could you please point me to a good guide for a simple class AB power amplifier design based on BJTs (referring to the "classic" schema with complementary push pull, diodes to remove cross over, resistances to bias the diodes, dual voltage) ? I already have good enough knowledge for class A, BJT biasing, emitter follower, etc. But I need to get clarified on the details of power stage like:

  1. correct chose of component values (resistances, diodes, power BJTs)
  2. how to get the maximum voltage swing
  3. how to reduce as much as possible the quiescent current of the power BJTs
  4. some advice on build on breadboard of the power stage
  5. any other is welcome

thank you!



closed as not a real question by Olin Lathrop, Dave Tweed, Brian Carlton, Anindo Ghosh, placeholder Jan 25 '13 at 19:52

It's difficult to tell what is being asked here. This question is ambiguous, vague, incomplete, overly broad, or rhetorical and cannot be reasonably answered in its current form. For help clarifying this question so that it can be reopened, visit the help center. If this question can be reworded to fit the rules in the help center, please edit the question.

  • \$\begingroup\$ There are votes to close your question. Maybe you will be provided better help if you split your question and ask them individually, i.e. (i) How do I get as much voltage swing as possible? (ii) How do I find out what's the lowest practical quiescent current (or the best tradeoff for it), ... \$\endgroup\$ – zebonaut Jan 24 '13 at 18:32

In a general sense a "good guide" would be this book: "Audio Power Amplifier Design Handbook" by Douglas Self, currently at fifth edition. If you don't have that book yet, I'd suggest getting it, as you'll learn a lot about power amplifiers.

Incidentally, Douglas Self has this to say about Class AB amps: "Class-AB is less linear than either A or B, and in my view its only legitimate use is as a fallback mode to allow Class-A amplifiers to continue working reasonably when faced with a low-load impedance."


Not the answer you're looking for? Browse other questions tagged or ask your own question.