Class D amplifier and electronic devices including the same

Patent metadata

Field	Value
Publication number	US-9825600-B2
Application number	US-201414540855-A
Country	US
Kind code	B2
Filing date	Nov 13, 2014
Priority date	Aug 29, 2014
Publication date	Nov 21, 2017
Grant date	Nov 21, 2017

Abstract

An electronic device includes a waveform generator, a comparator, and an amplifier. The waveform generator receives a voltage from a power supply to the electronic device and outputs a voltage waveform signal. The comparator compares an input signal and the voltage waveform signal to output a first pulse-width-modulated signal. The amplifier receives the first pulse-width-modulated signal and outputs a second pulse-width-modulated signal.

First claim

What is claimed is:

1. An electronic device, comprising:
a power supply;
a sampling circuit that includes a filter circuit that receives a voltage of the power supply and outputs a filtered voltage, and a voltage divider circuit that receives the filtered voltage and outputs a voltage divided version of the filtered voltage as an output of the sampling circuit;
a waveform generator that receives the output voltage of the sampling circuit and outputs a voltage waveform signal based on the output voltage of the sampling circuit;
a comparator that compares an input signal and the voltage waveform signal to output a first pulse-width-modulated signal; and
an amplifier that receives the first pulse-width-modulated signal and outputs a second pulse-width-modulated signal.

2. The electronic device of claim 1 , wherein the voltage waveform signal comprises a non-sinusoidal wave signal that serves as a negative feedback control signal to the electronic device.

3. The electronic device of claim 1 , further comprising:
a second filter circuit that receives the second pulse-width-modulated signal from the amplifier and outputs an amplified signal.

4. The electronic device of claim 3 , wherein the waveform generator comprises a non-sinusoidal waveform generator that generates the voltage waveform signal based on the voltage.

5. The electronic device of claim 4 , wherein the sampling circuit outputs a sampled voltage signal to the waveform generator.

6. The electronic device of claim 1 , wherein the voltage divider circuit comprises a plurality of resistors connected in series.

7. The electronic device of claim 1 , wherein when the voltage from the power supply rises, an amplitude of the voltage waveform signal increases and causes the comparator to decrease a duty cycle of the first pulse-width-modulated signal.

8. A method, comprising:
filtering a voltage of a power supply circuit to thereby generate a filter voltage;
dividing the filtered voltage to thereby generate a filtered-divided voltage;
generating, by a waveform generator of an electronic device, a voltage waveform signal based on the filtered-divided voltage;
comparing, by a comparator of the electronic device, an input signal and the voltage waveform signal to output a first pulse-width-modulated signal;
receiving, by an amplifier of the electronic device, the first pulse-width-modulated signal; and
outputting, by the amplifier, a second pulse-width-modulated signal.

9. The method of claim 8 , wherein the voltage waveform signal comprises a non-sinusoidal wave signal that serves as a negative feedback control signal to the electronic device.

10. The method of claim 8 , further comprising:
receiving, by a second filter circuit of the electronic device, the second pulse-width-modulated signal from the amplifier and outputting an amplified signal.

11. The method of claim 8 , wherein the waveform generator is a non-sinusoidal waveform generator.

12. The method of claim 11 , further comprising:
receiving, by a sampling circuit, the voltage from the power supply and outputting a sampled voltage signal to the waveform generator.

13. The method of claim 8 , further comprising:
decreasing, by the comparator, a duty cycle of the first pulse-width-modulated signal when the voltage from the power supply increases.

14. The method of claim 8 , further comprising:
increasing, by the comparator, a duty cycle of the first pulse-width-modulated signal when the voltage from the power supply decrease.

15. A system, comprising:
a class-D amplifier directly connected to a power supply, the class-D amplifier comprising:
a sampling circuit that includes a filter circuit that receives a voltage of the power supply and outputs a filtered voltage, and a voltage divider circuit that receives the filtered voltage and outputs a voltage divided version of the filtered voltage as an output of the sampling circuit;
a waveform generator that receives the output voltage of the sampling circuit and outputs a voltage waveform signal based on the output voltage of the sampling circuit; and
a comparator that compares an input signal and the voltage waveform signal to output a first pulse-width-modulated signal,
wherein the voltage waveform signal comprises a non-sinusoidal wave signal that serves as a negative feedback control signal to the class-D amplifier.

16. The system of claim 15 , wherein the class-D amplifier receives the first pulse-width-modulated signal and outputs a second pulse-width-modulated signal.

17. The system of claim 15 , wherein the waveform generator is a non-sinusoidal waveform generator, and wherein the system does not comprise an integrator in a feedback loop that generates the negative feedback control signal.

18. The system of claim 15 , wherein:
when the voltage from the power supply increases, an amplitude of the voltage waveform signal increases and causes the comparator to decrease a duty cycle of the first pulse-width-modulated signal; and
when the voltage from the power supply decreases, the amplitude of the voltage waveform signal decreases and causes the comparator to increase the duty cycle of the first pulse-width-modulated signal.

Assignees

• Hisense Electric Co Ltd
• Hisense Usa Corp
• Hisense Int Co Ltd

Inventors

• Sun Xuebin
• Liu Jin

Classifications

• H03F2203/45594

  the IC comprising one or more resistors, which are not biasing resistor · CPC title

• H03F3/217 Primary

  Class D power amplifiers; Switching amplifiers · CPC title

• H03F3/245

  with semiconductor devices only · CPC title

• H03F1/0222

  by using a signal derived from the input signal · CPC title

• H03F2200/78

  A comparator being used in a controlling circuit of an amplifier · CPC title