Stereo/monaural switching circuit and integrated circuit having the same
AssigneeYamaha Corporation
InventorHiroyuki Toda
Life of this patent
Estimating the term…
Abstract
An adder mixes an L-channel sound signal and an R-channel sound signal with each other and then outputs a mixed signal. A switching unit performs a switching operation such that, if power is being supplied to loudspeaker amplifiers, the L-channel sound signal and the R-channel sound signal are respectively supplied to the loudspeaker amplifiers, and if power is not being supplied to the loudspeaker amplifier, an output signal of the adder is supplied to the loudspeaker amplifier. A power down control unit forces a loudspeaker amplifier to which power is not supplied and a preamplifier for driving the loudspeaker amplifier to be in a power-down state.
Claims12
A stereo/monaural switching circuit comprising:
- first and second loudspeaker amplifiers that drive loudspeakers, respectively;
- a determination unit that determines whether or not power is being supplied to at least the second loudspeaker amplifier;
- a mixing unit that mixes a first-channel sound signal and a second-channel sound signal with each other and outputs a mixed signal;
- a switching unit that performs a switching operation with respect to a transmission path of a sound signal so that, when the determination unit determines that power is being supplied to the second loudspeaker amplifier, the first-channel sound signal and the second-channel sound signal are respectively supplied to the first loudspeaker amplifier and the second loudspeaker amplifier, and when the determination unit determines that power is not being supplied to the second loudspeaker amplifier, an output signal of the mixing unit is supplied to the first loudspeaker amplifier;
- and
- a power down control unit that, if the determination unit determines that power is not being supplied to the second loudspeaker amplifier, forces the second loudspeaker amplifier and a circuit for driving the second loudspeaker amplifier to be in a power-down state.
A stereo/monaural switching circuit comprising:
- first and second loudspeaker amplifiers that drive loudspeakers, respectively;
- a determination unit that determines whether or not power is being supplied to each of the first and second loudspeaker amplifiers;
- a mixing unit that mixes a first-channel sound signal and a second-channel sound signal with each other and outputs a mixed signal;
- a switching unit that performs a switching operation with respect to a transmission path of a sound signal so that, when the determination unit determines that power is being supplied to both the first and second loudspeaker amplifiers, the first-channel sound signal and the second-channel sound signal are respectively supplied to the first and second loudspeaker amplifiers, and when the determination unit determines that power is being supplied to only one of the first and second loudspeaker amplifiers, an output signal of the mixing unit is supplied to the only one loudspeaker amplifier to which power is being supplied;
- and
- a power down control unit that, when the determination unit determines that power is not being supplied to the first or second loudspeaker amplifier, forces the corresponding loudspeaker amplifier to which power is not being supplied and a circuit for driving the corresponding loudspeaker amplifier to be in a power-down state.
Dependencies are inferred from the claim text.