Earlier the size of the computer used to be very big. However, nowadays laptop computers and palmtop computers are available. Wondering what made the miniaturization of electronic gadgets possible, the answer is ICs. IC stands for Integrated circuits. ICs have a big role to play in the miniaturization of electronic gadgets. In integrated circuits, many transistors and diodes are fabricated on a silicon wafer. Integrated into the same structure are the resistor and even the interconnection required to fabricate to complete gate or many gates or even an elaborate digital system. ICs are found in almost all gadgets like cars, Television, CD players, and cell phones. The size of IC is about 1mm x 1mm. ICs can be group into categories depending on the nature of the input signal.
TYPES OF ICs
- Linear or Analog ICs
- Digital ICs
- Mixed-signal ICs
- In linear ICs the input signal is an analog signal which changes smoothly and continuously over a range of values. In this case, the output is almost directly proportional to input i.e. It varies linearly with input.
Ex: Operational amplifier.
- The input signals are digital signals that have only two values. They contain circuits such as logic gates. They have several logic gates. In 1960, logic gates known as the 7400 series were commonly available as ICs, and technology of integrating circuits of a logic gate on a single chip became, known as small-scale integrated (SSI). As semiconductor technology advanced, more than 100 gates were fabricated on a single chip; this was called medium-scale integrated (MSI). A typical example of MSI is a decade counter. Within a few years, it was also possible to fabricate more than 1000 Gates on a single chip; this is known as large-scale integrated (LSI). After that very large-scale integrated (VLSI). Chips came. By convention, the designation SSI is applied when a chip has less than 12 logic gates, MSI for the range 13 to 99 gates, LSI for the range 100 to about 1000 gates, and VLSI beyond 1000 gates.
Mixed – signal ICs
- Mixed-signal integrated circuits are any ICs that have both analog and digital circuits on a semiconductor die. Mixed-signal designs are found everywhere, for example, in cell phones, sensor systems with on-chip standardized digital interference. A mixed-signal process on both signals analog as well as digital
Ex: ADC-analog to digital converter.
ICs and IC families
- The 555 timer IC
- The Operational amplifier
- 7400-series integrated circuits
- 4000-series integrated circuits, the CMOS counterpart to the 7400 series
- Intel 4004, generally regarded as the first commercially available microprocessor, led to the famous 8080 CPU and then the IBM PC’s 8088, 80286, 486, etc.
- The MOS Technology 6502 and Zilog Z80 microprocessors, used in many home computers of the early 1980s
- The Motorola 6800 series of computer-related chips, leading to the 68000 and 88000 series
- The LM-series of analog integrated circuits