Patent ID: 7038534
Filing Date: 2006-05-02
Classification: H03F

Abstract:
1. A class D audio amplifier without feedback loop containing a supply voltage source ( 8 ), an amplifier low-pass filter ( 14 ), a power stage ( 2 ) controlled by a pulse width modulated signal, a saw-shaped voltage generator ( 4 ) and a comparator ( 3 ), to one of which inputs an audio signal is sent, while its second input is connected to the adder ( 6 ) of the compensation circuit of supply voltage influence on the output audio signal, to which a voltage from a reference voltage source is sent, characterized in that a low-pass filter ( 9 ) and a high-pass filter ( 10 ) are connected to the supply voltage source ( 8 ), and the reference voltage source ( 12 ) is connected to an inverting circuit ( 11 ), whose input is connected to the low-pass filter ( 2 ) output, while the high-pass filter ( 10 ) output and the output of the inverting circuit ( 11 ) are connected to a multiplier ( 7 ), whose output is connected to the input of another multiplier ( 5 ), whose second input is connected to the saw-shaped voltage generator ( 4 ), and the multiplier ( 5 ) output is connected to one input of the adder ( 6 ), whose second input is connected to the saw-shaped voltage generator ( 4 ).