close

Вход

Забыли?

вход по аккаунту

?

JP2004056807

код для вставкиСкачать
Patent Translate
Powered by EPO and Google
Notice
This translation is machine-generated. It cannot be guaranteed that it is intelligible, accurate,
complete, reliable or fit for specific purposes. Critical decisions, such as commercially relevant or
financial decisions, should not be based on machine-translation output.
DESCRIPTION JP2004056807
An object of the present invention is to provide a balanced output type stereo signal output
device which is not damaged even when connected to a 3-terminal headphone. SOLUTION: An
operational amplifier 1 for inverting and amplifying an input signal S, an operational amplifier 2
for inverting and amplifying an input signal S, and an operational amplifier 3 for inverting and
outputting an input signal S And the operational amplifier 4 for inverting and amplifying the
input signal S, and the operational amplifier 2 and the reverse phase output terminal 10 are
connected via the resistor R1 having a resistance value equal to that of the voice coil resistance
component R3 of the headphone. A balanced output type stereo signal output device in which the
operational amplifier 4 and the negative phase output terminal 12 are connected via a resistor
R2 having a resistance value equal to the voice coil resistance component R4 of headphones.
[Selected figure] Figure 1
Signal output device and stereo device
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a
signal output device (for example, an amplifier) for outputting an audio signal and a stereo
device. 2. Description of the Related Art Most amplifiers of audio equipment currently on the
market are analog amplifiers that amplify and output analog signals. The configuration of a
typical analog amplifier is shown in FIG. The inverting input terminal of the operational amplifier
23 is grounded via the resistor R5 and connected to the output terminal of the operational
amplifier 23 via the resistor R6. The power supply voltage VCC is supplied to the operational
amplifier 23. Then, the analog audio signal Vi input to the non-inverting input terminal of the
operational amplifier 23 is amplified and output. Negative feedback is applied to the analog
amplifier of FIG. 6, and even if the power supply voltage VCC fluctuates, the influence of the
fluctuation of the power supply voltage VCC on the output voltage VO can be reduced. Therefore,
10-05-2019
1
the influence of the fluctuation of the power supply voltage VCC on the sound quality is reduced.
The connection node between the output terminal of the operational amplifier 23 and the
resistor R6 is connected to the output terminal 24 via the coupling capacitor C1. The coupling
capacitor C1 removes the DC component of the output signal of the operational amplifier 23.
That is, the coupling capacitor C1 removes low frequency components caused by the fluctuation
of the power supply voltage VCC included in the output signal of the operational amplifier 23. As
described above, most of the amplifiers of audio devices on the market are analog amplifiers, but
it is considered that digital amplifiers will be changed to analog amplifiers in the future. For
example, in the electric circuit of the MD reproducing apparatus, all circuits that can be digitized
are configured by digital circuits. The circuit that can not be digitized at present is only an
amplifier that outputs an audio signal to an audio output means such as headphones. That is, this
amplifier is the only analog circuit. If this amplifier is digitized, all the circuits become digital
circuits, the manufacture of the LSI for the MD reproducing device becomes easy, and the cost
reduction of the MD reproducing device can be achieved. SUMMARY OF THE INVENTION
However, when amplifying a digital signal, negative feedback can not be applied because the
input signal is a digital signal. Therefore, in the digital amplifier, when the fluctuation of the
power supply voltage VCC occurs, the influence is directly applied to the output signal, and the
sound quality is deteriorated.
