History of the domestic electronic component base (ECB). History of development of integrated circuits

Figure 4.8

Here the dielectric consists of two layers: silicon nitride (Si 3 N 4) and silicon oxide (SiO 2). The threshold voltage can be changed by applying short (about 100 μs) voltage pulses of different polarity, with a large amplitude of 30 ... 50 V to the gate. When a +30 V pulse is applied, the threshold voltage use a transistor or gate voltage U ZI \u003d ± 10V. In this mode, the MNOS transistor operates as a conventional MIS transistor with an induced channel. R-type.

When a pulse of -30 V is applied, the threshold voltage takes on the value U ZIthor ~ 20 V, as shown in fig. 4.8, 6 and in. In this case, the signals at the input of the transistor U ZI ± 10 V cannot bring the transistor out of the closed state. This phenomenon is used in RPZU.

The operation of MNOS transistors is based on the accumulation of charge at the boundary of the nitride and oxide layers. This accumulation is the result of unequal conduction currents in the layers. The accumulation process is described by the expression dq/ dt= I sio 2 - I si 3 n 4 . With a large negative voltage U ZI accumulates a positive charge at the boundary. This is equivalent to the introduction of donors into the dielectric and is accompanied by an increase in the negative threshold voltage. With a large positive voltage U ZI accumulates a negative charge at the boundary. This results in a decrease in the negative threshold voltage. At low voltages U ZI currents in dielectric layers decrease by 10...15 orders of magnitude, so the accumulated charge is retained for thousands of hours, and, consequently, the threshold voltage is also preserved.

There is another possibility of constructing a memory cell for RPZU based on MIS transistors with a single-layer dielectric. If a sufficiently high voltage is applied to the gate, then avalanche breakdown dielectric, resulting in the accumulation of electrons in it. In this case, the threshold voltage of the transistor will change. The electron charge is retained for thousands of hours. In order to carry out the rewriting of information, it is necessary to remove electrons from the dielectric. This is achieved by illuminating the crystal with ultraviolet light, which causes a photoelectric effect: knocking electrons out of the dielectric.

Using ultraviolet erasure it is possible to significantly simplify the RPZU circuit. The generalized block diagram of the RPZU with ultraviolet erasure (Fig. 4.9) contains, in addition to the MNP, an address signal decoder (DAS), a crystal selector (UVK) and a buffer amplifier (BU) for reading information.

Figure 4.9

According to the above structural diagram, in particular, a LSI RROM with ultraviolet erasure of the K573RF1 type with a capacity of 8192 bits is made.

4.8. Digital to Analog Converters

The purpose of the DAC is to convert a binary digital signal into an equivalent analog voltage. Such a conversion can be done using the resistive circuits shown in Fig. 4.10.

Figure 4.10

A DAC with binary weight resistors (Fig. 4.10, a) requires fewer resistors, but this requires a range of precision resistance values. Analog output voltage U An DAC is defined as a function of two-level input voltages:

U en =( U A+2 U B+4 U C +…)/(1+2+4+...).

On digital inputs U A , U B, U C, ... voltage can only take two fixed values, for example, either 0 or 1. For a DAC that uses resistors R and R/2, more resistors are required (Fig. 4.10.6), but with only two values. The analog voltage at the output of such a DAC is determined by the formula

U en =( U A+2 U B+4 U C+…+m U n)/2n

where n - number of DAC bits; t - coefficient depending on the number of DAC bits.

To ensure high accuracy, the resistive DAC circuits must operate on a high-resistance load. To match resistive circuits with a low-resistance load, buffer amplifiers based on operational amplifiers are used, shown in Fig. 4.10, a, b.

4.9. Analog to digital converters

The purpose of the ADC is to convert analog voltage into its digital equivalent. Typically, ADCs are more complex than DACs, with the DAC often being the node of the ADC. A generalized block diagram of an ADC with a DAC in the feedback circuit is shown in fig. 4.11.

Figure 4.11

ADCs made according to this scheme are widely used due to their good accuracy, speed, relative simplicity and low cost.

The ADC includes n-bit trigger register of conversion results DD 1 - DDn, bit control DAC; a comparator connected to the CU control device and containing a clock frequency generator. By implementing VUU various ADC operation algorithms, different characteristics of the converter are obtained.

Using fig. 4.11, we will consider the principle of operation of the ADC, assuming that a reverse counter is used as a trigger register. The up/down counter has a digital output, the voltage at which increases from each clock pulse, when the voltage level is high at the input of the counter "Direct count", and the voltage level is low at the input "Reverse count". Conversely, the voltage at the digital output decreases with each clock pulse when the Count Up input is low and the Count Down input is high.

