# US 7,411,447 B2 · Dynamic pulse width modulation amplifiers

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 7,411,447 B2
- Document ID: US7411447B2
- Status: Granted
- Kind: B2
- Application number: 11/331,095
- Filed: 2006-01-13
- Published: 2006-07-20
- Granted: 2008-08-12
- Earliest claimed: 2005-01-17
- Assignees: Biforst Technology Inc.
- Inventors: Lin-Jing Chang
- Web page: https://patentgrep.com/patent/US7411447B2

## CPC

- H03F 3/217: Class D power amplifiers; Switching amplifiers
- H03F: AMPLIFIERS

## Abstract

A dynamic pulse width modulation (PWM) amplifier comprising an input terminal, a dynamic PWM controller, a power stage, a low pass filter, and an output terminal. The input terminal receives an input signal. The dynamic PWM controller transforms the N-bit input signal sampled by a sampling frequency to a 1-bit PWM signal. The power stage receives and outputs the 1-bit PWM signal. The low pass filter receives and outputs the 1-bit PWM signal. The 1-bit PWM signal is used to drive the power stage and the low pass filter. The output terminal outputs the 1-bit PWM signal. The dynamic PWM amplifier is characterized in the dynamic PWM amplifier uses a register array to store the input signal processed immediately in each frame, regroups the input signal, and outputs the regroup signal, so that the 1-bit PWM signal is changed according to the input signal.

## Claims

### Claim 1

A dynamic pulse width modulation (PWM) amplifier, comprising:
an input terminal receiving an input signal;
a dynamic PWM controller transforming an N-bit input signal sampled by a sampling frequency to a 1-bit PWM signal, wherein N is an integer greater than or equal to one;
a power stage receiving and outputting the 1-bit PWM signal;
a low pass filter receiving and outputting the 1-bit PWM signal from the power stage, wherein the 1-bit PWM signal is used to drive the power stage and the low pass filter; and
an output terminal outputting the 1-bit PWM signal;
wherein the dynamic PWM amplifier is characterized in the dynamic PWM amplifier uses a register array to store the input signal processed immediately in each frame, regroups the input signal, and outputs the regroup input signal, so that the 1-bit PWM signal is changed according to the input signal.

### Claim 2 (depends on 1)

The dynamic PWM amplifier as claimed in claim 1, wherein the dynamic PWM amplifier is a low-voltage audio frequency amplifier.

### Claim 3 (depends on 1)

The dynamic PWM amplifier as claimed in claim 1, wherein the dynamic PWM amplifier is a low-voltage power amplifier.

### Claim 4 (depends on 1)

The dynamic PWM amplifier as claimed in claim 1, wherein the dynamic PWM amplifier is a high-voltage power amplifier.

### Claim 5 (depends on 1)

The dynamic PWM amplifier as claimed in claim 1, wherein the dynamic PWM amplifier is a DC power amplifier.