A Brief on IC Technology For Microcontrollers and Embedded Systems

Every electronic device that we use in our daily life is designed with electrical and electronics projects circuits. These electrical and electronics circuits can be designed using various technologies such as vacuum tubes technology, transistor technology, integrated circuit or IC technology, microprocessor technology, and microcontroller technology. These technologies can be implemented using discrete electrical and electronic components, integrated circuits, microprocessors, and microcontrollers. In this article, we will discuss about the best technology for embedded systems among IC technologies and advanced IC technology such as microcontroller IC technology. But, primarily before proceeding further, we must know what is IC technology and microcontroller IC technology.

IC Technology

In earlier days, embedded system devices were designed using vacuum tubes would be very larger in size and more expensive. The first point contact transistor was developed by John Bardeen and Walter Brattain at Bell Labs in 1947. Then, the invention of transistors has reduced and replaced the bulky expensive vacuum tubes in computers designs. Subsequently, the transistors usage reduced the size of circuits, as these transistors are less in size, economical, faster in performance, reliable, and consumes very less power. Circuits build using transistors and other discrete electronic components are called as discrete circuits.

Revolutionary change was made in designing electrical and electronics circuits and computers with the invention of integrated circuits or IC technology. Integrated circuits are very small in size, very reliable, most economical, and very simple to use. This concept of IC technology was introduced in 1958, and this IC technology miniaturized a lot of electrical and electronic gadgets like mobile phones, laptops, computers, and many other devices. Integrated circuit can be defined as a set of electronic circuits integrated on a small semiconductor material plate, typically called as silicon chip. Each IC can be very compact, containing numerous billion transistors and other components in very small area.

Generations Of IC Technology

There are different generations of integrated circuits, classified based on the number of transistors used on integrated circuit chips. They are: Small scale integration (SSI), integrated circuits containing a few numbers of tens of transistors. 1960s witnessed medium scale integration (MSI), integrated circuit chips containing hundreds of transistors. In 1970s there was large scale integration (LSI), wherein tens of thousands of transistors are integrated on each chip. In 1980s there was very large scale integration (VLSI), wherein hundreds of thousands of transistors are integrated on each chip. Furthermore, ultra large scale integration (ULSI), integrated more than one million transistors per chip, wafer-scale integration (WSI), system-on-chip (SOC), and three dimensional integrated circuits (3D-IC) are being developed. Integrated circuits such as 555timer IC, 741 operational amplifiers, CMOS, NMOS, BICMOS technology, and so on are considered as practical examples of IC technology.

There are different types of integrated circuits such as ADC, DAC, amplifiers, power management ICs, clock and timer ICs, and interface ICs that are used for various embedded systems applications.

Application of IC technology

Non-microcontroller based solar charge controller project is a simple application of IC technology. In this project, controlled charging mechanism is achieved to avoid under charge, over charge, and deep discharge conditions without using microcontroller. A set of operational amplifiers are used as comparators for monitoring panel voltage, and load current continuously. Green and red LEDs are used for indication. Green LEDs are used for indicating fully charged battery condition and under charged or overloaded or deep discharge conditions are indicated by red LEDs.

Power semiconductor switch MOSFET is used to cut off load, if red LEDs indicate low battery or overload condition. If green LEDs indicate fully charged condition of battery, then solar energy is bypassed to a dummy load in the circuit using a transistor. Thus, battery is protected form over charging. This project can be enhanced further with a GSM modem and microcontroller to achieve communication solar system and control room for monitoring status of the system.

Microcontroller IC

Microcontroller is an advanced IC or integrated circuit that is incorporated with additional peripherals. The development and usage of the embedded systems’applications is increasing with the advancement in IC technologies such as microprocessor technology, and microcontroller technology. Disadvantages of transistor technology, IC technology were diminished with the advanced IC technologies microprocessor and microcontroller technology. A microprocessor integrates functions of a computer’s central processing unit (CPU) on a single or a few integrated circuits. A microcontroller unit can be treated as a small computer on a single integrated circuit that consists of a small central processing unit, crystal oscillator, timers, watchdog and analog I/O. There are different types of registers, interrupts that are used for some specific tasks. Microcontrollers are of different types such as AVR microcontroller, PIC microcontroller, and so on. But typically 8051 microcontroller IC is used for most of the embedded systems applications.

