pll fm demodulator

Posted on Feb 7, 2014

This is a circuit about PLL system that can be used to implement an FM demodulator. Since the VCO output tracks the FM signal, and the VCO input voltage is proportional to the VCO output frequency, then the VCO input will be equal to the demodulated signal. This is the figure of the circuit. For this example, an FM signal consisting of a 10-kHz ca

Click here to download the full size of the above Circuit.

rrier frequency was modulated by a 400-Hz audio signal. The schematic diagram shows the connections of the CD4046B as an FM demodulator. The total FM signal amplitude is 500 mV, therefore, the signal must be ac coupled to the signal input (terminal 14). Phase comparator I is used for this application because a PLL system with a center frequency equal to the FM carrier frequency is needed. Phase comparator I lends itself to this application also because of its high signal-input-noise-rejection characteristics.

Visit page

Leave Comment

characters left:

Related Circuits

Double IC For Circuit an Infrared Toy Car Motor Controller

The following circuit shows about Circuit an Infrared Toy Car Motor Controller. This circuit based on the 4047 and4017 IC. Features: 16V Capacitor, 100k Resistor, Double IC. Component: IC, Switch,...

Drive Two-Six White LEDs (WLEDs) in Parallel

The parallel arrangement of LED backlights allows the control IC to utilize inexpensive low voltage CMOS processes as shown by the followingcircuit diagram which requires two to six white LEDs...

Drive relay with AVR microcontroller

To drive relay you need more than 20mA the current can one pin drive. This is why you cannot connect relay directly to microcontrollers pin. To drive relay you need to connect simple amplifier made...

Dual Litz Honeycomb Coils Crystal Radio

I hope that this crystal set is well received by all of you. My #62 radio combines the features of some of my earlier radios. It combines the one piece approach of my #48 set and the dual detector...

Dual Tone Single IC Siren

This circuit is a double tone Police sound and Single tone old ambulance sound. This circuit is usually installed on a on battery powered cars, motorcycles, .

Dynamic Microphone Preamp Mono by Transister C945 (with PCB)

We aim to transmit more information by carrying articles. Please send us an E-mail to wanghuali@hqew. net within 15 days if we are involved in the problems of article content, copyright or other...

Dynamic mic preamplifier circuit

This mic preamp uses the low noise IC uA739. The circuit is an example of how a good preamplifier can be designed for dynamic microphones. The IC houses tw.

EMF Probe Version 2

An electromagnetic field probe designed to detect changing electric and magnetic fields. The probe has switchable gain, a frequency response up to 400kHz and independent audio and meter monitoring....

New Circuits

Zero consumption Anti-theft High power Code Switch for E-Bike Batteries

This project fits more for custom made battery casing that can have more space to hide things inside. This switch with few alterations can be used for any other project as well but is designed based on e-bike needs! This project use a clever functionality of....
Ultrasonic distance finder circuit

The circuit described here uses ultrasonic oscillations and operates based on the propagation velocity of these oscillations in the air. Thus, we can easily determine the distance of two points if the time within which the wave travels this distance is....
Simple Metal detector circuit with CD4030

Sometimes the precious metals are hidden too deep and are not detected except with complicated devices. In many cases, however, small pieces of precious metal buried near the surface can be detected by relatively simple means. Everyone is very attractive to....
Fully automatic watering circuit for flower pots

Many times for various reasons we forget or can not water the plants that we have in our homes. And many humidity sensors units just notify us with a beeping sound or with a flashing light, that the pot needs watering. But what if we are away from home? This....
Simple deep searching metal detector circuit

The principle behind a metal detector is really very simple. Proof of this is the circuit that follows, in which it proves that the construction of a metal detector can be done in the minute, with few components that we find very easily everywhere. With the....
Sub-Harmonic Bass Converter for Electric Guitars

The sub-harmonic bass generator is a sound producing unit for guitars. The sound it produces looks very much like that of the bass guitar. The octave generator is sometimes quite unusual since it does not produce any of the usual ways of coloring the sound,....
Echo Depth Sounding Sonar for Boats

In the past the sounding (sea bottom measurement) was done with the "bullet", that is, with a heavy lead object that the seamen plucked into the sea hung from a calibrated rope. As soon as the "bullet" reached the bottom, the depth appeared directly from the....
100W HiFi Audio Amplifier Circuit

This Amplifier was designed to have the following specifications: Distortion less than 0.1% at full power of 100W even at 20KHz. Power has to be attributed to an extended bandwidth. The output transistors must be protected against short circuits. The power....
Plant-Pot Water Level Indicator Circuit

A series of LEDs serve to alert the gardener when plants need water. Using two conventional digital integrated LEDs and a series of LEDs, we make a very useful device for gardening. The device detects the amount of water in the pot and alerts the grower.....