Semiconductors#

The behavioral primitives that make active circuits possible. Semiconductor devices — diodes, BJTs, MOSFETs, thyristors — are the foundation for amplification, switching, regulation, and protection. Unlike passive components that simply obey constraints, semiconductors exploit those constraints to create useful nonlinear behavior.

This section focuses on device understanding: what each device is, how it behaves, and how to reason about it at the bench. The emphasis is on the device itself — its operating regions, its real-world deviations from ideal models, and its failure modes. Circuit techniques that use these devices (amplifiers, biasing networks, filters) live in their application domains: Analog Electronics, Digital Electronics, and power-related sections.

What This Section Covers#

• PN Junction Fundamentals — The physics that underlies all junction devices: forward bias, reverse bias, depletion regions, and the exponential I-V relationship.
• Diodes — Rectification, clamping, protection, Zener regulation, and real diode behavior vs. the ideal model.
• BJTs — Current-controlled devices: operating regions, biasing fundamentals, and small-signal vs. large-signal behavior.
• MOSFETs — Voltage-controlled devices: thresholds, regions, transconductance, and analog vs. logic-style usage.
• Thyristors — SCRs, triacs, and DIACs: latching behavior, AC phase control, commutation, and snubber networks.
• Protection & Clamping Devices — TVS diodes, Zener protection, clamping behavior, and choosing the right device for the job.