Patent ID: 9621185
Date: 2017-04-11
CPC Classifications: H03F,H03M

Claim:
1. A differential amplitude pulse width modulation (aPWM) DAC apparatus comprising: an aPWM module for generating differential pulse according to input signals received from an input digital audio data stream; a power driver, connected to said aPWM module; and for providing energy to a terminal load; and a filter, connected between said power driver and said terminal load, for removing unwanted harmonic signal to reconstruct analog signals before outputting to said terminal load; wherein said aPWM module further comprising: a PWM generator to connect and convert said received input signals to a series of pulses having time domain width; an amplitude modulation unit, to receive said input signals to increase the time domain resolution of said pulse width and to generate selection signals SX and SY; and a differential pulse generator, connected to said PWM to receive the series of pulses having time domain width and a positive/negative sign from said PWM generator and convert to differential form defined on voltage domain and time domain to output pulses DN and DP; wherein said power driver further comprising: a pulse amplitude selector, connected to a power source and receiving said selection signals SX and SY from said amplitude modulation unit to determine the amplitude of output pulses from said power source; and two power stages, connected respectively to said pulse amplitude selector and receiving said output pulses DN and DP from said differential pulse generator and outputting a pulse voltage VDN and a pulse voltage VDP.