The most important node of the ADC is the comparator (K), which has two analog inputs U DAC and U an and a digital output connected via the CU to a reversible counter. If the voltage at the output of the comparator is high, the level at the input of the "Direct count" counter will also be high. Conversely, when the output voltage of the comparator is low, the Count Up input will also be low.

Thus, depending on whether the comparator output is high or low, the up/down counter counts up or down respectively. In the first case at the input U The DAC of the comparator shows a step-increasing voltage, and in the second - a step-decreasing.

Since the comparator operates without feedback, its output voltage level goes high when the voltage at its input U en will become slightly more negative than at the input U DAC. Conversely, its output voltage level goes low as soon as the input voltage U en will become slightly more positive than the input voltage U DAC.

At the entrance U The comparator DAC receives the output voltage of the DAC, which is compared with the analog input voltage applied to the input U en .

If the analog voltage U en exceeds the voltage taken from the output of the DAC, the reversible counter counts in the forward direction, increasing the voltage at the input in steps U DAC up to the input voltage value U an. If U en<U DAC or becomes one during the counting process, the voltage at the output of the comparator is low and the counter counts in the opposite direction, again leading U DAC to U en . Thus, the system has a feedback that keeps the output voltage of the DAC approximately equal to the voltage U en . Therefore, the output of an up/down counter is always the digital equivalent of the analog input voltage. The output of the up/down counter reads the digital equivalent of the analog input signal of the ADC.

4.10. Digital and analog multiplexers

In microprocessor systems, ADCs, DACs, as well as in electronic switching systems, multiplexers are widely used: multi-channel switches (having 4, 8, 16, 32, 64 inputs and 1-2 outputs) with a digital control device. The simplest multiplexers of digital and analog signals are shown in fig. 4.12, a and b respectively.

Figure 4.12

The digital multiplexer (Fig. 4.12, a) allows for sequential or arbitrary polling of the logical states of signal sources X 0 , X 1 , X 2 , X 3 and passing the poll result to the output

According to this principle, multiplexers are built for any required number of information inputs. Some types of digital multiplexers also allow switching of analog information signals.

However, analog multiplexers have the best performance, containing a matrix of high-quality analog keys (AK 1 ... AK 4), working for an output buffer amplifier, digital control unit. The connection of the nodes to each other is illustrated in Fig. 4.12.6.

An example of an analog multiplexer LSI is a K591KN1 microcircuit, made on the basis of MIS transistors. It provides switching of 16 analog information sources to one output, allowing both addressing and serial channel sampling. When developing the LSI of analog multiplexers, the need for their compatibility with the microprocessor command system is taken into account.

Analog multiplexers are very promising products for electronic switching fields and multi-channel electronic switches for communication, broadcasting and television.

Just twenty-five years ago, radio amateurs and specialists of the older generation had to study new devices for that time - transistors. It was not easy to abandon the vacuum tubes that we were so used to and switch to the crowding and growing "family" of semiconductor devices.

And now this “family” has increasingly begun to give way in radio engineering and electronics to the latest generation of semiconductor devices - integrated circuits, often called ICs for short.

What is an integrated circuit

integrated circuit- This is a miniature electronic unit containing transistors, diodes, resistors and other active and passive elements in a common housing, the number of which can reach several tens of thousands.

One microcircuit Can replace the whole unit of a radio receiver, an electronic computer (ECM) and an electronic machine. The "mechanism" of an electronic wristwatch, for example, is just one larger chip.

According to their functional purpose, integrated circuits are divided into two main groups: analog, or linear-pulse, and logical, or digital, microcircuits.

Analog microcircuits are intended for amplifying, generating and converting electrical oscillations of different frequencies, for example, for receivers, amplifiers, and logical microcircuits for use in automation devices, in devices with digital timing, in computers.

This workshop is dedicated to getting acquainted with the device, the principle of operation and the possible application of the simplest analog and logic integrated circuits.

On an analog chip

Of the huge "family" of analog, the simplest are the twin microcircuits "K118UN1A (K1US181A) and K118UN1B (K1US181B), included in the K118 series.

Each of them is an amplifier containing ... However, it is better to talk about the electronic "stuffing" later. In the meantime, we will consider them "black boxes" with leads for connecting power supplies, additional parts, input and output circuits to them.

The difference between them lies only in their gains of low-frequency oscillations: the gain of the K118UN1A chip at a frequency of 12 kHz is 250, and the K118UN1B chip is 400.

