DIRECT-DRIVE DIGITAL AUDIO AMPLIFIER FOR ELECTROSTATIC LOUDSPEAKERS

摘要

A direct-drive digital audio amplifier for electrostatic loudspeakers (ESL) includes a pulse-width-modulation (PWM) generator that generates a PWM signal from a digital audio signal received from an audio source. The generated PWM signal is amplified to a high voltage, such as several hundred volts, by a high-voltage switching circuit. The amplified PWM signal is then applied to the stator panels of the electrostatic loudspeaker (ESL), whereupon the amplified PWM signal is low-pass filtered by the electrostatic loudspeaker to generate audible sound waves, which are then high-pass filtered by a listener's ears, so as to audibly reproduce the digital audio signal.

主权项

1. A digital audio amplifier for an electrostatic loudspeaker having a pair of fixed stators separated by a charged membrane, the digital audio amplifier comprising:
a pulse-width-modulation (PWM) generator adapted to receive a digital audio signal, said PWM generator formatting said digital audio signal into a digital pulse-width-modulation (PWM) input signal; a complement generator coupled to said PWM generator that is configured to output a PWM complement signal by generating a Boolean complement of said digital PWM input signal; and an amplification circuit having an input coupled to said PWM generator and coupled to said complement generator, such that said amplification circuit digitally amplifies said digital PWM input signal and said PWM complement signal; wherein an output of said amplification circuit is coupled to the stators of the electrostatic loudspeaker such that said amplified digital PWM signal is applied to one stator and said amplified digital PWM complement signal is applied to the other stator.