Power supply and amplifier

Abstract

To provide a technique that can obtain a desired output signal level while suppressing distortion of the output signal of an amplifier with a simple configuration.SOLUTION: In a power supply 10, a power supply unit 12 supplies a power supply voltage Vp to an amplifier 50. A current detection unit 14 detects a power supply current Ip supplied from the power supply unit 12 to the amplifier 50. An acquisition unit 16 acquires an upper limit current threshold value corresponding to the power supply voltage Vp. The higher the power supply voltage Vp, the larger the upper limit current threshold value. When the power supply current Ip detected by the current detection unit 14 becomes equal to or greater than an upper limit current threshold value acquired by the acquisition unit 16, a control unit 18 controls the power supply unit 12 to increase the power supply voltage Vp.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a power supply device and an amplifier device. [Background technology]

[0002] Patent Document 1 discloses a technology for calculating the maximum power consumption that can ensure the guaranteed operating voltage of the amplifier device itself, calculating a limit value for the signal level of an audio signal that will prevent the power consumption from exceeding the maximum value, and limiting the signal level of an input audio signal so that it does not exceed the limit value.

[0003] Non-Patent Document 1 discloses a technique for extracting amplitude information from a high-frequency input signal and varying the power supply voltage of a high-frequency amplifier in accordance with the amplitude information. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-21840 [Non-patent literature]

[0005] [Non-Patent Document 1] Toshiro Yukinaga and Seiji Fujiwara, "High-Power, High-Efficiency Amplifier Technology for Base Stations," Panasonic Technical Report, April 2009, Vol. 55, No. 1, pp. 27-29 Summary of the Invention [Problem to be solved by the invention]

[0006] There is a demand for high-output, low-distortion amplifiers. However, the technology of Patent Document 1 adjusts the input signal level, so there is a possibility that the output signal level desired by the user cannot be obtained.

[0007] The technique of Non-Patent Document 1 can obtain the desired output signal level required by the user, but requires a high-precision high-frequency circuit to extract amplitude information from the input signal.

[0008] The present invention has been made in view of these circumstances, and its purpose is to provide a technology that can obtain a desired output signal level while suppressing distortion in the output signal of an amplifier with a simple configuration. [Means for solving the problem]

[0009] In order to solve the above problem, a power supply device of one embodiment of the present invention comprises a power supply unit that supplies a set power supply voltage to an amplifier, a current detection unit that detects the power supply current supplied from the power supply unit to the amplifier, an acquisition unit that stores in advance the relationship between the power supply voltage and an upper limit current threshold and detects the power supply voltage to acquire the corresponding upper limit current threshold, and a control unit that controls the power supply unit to set it to increase the power supply voltage when the power supply current detected by the current detection unit becomes equal to or greater than the upper limit current threshold acquired by the acquisition unit.

[0010] Another aspect of the present invention is an amplifier device. The device includes an amplifier and a power supply device for the amplifier. The power supply device includes a power supply unit that supplies a set power supply voltage to the amplifier, a current detection unit that detects a power supply current supplied from the power supply unit to the amplifier, an acquisition unit that stores a relationship between the power supply voltage and an upper limit current threshold and detects the power supply voltage and acquires the corresponding upper limit current threshold, and a control unit that controls the power supply unit to increase the power supply voltage when the power supply current detected by the current detection unit exceeds the upper limit current threshold acquired by the acquisition unit.

[0011] Any combination of the above components, and any transformation of the present invention into a method, device, system, recording medium, computer program, etc., are also valid aspects of the present invention. [Effects of the Invention]

[0012] According to the present invention, it is possible to obtain a desired output signal level while suppressing distortion of the output signal of an amplifier with a simple configuration. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is a diagram illustrating a schematic functional configuration of an amplifier device according to an embodiment. [Figure 2] 1 is a diagram showing the correspondence relationship between the power supply current and the power supply voltage required to obtain an output signal from an amplifier while ensuring a predetermined distortion rate. [Figure 3] 10A and 10B are diagrams for explaining control of the power supply voltage when the level of the input signal to the amplifier increases. [Figure 4] 10A and 10B are diagrams for explaining control of the power supply voltage when the level of the input signal to the amplifier decreases. [Figure 5] FIG. 10 is a diagram illustrating a schematic functional configuration of another example of the configuration of the amplification device. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the description, the same elements are denoted by the same reference numerals, and duplicate descriptions will be omitted as appropriate.