At high frequencies, the gain of these microcircuits is the same - about 50. So any of them can be used to amplify oscillations of both low and high frequencies, and therefore for our experiments. The appearance and symbolic designation of these amplifier circuits on the circuit diagrams of the devices are shown in fig. 88.

They have a rectangular plastic case. On top of the case is a label that serves as a reference point for pin numbers. The microcircuits are designed for power supply from a 6.3 V DC source, which is supplied through terminals 7 (+ Upit) and 14 (— U Pete).

The power source may be a regulated AC power supply or a battery composed of four cells 334 and 343.

The first experiment with the K118UN1A (or K118UN1B) microcircuit is carried out according to the scheme shown in fig. 89. As a circuit board, use a cardboard plate measuring approximately 50X40 mm.

microchip pins 1, 7, 8 and 14 solder to the wire staples passed through the holes in the cardboard. All of them will act as racks holding the microcircuit on the board, and the pin brackets 7. and 14, in addition, connecting contacts with the battery GB1 (or AC adapter).

Between them, on both sides of the microcircuit, strengthen two or three more contacts, which will be intermediate for additional details. Mount the capacitors on the board C1(type K50-6 or K50-3) and C2(KJAS, BM, MBM), connect headphones to the output of the microcircuit IN 2.

Connect to the input of the microcircuit (through a capacitor C1) electrodynamic microphone IN 1 of any type or a DEM-4m telephone capsule, turn on the power and, pressing the phones closer to your ears, lightly tap the microphone with a pencil. If there are no editing errors, the phones should hear sounds resembling clicks on a drum.

Ask a friend to say something in front of the microphone - you will hear his voice on the phones. Instead of a microphone, you can connect a radio broadcasting (subscriber) loudspeaker with its matching transformer to the input of the microcircuit. The effect will be about the same.

Continuing the experiment with a single-acting telephone device, connect between the common (negative) conductor of the power circuit and the output 12 IC electrolytic capacitor NW, indicated in the diagram by dashed lines. At the same time, the volume of the sound in the phones should increase.

Phones will sound even louder if the same capacitor is included in the output circuit 5 (in fig. 89 - capacitor C4). But if at the same time the amplifier is excited, then an electrolytic capacitor with a capacity of 5-10 microfarads will have to be connected between the common wire and terminal 11. nominal voltage 10 V.

Another experience: turn on between the conclusions 10 and 3 microcircuits ceramic or paper capacitor with a capacity of 5 - 10 thousand picofarads. What happened? In the phones appeared incessant -sound of medium tonality. With an increase in the capacitance of this capacitor, the tone of the sound in the phones should decrease, and with a decrease it should increase. Check this.

And now let's open this "black box" and consider its "stuffing" (Fig. 90). Yes, it is a two-stage amplifier with a direct connection between its transistors. Silicon transistors, structures n -R-n. The low-frequency signal generated by the microphone is fed (through capacitor C1) to the input of the microcircuit (pin 3).

Voltage drop created across the resistor R6 in the emitter circuit of the transistor V2, through resistors R4 and R5 applied to the base of the transistor VI and opens it. Resistor R1 — load of this transistor. The amplified signal taken from it enters the base of the transistor V2 for extra reinforcement.

In an experimental amplifier, the transistor load V2 there were headphones included in his collector circuit that converted the low frequency signal into sound.

But its load could be a resistor R5 microcircuits, if you connect the conclusions together 10 and 9. In this case, the telephones must be connected between the common wire and the connection point of these conclusions through an electrolytic capacitor with a capacity of several microfarads (positive lining to the microcircuit).

When a capacitor is connected between the common wire and the output 12 Chip sound volume increased, Why? Because he's shunting a resistor R6 microcircuit, weakened the negative feedback on alternating current acting in it.

Negative feedback became even weaker when you included a second capacitor in the base circuit of the transistor V1. And the third capacitor, connected between the common wire and the output 11, formed with resistor R7 IC decoupling filter to prevent excitation of the amplifier.

What happens when you turn on the capacitor between the terminals 10 and 5? He created a positive feedback between the output and input of the amplifier, which turned it into an audio frequency oscillation generator.

So, as you can see, the K118UN1B (or K118UN1A) chip is an amplifier that can be low-frequency or high-frequency, for example, in a receiver. But it can also become a generator of electrical oscillations of both low and high frequencies.

Chip in the radio

We propose to test this microcircuit in the high-frequency path of the receiver, assembled, for example, according to the circuit shown in Fig. 91. The input circuit of the magnetic antenna of such a receiver is formed by a coil L1 and a variable capacitor C1. The high-frequency signal of the radio station, on the wave of which the circuit is tuned, through the communication coil L2 and decoupling capacitor C2 goes to the input (output 3) microchips L1.

