JP2002252536A - Electronic volume circuit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic volume circuit that can realize both an improvement in low harmonic distortion factor and a reduction in switching noise. SOLUTION: This electronic volume circuit is constituted of a shift volume section 3 constituted of a resistance element 3a and a switch element 3s, and a ladder volume section 2 constituted of resistance elements 2a, 2b, etc., and 2c, 2d, etc., and switch elements 2s, 2t, etc., and 2u, and 2v, etc. The shift volume section 3 is connected in parallel with part 2c, 2d, etc., of the resistance elements 2a, 2b, etc., and 2c, 2d, etc., constituting the ladder volume section 2 so as to reduce the terminal voltage amplitude Va of the switch element 3s constituting the volume section 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic volume circuit, and more particularly, to an electronic volume circuit for realizing a low harmonic distortion factor, a reduction in switching noise, and a reduction in a chip area. Noise reduction,
The present invention relates to a shift volume circuit that realizes a reduction in chip area and the like.

[0002]

2. Description of the Related Art In order to realize various characteristics required in actual use, an electronic volume circuit generally uses a configuration shown in FIG. 7 in which a shift volume section and a ladder volume section are connected in series. In the conventional electronic volume circuit, the ladder volume section 2 is used when performing large steps, and the shift volume section 3 is used when performing small steps. A switch is always inserted between the input terminal 1 and the ladder volume unit 2, so that
The on-low high voltage dependency of this switch deteriorates the harmonic distortion factor.

Hitherto, the above problem has been solved by increasing the size of the transistor of the shift switch sufficiently and reducing the absolute value of the on-resistance. However, the following problems remain. (1) Increase in chip area in total electronic volume due to large size of shift switch. (2) Generation of switching noise due to the large size of the shift switch. (3) In principle, it is difficult to improve the harmonic distortion factor when a large signal is input.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and an electronic volume circuit capable of realizing an improvement in low harmonic distortion and a reduction in switching noise is provided. It is something to offer.

[0005]

An electronic volume circuit according to a first aspect of the present invention includes a shift volume section composed of a resistance element and a switch element, and a ladder volume section composed of a resistance element and a switch element. In the electronic volume circuit, the shift volume section is connected in parallel with a part of a resistance element constituting a ladder volume section so as to reduce a terminal voltage amplitude of a switch element constituting the shift volume section.

According to a second aspect of the present invention, in the electronic volume circuit according to the first aspect, a first switch element connected in series to the resistance element of the shift volume section, and a part of the resistance element of the shift volume section And a second switch element connected in parallel with a series connection of the first switch element and the second switch element.

According to a third aspect of the present invention, in the electronic volume circuit according to the first aspect, the shift volume section is configured by connecting a plurality of series bodies in which a resistance element and a switch element are connected in series to each other in parallel. It is.

In an electronic volume according to a fourth aspect, in the first aspect, a resistance element connected between a connection terminal of the shift volume section to the ladder volume section and a ground portion, And the switch element connected in parallel to a part of the resistance element described above.

According to a fifth aspect of the present invention, in the electronic volume circuit according to the first aspect, a first resistance element connected between a connection terminal of the shift volume section to the ladder volume section and a ground portion is provided. Together with the first
The shift volume unit is configured by connecting a series connection body of a second resistance element and a switch element in parallel to the resistance element.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 FIGS. 1 and 2 show an electronic volume circuit according to a first embodiment of the present invention.
Will be described. FIG. 1 is a connection diagram showing a circuit configuration according to the first embodiment. FIG. 2 is an explanatory diagram showing characteristics in the first embodiment. In the figure, 1 is an input terminal of an electronic volume circuit, 2 is a ladder volume section, 3 is a shift volume section, T is a connection terminal of the shift volume section 3, and G is a ground portion. In the ladder volume section 2,
, 2c, 2d, ..., and switch elements 2s, 2t, ..., 2u, 2v, ... are provided. The shift volume unit 3 includes a resistance element 3a and a switch element 3s.

