Important Short Questions and Answers: Spical ICs

Special ICs

1.What are the applications of 555 Timer ?

·           astable multivibrator

·           monostable multivibrator

·           Missing pulse detector

·           Linear ramp generator

·           Frequency divider

·           Pulse width modulation

·           FSK generator

·           Pulse position modulator

·           Schmitt trigger

2.List the applications of 555 timer in monostable mode of operation: *missing pulse detector

*Linear ramp generator

*Frequency divider

*Pulse width modulation.

3. List the applications of 555 timer in Astable mode of operation:

*FSK generator

*Pulse-position modulator

4.Define 555 IC?

The 555 timer is an integrated circuit specifically designed to perform signal generation and timing functions.

5.List the basic blocks of IC 555 timer?

·           A relaxation oscillator

·           RS flip flop

·           Two comparator

·           Discharge transistor.

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6.List the features of 555 Timer?

·           It has two basic operating modes: monostable and astble

·           It is available in three packages. 8 pin metal can , 8 pin dip, 14 pin dip.

·           It has very high temperature stability.

7.Define duty cycle?

The ratio of high output and low output period is given by a mathematical parameter called duty cycle. It is defined as the ratio of ON Time to total time.

8.Define VCO.

A voltage controlled oscillator is an oscillator circuit in which the frequency of oscillations can be controlled by an externally applied voltage.

9.List the features of 566 VCO.

·           Wide supply voltage range(10-24V)

·           Very linear modulation characteristics

·           High temperature stability

9.        What do u mean by PLL?

A PLL is a basically a closed loop system designed to lock output frequency and phase to the frequency and phase of an input signal.

11.   Define lock range.

When PLL is in lock, it can trap freq changes in the incoming signal. The range of frequencies over which the PLL can maintain lock with the incoming signal is called as lock range.

12. Define capture range.

The range of frequencies over which the PLL can acquire lock with the input signal is called as capture range.

13.   Define pull- in time.

The total time taken by the PLL to establish lock is called pull- in time.

14.   List the applications of 565 PLL.

·           Frequency multiplier

·           Frequency synthesizer

·           FM detector

15.   What are the two types of analog multiplier Ics?

a)        IC AD 533

b)       IC AD 534

16.   What is ICAD 533?

It is a multiplier IC by analog devices. It is a low cost IC comprising a transconductance multiplying element, stable reference and an output amplifier.

17.   List the features of ICAD533.

·           Its operation is very simple.

·           Only 4 external adjustments are necessary

·           Maximum 4 quadrant error is below 0.5%

18. What is ICAD 534?

It is a multiplier IC by analog devices. It is the first general purpose multiplier capable of providing gain upto X100.

19.   List the features of ICAD534.

·           Adjustable scale factor

·           Low noise

·           Excellent long time stability

20.   List the few applications of ICAD534.

·           Multiplier

·           Divider

·           High quality signal processing