[0015] In the embodiment, an amplifier device is provided that includes a simple circuit that monitors the power supply current of the amplifier and controls the power supply voltage of the amplifier based on the power supply current, thereby reducing power consumption and suppressing an increase in distortion of the amplified output signal while obtaining a desired output signal level.

[0016] 1 shows a schematic functional configuration of an amplifying device 1 according to an embodiment. The amplifying device 1 includes a power supply device 10 and an amplifier 50. The power supply device 10 is a power source for the amplifier 50 and supplies power to the amplifier 50.

[0017] The amplifier 50 operates based on the power supplied from the power supply device 10. The amplifier 50 is, for example, a high-frequency amplifier. The amplifier 50 is a power amplifier that amplifies the power of a radio-frequency input signal supplied to an input terminal 52 and outputs the amplified output signal from an output terminal 54.

[0018] When distortion occurs in the output signal, the amplifier 50 flows a larger power supply current Ip as the input signal level increases. The power supply current Ip is the average current value of the current flowing through the power supply terminals of the amplifier 50. The signal level corresponds to, for example, the signal amplitude or power. Any of various well-known amplifiers can be used as the amplifier 50 as long as it has such a relationship between the input signal level and the power supply current Ip. The input signal may be an AC signal, and the frequency band of the input signal is not particularly limited. For example, the amplifier 50 may be a power amplifier that amplifies audio signals, etc.

[0019] The power supply device 10 includes a power supply unit 12, a current detection unit 14, an acquisition unit 16, and a control unit 18.

[0020] The power supply unit 12 supplies a power supply voltage Vp to a power supply terminal of the amplifier 50. The power supply unit 12 is a variable voltage source having a power supply voltage control function, and can change the power supply voltage Vp in response to a control signal from the control unit .

[0021] The current detection unit 14 includes a current sensor and detects the power supply current Ip supplied from the power supply unit 12 to the power supply terminal of the amplifier 50. The current detection unit 14 supplies the control unit 18 with information on the detected power supply current Ip.

[0022] The acquisition unit 16 has a memory (not shown) that stores, as a table, correspondence relationships between predetermined upper limit current thresholds and power supply voltages Vp and correspondence relationships between predetermined lower limit current thresholds and power supply voltages Vp. These correspondence relationships will be described later. The acquisition unit 16 detects the current power supply voltage Vp output from the power supply unit 12 (not shown), acquires from the table the upper limit current threshold corresponding to that power supply voltage Vp and the lower limit current threshold corresponding to that power supply voltage Vp, and supplies the acquired upper limit current threshold and lower limit current threshold to the control unit 18.

[0023] The control unit 18 controls the power supply unit 12 based on the power supply current Ip detected by the current detection unit 14 and the upper limit current threshold and the lower limit current threshold acquired by the acquisition unit 16.

[0024] The control unit 18 controls the power supply unit 12 to increase the power supply voltage Vp when the power supply current Ip detected by the current detection unit 14 becomes equal to or greater than the upper limit current threshold acquired by the acquisition unit 16. The control unit 18 controls the power supply unit 12 to decrease the power supply voltage Vp when the power supply current Ip detected by the current detection unit 14 becomes equal to or less than the lower limit current threshold acquired by the acquisition unit 16. The control unit 18 controls the power supply unit 12 to maintain the current power supply voltage Vp when the detected power supply current Ip is greater than the acquired lower limit current threshold and smaller than the acquired upper limit current threshold.

