| US 7,586,370 B2 | ||
| Class D amplifier | ||
| Morito Morishima, Fukuroi (Japan) | ||
| Assigned to Yamaha Corporation, Hamamatsu-shi (Japan) | ||
| Filed on Dec. 11, 2008, as Appl. No. 12/316,268. | ||
| Application 12/316268 is a division of application No. 11/376580, filed on Mar. 15, 2006. | ||
| Claims priority of application No. 2005-079062 (JP), filed on Mar. 18, 2005; application No. 2005-298562 (JP), filed on Oct. 13, 2005; and application No. 2006-054716 (JP), filed on Mar. 01, 2006. | ||
| Prior Publication US 2009/0102557 A1, Apr. 23, 2009 | ||
| Int. Cl. H03F 3/217 (2006.01) | ||
| U.S. Cl. 330—251 [330/10; 330/207 A] | 4 Claims |
| 1. A class D amplifier comprising:
a first PWM circuit for receiving input data and converting the input data to a first PWM signal;
a power amplifier for amplifying the first PWM signal;
a low pass filter for passing low frequency components of the amplified first PWM signal to a load;
a second PWM circuit for converting the input data to a second PWM signal;
a first filter for only passing wanted frequency components of the second PWM signal;
a second filter for only passing wanted frequency components of the amplified first PWM signal from the power amplifier;
a difference detector for detecting a difference between a first filter output signal output from the first filter and a second
filter output signal output from the second filter;
a conversion unit for converting the detected signal difference to digital data; and
a feedback unit for feeding back the converted digital data to an input of the first PWM circuit.
|