A control terminal driver circuit for a switching amplifier including a driver
for each of a pair of output power transistors responsive to a PWM information
signal. The circuit operates in response to an operating state signal indicating
a start up condition for the amplifier to vary the amplitude of the drive pulses
for the output transistors between a zero value and a maximum value for normal
operation of the amplifier over a start up interval, and to reverse the process
during a shut down interval. A DC offset detector is provided to detect a DC offset
at amplifier output, and an error circuit responsive to an output of the DC offset
detector controls the relative amplitude of the driver outputs during at least
a portion of the start up interval to substantially eliminate the DC offset. Also
disclosed is a switching amplifier including a control terminal driver circuit
as described above.