[0025] The control unit 18 has a comparator 20 and a time constant circuit 22. In this configuration example, the control unit 18 can be configured with an analog circuit.

[0026] The comparator 20 compares the upper and lower current threshold values ​​acquired by the acquisition unit 16 with the power supply current Ip detected by the current detection unit 14 , and supplies the comparison result to the time constant circuit 22 .

[0027] The time constant circuit 22 is a nonlinear filter or delay circuit that determines the amount of change in the power supply voltage Vp to stably operate a feedback loop that controls the voltage of the power supply unit 12 based on the comparison result of the comparator 20. Stable operation of the feedback loop includes, for example, preventing oscillation. The delay circuit is, for example, a low-pass filter. The output signal of the time constant circuit 22 is supplied to the power supply unit 12 as a control signal.

[0028] 2 shows a correspondence relationship 100 between the power supply current Ip and the power supply voltage Vp required to obtain an output signal while ensuring a predetermined distortion factor from amplifier 50. In Fig. 2, the horizontal axis represents the power supply current Ip, and the vertical axis represents the power supply voltage Vp. The distortion factor is, for example, total harmonic distortion (THD).

[0029] Correspondence 100 indicates the minimum power supply voltage Vp required to ensure a predetermined distortion factor, i.e., a desired amplification factor, when power supply current Ip supplied from power supply unit 12 changes in proportion to the level of the input signal or output signal of amplifier 50. This indicates that when the level of the input signal increases and the power supply current Ip detected by current detection unit 14 increases, the predetermined distortion factor cannot be ensured unless power supply voltage Vp is increased. In other words, by controlling power supply voltage Vp so that it is close to the solid line of correspondence 100 in FIG. 2 but does not fall below the solid line of correspondence 100, an output signal can be obtained with the minimum necessary power consumption and without distorting the output signal to a degree that exceeds the predetermined distortion factor.

[0030] 3, an upper limit current threshold Th1 for increasing the power supply voltage Vp and a lower limit current threshold Th2 for decreasing the power supply voltage Vp are provided, providing a so-called hysteresis characteristic, and controlling the increase and decrease of the power supply voltage Vp through feedback control, thereby preventing oscillation due to the feedback loop.

[0031] Fig. 3 is a diagram illustrating control of power supply voltage Vp when the level of the input signal to amplifier 50 increases. Fig. 3 also shows the correspondence relationship between upper current threshold Th1 and power supply voltage Vp, and the correspondence relationship between lower current threshold Th2 and power supply voltage Vp. In Fig. 3, the horizontal axis represents power supply current Ip, and the vertical axis represents power supply voltage Vp.

[0032] The correspondence relationship between the upper limit current threshold Th1 and the power supply voltage Vp represents the correspondence relationship between the power supply current Ip of the amplifier 50 and the power supply voltage Vp at which the distortion rate of the output signal of the amplifier 50 becomes a predetermined value. The higher the power supply voltage Vp, the larger the upper limit current threshold Th1. The higher the power supply voltage Vp, the larger the lower limit current threshold Th2. For each of multiple power supply voltages Vp, the lower limit current threshold Th2 is smaller than the upper limit current threshold Th1. In the example of FIG. 3, for each power supply voltage Vp, the lower limit current threshold Th2 is smaller than the upper limit current threshold Th1 by a fixed value. This fixed value can be determined appropriately through experiments or simulations. Note that the difference between the upper limit current threshold Th1 and the lower limit current threshold Th2 may vary for each power supply voltage Vp.

