A convergence correction voltage waveform is applied to a power amplifier circuit. An output stage of the power amplifier drives a deflection coil of a cathode ray tube with a convergence correction current, which is proportional to the convergence correction voltage waveform. A differential voltage potential across an output device of the output stage is compared against a predetermined reference voltage. As the differential voltage potential begins to drop below the predetermined reference voltage, a buck-topology voltage regulator, which is coupled to the output device, turns on. The differential voltage potential is thereby maintained at a level greater than the predetermined reference voltage.