SUMMARY OF THE INVENTION In view of the above problems, it is a first object of the present
invention to provide a digital signal output device which is not affected by fluctuations in power
supply voltage. When a digital amplifier that is not affected by fluctuations in power supply
voltage is implemented by means described later, four output terminals are required to output
two channels of stereo. When headphones are connected to an amplifier having such four output
terminals, a four-terminal headphone having a plug consisting of four terminals 28, 29, 30, and
31 as shown in FIG. 7 is used. However, in the market, a three-terminal headphone having a plug
consisting of three terminals 32, 33 and 34 as shown in FIG. 8 is the majority. For this reason, it
is desirable to be able to use three-terminal headphones as well. However, if this three-terminal
headphone is connected to a digital amplifier that is not affected by the fluctuation of the power
supply voltage having the four output terminals described above, the digital amplifier may be
damaged or a large crosstalk may occur. Similarly, in a balanced output type analog amplifier
that outputs two channels of stereotypes, when a three-terminal headphone is connected, the
analog amplifier may be damaged or a large crosstalk may occur. In view of the above problems,
it is a second object of the present invention to provide a balanced output type signal output
device and a stereo device that outputs two channels of stereotypes that are not damaged even
when connected to a three-terminal headphone. I assume. In order to achieve the above first
object, in a digital signal output device according to the present invention, positive phase
amplification means for non-inverting amplifying an input signal and outputting the same It is
connected to the output side of the negative phase amplification means, a pair of amplification
means consisting of negative phase amplification means for inverting and amplifying the signal
10-05-2019
2
and outputting it, a first output terminal connected to the output side of the positive phase
amplification means, and A second output terminal, and a binary quantization signal is used as an
input signal to be input to the amplification means. In order to achieve the above second object,
in a signal output apparatus according to the present invention, a first positive phase
amplification means and a second positive phase amplification means for non-inverting
amplifying an input signal and outputting the same First and second reverse phase amplification
means for inverting and amplifying an input signal and outputting the first negative phase output
terminal connected to the output side of the first positive phase amplification means; A second
positive phase output terminal connected to the output side of the second positive phase
amplification means, a first negative phase output terminal connected to the output side of the
first negative phase amplification means, and And a second negative phase output terminal
connected to the output side of the second negative phase amplification means, wherein the first
positive phase amplification means and the first negative phase amplification means produce the
first input signal. And the second positive phase amplification means and the second negative
phase amplification means receive a second input signal, and the first positive phase
amplification means The first positive phase output terminal is connected via a first resistor, and
the second positive phase amplification means and the second positive phase output terminal are
connected via a second resistor. Make it
Then, a three-terminal plug, a third resistor provided between the first and third terminals of the
three-terminal plug, and a second resistor and a third terminal of the three-terminal plug. When
the audio output means having the fourth resistor provided in the second output terminal is
connected, the first negative phase output terminal and the first terminal of the three-terminal
plug are connected, and the second negative phase output is connected The terminal and the
second terminal of the three-terminal plug are connected, and the first positive phase output
terminal, the second positive phase output terminal, and the third terminal of the three-terminal
plug are connected Do. In order to achieve the above second object, in a signal output apparatus
according to the present invention, a first positive phase amplification means and a second
positive phase amplification means for non-inverting amplifying an input signal and outputting
the same First and second reverse phase amplification means for inverting and amplifying an
input signal and outputting the first negative phase output terminal connected to the output side
of the first positive phase amplification means; A second positive phase output terminal
connected to the output side of the second positive phase amplification means, a first negative
phase output terminal connected to the output side of the first negative phase amplification
means, and And a second negative phase output terminal connected to the output side of the
second negative phase amplification means, wherein the first positive phase amplification means
and the first negative phase amplification means produce the first input signal. And the second
positive phase amplification means and the second negative phase amplification means receive a
second input signal, and the first negative phase amplification means The first negative-phase
output terminal is connected via a first resistor, and the second negative-phase amplifier means
10-05-2019
3
and the second negative phase output terminal are connected via a second resistor. Make it Then,
a three-terminal plug, a third resistor provided between the first and third terminals of the threeterminal plug, and a second resistor and a third terminal of the three-terminal plug. The first
positive-phase output terminal and the first terminal of the three-terminal plug are connected,
and the second positive-phase output is connected The terminal and the second terminal of the
three-terminal plug are connected, and the first negative-phase output terminal, the second
negative-phase output terminal, and the third terminal of the three-terminal plug are connected
Do. Also, a three-terminal plug, a third resistor provided between the first terminal and the third
terminal of the three-terminal plug, and second and third terminals of the three-terminal plug.
And, when connected, an audio output means having a fourth resistor provided therebetween,
outputting a voltage obtained by amplifying the first input signal to both ends of the third
resistor; The amplified voltage of the signal is output to both ends of the fourth resistor.
