much sturdier, easier to work with, more reliable, much smaller, and less expensive than vacuum tubes.
Using the same principles and materials, engineers soon learned to create other electrical components, such as resistors and capacitors. Now that electrical devices could be made so small, the largest part of a circuit was the awkward wiring between the devices.qq英文情侣名
祈福英语实验学校In 1958 Jack Kilby of Texas Instruments, Inc., and Robert Noyce of Fairchild Semiconductor Corporation independently thought of a way to reduce circuit size further. They laid very thin paths of metal (usually aluminum or copper) directly on the same piece of material as their devices. The small paths acted as wires. With this technique an entire circuit could be “integrated” on a single piece of sol id material and an integrated circuit (IC) thus created. ICs can contain hundreds of thousands of individual transistors on a single piece of material the size of a pea. Working with that many vacuum tubes would have been unrealistically awkward and expensive. The invention of the integrated circuit made technologies of the Information Age feasible. ICs are now ud extensively in all walks of life, from cars to toasters to amument park rides.
Basic IC types
Analog versus digital circuits柬埔寨怎么读
Analog, or linear, circuits typically u only a few components and are thus some of the simplest types of ICs. Generally, analog circuits are connected to devices that collect sign
als from the environment or nd signals back to the
environment. For example, a microphone converts fluctuating vocal sounds into an electrical signal of varying voltage. An analog circuit then modifies the signal in some uful way—such as amplifying it or filtering it of undesirable noi. Such a signal might then be fed back to a loudspeaker, which would reproduce the tones originally picked up by the microphone.
Another typical u for an analog circuit is to control some device in respon to continual changes in the environment. For example, a temperature nsor nds a varying signal to a thermostat, which can be programmed to turn an air conditioner, heater, or oven on and off once the signal has reached a certain value.
A digital circuit, on the other hand, is designed to accept only voltages of specific given values. A circuit that us only two states is known as a binary circuit. Circuit design with binary quantities, “on” and “off” reprenting 1 and 0 (i.e., true and fal), us the logic of Boolean algebra. The three basic logic functions—NOT, AND, and OR—together with t
会计证怎么考取需要什么条件heir truth tables are given in the figure. (Arithmetic is also performed in the binary number system employing Boolean algebra.) The basic elements are combined in the design of ICs for digital computers and associated devices to perform the desired functions.
Microprocessor circuits
Microprocessors are the most complicated ICs. They are compod of millions of transistors that have been configured
as thousands of individual digital circuits, each of which performs some specific logic function. A microprocessor is built entirely of the logic circuits synchronized to each other.
gigabyteJust like a marching band, the circuits perform their logic function only on direction by the bandmaster. The bandmaster in a microprocessor, so to speak, is called the clock. The clock is a signal that quickly alternates between two logic states. Every time the clock changes state, every logic circuit in the microprocessor does something. Calculations can be made very quickly, depending on the speed (“clock frequency”) of the microprocessor.
husband是什么意思>2021四六级考试时间Microprocessors contain some circuits, known as registers, that store information. Registers are predetermined memory locations. Each processor has many different types of registers. Permanent registers are ud to store the preprogrammed instructions required for various operations (such as addition and multiplication). Temporary registers store numbers that are to be operated on and also the result. Other examples of registers include the “program counter,” the “stack pointer,” and the “address” register.
