Voltage regulator

Voltage Regulators

john August 9, 2018 5 Comments
A voltage regulator is designed to automatically ‘regulate’ voltage level. It basically steps down the input voltage to the desired level and keeps that in that same level during the supply. This makes sure that even when a load is applied the voltage doesn’t drop. Thus, a voltage regulator is used for two reasons:- To regulate or vary the output voltage of the circuit. To keep the output voltage constant at the desired value in-spite of variations in the...
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Regulated power supply

Regulated Power Supply

john August 13, 2018 21 Comments
INTRODUCTION Almost all basic household electronic circuits need an unregulated AC to be converted to constant DC, in order to operate the electronic device. All devices will have a certain power supply limit and the electronic circuits inside these devices must be able to supply a constant DC voltage within this limit. This DC supply is regulated and limited in terms of voltage and current. But the supply provided from mains may be fluctuating and could easily break down...
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FSK Demodulator

jojo September 20, 2009 4 Comments
PLL Application – FSK (Frequency Shift Keying) Demodulator FSK demodulator  using NE-SE 565 IC A very useful application of the 565 PLL is as a FSK demodulator. In the 565 PLL the frequency shift is usually accomplished by driving a VCO with the binary data signal so that the two resulting frequencies corre­spond to the logic 0 and logic 1 states of the binary data signal. The frequencies corresponding to logic 1 and logic 0 states are commonly called...
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Frequency Demodulation

jojo September 20, 2009 1 Comment
PLL Application – Frequency Demodulation Using NE-SE 565 IC Frequency demodulation or detection can be obtained directly by using the PLL circuit. When the centre frequency of the PLL is selected or designed at the FM carrier frequency, the filtered or output voltage in the circuit shown in figure, is obviously the desired demodulated voltage, that varies in magnitude in proportion to the signal frequency. The PLL circuit thus can be operated as complete IF strip, limiter, and detector as...
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Frequency Multiplication

jojo September 20, 2009 1 Comment
PLL Applications 1. Frequency Multiplication or Frequency Synthesis The block diagram of a frequency muliplier (or synthesizer) is shown in figure. In this circuit, a frequency divider is inserted between the output of the VCO and the phase comparator (PC) so that the loop signal to the PC is at frequency fOUT while the output of VCO is N fOUT. This output is a multiple of the input frequency as long as the loop is in lock. The desired...
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PLL Operation

jojo April 3, 2014 3 Comments
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...
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Phase Locked Loop IC’s

jojo April 3, 2014 3 Comments
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...
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PLL Operating Principle

jojo April 3, 2014 3 Comments
Operating principle of Phase Locked Loops The block diagram showing operating principle of PLLis given in figure. As illustrated in this fig, the PLL consists of a phase detector, a low-pass filter and a voltage controlled oscillator. YOU MAY ALSO REFER: PHASE LOCKED LOOP IC’s, DESIGN A PLL, PLL OPERATION, and PLL FM DEMODUATOR CIRCUIT Phase Detector A phase detector is basically a comparator that compares the input frequency fin with feedback frequency fout. The phase detector receives two digital signals, one from...
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PLL-Phase Locked Loops

jojo January 23, 2018 9 Comments
Phase Locked Loops (PLL) Introduction to PLL The concept of Phase Locked Loops (PLL) first emerged in the early 1930’s.But the technology was not developed as it now, the cost factor for developing this technology was very high. Since the advancement in the field of integrated circuits, PLL has become one of the main building blocks in the electronics technology. In present, the PLL is available as a single IC in the SE/NE560 series (560, 561, 562, 564, 565...
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Op Amps-Operational Amplifiers

jojo February 17, 2014 No Comments
Introduction to Operational Amplifiers In this post, the basics of an operational amplifier (generally abbreviated as op-amp) will be analysed along with its block diagram, basic structure, symbol, types and a detailed explanation of the typical op-amp. What is an operational amplifier (op-amp)? An op-amp is a multi-stage , direct coupled, high gain negative feedback amplifier that has one or more differential amplifiers and its concluded with a level translator and an output stage.A voltage-shunt feedback is provided in...
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