The linear integrated circuit can be referred to as any integrated circuit that is based on the amplifier. Linear here is useful in revealing that the amplifier’s response relationship to your input signal has a linear pattern.
In this article, we will be discussing what a linear integrated circuit is. We will then go ahead to talk about the development of the linear integrated circuit as well as the types. Please read this article to learn more.
The Development of the Linear Integrated Circuit
During the development of the linear integrated circuit, a lot had occurred before 1966. However, in 1966, the first-ever general-purpose high-performance operational amplifier was released. This possesses a small size and you can make it take a flexible form in circuits. This ensured the promotion of electronics development.
During the 1960s, different linear circuits were becoming widely used. Then, during the 1970s, digital-to-analog converters (high-precision) as well as analog to digital converters were now the main devices for applying microprocessors and digital technology in process control and information processing.
Using the MSOS technology in manufacturing the voice frequency filter was a brand new development in the world of the linear integrated circuit. The working principle of this is making use of switches to connect the capacitors alternately to the different voltage nodes present in the circuit to help in transferring charges. Therefore, this creates or generates an equivalent resistance.
Besides, as a result of applying the analog sampling techniques, the MOS technology is useful in producing the operational high stability amplifiers, as well as high precision ADCs and DACs.
Combining both technologies help in opening up some broad prospects to serve the integration of the analog information communication and processing equipment subsystems.
High Frequency Technology and Production Process of the Linear Integrated Circuit
The Production Process
The manufacturing of a vast majority of the linear integrated systems happens via bipolar processes. To be able to achieve high-performance circuits, there are modifications added so as to create or produce components that have different performances on one chip.
Bipolar Compatible Technology
This field-effect technology is useful in manufacturing the high-performance junction transistors present on the bipolar chips. Furthermore, after the formation of the NPN transistor on the chip, you make use of the ion implantation technique twice in forming a P-type low-concentration channel as well as a high-concentration gate region (N + type). This breakdown voltage has the ability to reach 50 – 60 volts. Also, you can control the pinch-off voltage at around 1 volt.
Supergain Transistor
This is a NPN transistor having the common emitter’s current gain that can reach 1000-5000. In addition, this base region appears via ion implantation. In addition, the base region’s doping density is the magnitude’s order that is lower than the standard NPN transistor. Also, the base region’s thickness is thinner compared to the standard NPN transistor.
Subsurface Breakdown Diode
Here, the usual diode makes use of the NPN transistor’s eb junction. Furthermore, the breakdown phenomenon that occurs takes place on the surface of the junction. Whereas for the breakdown diode of the subsurface, there is a forming of a P+ high concentration type layer with an ion implantation that is found underneath the emitter region of the N+ type. Also, underneath the surface is where the formation of the N + -P + junction takes place.
This transistor’s breakdown voltage is lesser compared to that of its surface junction. Also, the surface condition does not affect the process of the breakdown. Besides, this usually has long-term stability and a low noise.
High-Frequency Technology
The NPN transistors’ characteristic frequency manufactured with the help of the usual bipolar process is usually less than 1000 MHz. Anytime there is a need for high-speed and high-frequency performance, we usually make use of shallow junction, thin-layer epitaxy and micro machining techniques. This could help the characteristic frequency to reach 3000 to 5000 MHz.
High-Voltage Withstand Technology
Here, the value of the voltage resistance of the linear integrated circuit bipolar process can reach about 50 – 60 volts. If there is a need to have your value for voltage resistance to reach almost 100 volts or more, then use these measures.
- Raise the epitaxial N-type layer’s thickness to help in increasing the NPN transistor’s breakdown voltage
- Whenever the metal forms an interconnection with the negative potential and crosses its lateral PNP transistor, there is an increase in the oxide layer’s thickness to stop the MOS parasitic transistor effect
- Make use of the field electrode in protecting the isolation junction’s surface. This prevents too much concentration of the electric field. There will also be a reduction in the breakdown voltage
Linear CMOS Technology
This is known as a versatile and complex linear technology that has the ability to produce the CMOS and bipolar devices simultaneously. With the linear technologies, the high speed logic circuits and the high performance linear systems will be able to combine into just one chip.
Furthermore, it makes use of molybdenum (the refractory metal) as its gate material. Also, you will be able to make the N-channel and the P-channel MOSFET on the linear bipolar chip’s N-type epitaxial layer with the photoetching for just ten times. Besides two interconnects layers of molybdenum and aluminum are present. Also, the N-channel and P-channel devices will be useful in one of the N-region
What are the Different Types of Linear Integrated Circuit?
With respect to the use and function, you can divide the linear integrated circuit into:
General-purpose Linear Integrated Circuits
This type includes voltage comparators, operational amplifiers, stabilized voltage circuits, and voltage reference circuits.
Industrial Control and Measurement Circuits
This type includes waveform generators, sensor circuits, detector, analog multiplier circuits, phase locked loop circuits, timers, analog switch circuits, power control circuits, and motor driver circuits
Data Conversion Circuits
The data conversion linear integrated circuit involves the analog to digital converters, digital to analog converters, as well as voltage to frequency converters.
Communication linear integrated circuits
These include the mobile and the telephone communication circuits
Consumer Electronics Circuits
The consumer electronics circuits include audio circuits, video recorder circuits, and the television circuits
Conclusion
WE hope you understand what the linear integrated circuit is. We have also discussed the different types and applications of the linear integrated circuit.