[0033] The upper limit current threshold Th1 and the lower limit current threshold Th2 can be determined from the power supply voltage Vp, the power supply current Ip, and the distortion rate of the output signal, which have been measured or simulated in advance. For example, the level of the input signal is varied at a certain power supply voltage Vp through experiment or simulation, and the power supply current Ip at which the distortion rate of the output signal becomes a predetermined value is obtained as the upper limit current threshold Th1. This process is repeated for each of multiple power supply voltages Vp to obtain the correspondence relationship between the power supply voltage Vp and the upper limit current threshold Th1. Then, for each power supply voltage Vp, a value obtained by subtracting a certain value from the upper limit current threshold Th1 is obtained as the lower limit current threshold Th2, thereby obtaining the correspondence relationship between the power supply voltage Vp and the lower limit current threshold Th2, as shown in FIG. 3. Alternatively, similar to the upper limit current threshold Th1, the level of the input signal is varied at a certain power supply voltage Vp through experiment or simulation, and the power supply current Ip at which the distortion rate of the output signal becomes a different predetermined value smaller than the predetermined value is obtained as the lower limit current threshold Th2. This process is repeated for each of multiple power supply voltages Vp to obtain the correspondence relationship between the power supply voltage Vp and the lower limit current threshold Th2.

[0034] Next, the control of the power supply voltage Vp based on the upper limit current threshold Th1 and the lower limit current threshold Th2 will be explained using Figures 3 and 4. First, with reference to Figure 3, the role of the upper limit current threshold Th1 in preventing an increase in distortion of the output signal will be explained.

[0035] 3, let us assume that, from point A1 where power supply voltage Vp is voltage V1 and power supply current Ip is current I1, the level of the input signal to amplifier 50 increases, causing the power supply current Ip to increase. Until the power supply current Ip reaches an upper current threshold value Th1, power supply voltage Vp maintains a constant voltage V1.

[0036] As the power supply current Ip increases, it reaches point A2. At point A2, the power supply voltage Vp is voltage V1, and the power supply current Ip is current I2. Current I2 is equal to the upper current threshold Th1 at voltage V1.

[0037] If the power supply current Ip increases beyond point A2, where it coincides with the upper limit current threshold Th1, the distortion rate will exceed a predetermined value, making it impossible to ensure the desired distortion rate. Therefore, when the power supply current Ip reaches the upper limit current threshold Th1, the control unit 18 increases the power supply voltage Vp to point A3, which is the midpoint between points A2 and P1. At point P1, the power supply voltage Vp is voltage V3, and the power supply current Ip is current I2. Voltage V3 is the power supply voltage Vp when the lower limit current threshold Th2 is equal to current I2. At point A3, the power supply voltage Vp is voltage V2, and the power supply current Ip is current I2. Voltage V2 is the midpoint between voltage V1 and voltage V3.

[0038] That is, when the detected power supply current Ip becomes equal to or greater than the acquired upper current threshold Th1, the control unit 18 controls the power supply unit 12 to increase the power supply voltage Vp to the first voltage. The first voltage is an intermediate voltage between the third voltage and the power supply voltage Vp corresponding to the lower current threshold Th2 equal to the power supply current Ip when the power supply voltage Vp is the third voltage and the power supply current Ip is the upper current threshold Th1. In the example of FIG. 3, the third voltage is voltage V1. The power supply voltage Vp corresponding to the lower current threshold Th2 equal to the power supply current Ip when the power supply current Ip is the upper current threshold Th1 is voltage V3. The first voltage is voltage V2.

[0039] The time constant of the time constant circuit 22 can be determined appropriately by experiment or simulation so that the power supply voltage Vp increases to the first voltage when the detected power supply current Ip becomes equal to or greater than the acquired upper limit current threshold Th1.

[0040] The first voltage need only be lower than the power supply voltage Vp corresponding to the lower limit current threshold Th2, which is equal to the power supply current Ip when the power supply current Ip is at the upper limit current threshold Th1, and need not be an intermediate voltage. In other words, in the example of Fig. 3, the first voltage does not have to be voltage V2 as long as it is higher than voltage V1 and lower than voltage V3.

[0041] In this way, when the input signal level increases and the power supply current Ip increases, the power supply voltage Vp is increased so that the power supply current Ip does not exceed the upper current threshold Th1, and the distortion of the output signal does not increase beyond a predetermined value.