The electronic volume circuit will be described with reference to FIG. As shown in FIG. 7, a shift volume unit 3 and a ladder volume unit 2 conventionally connected in series are connected.
Are connected and arranged in parallel as shown in FIG. In FIG. 1 showing the circuit configuration according to the first embodiment, the connection terminal T of the shift volume unit 3 is connected to the input terminal 1 side of the resistance element 2c constituting the ladder volume unit 2, and the other end of the shift volume unit 3 It is connected to the ground part G.
That is, the shift volume 3 is the ladder volume unit 2
Are connected in parallel with the resistance elements 2c, 2d,... Which are part of the resistance elements 2a, 2b,. The usage of the shift volume unit 3 and the ladder volume unit 2 is the same as that of the related art. The shift volume unit 3 is used for small steps, and the ladder volume unit 2 is used for large steps.

Next, the operation of the first embodiment will be described with reference to FIGS. Embodiment 1
In contrast to FIG. 7, as shown in FIG. 1, a shift volume unit 3 and a ladder volume unit 2 conventionally connected in series with a signal line are connected in parallel. Thus, in the conventional electronic volume, the voltage amplitude at the shift switch terminal was close to the input signal, but in the first embodiment, the terminal voltage Va of the switch element 3s is expressed by the following equation. Since the signal is attenuated, the voltage amplitude Va at the switch terminal is significantly reduced. Va = (R2 / R1 + R2) × (Ron / Rs + Ron)
× Vi where (R2 / R1 + R2) is the ladder volume 2
And (Ron / Rs + Ron) is the amount of attenuation by the shift volume unit 3. For example, R1 = R2
, Rs = 20 kΩ, Ron = 300Ω, Vi = 1 Vrms
Then, Va = 0.0074 Vrms (approximately 135 times smaller than the input signal Vi), and the voltage amplitude range of the switch terminal is greatly reduced.

Therefore, the following contents can be realized. (1) Improvement of harmonic distortion factor due to reduced influence of switch on-resistance voltage dependence (see FIG. 3). (2) Reduction in switching noise due to the above-mentioned improvement in the distortion factor, whereby the transistor size of the shift switch can be made smaller than in the prior art. (3) Reduction in chip area due to the small switch size.

As described above, the electronic volume circuit configuration of the first embodiment can realize high accuracy (1) and (2) and low cost (3) by reducing the chip area.

According to the first embodiment of the present invention, shift volume unit 3 constituted by resistance element 3a and switch element 3s, and resistance elements 2a, 2b,.
c, 2d,... and switch elements 2s, 2t,.
, 2v,..., the ladder volume unit 2 is composed of one of the resistance elements 2a, 2b,..., 2c, 2d,. Parts 2c, 2d, ...
Are connected in parallel with each other to reduce the terminal voltage amplitude Va of the switch element 3 s constituting the shift volume section 3, so that the resistance element 2 constituting the ladder volume section 2 is reduced.
a, 2b,..., 2c, 2d,.
Shift volume unit 3 connected in parallel with c, 2d, ...
Thus, it is possible to provide an electronic volume circuit capable of realizing an improvement in low harmonic distortion, a reduction in switching noise, and a reduction in chip area.

Embodiment 2 Embodiment 2 of the present invention will be described with reference to FIG. FIG. 3 is a connection diagram showing a circuit configuration of a shift volume unit according to the second embodiment.
In the figure, 3 is a shift volume section, 3a, 3b, 3
c is a resistance element provided in the shift volume unit 3, 3
s, 3t, 3u are switch elements provided in the shift volume unit 3, T is a connection terminal of the shift volume unit 3, G
Is a ground contact portion.

This shift volume circuit is supposed to be used in the electronic volume circuit according to the first embodiment shown in FIG. 1, and a shift resistor and a shift switch are arranged as shown in FIG. Each switch is ON / O
By performing FF, the resistance value of the shift volume changes, and the step of the electronic volume switches (four steps of 0 / −1 / −2 / −3 dB in this configuration).

Next, the operation of the second embodiment will be described with reference to FIG.
This will be described with reference to FIG. In FIG. 3, the switch is O
By performing N / OFF, the resistance value of the shift volume changes, and the steps of the electronic volume are switched in four ways. In this configuration, the step of 0 dB is realized by the shift switch ALL OFF.

