This course focusses on the fundamental knowledge of these three devices: Diodes, BJT and MOSFET. For each device the associated solid-state semiconductor physics concepts are covered, followed by studying their structure and developing the IV characteristics eventually followed by their electrical modeling and analysis of circuits. The course mainly focuses on a quick entry to the associated circuits through the understanding of the associated physics. MOSFET is the current workhorse of the modern micro electronic devices but for lab-based experimentation in the form of discrete devices, junction devices are more feasible and therefore the course covers Diodes, BJTs and MOSFET together using a similar framework to establish and equip students with a comparative narrative of pros and cons of each device. This would mainly focus on DC aspects of the devices, however, at the end, it would introduce the high-frequency device models and AC perspective.