D-class power amplifier with electric power regeneration function

• US 6,710,653 B2
• Filed: 05/16/2002
• Issued: 03/23/2004
• Est. Priority Date: 05/17/2001
• Status: Expired due to Fees

• Current Assignee: Pioneer Corporation
• Original Assignee: Pioneer Corporation
• Inventors: Honda, Jun, Kawamoto, Tsutomu
• Primary Examiner(s): Mottola, Steven J.
• Application Number:
  US10/146,131
• Publication Number:
  US 20020180524A1
• Time in Patent Office: 677 Days
• Field of Search: 330/10, 330/207.A, 330/251, 330/304, 381/120
• US Class Current: 330/207.00A
• CPC Class Codes: H03F 3/217 Class D power amplifiers; Switching amplifiers

Abstract

A D-class power amplifier of two channels in which an increase in power voltage due to a regenerative current is prevented and a high efficiency in utilization of electric power is attained. Two D-class power amplifying circuits included in the D-class power amplifier of the two channels are constructed by opposite phases. A preprocess is performed only to low frequency components of input signals so that they have a substantially equal amplitude in the two channels, and the resultant low frequency components are supplied to the D-class power amplifying circuits, respectively. The other ends of loads connected to the D-class power amplifying circuits are connected to a neutral potential point of the power voltage.

Claims

1. A D-class power amplifier for supplying an amplification signal obtained by amplifying two input signals to two loads which are mutually connected at one end of each load, comprising:

two D-class power amplifying circuits having output terminals connected to the other ends of said two loads, respectively;

a preprocessing circuit for performing a predetermined preprocess to said two input signals and supplying the processed signals to said two D-class power amplifying circuits; and

a power supply circuit for supplying an electric power to said two D-class power amplifying circuits,

wherein one of said two D-class power amplifying circuits executes an anti-phase power amplifying process and the other of said two D-class power amplifying circuits executes an in-phase power amplifying process,

said preprocessing circuit executes a process for equalizing amplitudes of the two input signals in a low frequency band, and

a node of said two loads is connected to a neutral potential point of an output voltage from said power supply circuit.

2. The D-class power amplifier according to claim 1, wherein said preprocessing circuit comprises:

two high pass filters for extracting high frequency components included in said two input signals of two channels respectively;

a first signal adding circuit for adding said two input signals of said two channels;

a low pass filter which has a same cut-off frequency as that of said two high pass filters and extracts low frequency components included in an output of said first signal adding circuit; and

two second signal adding circuits for adding an output of said low pass filter to each of outputs of said two high pass filters of said two channels respectively, and

wherein each output from said two second signal adding circuits is supplied to each of said two D-class power amplifying circuits.

3. The D-class power amplifier according to claim 1, wherein said power supply circuit has output voltages of positive and negative polarities, and the neutral potential point of said output voltages is a grounding potential.

4. The D-class power amplifier according to claim 2, wherein said power supply circuit has output voltages of positive and negative polarities, and the neutral potential point of said output voltages is a grounding potential.