With the above configuration, the following contents can be realized. (1) Improvement of the shift switch ALL OFF distortion rate. Reason: When ALL is turned off, all switches related to the characteristics in the electronic volume circuit are turned off. (2) Reduction of chip area by sharing a resistor used for a shift switch. (3) Reduction of switching noise by making one terminal of the switch low impedance. Reason: Since one terminal has low impedance, the electric charge at the time of switch ON / OFF switching moves to the low impedance side (ground in the figure, but a low impedance reference has the same effect).

According to the second embodiment of the present invention, in the electronic volume circuit having the same configuration as in the first embodiment, the resistance elements 3a, 3b, 3c of the shift volume unit 3 are provided.
A first switch element 3s connected in series with the first switch element 3s and a part 3 of the resistance elements 3a, 3b and 3c of the shift volume section.
c and the second switch elements 3t and 3u connected in parallel with the series connection of the first switch element 3s are provided in the shift volume section 3, so that the low harmonic distortion is improved and the switching noise is reduced. It is possible to provide an electronic volume circuit capable of realizing a reduction in chip size and chip area.

Embodiment 3 Third Embodiment A third embodiment according to the present invention will be described with reference to FIG. FIG. 4 is a connection diagram showing a circuit configuration of the shift volume circuit according to the third embodiment. In the figure, 3 is a shift volume section, 3a, 3
b and 3c are resistance elements provided in the shift volume unit 3, 3s, 3t and 3u are switch elements provided in the shift volume unit 3, T is a connection terminal of the shift volume unit 3, and G is a grounding part.

This shift volume circuit is assumed to be used in the electronic volume circuit according to the first embodiment shown in FIG. 1, and as shown in FIG.
3b, 3c and shift switches 3s, 3t, 3u are arranged. Each switch 3s, 3t, 3u is ON / OF
By performing F, the resistance value of the shift volume changes, and the step of the electronic volume switches (four steps of 0 / −1 / −2 / −3 dB in this configuration).

Next, the operation of the third embodiment will be described with reference to FIG.
This will be described with reference to FIG. In FIG. 4, switch 3
When s, 3t, and 3u are turned ON / OFF, the resistance value of the shift volume changes, and the steps of the electronic volume are switched in four ways. In this configuration, the step of 0 dB is realized by the shift switch ALL OFF.

With the above configuration, the following contents can be realized. (1) Improvement of the shift switch ALL OFF distortion rate. Reason: When ALL is turned off, all switches related to the characteristics in the electronic volume circuit are turned off. (2) Reduction of switching noise by making one terminal of the switch low impedance. Reason: Since one terminal has low impedance, the electric charge at the time of switch ON / OFF switching moves to the low impedance side (ground in the figure, but a low impedance reference has the same effect). As described above, the shift volume circuit according to the third embodiment can reduce the distortion factor and the switching noise when the shift switch ALL is OFF.

According to the third embodiment of the present invention, in an electronic volume circuit having the same configuration as that of the first embodiment, a resistance element 3a and a switch element 3s are connected in series, and a resistance element 3b and a switch element 3t are connected. Are connected in series, and a plurality of series bodies in which a resistance element 3c and a switch element 3u are connected in series are connected in parallel to each other to form the shift volume circuit 3, so that the low harmonic distortion is improved and the switching noise is reduced. An electronic volume circuit capable of realizing reduction can be provided.

Embodiment 4 Embodiment 4 of the present invention will be described with reference to FIG. FIG. 5 is a connection diagram showing a circuit configuration of a shift volume unit according to the second embodiment.
In the figure, 3 is a shift volume section, 3a, 3b, 3
c and 3d are resistance elements provided in the shift volume section 3, 3s, 3t and 3u are switch elements provided in the shift volume section 3, T is a connection terminal of the shift volume section 3, and G is a grounding portion.

This shift volume circuit is assumed to be used in the electronic volume circuit according to the first embodiment shown in FIG. 1, and as shown in FIG.
3b, 3c, 3d and shift switches 3s, 3t, 3u are arranged. Each switch 3s, 3t, 3u is ON
By turning on / off, the resistance value of the shift volume unit 3 changes, and the steps of the electronic volume are switched (four steps of 0 / −1 / −2 / −3 dB in this configuration).