Also, a three-terminal plug, a third resistor provided between the first terminal and the third
terminal of the three-terminal plug, and a second terminal and a third terminal of the threeterminal plug And the second output terminal connected to the third terminal of the threeterminal plug is shorted to have substantially the same potential when the audio output means
having the fourth resistor provided therebetween is connected. Is desirable. Also, a three-terminal
plug, a third resistor provided between the first terminal and the third terminal of the threeterminal plug, and a second terminal and a third terminal of the three-terminal plug When the
audio output means having the fourth resistor provided therebetween is connected, the
resistance value of the first resistor and the resistance value of the third resistor are substantially
equal, and It is desirable that the resistance value and the resistance value of the fourth
resistance be approximately equal. The first input signal and the second input signal may be
binary quantization signals. Further, the first resistor and the second resistor may be variable
resistors. Further, each of the first resistor and the second resistor may be a resistor unit
including a plurality of resistors and switching means for switching the connection state of the
plurality of resistors. Also, a four-terminal plug, a third resistor provided between the first
terminal and the third terminal of the four-terminal plug, and a second terminal and a fourth
terminal of the three-terminal plug And a fourth resistor provided between the first and second
terminals, the first positive-phase output terminal and the first terminal of the four-terminal plug
being connected when the second output terminal is connected. The positive phase output
terminal and the second terminal of the four terminal plug are connected, the first negative
phase output terminal and the third terminal of the four terminal plug are connected, and the
second negative phase output terminal And the fourth terminal of the four-terminal plug are
connected, a voltage obtained by amplifying the first input signal is outputted to both ends of the
third resistor, and a voltage obtained by amplifying the second input signal is Output to both
ends of 4 resistance. In order to achieve the above second object, in the stereo device according
to the present invention, a first positive phase amplification means and a second positive phase
amplification means for non-inverting amplifying an input signal and outputting the same; First
10-05-2019
4
reverse phase amplification means and second reverse phase amplification means for inverting
and amplifying an input signal and outputting the first positive phase output terminal connected
to the output side of the first positive phase amplification means; A second positive phase output
terminal connected to the output side of the second positive phase amplification means; a first
negative phase output terminal connected to the output side of the first negative phase
amplification means; A second negative-phase output terminal connected to the output side of
the negative-phase amplification means of No. 2; and the first positive-phase amplification means
and the first negative-phase amplification means receive a first input signal The second positive
phase amplification means and the second negative phase amplification means input a second
input signal, and the first positive phase amplification means The first positive phase output
terminal is connected via a first resistor, and the second positive phase amplification means and
the second positive phase output terminal are connected via a second resistor. Make it
In order to achieve the above second object, in the stereo device according to the present
invention, a first positive amplification means and a second positive amplification means for noninverting amplifying an input signal and outputting the same; First reverse phase amplification
means and second reverse phase amplification means for inverting and amplifying an input
signal and outputting the first positive phase output terminal connected to the output side of the
first positive phase amplification means; A second positive phase output terminal connected to
the output side of the second positive phase amplification means; a first negative phase output
terminal connected to the output side of the first negative phase amplification means; A second
negative-phase output terminal connected to the output side of the negative-phase amplification
means of No. 2; and the first positive-phase amplification means and the first negative-phase
amplification means receive a first input signal The second positive phase amplification means
and the second negative phase amplification means input a second input signal, and the first
negative phase amplification means The first negative-phase output terminal is connected via a
first resistor, and the second negative-phase amplifier means and the second negative phase
output terminal are connected via a second resistor. Make it An embodiment of the present
invention will be described with reference to the drawings. First, the digital amplifier according
to the first embodiment of the present invention will be described. The configuration of the
digital amplifier of the first embodiment is shown in FIG. A terminal to which the binary
quantization signal S 1 is input is connected to the terminal 16 a of the switch circuit 16. A
terminal to which the analog audio signal S2 is input is connected to the terminal 16b of the
switch circuit 16 via the delta sigma modulation circuit 13. Further, the 16-bit digital signal S3 is
connected to the terminal 16c of the switch circuit 16 via the interpolation circuit 14 and the
delta sigma modulation circuit 15. The terminal 16 d of the switch circuit 16 is connected to the
non-inverted input terminal of the operational amplifier 17 and the inverted input terminal of the
operational amplifier 18. The inverting input terminal of the operational amplifier 17 and the
non-inverting input terminal of the operational amplifier 18 are grounded. The output terminal
of the operational amplifier 17 is connected to the positive phase output terminal 21 via a low
10-05-2019
5
pass filter 19 consisting of a resistor and a capacitor. The output terminal of the operational
amplifier 18 is connected to the negative phase output terminal 22 via a low pass filter 20
consisting of a resistor and a capacitor. The operation of the digital amplifier according to the
first embodiment having such a configuration will be described. The analog audio signal S2 is
converted by the delta sigma modulation circuit 13 into a binary quantized signal. Also, the 16bit digital signal is converted by the interpolation circuit 14 into, for example, a 32-bit digital
signal having a sampling frequency N times the original sampling frequency.
The 32-bit digital signal is converted into a binary quantization signal by the delta sigma
modulation circuit 15. Therefore, the signals input to the terminals 16a, 16b and 16c of the
switch circuit 16 are all binary quantization signals. The switch circuit 16 selects one of the
terminals 16 a to 16 c in response to a control signal from a control circuit (not shown) and
connects it to the terminal 16 d. Thus, the binary quantization signal is input to the operational
amplifiers 17 and 18. Here, the binary quantization signal input to the operational amplifiers 17
and 18 is S [V], the gain of the operational amplifiers 17 and 18 is A, and the power supply
voltage of the operational amplifiers 17 and 18 is VCC [V The fluctuation of the power supply
voltage of the operational amplifiers 17 and 18 is .DELTA.VCC [V]. The operational amplifiers 17
and 18 perform voltage level shift so that the reference potential of the output signal is half the
power supply voltage. Since the operational amplifier 17 non-inverts amplifies the binary
quantization signal and outputs it, the output signal of the operational amplifier 17 is A × S +
(VCC + ΔVCC) / 2 [V]. On the other hand, since the operational amplifier 18 non-inverts
amplifies the binary quantization signal and outputs it, the output signal of the operational
amplifier 18 is A × (−S) + (VCC + ΔVCC) / 2 [V]. The low pass filter circuit 19 removes high
frequency components of the output signal of the operational amplifier 17, and outputs only the
audible range component of the output signal of the operational amplifier 17 to the positive
phase output terminal 21. The low pass filter circuit 20 removes high frequency components of
the output signal of the operational amplifier 18 and outputs only the audible range component
of the output signal of the operational amplifier 18 to the negative phase output terminal 22.
