-Semiconductor Logic (CMOS, pronounced sea-moss), Low Voltage TTL Logic (LVTTL), and Low Voltage CMOS Logic (LVCMOS). Their logic levels are compared in Table 1.4.
What is fan in and fan in electronics?
Fan-out is a term that defines the maximum number of digital inputs that the output of a single logic gate can feed. Most transistor-transistor logic ( TTL ) gates can feed up to 10 other digital gates or devices. Thus, a typical TTL gate has a fan-out of 10.
What are the categories of logic families?
The logic families which fall under the first kind are called bipolar families, this include diode logic (DL), emitted coupled logic (ECL), resistor transistor logic (RTL), diode transistor logic (DTL), transistor transistor logic (TTL).
What is TTL family?
Transistor–transistor logic (TTL) is a logic family built from bipolar junction transistors. Its name signifies that transistors perform both the logic function (the first “transistor”) and the amplifying function (the second “transistor”), as opposed to resistor–transistor logic (RTL) or diode–transistor logic (DTL).
What is fan-in with example?
Fan-in is a term that defines the maximum number of digital inputs that a single logic gate can accept. Most transistor-transistor logic ( TTL ) gates have one or two inputs, although some have more than two. A typical logic gate has a fan-in of 1 or 2.
What is fan-in in CMOS?
Fan-in is the number of inputs a gate can handle. Physical logic gates with a large fan-in tend to be slower than those with a small fan-in. Fan in of CMOS family can be more than 2 by extending series-parallel design of CMOS using NAND and NOR gates.
What is CMOS family?
“CMOS” refers to both a particular style of digital circuitry design and the family of processes used to implement that circuitry on integrated circuits (chips). CMOS circuitry dissipates less power than logic families with resistive loads.
What is difference TTL and CMOS?
CMOS stands for Complimentary Metal-oxide Semicodictor while in TTL stand for Transistor-Transistor Logic. CMOS circuit uses a field-effect transistor by connecting NMOS and PMOS, the TTL circuit uses bipolar junction transistor. The design of the CMOS can be considered to be very simpler as compared to the TTL.
What are the advantages of DCTL over other logic schemes?
Of the various logic schemes, DCTL has one of the lowest noise margins, typically 0.1 V at 125°C to about 0.2 V at room temperature, depending on the fan-out and, whether the transistor is on or off. In spite of its severe limitations, DCTL still has several desirable features.
What are the advantages of the digital electronics text book?
• The contents are symmetrically arranged. • It will prove to be good text book for all those who study digital Electronics. It will help the students preparing for NET/SET competitive examination. decimal number system. The ‘deci’ means ten so this system has 10 distinct digits or
What is direct-coupled transistor-logic (DCTL)?
Such circuits are referred to as direct-coupled transistor-logic circuits or, more commonly, DCTL. There are several advantages and some disadvantages of DCTL, and we consider these after discussing how this type of configuration works.
What is a parallel DCTL gate?
Series DCTL gate. The figure below shows a parallel DCTL gate, which is really the previously considered “inverter” stage with three transistors having individual inputs instead of a single transistor. Obviously, this configuration is a NOR circuit.