How are transistors used in microprocessors?
Negative-channel metal-oxide semiconductors (NMOS) employ a positive secondary voltage to switch a shallow layer of p-type semiconductor material below the gate into n-type. For positive-channel metal-oxide semiconductors (PMOS), all these polarities are reversed. NMOS transistors are more expensive, but faster, than PMOS transistors.
In microprocessors, transistors function as fundamental electronic switches that enable the processing of digital information. By controlling the flow of current between a source and a drain via a gate electrode, a transistor can exist in one of two states: "on" (conducting current) or "off" (blocking current). These states correspond to the binary 1s and 0s that form the basis of all digital computer operations.1
Microprocessors are composed of billions of these transistors configured into thousands of individual logic circuits. These circuits are synchronized by a clock signal, allowing the processor to perform complex calculations and execute instructions at high speeds.2
To manage power consumption and heat, modern microprocessors predominantly utilize complementary metal-oxide semiconductor (CMOS) technology. CMOS pairs n-type and p-type transistors so that they respond in a complementary fashion; because only one transistor in the pair is typically active at a time, these circuits draw minimal power during operation. This efficiency is essential for packing millions of components onto a single integrated circuit without the device overheating.34