Next, the operation of the second embodiment will be described with reference to FIG.
This will be described with reference to FIG. In FIG. 5, switch 3
When s, 3t, and 3u are turned ON / OFF, the resistance value of the shift volume unit 3 changes, and the steps of the electronic volume are switched in four ways. In this configuration, 0d
Step B is realized by the shift switch ALL OFF.

With the above configuration, the following contents can be realized. (1) Improvement of the shift switch ALL OFF distortion rate. Reason: When ALL is turned off, all switches related to the characteristics in the electronic volume circuit are turned off. (2) Reduction of chip area by using a common resistor for shift switches (however, shift switches AL
Since the resistance at the time of L OFF is included in the shift volume, the effect is smaller than in the second embodiment.) (3) Reduction of switching noise by making one terminal of the switch low impedance. Reason: Since one terminal has low impedance, the electric charge at the time of switch ON / OFF switching moves to the low impedance side (ground in the figure, but a low impedance reference has the same effect). As described above, the shift volume circuit according to the fourth embodiment can realize the reduction of the distortion factor, the chip area, and the switching noise when the shift switch ALL is OFF.

According to the fourth embodiment of the present invention, in the electronic volume circuit having the same configuration as that of the first embodiment, the connection between the connection terminal T of the shift volume section 3 to the ladder volume section 2 and the ground portion G is provided. Connected resistance element 3
a, 3b, 3c, 3d, and parts 3b, 3c, 3 of the resistance elements 3a, 3b, 3c, 3d of the shift volume unit 3.
Since the shift volume unit 3 is constituted by the switch elements 3s, 3t, and 3u connected in parallel to d, an improvement in low harmonic distortion, a reduction in switching noise, and a reduction in chip area are realized. The resulting electronic volume circuit can be provided.

Embodiment 5 Embodiment 5 of the present invention will be described with reference to FIG. FIG. 6 is a connection configuration diagram showing a shift volume unit according to the second embodiment. In the figure, 3 is a shift volume section, 3a, 3b, 3c, 3
d is a resistance element provided in the shift volume unit 3, 3
s, 3t, 3u are switch elements provided in the shift volume unit 3, T is a connection terminal of the shift volume unit 3, G
Is a ground contact portion.

This shift volume circuit is assumed to be used in the electronic volume circuit according to the first embodiment shown in FIG. 1, and as shown in FIG.
3b, 3c, 3d and shift switches 3s, 3t, 3u are arranged. Each switch 3s, 3t, 3u is ON
By turning on / off, the resistance value of the shift volume changes, and the steps of the electronic volume are switched (four steps of 0 / −1 / −2 / −3 dB in this configuration).

Next, the operation of the fifth embodiment will be described with reference to FIG.
This will be described with reference to FIG. In FIG. 6, switch 3
When s, 3t, and 3u are turned ON / OFF, the resistance value of the shift volume changes, and the steps of the electronic volume are switched in four ways. In this configuration, the step of 0 dB is realized by the shift switch ALL OFF.

With the above configuration, the following contents can be realized. (1) Improvement of the shift switch ALL OFF distortion rate. Reason: When ALL is turned off, all switches related to the characteristics in the electronic volume circuit are turned off. (2) Reduction of switching noise by making one terminal of the switch low impedance. Reason: Since one terminal has low impedance, the electric charge at the time of switch ON / OFF switching moves to the low impedance side (ground in the figure, but a low impedance reference has the same effect). As described above, the shift volume circuit according to the fourth embodiment can reduce the distortion factor and the switching noise when the shift switch ALL is OFF.

According to the fifth embodiment of the present invention, in the electronic volume circuit having the same configuration as that of the first embodiment, the connection between the connection terminal T of the shift volume section 3 to the ladder volume section 2 and the ground portion G is provided. A connected first resistance element 3a, a series connection of a second resistance element 3b and a switch element 3s to the first resistance element 3a, and a series connection of a second resistance element 3c and a switch element 3t , The serially connected body of the second resistance element 3d and the switch element 3u are connected in parallel with each other to constitute the shift volume section 3, thereby realizing an improvement in low harmonic distortion and a reduction in switching noise. The resulting electronic volume circuit can be provided.

