Patent Publication Number: US-2013236026-A1

Title: Circuit capable of reducing audio interference

Description:
BACKGROUND 
     1. Technical Field 
     The present disclosure relates to audio signal processing technology and, particularly, to a circuit capable of reducing audio interference. 
     2. Description of the Related Art 
     Audio interference affects the performance of electronic devices. A common mode inductor may be connected to an output port of a circuit of the electronic device to reduce the audio interference. However, the common mode inductor increases manufacturing cost of the electronic device. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
       The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the disclosure. Moreover, in the drawing, like reference numerals designate corresponding parts throughout the several views. 
       The FIGURE is a circuit diagram of a circuit for reducing audio interference in accordance with an exemplary embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     Referring to the FIGURE, a circuit  10  capable of reducing audio interference is employed in a multimedia electronic device. The circuit  10  includes an audio output circuit  11  and an earphone output circuit  12 . The audio output circuit  11  includes an audio interface  110  used to connect an electronic device (not shown), such as a sound generating device, for outputting audio signals to the electronic device. The earphone output circuit  12  includes an earphone interface  120  used to connect an earphone (not shown) for outputting audio signals to the earphone. 
     The audio output circuit  11  further includes a first capacitor C 1  and a second capacitor C 2 . The audio interface  110  includes a right port R_Out 1 , a left port L_Out  1 , and a ground port GND 1 . A first terminal of the first capacitor C 1  is connected to the left port L_Out  1 , and a second terminal of the first capacitor C 1  is grounded. A first terminal of the second capacitor C 2  is connected to the right port R_Out 1 , and a second terminal of the second capacitor C 2  is grounded. The first capacitor C 1  and the second capacitor C 2  are configured to remove different types of well-known audio interference. 
     The earphone output circuit  12  includes a third capacitor C 3 , a fourth capacitor C 4 , a first inductance L 1 , and a second inductance L 2 . The earphone interface  120  includes an earphone detecting port EAR_DET, a right port R_Out 2 , a left port L_Out 2 , and a ground port GND 2 . A first terminal of the inductance L 1  is connected to a first power input port  121 , a second terminal of the inductance L 1  and a first terminal of the third capacitor C 3  are both connected to the right port R_Out 2 , and a second terminal of the third capacitor C 3  is grounded. A first terminal of the first inductance L 1  is connected to a second power input port  122 , a second terminal of the first inductance L 1  and a first terminal of the fourth capacitor C 4  are both connected to the left port L_Out 2 , and a second terminal of the fourth capacitor C 4  is grounded. The first inductance L 1  and the third capacitor C 3  are configured to remove audio interference, as are the second inductance L 2  and the fourth capacitor C 4 . 
     In the embodiment, the audio output circuit  11  and the earphone output circuit  12  further include other elements which are used in audio output circuits and earphone output circuits of related art and will not be discussed here. 
     It is understood that the present disclosure may be embodied in other forms without departing from the spirit thereof. Thus, the present examples and embodiments are to be considered in all respects as illustrative and not restrictive, and the disclosure is not to be limited to the details given herein.