If we use IC technology, then multiple numbers of discrete components are required to perform some tasks in embedded systems. If we use advanced IC technology such as microcontroller technology, then just by writing a few simple programming lines we can perform multiple tasks. Thus, the number of discrete components, the size of circuits, complexity, and cost can be reduced in embedded systems by using microcontroller technology.

Application Of Microcontroller Technology

Solar charge controller using microcontroller is a typical application of microcontroller advanced IC technology. To utilize the solar energy efficiently, solar powered lighting systems including solar lanterns, solar street lights, and solar house & garden lighting systems are being used in rural as well as urban areas. Solar power system mainly consists of four major components: photovoltaic module, rechargeable battery, load, and solar charge controller.

The block diagram of a solar power system with four major blocks using microcontroller technology is shown in the figure. Among these four components, consider the solar charge controller using microcontroller that plays a major role in increasing the overall performance of the solar power system. The hardware components used for solar charge controller circuit are AT89C2051 microcontroller, serial ADC0831, voltage regulator IC7805, power semiconductor switch MOSFET, LCD display, rechargeable battery, charge control, dusk to dawn sensor, and a load control.

A battery is used to provide 5V DC regulated supply to power up the microcontroller that is used to monitor the battery voltage using ADC. The voltage of 0V-20V is scaled down to V-5V using a potential divider with a resistor arrangement made at the pin 2 of ADC and these values are displayed on LCD display. Using a parallel regulation technique, charging current is allowed to flow into the battery and stops charging the battery if the battery is fully charged. Based on the input signals received from the dusk to dawn sensor, the microcontroller switches the charging or load relay. The LCD display is driven by the microcontroller to display charging message.

If the battery is fully charged (upto 14V), then relay is energized through MOSFET to interrupt charging. Then 5 minute timer will be started by microcontroller and LCD displays the message as full battery. If this timer is elapsed, then the battery is reconnected to the solar panel by a relay and thus the solar charging current is pulsed as long as solar voltage is present. If the solar panel voltage falls below zener diode voltage of the dusk to dawn sensor, then the microcontroller receives a signal from the dusk to dawn sensor, then activates the load through the MOSFET and a load ON message is displayed on the LCD display. If voltage falls below 10V of the dusk to dawn sensor, then the microcontroller turns off the load through the MOSFET.

Best Technology For Embedded Systems

In this article, earlier the IC technology and microcontroller IC technology along with their examples, types, and practical application of microcontroller and IC technology in embedded systems applications have been discussed in brief. The above discussed solar charge controller with the former IC technology and with advanced IC technology such as microcontroller IC technology shows differences between both the technologies. And it also shows that both technologies are still being used based on the requirement. Both technologies are having some advantages and disadvantages while used for embedded systems.

IC technology reduced the size of circuits compared to the circuit size built using discrete components. An advanced microcontroller IC technology reduces the size of circuits by replacing many integrated circuits in the circuit with a single microcontroller IC. Thus, cost of the circuits with the IC technology is less than the discrete or transistor technology. Microcontroller IC technology circuits cost is less, compared to the cost of circuits designed with IC technology. Similarly, for several numbers of parameters, the microcontroller technology is preferable for embedded systems compared to IC technology and discrete component or transistor technology.

Figure shows embedded systems applications designed with different technologies. For some specific applications of embedded systems, IC technology is preferable than microcontroller technology. But most of the embedded systems applications utilize microcontroller technology, as it is more advanced and has more advantages compared to IC technology. Furthermore, technical help will be provided to you from Edgefx technologies in choosing particular technology for your academic project work based on your interest in embedded systems.