Since the voltage drop in the low pass filter circuits 19 and 20 is very small, it is regarded that
there is no voltage drop. Then, the voltage between the positive phase output terminal 21 and
the negative phase output terminal is {A × S + (VCC + ΔVCC) / 2} − {A × (−S) + (VCC + ΔVCC)
/ 2} [V]. X 2 S [V]. Therefore, the audio signal output from the digital amplifier is not affected by
the fluctuation of the power supply voltage. Of course, the coupling capacitor provided in the
conventional analog amplifier (see FIG. 6) is not required. Next, the case where the amplifier of
the first embodiment described above is applied to a two-channel stereo amplifier will be
described with reference to FIG. The stereo amplifier of FIG. 3 receives a binary quantization
signal SL which is a left channel input signal and a binary quantization signal SR which is a right
channel input signal.
10-05-2019
6
A terminal to which the binary quantization signal SL is input is connected to the non-inversion
input terminal of the operational amplifier 1 and the inversion input terminal of the operational
amplifier 2. The inverting input terminal of the operational amplifier 1 and the non-inverting
input terminal of the operational amplifier 2 are grounded. The output terminal of the
operational amplifier 1 is connected to the left channel positive phase output terminal 9 through
a low pass filter 5 consisting of a resistor and a capacitor. The output terminal of the operational
amplifier 2 is connected to the left channel negative phase output terminal 10 via a low pass
filter 6 consisting of a resistor and a capacitor. A terminal to which the binary quantization signal
SR is input is connected to the non-inverted input terminal of the operational amplifier 3 and the
inverted input terminal of the operational amplifier 4. The inverting input terminal of the
operational amplifier 3 and the non-inverting input terminal of the operational amplifier 4 are
grounded. The output terminal of the operational amplifier 3 is connected to the right channel
positive phase output terminal 11 via a low pass filter 7 consisting of a resistor and a capacitor.
The output terminal of the operational amplifier 4 is connected to the right channel negative
phase output terminal 12 via a low pass filter 8 consisting of a resistor and a capacitor. The
stereo amplifier of such a configuration operates as follows. First, the left channel side will be
described. Since the operational amplifier 1 non-inverts amplifies the binary quantization signal
SL and outputs it, the output signal of the operational amplifier 1 is A × SL + (VCC + ΔVCC) / 2
[V]. On the other hand, since the operational amplifier 2 inverts and amplifies the binary
quantization signal SL and outputs it, the output signal of the operational amplifier 2 is A ×
(−SL) + (VCC + ΔVCC) / 2 [V]. The low pass filter circuit 5 removes high frequency components
of the output signal of the operational amplifier 1 and outputs only the audible range component
of the output signal of the operational amplifier 1 to the left channel positive phase output
terminal 9. The low pass filter circuit 6 removes high frequency components of the output signal
of the operational amplifier 2 and outputs only the audible range component of the output signal
of the operational amplifier 2 to the left channel negative phase output terminal 10. Since the
voltage drop in the low pass filter circuits 5 and 6 is very small, it is considered that there is no
voltage drop. Then, the output signal SL + of the left channel positive phase output terminal 9
becomes A × SL + (VCC + ΔVCC) / 2 [V], and the output signal SL− of the left channel negative
phase output terminal 10 becomes A × (−SL) + (VCC + ΔVCC) ) / 2 [V]. Therefore, the left
channel output audio signal (SL + −SL−) is {A × SL + (VCC + ΔVCC) / 2} − {A × (−SL) + (VCC
+ ΔVCC) / 2} [V], and X 2 SL [V].
