Class-D amplifier of BTL output type using filter coil and low-pass filter

A class-D amplifier of a Bridged Tied Load output type, comprising:

• a pulse-width modulator for producing pulse-width modulated signals in response to input signals;
• a first driver for amplifying the pulse-width modulated signals with a first polarity;
• a second driver for amplifying the pulse-width modulated signals with a second polarity;
• a first low-pass filter coupled to the first driver to drive a load with the first polarity;
• and
• a second low-pass filter coupled to the second driver to drive the load with the second polarity,
• wherein the first low-pass filter having a first coil and the second low-pass filter having a second coil, each of the first coil and the second coil having equal inductance, differing from each other in winding directions and being arranged adjacent to each other along axial directions thereof in a single package, wherein a winding start portion of the first coil and a winding end portion of the second coil of the coils are respectively connected with terminals arranged at the same side of the single package.

A class-D amplifier of a Bridged Tied Load output type, comprising:

• a pulse-width modulator for producing pulse-width modulated signals in response to input signals;
• a first driver for amplifying the pulse-width modulated signals with a first polarity;
• a second driver for amplifying the pulse-width modulated signals with a second polarity;
• a first low-pass filter coupled to the first driver to drive a load with the first polarity;
• and
• a second low-pass filter coupled to the second driver to drive the load with the second polarity,
• wherein the first and second low-pass filters contain coils, each coil having equal inductance, differing from each other in winding directions and being arranged adjacent to each other along axial directions thereof in a single package, wherein a magnetic shield is interposed between the adjacent coils.

A class-D amplifier of a Bridged Tied Load output type, comprising:

• a pulse-width modulator for producing pulse-width modulated signals in response to input signals;
• a first driver for amplifying the pulse-width modulated signals with a first polarity;
• a second driver for amplifying the pulse-width modulated signals with a second polarity;
• a first low-pass filter coupled to the first driver to drive a load with the first polarity;
• and
• a second low-pass filter coupled to the second driver to drive the load with the second polarity,
• wherein the first and second low-pass filters contain coils, each coil having equal inductance, which differ from each other in winding directions and are arranged adjacent to each other along axial directions thereof in a single package and are respectively wound about a single core along the axial direction in the single package, and,
• wherein a magnetic shield is interposed between the adjacent coils.