Which class of amplifier provides the...

Which class of amplifier provides the highest efficiency?

🔍 Key Concepts

• Amplifier classes (A, B, AB, C) and how the conduction angle (how much of the input signal cycle the transistor conducts) affects efficiency • The trade‑off between linearity (signal fidelity) and efficiency (power wasted as heat) • Which amplifier classes are typically used in RF (radio frequency) vs audio applications because of their efficiency needs

💭 Think About

• Think about which class of amplifier has the smallest conduction angle and what that means for how often current is flowing (and wasting power) • Ask yourself: as we reduce the portion of the signal cycle during which the active device conducts, what happens to efficiency and what happens to distortion? • Of the listed classes, which one is usually associated with very high efficiency but poor linearity, often used in tuned RF circuits rather than hi‑fidelity audio?

✅ Before You Answer

• Be clear on the conduction angle (in degrees of the input cycle) typical for each class (A, B, AB, C) • Verify which class is commonly cited in textbooks as having theoretical efficiency well above 70–80% in ideal conditions • Confirm that the most efficient class in the list is usually not used for low‑distortion audio amplification but for tuned RF power stages