Electronics Engineering (ELEX) Board Practice Exam

Which technology did Intel utilize to design its first 8-bit microprocessor?

1. NMOS technology

2. Bipolar technology

3. CMOS technology

4. PMOS technology

The correct answer is: PMOS technology

Intel's first 8-bit microprocessor, the 8080, was designed using PMOS (P-type Metal-Oxide-Semiconductor) technology. PMOS technology was favorable at that time due to its relatively low power consumption and simplicity in fabrication, which allowed for the production of compact and efficient circuits. The characteristics of PMOS technology made it suitable for early microprocessor design, as it required fewer transistors to achieve the required logic functions compared to some other technologies. While NMOS, CMOS, and Bipolar technologies have their own advantages, they were not utilized for the design of the 8080 microprocessor. For instance, NMOS was noted for its faster switching speeds but tended to consume more power. CMOS technology, which combines both PMOS and NMOS, came later and is known for its low power consumption and high noise immunity, but it was not in use for the 8080. Bipolar technology also offers high speed but presents challenges in power consumption and fabrication complexity for integrated circuits at that time. Thus, the choice of PMOS technology for the 8080 is pivotal in understanding the context and limitations of early microprocessor designs and their technological environments.