Pulse Generator using Op-Amp

How to make a Monostable Multi Vibrator using 741 IC ? As already explained , a monostable multivibrator (MMV) has one stable state and one quasi-stable state. The circuit remains in its stable state till an external triggering pulse causes a transition to the quasi-stable state. The circuit comes back to its stable state after a time period T. Thus it generates a single output pulse in response to an input pulse and is referred to as a one-shot or single shot. Monostable multivibrator circuit illustrated in figure  is obtained by modifying the astable multivibrator circuit  by connecting a diode…

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Zero Crossing Detector using IC 311

How to make a Zero Crossing Detector using  311 Op-Amp IC ? A zero-crossing detector using IC 311 (8 pin DIP unit) is illustrated in figure. The positive (above 0 V) going input signal drives the output transistor on, the output going low (- 10 V in this connection). The negative (below 0 V) go­ing input drives the output transistor off, the output going high (+ 10 V in this connection). The output is thus an indication of whether the input is above or below 0 V. When the input is any positive voltage (above 0 V), the output is…

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Zero Crossing Detector

In this article, we discuss Zero Crossing Detector in detail with two different circuits. In the initial paragraphs of the tutorial, you will learn zero crossing detector using op amp designed using the popular 741 IC. We have a neat draw circuit diagram of zero crossing detector and we have explained its working principle and theory behind the scene in easy to understand words. Towards the middle of this tutorial, you will learn about 2 applications of zero crossing detector – which are time marker generator and phasemeter. Towards the end of article, we have drawn another circuit diagram of…

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Op-Amp Comparator

In this post we will be discussing about the op-amp as a comparator.We have already discussed other applications of the op-amp in rectangular wave form generator circuits like astable (or free-running) multivibrators, monostable multivibrators (or one-shot) and bistable multivibrators (or flip-flops). To get a better understanding of operational amplifiers click here:- Operational Amplifiers (Op-amp)  Op-amp Comparator A comparator finds its importance in circuits where two voltage signals are to be compared and to be distinguished on which is stronger. A comparator is also an important circuit in the design of non-sinusoidal waveform generators as relaxation oscillators. In an op-amp with an open loop…

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PLL Operation

How a PLL works ? Consider VCO operating without input signal at free-running frequency fr and input signal of frequency fIN increasing from zero is applied to the PC. If the input frequency is less than fIN1, then the error voltage Ve is zero as illustrated in figure and VCO operates at a frequency fr. When the input signal frequency fIN reaches a frequency fin1 (the lower edge of the capture range), then the output or error voltage Ve jumps from zero to some negative voltage with beat notes of frequency (difference between input signal frequency and actual VCO output…

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Phase Locked Loop IC’s

MONOLITHIC PHASE-LOCKED LOOP (PLL) ICS Although the evolution of the PLL began in the early 1930s but its cost outweighted its advantage in the beginning. Today the PLL is even available as a single package, typical examples of which are the Signetic’s SE/NE series such as 560, 561, 562, 564, 565 and 567. They only differ in operating frequency range, power requirements, and frequency and bandwidth (BW) adjustment ranges. SE/NE 565 is the most widely employed IC of the series. The device is available as a 14-pin DIP package  and as a 10-pin metal can package. Its important electrical characteristics…

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MOS (Metal Oxide Semiconductor) IC’s

We have already explained in integrated circuits, Hybrid IC’s about the classification of IC’s as bipolar IC’s and Unipolar IC’s. In bipolar IC’s, devices like BJT’s are used. In unipolar IC’s, devices like Field Effect Transistors are used. Metal oxide semiconductor IC (MOS IC) based on MOSFET structure have found wide applications in the digital field. Here are some comparisons and advantages over bipolar IC’s. 1. Reduction in size MOS IC’s are more suitable than bipolar IC’s I applications like large scale integration (LSI), and very large scale integration (VLSI). They are also used in memory chips and microprocessors. This…

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Integrated Transistor Amplifier

How to make an integrated transistor amplifier ? We are now in a position to illustrate how a complete tran­sistor amplifier circuit including bias resistors can be formed on a silicon wafer using the masking and photolithographic processes, described earlier. The difference now is that the masking pattern must be layed out to include the appropri­ate interconnections as well. Appearing in figures is the complete IC layout of the transistor amplifier circuit shown in figure. The five circuit elements—one capacitor, three resistors, and one transistor—and all the interconnections are produced by the same masking, etching, and diffusion process-. In an…

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IC Packages

Types of IC Packages For the protection of ICs from external environment and to provide mechanical protection and terminals for electrical connections, various types of packages are used. Several standard packages in general use are shown in figure. The metal can type of container provides electromagnetic shielding for the IC chip which cannot be provided by plastic or ceramic packages. The plastic dual-in-line package is much cheaper than other types of packages and is widely employed for general industrial and consumer applications where high temperatures are not met with. Ceramic or metal contain­ers are used where ICs are subjected to…

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Monolithic IC-Component Fabrication

The outstanding feature of an IC is that it comprises a number of circuit elements insepa¬rably associated in a single small package to perform a complete electronic circuit. We shall now see how various circuit elements (such as transistors, diodes, resistors etc.) can be fabricated in an IC form. 1.    Transistors   and   Diodes. Transistors and diodes are usually formed using the epitaxial planar diffusion process described in previous blog post. Collector, base, and emitter regions are diffused into a P-type silicon substrate, as shown in figure, and surface terminals are provided for connection. In discrete transistors the…

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