Table of Contents
What is an Integrated circuit?
An integrated circuit, also known as a microelectronic circuit or microchip is the result of an assembly of active components and passive components. An example of active components is transistors and diodes and some passive components are capacitors and resistors. The interconnections between these devices are built on a thin substrate of a semiconductor material which is often silicon. The result is the integrated circuit which may be anywhere between a couple square centimeters or a couple square millimeters large. The active and passive components are not easily seen as they are normally microscopically small.
Types
Analog VS. Digital circuits
Analog circuits, also known as linear as some of the simplest integrated circuits and have few components. They are mainly used to send signals to an environment or collect signals from an environment. One such example is the use of a microphone. The microphone will convert the sound waves to varying voltages and the analog circuit will do something useful with this like amplifying of filtering the sound. Another use of analog circuits is when a temperature sensor shows a change in temperature, the analog circuit turns on the heater once the temperature has passed a certain threshold.
On the other hand digital circuits are circuits that are designed to only accept voltages of certain values. They include binary circuits which can be used to express Boolean algebra.
Microprocessor circuits
These are the most complicated kinds of integrated circuits and are made up of billion of transistors that have been created as thousands of individual circuits. Each of these smaller circuits has it's own logic function and the entire microprocessor circuit is built of these logic gates synchronized with one another. The director in the microprocessor is called the clock (a signal that alternates quickly between two logic states). Every logic gate in the microprocessor executes some function when the clock changes state. Microprocessors also contain some circuits known as registers that are memory locations. There are many types of registers; permanent, temporary, program counter, stack point and the memory address register. Permanent registers hold the preprogrammed instructions for operations such as addition and temporary registers store in numbers to be operated on and the result. The program contains the address in memory of the next instruction, the stack pointer contains the address of the last instruction in the stack and the memory address register contains the address of the data to be worked on or were the result (data that has been processed) should be stored. Microprocessors are powerful and can perform billions of operations per second. They are used in computers, televisions, cars and more.
Memory circuits
Design
Integrated circuits all follow the principles of voltage, current and resistance. Equations based on Ohm's law, V=IR, are the determining factor for many design choices. The properties of electronic components also have an effect on the design and as such the engineers designing the circuit must know what these properties are.