[0042] When the power supply voltage Vp is controlled to the voltage V2 at point A3, if the input signal level increases and the power supply current Ip increases, the power supply voltage Vp will maintain the voltage V2 until the power supply current Ip reaches the upper limit current threshold Th1.

[0043] Next, the role of the lower limit current threshold Th2 for preventing an unnecessary increase in power consumption will be described with reference to Fig. 4. Fig. 4 is a diagram for explaining control of the power supply voltage Vp when the level of the input signal to the amplifier 50 decreases.

[0044] 4, let us assume that the input signal level decreases and the power supply current Ip decreases from point A4, where the power supply voltage Vp is at voltage V4 and the power supply current Ip is at current I4. Until the power supply current Ip reaches the lower current threshold Th2, the power supply voltage Vp maintains a constant voltage V4.

[0045] As the power supply current Ip decreases, it reaches point A5. At point A5, the power supply voltage Vp is at voltage V4, and the power supply current Ip is at current I3. Current I3 is equal to the lower current threshold Th2 at voltage V4.

[0046] When the power supply current Ip decreases below point A5, where it coincides with the lower limit current threshold Th2, the power supply voltage Vp becomes too high for the input signal level, resulting in more power consumption than necessary. Therefore, when the power supply current Ip reaches the lower limit current threshold Th2, the control unit 18 lowers the power supply voltage Vp to point A6, which is the midpoint between points A5 and P2. At point P2, the power supply voltage Vp is voltage V6, and the power supply current Ip is current I3. Voltage V6 is the power supply voltage Vp when the upper limit current threshold Th1 is equal to current I3. At point A6, the power supply voltage Vp is voltage V5, and the power supply current Ip is current I3. Voltage V5 is the midpoint between voltage V6 and voltage V4.

[0047] That is, when the detected power supply current Ip becomes equal to or less than the acquired lower limit current threshold Th2, the control unit 18 controls the power supply unit 12 to reduce the power supply voltage Vp to the second voltage. The second voltage is an intermediate voltage between the fourth voltage and the power supply voltage Vp corresponding to the upper limit current threshold Th1 equal to the power supply current Ip when the power supply voltage Vp is the fourth voltage and the power supply current Ip is the lower limit current threshold Th2. In the example of FIG. 4, the fourth voltage is voltage V4. The power supply voltage Vp corresponding to the upper limit current threshold Th1 equal to the power supply current Ip when the power supply current Ip is the lower limit current threshold Th2 is voltage V6. The second voltage is voltage V5.

[0048] The time constant of the time constant circuit 22 can be determined appropriately by experiment or simulation so that the power supply voltage Vp decreases to the second voltage when the detected power supply current Ip becomes equal to or less than the acquired lower limit current threshold Th2.

[0049] The second voltage need only be higher than the power supply voltage Vp corresponding to the upper current threshold Th1, which is equal to the power supply current Ip when the power supply current Ip is at the lower current threshold Th2, and need not be an intermediate voltage. In other words, in the example of Fig. 4, the second voltage does not have to be voltage V5 as long as it is higher than voltage V6 and lower than voltage V4.

[0050] In this way, when the input signal level decreases and the power supply current Ip decreases, the power supply voltage Vp is lowered so that the power supply current Ip does not fall below the lower current threshold Th2, thereby preventing an unnecessary increase in the power consumption of the amplifier 50.

[0051] When the input signal level decreases and the power supply current Ip decreases while the power supply voltage Vp is controlled to the voltage V5 at point A6, the power supply voltage Vp remains at voltage V5 until the power supply current Ip reaches the lower limit current threshold Th2.