As a result, the left channel output audio signal is not affected by the fluctuation of the power
supply voltage. Here, an example of voltage waveforms of the output signal SL + of the left
channel positive phase output terminal 9 and the output signal SL− of the left channel negative
phase output terminal 10 is shown in FIG. The broken line in the figure is the reference potential,
and its value is (VCC + ΔVCC) / 2 [V]. Next, the right channel side will be described. Since the
operational amplifier 3 non-inverts amplifies the binary quantization signal SR and outputs it, the
output signal of the operational amplifier 3 is A × SR + (VCC + ΔVCC) / 2 [V]. On the other
10-05-2019
7
hand, since the operational amplifier 4 inverts and amplifies the binary quantization signal SR
and outputs it, the output signal of the operational amplifier 4 is A × (−SR) + (VCC + ΔVCC) / 2
[V]. The low pass filter circuit 7 removes high frequency components of the output signal of the
operational amplifier 3, and outputs only the audible range component of the output signal of the
operational amplifier 3 to the right channel positive phase output terminal 11. The low pass filter
circuit 8 removes high frequency components of the output signal of the operational amplifier 4
and outputs only the audible range component of the output signal of the operational amplifier 4
to the right channel reverse phase output terminal 12. Since the voltage drop in the low pass
filter circuits 7 and 8 is very small, it is regarded that there is no voltage drop. Then, the output
signal SR + of the right channel positive phase output terminal 11 becomes A × SR + (VCC +
ΔVCC) / 2 [V], and the output signal SR− of the right channel reverse phase output terminal 12
becomes A × (−SR) + (VCC + ΔVCC) ) / 2 [V]. Therefore, the right channel output audio signal
(SR + −SR−) is {A × SR + (VCC + ΔVCC) / 2} − {A × (−SR) + (VCC + ΔVCC) / 2} [V], and X 2
SR [V] is obtained. As a result, the right channel output audio signal is not affected by the
fluctuation of the power supply voltage. Here, an example of voltage waveforms of the output
signal SR + of the right channel positive phase output terminal 11 and the output signal SR− of
the right channel negative phase output terminal 12 is shown in FIG. The broken line in the
figure is the reference potential, and its value is (VCC + ΔVCC) / 2 [V]. A four-terminal
headphone is connected to the output terminal of the stereo amplifier of FIG. Therefore, one end
of the resistor R3 which is a resistance component of the voice coil of the left channel of the
stereo headphone is connected to the left channel positive phase output terminal 9, and the other
end of the resistor R3 is connected to the left channel negative phase output terminal 10 One
end of a resistor R4, which is a resistive component of the voice coil of the right channel of the
headphone, is connected to the right channel positive phase output terminal 11, and the other
end of the resistor R4 is connected to the right channel negative phase output terminal 12.
A × 2 SL [V] is applied to both ends of the resistor R 3, and a sound pressure corresponding to
the left channel output audio signal which is A × 2 SL [V] is generated from the voice coil of the
left channel. Further, A × 2 SR [V] is applied to both ends of the resistor R4, and a sound
pressure corresponding to the right channel output audio signal which is A × 2 SR [V] is
generated from the voice coil of the right channel. As described above, when connecting the fourterminal headphone to the stereo amplifier of FIG. 3, no problem occurs. However, when 3terminal headphones are connected to the stereo amplifier in FIG. 3, the left channel positive
phase output terminal 9 and the right channel positive phase output terminal 11 are connected
or the left channel negative phase output terminal 10 and the right channel negative phase
output The terminal 12 is to be connected. In the following description, it is assumed that the left
channel reverse phase output terminal 10 and the right channel reverse phase output terminal
12 are connected when the three-terminal headphone is connected. The output signal SL− of the
left channel reverse phase output terminal 10 and the output signal SR− of the right channel
reverse phase output terminal 12 have different voltage values (see FIG. 4). Also, in general, the
10-05-2019
8
output resistance of an amplifier that outputs an audio signal to audio output means such as
headphones may be considered to be substantially zero. Therefore, when the left channel reverse
phase output terminal 10 and the right channel reverse phase output terminal 12 are connected,
a large short circuit current is generated between the left channel reverse phase output terminal
10 and the right channel reverse phase output terminal 12. In the worst case, the amplifier is
broken. Also, even if the amplifier is not damaged, a large level of crosstalk occurs because an
intermediate level signal is generated between the output signal SL− of the left channel negative
phase output terminal 10 and the output signal SR− of the right channel negative phase output
terminal 12 It will Therefore, in the amplifier according to the second embodiment of the present
invention, a stereo amplifier is realized in which problems do not occur even if headphones of
three terminals are connected. The amplifier of the second embodiment is shown in FIG. The
same parts as those in FIG. 3 are assigned the same reference numerals and descriptions thereof
will be omitted. A resistor R 1 is provided between the low pass filter 6 and the left channel
negative phase output terminal 10, and a resistor R 2 is provided between the low pass filter 8
and the right channel negative phase output terminal 12. The resistance value of the resistor R1
is equal to the resistance value of the resistor R3, and the resistance value of the resistor R2 is
equal to the resistance value of the resistor R4. Since the three-terminal headphone is connected
to the amplifier of the second embodiment, the left channel reverse phase output terminal 10
and the right channel reverse phase output terminal 12 are connected.