[0036]

According to the first aspect of the present invention, there is provided an electronic volume circuit including a shift volume section composed of a resistance element and a switch element and a ladder volume section composed of a resistance element and a switch element. Since the volume section is connected in parallel with a part of the resistance element constituting the ladder volume section to reduce the terminal voltage amplitude of the switch element constituting the shift volume section, the improvement and switching of the low harmonic distortion are achieved. It is possible to provide an electronic volume circuit that can reduce noise and chip area.

According to a second invention, in the first invention, a first switch element connected in series with the resistance element of the shift volume section, a part of the resistance element of the shift volume, and the first switch element. Since the shift volume unit is provided with the second switch element connected in series with the switch element and the second switch element, it is possible to achieve an improvement in low harmonic distortion, a reduction in switching noise, and a reduction in chip area. The resulting electronic volume circuit can be provided.

According to the third invention, in the first invention, the shift volume section is constituted by connecting a plurality of series members in which a resistance element and a switch element are connected in series to each other in parallel, so that An electronic volume circuit capable of improving the wave distortion factor and reducing the switching noise can be provided.

According to a fourth aspect, in the first aspect, a resistance element connected between a connection terminal of the shift volume section to the ladder volume section and a ground portion, and a resistance of the shift volume section Since the shift volume section is constituted by switch elements connected in parallel to some of the elements, an electronic volume circuit capable of realizing an improvement in low harmonic distortion, a reduction in switching noise, and a reduction in chip area is provided. be able to.

According to a fifth aspect, in the first aspect, a first resistance element connected between a connection terminal of the shift volume portion to the ladder volume portion and a ground portion is provided, and Since the shift volume section is configured by connecting a series connection body of the second resistance element and the switch element to the first resistance element in parallel, it is possible to achieve an improvement in low harmonic distortion and a reduction in switching noise. An electronic volume circuit can be provided.

[Brief description of the drawings]

FIG. 1 is a connection diagram showing a circuit configuration of an electronic volume circuit according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram illustrating voltage characteristics according to the first embodiment of the present invention.

FIG. 3 is a connection diagram showing a circuit configuration of a shift volume circuit according to a second embodiment of the present invention.

FIG. 4 is a connection diagram showing a circuit configuration of a shift volume circuit according to a third embodiment of the present invention.

FIG. 5 is a connection diagram showing a circuit configuration of a shift volume circuit according to a fourth embodiment of the present invention.

FIG. 6 is a connection diagram showing a circuit configuration of a shift volume circuit according to a fifth embodiment of the present invention.

FIG. 7 is a connection diagram illustrating a circuit configuration of an electronic volume circuit according to the related art.

[Explanation of symbols]

1 input terminal, 2 ladder volume section, 2a, 2b,
2c, 2d resistance elements provided in the ladder volume unit 2,
2s, 2t, 2u, 2v Switch elements provided in the ladder volume section 2, 3 shift volume sections, 3a, 3
b, 3c, 3d Resistance elements provided in the shift volume unit 3, 3s, 3t, 3u Switch elements provided in the shift volume unit 3, T connection terminal.

Claims (5)

[Claims] 1. An electronic volume circuit comprising a shift volume section composed of a resistance element and a switch element, and a ladder volume section composed of a resistance element and a switch element, wherein the shift volume section constitutes a ladder volume section. An electronic volume circuit connected in parallel with a part of the resistance element to reduce a terminal voltage amplitude of a switch element constituting the shift volume section. 2. A first switch element connected in series with a resistance element of the shift volume section, and a first switch element connected in series with a part of the resistance element of the shift volume section and the first switch element. The electronic volume circuit according to claim 1, wherein a second switch element to be connected is provided in the shift volume section. 3. The electronic volume circuit according to claim 1, wherein a plurality of series bodies in which a resistance element and a switch element are connected in series are connected in parallel to each other to form the shift volume section. 4. A resistance element connected between a connection terminal of the shift volume section to the ladder volume section and a ground portion, and a switch element connected in parallel to a part of the resistance element of the shift volume section. 2. The electronic volume circuit according to claim 1, wherein the shift volume section is constituted by: 5. A first resistance element connected between a connection terminal of the shift volume section to the ladder volume section and a ground portion, and a second resistance element is provided on the first resistance element. 2. The electronic volume circuit according to claim 1, wherein the shift volume section is configured by connecting a series connection body with a switch element in parallel.