PRESENTATION DE INTEGERATED

ELECTRONICS

ANALOG FUNCTION GENERATOR

MUHAMMAD AMEER MOHAVIA

BS(ELECTRONICS ENGINEERING)

BALOCHISTAN UNIVERSITY OF INFROMATION TECHNOLOGY ENGINEERING AND

MANAGEMENT SCIENCE’S, QUETTA, PAKISTAN.

FUNCTION GENERATOR

CONTENTS

1. INTRODUCTION2. OPERATING PRINCIPLE3. CIRCUIT DIAGRAM4. WORKING OF CIRCUIT5. Applications 

INTRODUCTION A function generator is a piece of

electronic test equipment used to generate electrical waveforms. These waveforms can be either repetitive, or single-shot (once only) in which case some kind of triggering source is required (internal or external). The resultant waveforms can be applied to a device under test and analyzed as they progress through the device, confirming the proper operation of the device or pinpointing a fault in it.

BLOCK DIAGRAM

OPERATING PRINCIPLE An electronic instrument which

generates periodic voltage or current waveforms that duplicate various types of well-defined mathematical functions. The simplest function generator usually generates a combination of square waves, triangular waves, and sine waves.

A typical function generator can provide frequencies up to 20 MHz.

CIRCUIT DIAGRAM

WORKING OF CIRCUIT

The ICL8038 is a function generator chip, capable of generating triangular, square , sine, pulse and sawtooth waveforms . From these sine, square & triangular wave forms can be made simultaneously.

There is an option to control the parameters like frequency, duty cycle and distortion of these functions.

This is the best function generator circuit for a beginner to start with and is of course a must on the work bench of an electronics hobbyist.

The circuit here is designed to produce waveforms from 20Hz to 20 kHz

WORKING OF CIRCUIT

The circuit needs a dual power supply. A +15 -15 power supply as shown in the circuit is enough for the purpose.

The frequency of the output wave form can be adjusted using R7.It must be a 100K Log POT.

The duty cycle can be adjusted using R3 , a 1K POT.

The distortion of the wave form can be adjusted using R5 , a 100K POT.

Square, triangle & sine waveforms can be obtained simultaneously at pins 9,3,2 respectively.

WORKING OF CIRCUIT Square, sine and triangle waves are

produced using an LM348 and passive components. The LM348 is a quad operational amplifier IC package; that is, it contains four separate opamps all in the one IC. They are marked A, B, C & D in the schematic diagram

GENERATION OF SINE WAVE:- A pseudo or imitation sine wave is

produced by a wave shaping circuit. A diode is a non-linear device. As the potential difference across it increases the current rises in the characteristic way. This circuit 'joins together' this characteristic curve to produce an approximation to a sine wave. Two diodes have been joined together as a series pair in order to provide a higher amplitude than would be obtained using only a single diode

GENERATION OF SQUARE WAVE:-

One opamp (LM324:D) is used. The voltage level to pin 13 is set by the resistor divider pair R1 and R2. The input to pin 12 depends on two things; firstly the potential of pin 14, and secondly, the voltage output of opamp C at pin 8. When the input at pin 13 is higher than the input at pin 12 the output goes low. If it is lower then the output goes high. Switching back and forth between the two states causes a square wave to be produced. The time constant (R4+R5)C2 determines the frequency.

APPLICATIONS

Function Generators are used in development, testing and repair of electronic equipment, e.g. as a signal source to test amplifiers, or to introduce an error signal into a control loop

They are generally used in designing, testing, troubleshooting, and repairing electronic or electroacoustic devices; though they often have artistic uses as well.. A device such as an oscilloscope is then used to measure the circuit's output.

There are many different types of signal generators, with different purposes and applications (and at varying levels of expense); in general, no device is suitable for all possible applications.

Another type of function generator is a sub-system that provides an output proportional to some mathematical function of its input; for example, the output may be proportional to the square root of the input. Such devices are used in feedback control systems and in analog computers

Technology Behind Multi-Instrument Synchronization

Semiconductor Characterization Ultrasonic Phase Array Testing Disk Array Configuration Response testing using square waves,

pulses, and noise.