[0052] In this way, the acquisition unit 16 acquires the upper limit current threshold Th1 and the lower limit current threshold Th2 of the power supply current Ip determined from the current power supply voltage Vp, the comparator 20 compares the upper limit current threshold Th1 and the lower limit current threshold Th2 with the current power supply current Ip to determine which is larger, and the time constant circuit 22 controls the increase or decrease of the power supply voltage Vp. These processes are repeated.

[0053] As described above, according to the embodiment, when the power supply current Ip becomes equal to or greater than the upper current threshold Th1, the power supply unit 12 is controlled to increase the power supply voltage Vp. This makes it possible to increase the output signal level while suppressing an increase in distortion in a situation where the power supply current Ip increases due to an increase in the level of the input signal to the amplifier 50. This control does not require monitoring or processing of the input signal, and therefore does not require a high-precision high-frequency circuit. Therefore, with a simple configuration, it is possible to obtain a desired output signal level while suppressing distortion in the output signal of the amplifier 50.

[0054] Furthermore, the correspondence relationship between the upper limit current threshold Th1 and the power supply voltage Vp represents the correspondence relationship between the power supply current Ip and the power supply voltage Vp at which the distortion rate of the output signal becomes a predetermined value, so that even when the level of the input signal increases, the distortion rate of the output signal can be maintained below the predetermined value.

[0055] Furthermore, when the power supply current Ip becomes equal to or less than the lower limit current threshold Th2, the power supply unit 12 is controlled so that the power supply voltage Vp decreases, thereby reducing the power consumption of the amplifier 50.

[0056] Furthermore, when the power supply current Ip becomes equal to or greater than the upper current threshold Th1, the power supply unit 12 is controlled so that the power supply voltage Vp increases to the first voltage, and when the power supply current Ip becomes equal to or less than the lower current threshold Th2, the power supply unit 12 is controlled so that the power supply voltage Vp decreases to the second voltage, thereby suppressing distortion in the output signal of the amplifier 50 and reducing the power consumption of the amplifier 50. By using the above-mentioned intermediate voltages as each of the first voltage and the second voltage, the frequency of adjustment of the power supply voltage Vp can be optimized.

[0057] 1 shows an example in which the control unit 18 is configured as an analog circuit, but as will be explained below, the control unit 18 may be configured as a digital circuit. This allows for greater flexibility in the configuration of the power supply device 10. The following explanation will focus on the differences from the configuration example in FIG. 1.

[0058] 5 shows a schematic functional configuration of another example of the configuration of the amplification device 1. The acquisition unit 16 and the control unit 18 can be configured as a processing unit 26. The processing unit 26 can be configured by, for example, a microcomputer.

[0059] The processing unit 26 can be configured using a combination of hardware and software resources, or using only hardware resources. Examples of hardware resources that can be used include analog elements, microcomputers, CPUs, DSPs, ROMs, RAMs, ASICs, FPGAs, and other LSIs. Examples of software resources that can be used include programs such as firmware.

[0060] The control unit 18 executes the above-described control by digital signal processing. For example, a correspondence relationship between the target voltage acquired as the above-described first voltage or second voltage and the power supply current Ip is obtained in advance based on the correspondence relationship between the upper limit current threshold Th1 and the lower limit current threshold Th2 and the power supply voltage Vp, and this correspondence relationship is stored as a table in a memory (not shown) in the control unit 18. In the example of Fig. 3, the correspondence relationship between the target voltage and the power supply current Ip is a straight line passing through the middle between the straight line representing the correspondence relationship between the upper limit current threshold Th1 and the power supply voltage Vp and the straight line representing the correspondence relationship between the lower limit current threshold Th2 and the power supply voltage Vp.

[0061] When the power supply current Ip detected by the current detection unit 14 becomes equal to or greater than the upper limit current threshold Th1 acquired by the acquisition unit 16, the control unit 18 acquires a target voltage corresponding to the power supply current Ip from the table as a first voltage, and controls the power supply unit 12 so that the power supply voltage Vp increases to the first voltage. When the detected power supply current Ip becomes equal to or less than the acquired lower limit current threshold Th2, the control unit 18 acquires a target voltage corresponding to the power supply current Ip from the table as a second voltage, and controls the power supply unit 12 so that the power supply voltage Vp decreases to the second voltage.

