FET Output Stages
The Characteristics of Power FETs
A field-effect transistor (FET) is essentially a voltage-controlled device. So are bipolar junction transistors (BJTs), despite the conventional wisdom that persists in regarding them as current controlled. They are not, even if BJT base currents are non-negligible.
The power FETs normally used are enhancement devices – in other words, with no voltage between gate and source they remain off. In contrast, the junction FETs found in small-signal circuitry are depletion devices, requiring the gate to be taken negative of the source (for the most common N-channel devices) to reduce the drain current to usable proportions. (Please note that the standard information on FET operation ...
Get Audio Power Amplifier Design Handbook, 5th Edition now with the O’Reilly learning platform.
O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.