From the output of the microcircuit (output 10, connected to output 9) amplified signal is fed through a capacitor C4 for detector, diodes VI and V2 which are connected according to the voltage multiplication circuit, and the low-frequency signal allocated to them by telephones IN 1 converted to sound. Receiver powered by battery GB1, composed of four elements 332, 316 or five batteries D-01.

In many transistor receivers, the amplifier of the high-frequency path is formed by transistors, and in this one - a microcircuit. This is the only difference between them. With the experience of previous workshops, I hope you will be able to independently mount and G set up such a receiver and even, if you wish, supplement it with an LF amplifier for loud-speaking radio reception.

On a logic chip

An integral part of many digital integrated circuits is the AND-NOT logic element, the symbol of which you see in fig. 92, a. Its symbol is an "&" placed inside a rectangle, usually in the upper left corner, replacing the "and" conjunction in English. Two or more inputs on the left, one output on the right.

A small circle, which begins the output signal connection line, symbolizes the logical Negation "NOT" at the output of the microcircuit. In the language of digital technology, "NOT" means that the AND-NOT element is an inverter, that is, a device whose output parameters are opposite to the input ones.

The electrical state and operation of a logic element is characterized by the signal levels at its inputs and outputs. A signal of a small (or zero) voltage, the level of which does not exceed 0.3 - 0.4 V, is usually (in accordance with the binary number system) called logical zero (0), and a higher voltage signal (compared to logical 0), the level of which can be 2.5 - 3.5 V, - a logical unit (1).

For example, they say: "at the output of the element, logical 1." This means that at the moment a signal has appeared at the output of the element, the voltage of which corresponds to the level of logic 1.

In order not to delve into the technology and device of the NAND element, we will consider it as a “black box”, which has two inputs and one output for an electrical signal.

The logic of the element lies in the fact that when one of its inputs is supplied with logical O, and at the second input with logical 1, a logical 1 signal appears at the output, which disappears when signals corresponding to logical 1 are applied to both inputs.

For experiments that fix this property of the element in memory, you will need the most common K155LAZ microcircuit, a DC voltmeter, a fresh 3336L battery and two resistors with a resistance of 1 ... 1.2 kOhm.

The K155LAZ chip consists of four 2I-NOT elements (Fig. 92, b) powered by one common 5 V DC source, but each of them operates as an independent logic device. The number 2 in the name of the microcircuit indicates that its elements have two inputs.

Outwardly and structurally, it, like all microcircuits of the K155 series, does not differ from the analog K118UN1 microcircuit already familiar to you, only the polarity of connecting the power source is different. Therefore, the cardboard board you made earlier is also suitable for experiments with this microcircuit. The power supply is connected: +5 V - to pin 7 " — 5 B - to the conclusion 14.

But these conclusions are not usually indicated on the schematic image of the microcircuit. This is explained by the fact that on the circuit diagrams the elements that make up the microcircuit are depicted separately, for example, as in Fig. 92, c. For experiments, you can use any of its four elements.

Chip pins 1, 7, 8 and 14 solder to wire racks on a cardboard board (as in Fig. 89). One of the input pins of any of its elements, for example, an element with pins 1 — 3, connect through a resistor with a resistance of 1 ... 1.2 kOhm to the output 14, the output of the second input is directly with a common (“grounded”) conductor of the power circuit, and connect a DC voltmeter to the output of the element (Fig. 93, a).

Turn on the power. What does the voltmeter show? A voltage of approximately 3 V. This voltage corresponds to a logic 1 signal at the output of the element. With the same voltmeter, measure the voltage at the output of the first input, and here, as you can see, it is also a logical 1. Therefore, when one of the inputs of the element has a logical 1, and the second has a logical 0, the output will be a logical 1.

Now connect the output and the second input through a resistor with a resistance of 1 ... 1.2 kOhm with the output 14 and at the same time a wire jumper - with a common conductor, as shown in fig. 93b.

In this case, the output, as in the first experiment, will be logical 1. Further, following the arrow of the voltmeter, remove the wire jumper in order to apply a signal corresponding to logical 1 to the second input.

What does a voltmeter measure? The signal at the output of the element has been converted to logical 0. This is how it should be! And if any of the inputs is periodically closed to a common wire and thereby simulates the supply of a logical 0 to it, then current pulses will appear at the output of the element with the same frequency, as evidenced by the fluctuations of the voltmeter needle. Check it out experimentally.

The property of the AND-NOT element to change its state under the influence of input control signals is widely used in various digital computing devices. Radio amateurs, especially beginners, very often use a logic element as an inverter - a device whose output signal is opposite to the input signal.