[0062] The correspondence between the target voltage and the power supply current Ip does not have to be stored in memory. In this case, the control unit 18 may calculate the first voltage or the second voltage. When the detected power supply current Ip becomes equal to or greater than the acquired upper current threshold Th1, the control unit 18 calculates a first voltage corresponding to the power supply current Ip and controls the power supply unit 12 so that the power supply voltage Vp increases to the first voltage. When the detected power supply current Ip becomes equal to or less than the acquired lower current threshold Th2, the control unit 18 calculates a second voltage corresponding to the power supply current Ip and controls the power supply unit 12 so that the power supply voltage Vp decreases to the second voltage.

[0063] As shown in the example of FIG. 3, when the lower limit current threshold Th2 is smaller than the upper limit current threshold Th1 by a certain value for each power supply voltage Vp, the difference between the power supply voltage Vp corresponding to the lower limit current threshold Th2 and the power supply voltage Vp corresponding to the upper limit current threshold Th1 is the certain voltage. When the power supply voltage Vp is the third voltage and the detected power supply current Ip is equal to or greater than the acquired upper limit current threshold Th1, the control unit 18 may set the first voltage to a value obtained by adding half of the certain voltage to the third voltage. When the power supply voltage Vp is the fourth voltage and the detected power supply current Ip is equal to or less than the acquired lower limit current threshold Th2, the control unit 18 may set the second voltage to a value obtained by subtracting half of the certain voltage from the fourth voltage. Other ratios may be used instead of half. This simplifies the processing of the control unit 18.

[0064] 3 and 4, the correspondence relationship between the upper limit current threshold Th1 and the power supply voltage Vp and the correspondence relationship between the lower limit current threshold Th2 and the power supply voltage Vp are shown as straight lines, but they may also be curved lines or straight lines when the vertical and horizontal axes are logarithmic axes, and are not limited to these. These correspondence relationships can be determined appropriately depending on the characteristics of amplifier 50.

[0065] The gain of the amplifier 50 may be adjusted by gain control.

[0066] 3 and 4, when the difference between the upper limit current threshold Th1 and the lower limit current threshold Th2 at each power supply voltage Vp is a constant value, the constant value may be externally set and changeable. In this case, a receiving unit (not shown) may be provided in power supply device 10, and the receiving unit may receive a setting input of the constant value from an operator or the like when amplifying device 1 is shipped from a factory, and may supply the received constant value to acquisition unit 16 and control unit 18.

[0067] The acquiring unit 16 may acquire an upper limit current threshold Th1 corresponding to the current power supply voltage Vp from the table, and may acquire a value obtained by subtracting the constant value received from the accepting unit from the acquired upper limit current threshold Th1 as a lower limit current threshold Th2 corresponding to the current power supply voltage Vp. The acquiring unit 16 may update the correspondence relationship between the lower limit current threshold Th2 and the power supply voltage Vp stored in memory based on the constant value received from the accepting unit. The control unit 18 may set the first voltage and the second voltage based on the constant value received from the accepting unit. The control unit 18 may update the correspondence relationship between the target voltage and the power supply current Ip stored in memory based on the constant value received from the accepting unit. The time constant circuit 22 may set a time constant based on the constant value received from the accepting unit.

[0068] The smaller the constant value, the closer the line representing the correspondence relationship between the lower limit current threshold Th2 and the power supply voltage Vp is to the line representing the correspondence relationship between the upper limit current threshold Th1 and the power supply voltage Vp. Therefore, the smaller the constant value, the closer the power supply voltage Vp is controlled to the line representing the correspondence relationship between the upper limit current threshold Th1 and the power supply voltage Vp, and the greater the effect of reducing power consumption. The smaller the constant value, the narrower the range over which the power supply current Ip can change at the same power supply voltage Vp, and the more frequently the power supply voltage Vp needs to be adjusted.

