TLE Basic Electronics - Integrated Circuit

Integrated Circuit

What you are expected to learn

At the end of this module, you should be able to:

Explain the importance of integrated circuits.
Identify advantages and disadvantages of integrated circuits.
Identify the major components of an integrated circuit.
Describe the four processes used to construct integrated circuits.
Identify the major integrated circuit packages.
List the families of integrated circuits.

How to learn from this module

Going through this module can be both a fun and a meaningful learning experience. All you need to do is make use of your time and resources efficiently. To do this, here are some

tips for you:

1. Take time in reading and understanding each lesson. It is better to be slow but sure than to hurry finishing the module only to find out that you missed the concepts you are supposed to learn.

2. Do not jump from one chapter to another. Usually, the lessons are arranged such that one is built upon another, hence an understanding of the first is essential in comprehending the succeeding lessons.

3. Be honest. When answering the test items, do not turn to the key to correction page unless you are done. Likewise, when performing experiments, record only what you have really observed.

4. Safety first. Perform the experiments with extra precaution. Wear safety gears whenever necessary.

5. Don’t hesitate to ask. If you need to clarify something, approach your teacher or any knowledgeable person.

What to do before (Pretest)

Transistors and other semiconductor devices have made it possible to reduce the size of electronic circuits because of their small size and low power consumption. It is now possible to extend the principles behind semiconductors to complete circuits as well as individual components. The goal of the integrated circuit is to develop a single device to perform a specific function, such as amplification or switching, eliminating the separation between components and circuits.

Several factors have made the integrated circuit popular:

It is reliable with complex circuits.
It meets the need for low power consumption.
It offers small size and weight.
It is economical to produce.
It offers new and better solutions to system problems.

Discrete circuits use individual components to achieve a function.
Integrated circuits decrease the number of discrete components and reduce cost.
Integrated circuits can reduce the size of equipment and the power required, and eliminate some factory alignment procedures.
Integrated circuits often outperform their discrete equivalents.
It is possible to increase the reliability of electronic equipment by using more ICs and fewer discrete components.
Integrated circuits cannot handle large amounts of current or voltage.
Only diodes, transistors, resistors, and capacitors are available as integrated circuits.
Integrated circuits cannot be repaired, only replaced.
Integrated circuits are constructed by monolithic, thin-film, thick-film, or hybrid techniques.
Monolithic integrated circuits are batch-processed into 10-mil-thick silicon wafers.
The core process in making monolithic ICs is photolithography.
Photoresist is the light-sensitive material used to coat the wafer.
Aluminum is evaporated onto the wafer to interconnect the various components.
A monolithic IC uses a single-stone type of structure.
A hybrid IC combines several types of components on a common substrate.
The most popular integrated circuit package is the DIP (dual-inline package).
Integrated circuit packages are made of ceramic or plastic, with plastic most often used.
Analog ICs contain circuits that are not normally in saturation or cutoff.
Mixed-signal ICs combine analog and digital circuit functions.
A phase-locked loop compares an incoming signal with a reference signal and produces an error voltage proportional to any phase (or frequency) difference.
Phase-locked loops are used as FM detectors, as tone decoders, and as part of frequency synthesizers.
Switched capacitor ICs provide voltage conversion, integration, and filtering.
Check the power-supply voltages first when troubleshooting IC stages.
When troubleshooting ICs, check the dc voltages at all of the pins.
Always remove and insert socketed ICs with the power turned off.

The Fabulous 555 Timer IC

The 555 timer IC is an integrated circuit (chip) used in a variety of timer, pulse generation, and oscillator applications. The 555 can be used to provide time delays, as an oscillator, and as a flip-flop element. Derivatives provide two (556) or four (558) timing circuits in one package.
Introduced in 1972 by Signetics, the 555 is still in widespread use due to its low price, ease of use, and stability. It is now made by many companies in the original bipolar and in low-power CMOS technologies. As of 2003, it was estimated that 1 billion units were manufactured every year. The 555 is the most popular integrated circuit ever manufactured.
The 555 timer can be used in the monostable mode, the astable mode, and the time-delay mode.
The output of a 555 timer IC is a digital signal.
The 555 timer uses three identical internal resistors in its voltage divider.
The internal divider sets trip points at one-third and two-thirds of the supply voltage.
The pulse width of a timer IC is controlled by external parts.
Applying a voltage to the control pin of the 555 timer allows it to be used as a VCO or as a variablepulse- width modulator.