The following experiment can confirm this property of an element. Connect together the terminals of both inputs of the element and through a resistor with a resistance of 1 ... 1.2 kΩ, connect them to the terminal 14 (Fig. 93, in).

So you will apply to the common input of the element a signal corresponding to logical 1, the voltage of which can be measured with a voltmeter. What is the output of this?

The needle of the voltmeter connected to it slightly deviated from the zero mark of the scale. Here, therefore, as expected, the signal corresponds to logical 0.

Then, without disconnecting the resistor from the output 14 microcircuit, several times in a row close the input of the element to a common conductor with a wire jumper (in Fig. 93, in shown by a dashed line with arrows) and at the same time follow the voltmeter needle. So you will make sure that when the input of the inverter is logical 0, the output at this time is logical 1 and, conversely, when the input is logical 1, the output is logical 0.

This is how an inverter works, which is especially often used by radio amateurs in the impulse devices they design.

An example of such a device is a pulse generator assembled according to the circuit shown in Fig. 94. You can verify its efficiency right now, spending only a few minutes on it.

Connect the output of the element D1.1 to the inputs of the element D1.2 the same microcircuit, its output is with the inputs of the element DJ.3, and the output of this element (output 8) - with element input D1.1 through a variable resistor R1 . To element output D1.3 (between output 8 and a common conductor) connect headphones B1, a parallel to elements D1.1 and D1.2 electrolytic capacitor C1.

Set the variable resistor engine to the right (according to the diagram) position and turn on the power - you will hear a sound in the phones, the tone of which can be changed by a variable resistor.

In this experiment, the elements D1.1, D1.2 andD1.3, interconnected in series, like the transistors of a three-stage amplifier, they formed a multivibrator - a generator of rectangular electrical impulses.

The microcircuit became a generator thanks to the capacitor and resistor, which created frequency-dependent feedback circuits between the output and input of the elements. With a variable resistor, the frequency of the pulses generated by the multivibrator can be smoothly changed from about 300 Hz to 10 kHz.

What practical application can such a pulsed device find? It can become, for example, a house bell, a probe for checking the performance of the cascades of the receiver and bass amplifier, a generator for training in listening to the telegraph alphabet.

Homemade slot machine on a chip

Such a device can be turned into a Red or Green slot machine. A diagram of such an impulse device is shown in Fig. 95. Here are the elements D1.1, D1.2, D1.3 the same (or the same) K155LAZ chip and a capacitor C1 form a similar multivibrator whose pulses control transistors VI and V2, connected according to the scheme with a common emitter.

Element D1.4 works like an inverter. Thanks to him, the multivibrator pulses arrive at the bases of the transistors in antiphase and open them one by one. So, for example, when the level of logic 1 is at the input of the inverter, and the level of logic 0 is at the output, then at these moments, the transistor IN 1 open and light bulb HI in its collector circuit is on, and the transistor V2 closed and his light bulb H2 does not burn.

On the next pulse, the inverter will reverse its state. Now the transistor will open V2 and the light will turn on H2, a transistor VI turn on the light bulb H1 will go out.

But the frequency of the pulses generated by the multivibrator is relatively high (at least 15 kHz) and the light bulbs, of course, cannot respond to each pulse.

Therefore, they glow dimly. But it is worth pressing the S1 button to short-circuit the capacitor with its contacts C1 and thereby disrupt the generation of the multivibrator, as soon as the light of one of the transistors lights up brightly, on the basis of which at that moment there will be a voltage corresponding to logical 1, and the other light goes out completely.

It is impossible to say in advance which of the bulbs after pressing the button will continue to burn - one can only guess. This is the meaning of the game.

The gaming machine, together with a battery (3336L or three 343 cells connected in series), can be placed in a small box, for example, in the case of a "pocket" receiver.

Incandescent light bulbs HI and H2(MH2.5-0.068 or MH2.5-0.15) place under the holes in the front wall of the case and close them with caps or plates of red and green organic glass. Here also fix the power switch (toggle switch TV-1) and the push-button switch §one(type P2K or KM-N) stops the multivibrator.

Establishing a slot machine consists in careful selection of a resistor R1. Its resistance should be such that when you stop the multivibrator with the button S1 at least 80 - 100 times the number of fires of each of the bulbs was approximately the same.

First check if the multivibrator is working. To do this, parallel to the capacitor C1, e, the capacitance of which can be 0.1 ... 0.5 μF, connect an electrolytic capacitor with a capacity of 20 ... 30 μF, and headphones to the output of the multivibrator - a low-pitched sound should appear in the phones.