[0069] On the other hand, the larger the constant value, the farther the line representing the correspondence relationship between the lower limit current threshold Th2 and the power supply voltage Vp moves from the line representing the correspondence relationship between the upper limit current threshold Th1 and the power supply voltage Vp. Therefore, the larger the constant value, the farther the power supply voltage Vp may become from the line representing the correspondence relationship between the upper limit current threshold Th1 and the power supply voltage Vp, which may reduce the effect of reducing power consumption. The larger the constant value, the wider the range over which the power supply current Ip can change at the same power supply voltage Vp, and the more likely it is that the power supply voltage Vp will need to be adjusted less frequently.

[0070] According to this configuration example, the control characteristics of the power supply voltage Vp can be changed depending on the application of the amplifying device 1, etc.

[0071] The present invention has been described above based on the embodiments. These embodiments are merely examples, and it will be understood by those skilled in the art that various modifications are possible in the combination of the components and treatment processes, and that such modifications are also within the scope of the present invention.

[0072] This disclosure will contribute to the realization of the SDG "take urgent action to combat climate change" and includes matters that contribute to the reduction of GHG emissions. [Explanation of symbols]

[0073] 1...amplification device, 10...power supply device, 12...power supply unit, 14...current detection unit, 16...acquisition unit, 18...control unit, 20...comparator, 22...time constant circuit, 26...processing unit, 50...amplifier

Claims

1. a power supply unit that supplies a set power supply voltage to the amplifier; a current detection unit that detects a power supply current supplied from the power supply unit to the amplifier; an acquisition unit that stores a relationship between the power supply voltage and an upper limit current threshold value in advance, and detects the power supply voltage and acquires the corresponding upper limit current threshold value; a control unit that controls the power supply unit to increase the power supply voltage when the power supply current detected by the current detection unit becomes equal to or greater than the upper limit current threshold value acquired by the acquisition unit; and A power supply device comprising:

2. the acquisition unit stores a relationship between the power supply voltage and a lower limit current threshold value in advance, detects the power supply voltage, and acquires the corresponding lower limit current threshold value; the control unit controls the power supply unit to reduce the power supply voltage when the power supply current detected by the current detection unit becomes equal to or less than the lower limit current threshold value acquired by the acquisition unit.

2. The power supply device according to claim 1.

3. the control unit controls the power supply unit so that the power supply voltage increases to a first voltage when the power supply current detected by the current detection unit becomes equal to or greater than the upper limit current threshold value acquired by the acquisition unit; the control unit controls the power supply unit so that the power supply voltage decreases to a second voltage when the power supply current detected by the current detection unit becomes equal to or less than the lower limit current threshold value acquired by the acquisition unit.

3. The power supply device according to claim 2.

4. when the power supply voltage is a third voltage and the power supply current is the upper limit current threshold, the first voltage is an intermediate voltage between the power supply voltage corresponding to the lower limit current threshold that is equal to the power supply current and the third voltage; when the power supply voltage is a fourth voltage and the power supply current is the lower limit current threshold, the second voltage is an intermediate voltage between the power supply voltage corresponding to the upper limit current threshold that is equal to the power supply current and the fourth voltage; 4. The power supply device according to claim 3.

5. An amplifier; a power supply for the amplifier; The power supply device a power supply unit that supplies a set power supply voltage to the amplifier; a current detection unit that detects a power supply current supplied from the power supply unit to the amplifier; an acquisition unit that stores a relationship between the power supply voltage and an upper limit current threshold value in advance, and detects the power supply voltage and acquires the corresponding upper limit current threshold value; a control unit that controls the power supply unit to increase the power supply voltage when the power supply current detected by the current detection unit becomes equal to or greater than the upper limit current threshold value acquired by the acquisition unit; and An amplifier comprising:

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