Astable, Monostable & Bistable Multivibrator Multivibrators, like the familiar sinusoidal oscillators, are circuits with regenerative feedback, with the difference that they produce pulsed output. There are three basic types of multivibrator, namely Bistable Multivibrator A bistable multivibrator circuit is one in which both LOW and HIGH output states are stable. Irrespective of the logic status […]
IC Based Multivibrator Circuits In this article, we will discuss monostable and astable multivibrator circuits that can be configured around some of the popular digital and linear integrated circuits. Digital IC Based Monostable Multivibrator Some of the commonly used digital ICs that can be used as monostable multivibrators include 74121 (single monostable multivibrator), 74221 (dual
Interfacing Devices with Microcontroller This section briefly describes the interfacing of some common external peripheral devices with the microcontroller. The peripheral devices discussed in this section include LEDs, electromechanical relays, seven-segment displays, keypads, LCD displays and analogue-to-digital and digital-to-analogue converters. Only the basic fundamentals are discussed here. A detailed description of the software routines is
Components of Microcontroller Microcontrollers are hidden inside almost every product or device with which its user can interact. In fact, any device that has a remote control or has an LED/LCD screen and a keypad has an embedded microcontroller. Some common products where one is sure to find the use of a microcontroller include automobiles,
Microcontroller Architecture Microcontroller architecture may be defined in several ways. These include architecture used by the processor to access memory, architecture used for mapping special-function registers into memory space and the processor architecture itself. Architecture to Access Memory There are two fundamental architectures used by the processing units to access memory, namely Von Neumann architecture
Interfacing of Logic Families CMOS and TTL are the two most widely used logic families. Although ICs belonging to the same logic family have no special interface requirements, that is, the output of one can directly feed the input of the other, the same is not true if we have to interconnect digital ICs belonging
CMOS Logic Family The CMOS (Complementary Metal Oxide Semiconductor) logic family uses both N-type and P-type MOSFETs (enhancement MOSFETs, to be more precise) to realize different logic functions. The two types of MOSFET are designed to have matching characteristics. That is, they exhibit identical characteristics in switch-OFF and switch-ON conditions. The main advantage of the
ECL Logic Family The ECL family is the fastest logic family in the group of bipolar logic families. The characteristic features that give this logic family its high speed or short propagation delay are outlined as follows: Subfamilies of ECL Logic Family Different subfamilies of ECL logic include MECL-I, MECL-II, MECL-III, MECL 10K, MECL 10H
TTL Logic Family TTL stands for transistor transistor logic. It is a logic family implemented with bipolar process technology that combines or integrates NPN transistors, PN junction diodes and diffused resistors in a single monolithic structure to get the desired logic function. The NAND gate is the basic building block of this logic family. Different
Characteristics Parameters of Logic Families In this atricle, we will briefly describe the parameters used to characterize different logic families. Some of these characteristic parameters, as we will see in the paragraphs to follow, are also used to compare different logic families. HIGH-level input current, IIH. This is the current flowing into (taken as positive)