This sound is a sign of the operation of the multivibrator. Then remove the electrolytic capacitor, resistor R1 replace with a trimming resistor with a resistance of 1.2 ... 1.3 kOhm, and between the terminals 8 and 11 elements DI.3 and D1.4 turn on the DC voltmeter. By changing the resistance of the tuning resistor, achieve such a position that the voltmeter shows zero voltage between the outputs of these microcircuit elements.

The number of players can be any. Everyone in turn presses the stop button of the multivibrator. The winner is the one who, with an equal number of moves, for example, twenty clicks on the button, guesses the colors of the lights on after the multivibrator stops more times.

Unfortunately, the frequency of the multivibrator of the simplest gaming machine described here changes somewhat due to the discharge of the battery, which, of course, affects the equiprobability of ignition of different bulbs, so it is better to power it from a stabilized voltage source of 5 V.

Literature: Borisov V. G. Practicum for a beginner radio amateur. 2nd ed., Revised. and additional — M.: DOSAAF, 1984. 144 p., ill. 55k.

In early electrical computers, the circuit components that performed the operations were vacuum tubes. These tubes, reminiscent of light bulbs, consumed a lot of electricity and generated a lot of heat. Everything changed in 1947 with the invention of the transistor. This little device used a semiconductor material, so named for its ability to both conduct and retain electrical current, depending on whether or not there was electrical current in the semiconductor itself. This new technology made it possible to build all kinds of electrical switches on silicon chips. Transistor circuits took up less space and consumed less power. For more powerful computers, integrated circuits, or ICs, were created.

Nowadays, transistors have become microscopically small, and the entire circuit of the IC is placed on a piece of semiconductor with an area of ​​1 inch square. Small blocks, mounted in rows on a computer circuit board, are integrated circuits enclosed in plastic cases. Each microcircuit contains a set of the simplest circuit elements, or devices. Most of them are transistors. An IC may also include diodes, which only allow electrical current to flow in one direction, and resistors, which block the current.
Fixed parts. Inside the computer, rows of integrated circuits in protective cases, as shown below, are mounted on the computer's printed circuit board (green). Each pale green line represents a path through which an electric current flows; together they form "highways" through which electric current is carried from circuit to circuit.

Tiny connections. Along the edge of the microcircuit, highly magnetized wires resembling human hairs send electrical signals from the electrical circuit (named above). These gold or aluminum wires are virtually corrosion resistant and conduct electricity well.

Anatomy of a transistor
Transistors - the basic microscopic elements of an electronic circuit - are switches that turn an electric current on and off. Small metal tracks (grey) conduct current (red and green) from these devices. Arranged in a combination called a logic gate (logic circuit), transistors respond to electrical impulses in a variety of predetermined ways, allowing the computer to perform a wide variety of tasks.

Logic scheme. In the event that an incoming electrical current (red arrows) activates the base of each transistor, the supply current (green arrows) will rush to the output wiring.

Varady G.K. 404 platoon.

Integrated circuits.

Plan:

1) Introduction (concept, device).

2) IS types.

3) Pros and cons of IS.

4) Production.

5) Application.

Introduction.

(from lat. integratio- "connection").

An IC is a microelectronic circuit formed on a tiny wafer (crystal, or "chip") of a semiconductor material, usually silicon, that is used to control and amplify electrical current. A typical IC consists of many interconnected microelectronic components, such as transistors, resistors, capacitors, and diodes, fabricated on the surface of a chip. The dimensions of the silicon crystals range from about 1.3 x 1.3 mm to 13 x 13 mm. Progress in the field of integrated circuits has led to the development of technologies for large and very large integrated circuits (LSI and VLSI).

Classification.

Depending on the degree of integration (the number of elements for digital circuits), the following names of integrated circuits are used:

small integrated circuit (MIS) - up to 100 elements in a crystal,

medium integrated circuit (SIS) - up to 1000 elements in a crystal,

large integrated circuit (LSI) - up to 10 thousand elements in a crystal,

very large integrated circuit (VLSI) - more than 10 thousand elements in a crystal.

Previously, obsolete names were also used: ultra-large-scale integrated circuit (ULSI) - from 1-10 million to 1 billion elements in a crystal and, sometimes, giga-large integrated circuit (GBIS) - more than 1 billion elements in a crystal. At present, in the 2010s, the names "UBIS" and "GBIS" are practically not used, and all microcircuits with more than 10 thousand elements are classified as VLSI.

Pros and cons of IS.

