A control circuit creates a self-sensing active-damping voice coil. The
control circuit includes a current sensor coupled to a voice coil. A
first filter is coupled to the current sensor to create an error voltage
that is proportional to the integral of an external acceleration applied
to the voice coil. A second filter with a lead-lag component is coupled
to the error voltage to create a voltage applied to the voice coil that
substantially cancels the external acceleration below a pole defined by a
lead-lag component thereby damping the external accelerations.