Voltage waveforms of the signals SL +, SL-, SR + and SR- outputted from the output terminal of
the amplifier of the second embodiment, a voltage waveform of the output signal SL- 'of the low
pass filter 6, and an output of the low pass filter 8 The voltage waveform of the signal SR- 'is
shown in FIG. The broken line in the figure is the reference potential, and its value is (VCC +
ΔVCC) / 2 [V]. The output signal SL + of the left channel positive phase output terminal 9 and
the output signal SL− ′ of the low pass filter 6 are signals that differ in phase by 180 °.
Further, since the resistance value of the resistor R1 and the resistance value of the resistor R3
are equal, the potential of the left channel negative phase output terminal 10 becomes an
intermediate potential between the left channel positive phase output terminal 9 and the output
side of the low pass filter 6. Therefore, the output signal SL− of the left channel negative phase
output terminal 10 is (VCC + ΔVCC) / 2 [V]. The output signal SR + of the right channel positive
phase output terminal 11 and the output signal SR− ′ of the low pass filter 8 are signals that
differ in phase by 180 °. Further, since the resistance value of the resistor R2 is equal to the
resistance value of the resistor R4, the potential of the right channel negative phase output
terminal 12 becomes an intermediate potential between the right channel positive phase output
terminal 11 and the output side of the low pass filter 8. Therefore, the output signal SR− of the
right channel reverse phase output terminal 12 becomes (VCC + ΔVCC) / 2 [V]. Since the
potential of left channel reverse phase output terminal 10 and the potential of right channel
reverse phase output terminal 12 are equal, the amplifier is damaged even if left channel reverse
phase output terminal 10 and right channel reverse phase output terminal 12 are connected.
10-05-2019
9
And there is no risk of crosstalk. The left channel output audio signal (SL + −SL−) is A × SL [V],
and the right channel output audio signal (SR + −SR−) is A × SR [V]. Therefore, the amplifier of
the second embodiment is an amplifier that is not affected by the fluctuation of the power supply
voltage, as in the amplifier of the first embodiment. And, of course, no problems occur even if a
4-terminal headphone is connected. When the resistance value of the resistor R1 and the
resistance value of the resistor R3 are not equal or when the resistance value of the resistor R2
and the resistance value of the resistor R4 are not equal, the potential of the left channel reverse
phase output terminal 10 and the right The potential of the channel reverse phase output
terminal 12 does not match. In this case, a short circuit current flows between the left channel
reverse phase output terminal 10 and the right channel reverse phase output terminal 12.
However, since the potential difference between the left channel reverse phase output terminal
10 and the right channel reverse phase output terminal 12 can be made smaller than that of the
amplifier shown in FIG. 3, there is no possibility that the amplifier is damaged.
Also, crosstalk is smaller than that of the amplifier shown in FIG. The resistors R1 and R2 of the
amplifier of the second embodiment may be variable resistors. When the resistors R1 and R2 are
variable resistors, it is possible to correspond to the resistance values of the resistors R3 and R4
which differ depending on the type of three-terminal headphone. Therefore, regardless of the
type of the three-terminal headphone, the potential of the left channel negative phase output
terminal 10 and the potential of the right channel negative phase output terminal 12 can be
equalized, and the occurrence of crosstalk can be prevented. Further, instead of the resistor R1, a
switching circuit for switching the connection state of the plurality of resistors and the resistors
is provided, and a switching circuit for switching the connection state of the plurality of resistors
and the resistors is provided instead of the resistor R2. The same effect as the configuration in
which the resistors R1 and R2 are variable resistors is also produced. As one embodiment of this
configuration, a plurality of resistors having resistance values corresponding to the resistances of
the resistors R3 and R4 which differ depending on the type of three-terminal headphone, and the
switching circuit alternatively selects one resistor from the plurality of resistors In one
embodiment, a plurality of resistors having the same resistance value may be provided, and the
switching circuit may switch the number of resistors connected in parallel to vary the resistance
value of the combined resistor. Although the amplifier according to the second embodiment
described above has a configuration in which a resistor is provided on the reverse phase side, a
resistor may be provided on the positive phase side. In the configuration in which the resistor is
provided on the positive phase side, the jack of the amplifier connected to the headphone plug so
that the left channel positive phase output terminal and the right channel positive phase output
terminal are connected when the 3-terminal headphone is connected The positions of the left
channel positive phase output terminal, the left channel negative phase output terminal, the right
channel positive phase output terminal, and the right channel negative phase output terminal
provided in Further, although the amplifier according to the second embodiment described above
is a digital amplifier that receives a binary quantization signal, it may be in the form of an analog
10-05-2019
10
amplifier that receives an analog audio signal. Also in the case of inputting an analog audio
signal, the same effect as in the case of inputting a binary quantization signal is obtained.