Integrated circuits have a number of advantages over their predecessors - analog circuits, which were assembled from separate components mounted on a chassis. ICs are smaller, faster and more reliable; they are also less expensive and less prone to failure due to vibration, moisture and aging. The miniaturization of electronic circuits was made possible by the special properties of semiconductors. Their main advantages are:

Reduced power consumption associated with the use of pulsed electrical signals in digital electronics. When receiving and converting such signals, the active elements of electronic devices (transistors) operate in the "key" mode, that is, the transistor is either "open" - which corresponds to a high level signal (1), or "closed" - (0), in the first case on transistor there is no voltage drop, in the second - it does not go through current. In both cases, the power consumption is close to 0, in contrast to analog devices, in which the transistors are in an intermediate (active) state most of the time.

High noise immunity digital devices is associated with a large difference between high (for example, 2.5-5 V) and low (0-0.5 V) level signals. A state error is possible at such a level of interference that a high level is interpreted as a low level and vice versa, which is unlikely. In addition, in digital devices, it is possible to use special codes that allow you to correct errors.

Large difference in signal state levels high and low levels (logical "0" and "1") and a fairly wide range of their allowable changes makes digital technology insensitive to the inevitable spread of element parameters in integrated technology, eliminates the need to select components and adjust adjustment elements in digital devices.

Reliability. The reliability of an integrated circuit is about the same as that of a single silicon transistor of equivalent shape and size. Theoretically, transistors can last for thousands of years without fail - one of the most important factors for applications such as rocket and space technology, where a single failure can mean complete failure of the ongoing project.

Production.

The fabrication of an integrated circuit can take up to two months because some areas of the semiconductor need to be doped with high precision. In a process called crystal growth or pulling, a cylindrical billet of high purity silicon is first produced. Plates with a thickness of, for example, 0.5 mm are cut from this cylinder. The wafer is ultimately cut into hundreds of small pieces, called chips, each of which is converted into an integrated circuit by the process described below. The processing of chips begins with the manufacture of masks for each layer of the IC. A large-scale stencil is made, having the shape of a square with an area of ​​approx. 0.1 m2. A set of such masks contains all the constituent parts of the IC: diffusion levels, interconnection levels, etc. The entire resulting structure is photographically reduced to size. crystal and reproduced layer by layer on a glass plate. A thin layer of silicon dioxide is grown on the surface of a silicon wafer. Each plate is coated with a light-sensitive material (photoresist) and exposed to light transmitted through the masks. The unexposed areas of the photosensitive coating are removed with a solvent, and with the help of another chemical agent that dissolves silicon dioxide, the latter is etched from those areas where it is now not protected by the photosensitive coating. Variations of this basic manufacturing process are used in the fabrication of the two main types of transistor structures: bipolar and field-effect (MOS).

Application. Local \ Global.

Local.

Directly in circuitry, an integrated circuit can take on a huge number of tasks. Among them may be:

Logic elements, Triggers, Counters, Registers, Buffer, Converters, Encoders, Decoders, Digital comparator, Multiplexers, Demultiplexers, Adders, Half adders, Keys, Microcontrollers, (Micro)processors (including CPUs for computers), Single-crystal microcomputers, Microcircuits and memory modules, FPGAs (programmable logic integrated circuits).

Global.

Microprocessors and minicomputers. First presented to the public in 1971, microprocessors performed most of the basic functions of a computer on a single silicon IC, implemented on a 5x5 mm chip. Thanks to integrated circuits it became possible to create minicomputers - small computers, where all functions are performed on one or more large integrated circuits. This impressive miniaturization has led to a dramatic reduction in the cost of computing. Minicomputers currently being produced under $1,000 are as powerful as the first very large computers, which cost up to $20 million in the early 1960s. Microprocessors are used in communications equipment, pocket calculators, wrist clocks, TV selectors, electronic games, automated kitchen and banking equipment, automatic fuel control and exhaust gas aftertreatment in cars, as well as in many other devices. Most of the global electronics industry, whose turnover exceeds 795 billion rubles, depends in one way or another on integrated circuits. On a global scale, integrated circuits are used in equipment, the total cost of which is many hundreds of billions of rubles.

Literature.

Meizda F. Integrated circuits: technology and applications. M., 1981 Zee S. Physics of semiconductor devices. M., 1984 VLSI technology. M., 1986 Muller R., Keimin S. Elements of integrated circuits. M., 1989 Shur M.S. Physics of semiconductor devices. M., 1992

To work any more or less complex electronics, usually you need a lot of parts. When there are many of them, they can be "combined", say, into integrated circuits. What are they? How are they classified? How are they made and what signals are transmitted?

