Barney Oliver: Crossover Distortion in Class B Audio Amplifiers
(Image above courtesy of Electronics Tutorials)
This is the famous analysis of class B amplifier cross-over distortion by the then head of HP Reasearch Labs, Dr. Barney Oliver, published in the February 1971 edition of the HP Journal. The bias current Iq for a class B emitter follower amplifier is shown to be approximately Iq = .026/(Re+re+(rb/hFE)). In practice, – the ideal value ending up somewhere between a 13 to 26mV drop across the output transistor emitter degeneration resistors. This paper provides the theoretical underpinings for that relationship. So, when you hear about the ‘Oliver’ voltage, you know where it came from. You can read more about Barney Oliver here and here
Download the PDF here: Cross Over Distortion in Class B Amplifiers
See the comments below. My practical experience over many amplifier builds is that indeed somewhere 13 and 26 mV is ideal.