According to the present invention, there is provided a pair of amplifying means comprising noninverting amplifying means for non-inverting amplifying the input signal and non-inverting
amplifying means for inverting and amplifying the input signal; A first output terminal connected
to the output side of the phase amplification means, and a second output terminal connected to
the output side of the reverse phase amplification means, and binary quantization as a signal to
be input to the amplification means Since the signal is used, it is possible to realize a digital
signal output device in which the output audio signal which is a voltage between the first output
terminal and the second output terminal is not affected by the power supply voltage.
Thereby, good sound quality can be obtained. In addition, the integrated circuit composed of the
digital signal output device and other digital circuits provided in the audio device can be easily
manufactured, and the cost of the audio device can be reduced. Further, according to the present
invention, the first positive phase amplification means and the second positive phase
amplification means, the first negative phase amplification means and the second negative phase
amplification means, and the first positive phase amplification means A first positive phase
output terminal connected to the output side of the means, a second positive phase output
terminal connected to the output side of the second positive phase amplification means, and an
output side of the first negative phase amplification means And a second negative phase output
terminal connected to the output side of the second negative phase amplification means, and a
first positive phase amplification means and a first The negative phase amplification means
receives the first input signal, and the second positive phase amplification means and the second
negative phase amplification means receive the second input signal, and the first positive phase
amplification means and the first The first positive phase is connected to the positive phase
output terminal via the first resistor, and the second positive phase amplifying means and the
second positive phase output terminal are connected via the second resistor. Output terminal
And the first negative phase output terminal is connected via the voice coil of the headphone to
the potential of the first positive phase output terminal, the output signal of the first positive
phase amplifier means and the first negative phase amplifier means When the second positive
phase output terminal and the second negative phase output terminal are connected via the voice
coil of the headphone, the potential of the second positive phase output terminal can be set near
the intermediate level with the output signal. Can be made near an intermediate level between
the output signal of the second positive phase amplification means and the output signal of the
second negative phase amplification means. Thereby, even if the first positive phase output
terminal and the second positive phase output terminal are connected by connecting the threeterminal headphone, the first positive phase output terminal and the second positive phase
output terminal Potential difference can be reduced. Therefore, damage to the signal output
device or the stereo device can be prevented, and crosstalk can be reduced. In addition, when the
resistance values of the first and second resistors match the resistance value of the resistance
10-05-2019
11
component of the voice coil of the headphone to be connected, the occurrence of crosstalk can be
prevented. The third terminal plug, the third resistor provided between the first terminal and the
third terminal of the three terminal plug, and the second and third terminals of the three terminal
plug And a fourth resistor provided between the first and second terminals, the first reverse
phase output terminal and the first terminal of the three-terminal plug being connected when the
second output terminal is connected. The negative phase output terminal and the second
terminal of the three terminal plug are connected, and the first positive phase output terminal,
the second positive phase output terminal, and the third terminal of the three terminal plug are
connected The first positive phase output terminal and the first negative phase output terminal
are connected via the voice coil of the headphone, and the second positive phase output terminal
and the second negative phase output terminal are connected. It can be made to be connected via
the voice coil of the headphone.
Also, a three-terminal plug, a third resistor provided between the first terminal and the third
terminal of the three-terminal plug, and a second resistor and a third terminal of the threeterminal plug. When the audio output means having the fourth resistor provided in the second
circuit is connected, the amplified voltage of the first input signal is output to both ends of the
third resistor, and the second input signal is amplified. By outputting the same voltage to both
ends of the fourth resistor, stereo output of two channels becomes possible. Further, according to
the present invention, the first positive phase amplification means and the second positive phase
amplification means, the first negative phase amplification means and the second negative phase
amplification means, and the first positive phase amplification A first positive phase output
terminal connected to the output side of the means, a second positive phase output terminal
connected to the output side of the second positive phase amplification means, and an output
side of the first negative phase amplification means And a second negative phase output terminal
connected to the output side of the second negative phase amplification means, and a first
positive phase amplification means and a first The negative phase amplification means receives
the first input signal, and the second positive phase amplification means and the second negative
phase amplification means receive the second input signal, and the first negative phase
amplification means and the first The first positive phase is connected to the negative phase
output terminal through the first resistor, and the second negative phase amplification means
and the second negative phase output terminal are connected through the second resistor.
