Amplifier circuit audio circuit and electronic device
View Patent ↗An amplifier circuit which, includes a first input for receiving a first input signal and a second input for receiving a second input signal. A first amplifier section is connected to the first input and the second input is present. The first amplifier section can combine the first signal and the second signal into a first combined signal, the first amplifier being connected to a first output, for outputting the first combined signal. A second amplifier section is connected to the first input and the second input, for combining the first signal and the second signal into a second combined signal, the second amplifier being connected to a second output, for outputting the second combined signal. A common mode section is connected to the first input and the second input, for generating a common mode signal based on a combination of the first signal and the second signal and outputting the common mode signal at a common output connected to the common mode amplifier. The first combined signal, the second combined signal and the common mode signal satisfy the condition that combining the first combined signal and the common mode signal results in a signal with an amplitude proportional to the amplitude of the first input signal and combining the second combined signal and the common mode signal results in a signal with an amplitude proportional to the amplitude of the second input signal.
1. An amplifier circuit, comprising:
a first input for receiving a first input signal;
a first amplifier connected to said first input for outputting a first amplified signal based upon the first input signal;
a second input for receiving a second input signal;
a second amplifier connected to said second input for outputting a second amplified signal based upon the second input signal;
a first combiner section connected to said first amplifier and said second amplifier, for combining said first amplified signal and said second amplified signal into a first combined signal, said first combiner section being connected to a first output, for outputting said first combined signal;
a second combiner section connected to said first amplifier and said second amplifier, for combining said first amplified signal and said second amplified signal into a second combined signal, said second combiner section being connected to a second output, for outputting said second combined signal; and
a common mode section connected to said first amplifier and said second amplifier, for generating a common mode signal based on a combination of said first amplified signal and said second amplified signal and outputting said common mode signal at a common output connected to said common mode section,
wherein the first combined signal, the second combined signal and the common mode signal satisfy the condition that combining the first combined signal and the common mode signal results in a third amplified signal with an amplitude proportional to the amplitude of the first input signal and combining the second combined signal and the common mode signal results in a fourth amplified signal with an amplitude proportional to the amplitude of the second input signal.
2. An amplifier circuit as claimed in claim 1 , wherein the first combined signal, the second combined signal and the common mode signal satisfy the condition that superimposing the first combined signal on the common mode signal or vice versa results in a signal with an amplitude proportional to the amplitude of the first input signal and superimposing the second combined signal on the common mode signal or vice versa results in a signal with an amplitude proportional to the amplitude of the second input signal.
3. An amplifier circuit as claimed in claim 1 , wherein at least one of said sections comprises:
a combining section connected to said first amplifier and to said second amplifier, for performing a superposition of said first input signal and said second input signal to obtain a combined signal.
4. An amplifier circuit as claimed in claim 1 , wherein:
said first output and said common output are connectable to a first transducer for converting said third amplified signal into a first acoustic signal and said second output and said common output are connectable to a second transducer for converting said fourth amplified signal into a second acoustic signal.
5. An amplifier circuit as claimed in claim 1 , wherein said first input signal and said second input signal are stereo audio signals.
6. An amplifier circuit as claimed in claim 1 , wherein at least one of said amplifiers includes a switched amplifier, wherein a switched amplifier includes a class D amplifier.
7. An amplifier circuit as claimed in claim 1 , wherein at least two of said first combiner section, said second combiner section and said common mode section are similar.
8. An amplifier circuit as claimed in claim 1 , including a first connector for connecting said first output and said common mode output of said amplifier circuit to a first load and a second connector for connecting said second output and said common mode output to a second load.
9. An amplifier circuit as claimed in claim 8 , wherein said first load and said second load are loudspeakers.
10. An amplifier circuit as claimed in claim 8 , including a multi-pole jack connector having at least three poles of which a first pair of poles forms said first connector and a second pair of poles forms said second connector.
11. An audio circuit for a set of at least two loudspeakers, comprising:
a signal processing unit having an input for receiving at least one audio signal, a first signal output for outputting a first processed audio signal and a second signal output for outputting a second processed audio signal; and
an amplifier circuit as claimed in claim 1 , with said first input of said amplifier circuit connected to said first signal output of said signal processing unit and with said second input of said amplifier circuit connected to said second signal output of said signal processing unit.
12. An electronic device including: a source of audio signals and an audio circuit as claimed in claim 11 .
13. An amplifier circuit as claimed in claim 2 , wherein at least one of said sections comprises:
a combining section connected to said first amplifier and to said second amplifier, for performing a superposition of said first input signal and said second input signal to obtain a combined signal.
14. An amplifier circuit as claimed in claim 2 , wherein:
said first output and said common output are connectable to a first transducer for converting said third amplified signal into a first acoustic signal and said second output and said common output are connectable to a second transducer for converting said fourth amplified signal into a second acoustic signal.
15. An amplifier circuit as claimed in claim 3 , wherein:
said first output and said common output are connectable to a first transducer for converting said third amplified signal into a first acoustic signal and said second output and said common output are connectable to a second transducer for converting said fourth amplified signal into a second acoustic signal.
16. An amplifier circuit as claimed in claim 2 , wherein said first input signal and said second input signal are stereo audio signals.
17. An amplifier circuit as claimed in claim 3 , wherein said first input signal and said second input signal are stereo audio signals.
18. An amplifier circuit as claimed in claim 4 , wherein said first input signal and said second input signal are stereo audio signals.
19. An amplifier circuit as claimed in claim 2 , wherein at least one of said amplifiers includes a switched amplifier.
20. An amplifier circuit as claimed in claim 3 , wherein at least one of said amplifiers includes a switched amplifier, wherein a switched a includes a class D amplifier.