The fast switching capability and zero reverse-recovery charge result in higher output linearity and low
crossover distortion for lower THD.
Class B eliminates the quiescent bias current of Class A and AB but, as a result, introduces
crossover distortion.
Class B is rarely used in practical applications because of the large
crossover distortion. Since the device is only on half the time, half the signal is missing.
This is the
crossover distortion which is introduced when the current monitor IC changes from conducting in one direction to conducting in the opposite direction.
The integrated, adaptive bias current control circuit of the FAN7031 significantly decreases
crossover distortion, even though it consumes low quiescent current.
It uses an integrated adaptive bias current control circuit to minimize
crossover distortion. The product's low bias-supply current, combined with low-shutdown current consumption (0.1 [micro]A), saves energy and extends battery life.
After much study, my colleagues and I concluded the boost-type power converter (Figure 2) best suits the implementation of a PFC circuit because of the absence of
crossover distortions and the viability of operating the converter in continuous-conduction mode.