Output terminal And the first negative phase output terminal is connected via the voice coil of
the headphone to the potential of the first negative phase output terminal, the output signal of
the first positive phase amplifier means and the first negative phase amplifier means When the
second positive-phase output terminal and the second negative-phase output terminal are
connected via the voice coil of the headphone, the potential of the second negative-phase output
terminal can be set near the intermediate level with the output signal. Can be made near an
intermediate level between the output signal of the second positive phase amplification means
and the output signal of the second negative phase amplification means. Thereby, even if the first
10-05-2019
12
reverse phase output terminal and the second reverse phase output terminal are connected by
connecting the three-terminal headphone, the first reverse phase output terminal and the second
reverse phase output terminal Potential difference can be reduced. Therefore, damage to the
signal output device or the stereo device can be prevented, and crosstalk can be reduced. In
addition, when the resistance values of the first and second resistors match the resistance value
of the resistance component of the voice coil of the headphone to be connected, the occurrence
of crosstalk can be prevented. Note that a three-terminal plug, a third resistor provided between
the first terminal and the third terminal of the three-terminal plug, and a second terminal and a
third terminal of the three-terminal plug. And the first output terminal of the first positive phase
output terminal is connected to the first terminal of the three-terminal plug, and the second
output terminal is connected to the second output terminal. The positive phase output terminal
and the second terminal of the three-terminal plug are connected, and the first negative phase
output terminal, the second negative phase output terminal, and the third terminal of the threeterminal plug are connected The first positive phase output terminal and the first negative phase
output terminal are connected via the voice coil of the headphone, and the second positive phase
output terminal and the second negative phase output terminal are connected. It can be made to
be connected via the voice coil of the headphone.
Also, a three-terminal plug, a third resistor provided between the first terminal and the third
terminal of the three-terminal plug, and a second resistor and a third terminal of the threeterminal plug. When the audio output means having the fourth resistor provided in the second
circuit is connected, the amplified voltage of the first input signal is output to both ends of the
third resistor, and the second input signal is amplified. By outputting the same voltage to both
ends of the fourth resistor, stereo output of two channels becomes possible. Further, according to
the present invention, since the first input signal and the second input signal are binary
quantization signals, the digital signal output device is obtained. This facilitates the manufacture
of an integrated circuit comprising this digital signal output device and other digital circuits
provided in the audio device, and can reduce the cost of the audio device. Further, according to
the present invention, since the first resistance and the second resistance are variable
resistances, the resistances of the first resistance and the second resistance are set to the voices
of the three-terminal headphones connected respectively. It can be matched with the resistance
value of the resistance component of the coil. This can prevent the occurrence of crosstalk.
Further, according to the present invention, each of the first resistor and the second resistor is a
resistor means including a plurality of resistors and switching means for switching the
connection state of the plurality of resistors. The resistance value of the resistance and the
second resistance can be matched with the resistance value of the resistance component of the
voice coil of the three-terminal headphone to be connected. This can prevent the occurrence of
crosstalk. Further, according to the present invention, a four-terminal plug, a third resistor
provided between a first terminal and a third terminal of the four-terminal plug, and a second
terminal of the three-terminal plug And the fourth terminal provided between the fourth terminal
10-05-2019
13
and the fourth terminal, the first positive phase output terminal and the first terminal of the fourterminal plug are connected when the audio output means having the fourth resistor is
connected. The second positive phase output terminal and the second terminal of the fourterminal plug are connected, and the first negative phase output terminal and the third terminal
of the four-terminal plug are connected, the second And the fourth terminal of the four-terminal
plug are connected, the amplified voltage of the first input signal is outputted to both ends of the
third resistor, and the second input signal is amplified. Output the voltage across the fourth
resistor, so connect a 4-terminal headphone and Le stereo output can be obtained.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram showing a configuration of an
amplifier according to a second embodiment of the present invention. FIG. 2 is a diagram
showing a voltage waveform of a signal output from an output terminal of the amplifier of FIG. 1;
FIG. 3 is a diagram showing a configuration when the amplifier of FIG. 5 is applied to a stereo
amplifier. 4 is a diagram showing a voltage waveform of a signal output from an output terminal
of the amplifier of FIG. 3; FIG. 5 is a diagram showing a configuration of an amplifier according to
a first embodiment of the present invention. FIG. 6 is a diagram showing a configuration of a
conventional analog amplifier. FIG. 7 is a view showing a plug of a four-terminal headphone. FIG.
8 is a view showing a plug of the 3-terminal headphone. [Explanation of the code] 1 to 4, 17, 18
operational amplifier 9 left channel positive phase output terminal 10 left channel negative
phase output terminal 11 right channel positive phase output terminal 12 right channel negative
phase output terminal 21 positive phase output terminal 22 reverse phase Output terminal R1 to
R4 Resistance S1, SL, SR Binary quantization signal S2 Analog audio signal S3 16-bit digital
signal
10-05-2019
14
Документ
Категория
Без категории
Просмотров
0
Размер файла
27 Кб
Теги
jp2004056807
1/--страниц
Пожаловаться на содержимое документа