What are logic integrated circuits (ICs)

In fact, this is a microelectronic device that is based on a crystal of arbitrary complexity, which is made on a semiconductor film or wafer. It is placed in a non-separable case (although it can do without it, but only when it is part of a microassembly). The first integrated circuit was patented in 1968. This was a kind of breakthrough in the industry, although the provided device did not very much correspond to modern ideas in terms of its parameters. Integrated circuits are generally manufactured for surface mounting. Often, an IC is understood to mean only one crystal or film. The most widely used integrated circuit on a silicon wafer. It turns out that its application in industry has a number of advantages, for example, the efficiency of signal transmission.

Design levels

These devices are complex, which is beautifully displayed. Now they are created using special CAD systems that automate and significantly speed up production processes. So, when designing, it is worked out:

1. Logic level (inverters, NAND, NOR and the like).
2. System and circuit engineering (triggers, encoders, ALUs, comparators, etc. are being worked out);
3. Electrical (capacitors, transistors, resistors and similar devices).
4. Topological level - photomasks for production.
5. Physical - how one transistor (or a small group) is implemented on a chip.
6. Software - instructions for microcontrollers, microprocessors and FPGAs are created. A behavior model is developed using a vertical scheme.

Classification

Speaking about how integrated circuits are distinguished, it is impossible to choose only one parameter of the type of complexity of the technology in question. Therefore, as many as three were selected within the framework of the article.

Degree of integration

1. Small integrated circuit. Contains less than a hundred elements.
2. Medium integrated circuit. The number of elements fluctuates in the range of one hundred/thousand.
3. Large integrated circuit. Contains from a thousand to 10,000 elements.
4. They have over ten thousand elements.

As a rule, a large integrated circuit is often used for consumer devices. Previously used other categories:

1. Ultra-large integrated circuit. It included those samples that could boast the number of elements in the range from 1 million to 1 billion.
2. giga-large integrated circuit. This included samples, the number of elements of which exceeded 1 billion elements.

But they don't apply at the moment. And all the samples that were previously referred to as UBIS and GBIS are now passed as VLSI. In general, this has allowed significant savings in the number of groups, since the last two types are usually used specifically in large research centers, where computer systems operate, the power of which is measured in tens and hundreds of terabytes.

Manufacturing technology

In view of the different manufacturing possibilities, integrated circuits are also classified according to how they are made and from what:

1. Semiconductor. In them, all elements and connections are made on the same semiconductor chip. Semiconductor integrated circuits use materials such as silicon, germanium, gallium arsenide, and hafnium oxide.

2. Film. All elements and connections are made as films:

Thick-film.

Thin-film.

3. Hybrid. It has unpackaged diodes, transistors or other electronic active components. Passive (such as resistors, inductors, capacitors) are placed on a common ceramic substrate. All of them are placed in one sealed case.

4. Mixed. There is not only a semiconductor crystal here, but also thin-film (or thick-film) passive elements that are placed on its surface.

Type of processed signal

And the third, most recent kind, is based on what signals the integrated circuit processes. They are:

1. Analog. Here, the input and output signals change according to the law They can take on a value in the range from negative to positive supply voltage.
2. Digital. Here, any input or output signal can have two values: a logical one or zero. Each of them corresponds to its predetermined voltage level. So, TTL-type microcircuits evaluate the range 0-0.4V to zero, and 2.4-5V to one. There may be other divisions, it all depends on the specific sample.
3. Analog-digital. Combine the advantages and features of previous models. For example, they may contain signal amplifiers and analog-to-digital converters.

Legal Features

What does the legislation say about integrated circuits? In our country, the legal protection of the topologies of integrated circuits has been granted. By it is meant the geometric-spatial arrangement of a certain set of specific elements and the connections between them fixed on a certain material carrier (according to Article 1448 of the Civil Code of the Russian Federation). The author of the topology has the following intellectual rights to his invention:

1. Copyright.
2. Exclusive right.

In addition, other preferences may belong to the author of the topology, including the possibility of receiving remuneration for its use. has been operating for ten years. During this time, the inventor, or the person to whom this status has been assigned, can register the topology with the relevant intellectual property and patent service.

Conclusion

That's all! If you have a desire to assemble your own scheme, you can only wish success. But at the same time I want to draw your attention to one feature. If there is a desire to assemble a microcircuit, then it is necessary to thoroughly prepare for this process. The fact is that its creation requires exceptional cleanliness at the level of a surgical operating room, and besides, due to the smallness of the parts, it will not work to work with a soldering iron in the usual mode - all actions are carried out by machines. Therefore, at home, you can only create schemes. If you wish, you can purchase industrial developments that will be offered on the market, but it is better to leave the idea of ​​making them at home without significant finances.