Current driver device

Abstract

The present application provides a current driver device capable of controlling the operating point voltage of a current driver circuit within a prescribed operating range and capable of suppressing reduction in drive current for driving a load including a capacitor. The current driver device for supplying a predetermined drive current to a load including a capacitor via an output terminal includes: a current driver circuit having an output section connected to the output terminal, driven by a supply voltage, and outputting an output alternating current from the output section in accordance with an input alternating voltage; a charging circuit charging a capacitor of the load and setting the voltage of the output terminal to an initial bias voltage; a drive current adjustment circuit detecting an alternating voltage, i.e., a monitoring voltage, generated at the output section of the current driver circuit, and applying an adjustment direct current to an adjustment terminal between the output section of the current driver circuit and the output terminal on the basis of the detection result of the monitoring voltage; and a control circuit controlling the current driver circuit, the charging circuit, and the drive current adjustment circuit.

Description

[0001] Related application: This application enjoys priority based on Japanese Patent Application No. 2025-045612 (filed on March 19, 2025). This application incorporates the entire contents of the basic application by reference to that basic application. Technical Field

[0002] Embodiments of the present invention relate to a current driver device. Background Technology

[0003] Previously, there were current driver devices for AC driving loads, including capacitors, such as LC loads. In such existing current driver devices, it is necessary to control the operating point voltage of the current driver device within a specified operating range. Summary of the Invention

[0004] Embodiments of the present invention provide a current driver device that can control the operating point voltage of the current driver circuit within a specified operating range and can suppress the reduction of the drive current driving a load including a capacitor.

[0005] The current driver device according to the embodiments is used to supply a preset drive current to a load including a capacitor via an output terminal. It is characterized by comprising: a current driver circuit having an output section connected to the output terminal, which is driven by a power supply voltage and outputs an AC current from the output section according to an input AC voltage; a charging circuit that charges the capacitor of the load and sets the voltage of the output terminal to an initial bias voltage; a drive current adjustment circuit that detects the AC voltage generated at the output section of the current driver circuit, i.e., a monitoring voltage, and applies an adjustment DC current to an adjustment terminal between the output section of the current driver circuit and the output terminal based on the detection result of the monitoring voltage; and a control circuit that controls the current driver circuit, the charging circuit, and the drive current adjustment circuit. Attached Figure Description

[0006] Figure 1 This is a diagram illustrating an example of the structure of the current driver device according to the first embodiment.

[0007] Figure 2 It means in Figure 1 The diagram shows an example of the waveforms of the AC voltage generated in the current driver circuit of the current driver device, namely the monitoring voltage (operating point voltage), the peak detection voltage of the monitoring voltage, and the valley detection voltage.

[0008] Figure 3 It means Figure 1The diagram shows an example of the waveforms of the drive current output by the current driver device, the adjustment DC current used to adjust the drive current, and the operating point voltage of the AC voltage generated in the current driver circuit.

[0009] Figure 4 This is a diagram illustrating an example of the structure of the current driver device according to the second embodiment.

[0010] Figure 5 It means Figure 4 The diagram illustrates an example of the relationship between the driving period and the stopping period of the current driver circuit of the shown current driver device and the operation of the drive current adjustment circuit.

[0011] Figure 6 It means Figure 5 The figure shows an example of the relationship between the monitoring voltage V1 and the reference voltage and the voltage comparison result information during the driving period of the current driver circuit of the current driver device shown.

[0012] Explanation of reference numerals in the attached figures

[0013] 100 and 200 current driver devices

[0014] A current driver circuit

[0015] W charging circuit

[0016] Y, Y200 drive current adjustment circuit

[0017] CNT control circuit Detailed Implementation

[0018] Hereinafter, the current driver device according to embodiments will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to these embodiments.

[0019] (First Implementation)

[0020] [Current Driver Device]

[0021] Figure 1 This is a diagram illustrating an example of the structure of the current driver device according to the first embodiment. Figure 2 It means in Figure 1 The diagram shows an example of the waveforms of the AC voltage generated in the current driver circuit of the current driver device, namely the monitoring voltage (operating point voltage), the peak detection voltage of the monitoring voltage, and the valley detection voltage. Figure 3 It means Figure 1 The diagram shows an example of the waveforms of the drive current output by the current driver device, the adjustment DC current used to adjust the drive current, and the operating point voltage of the AC voltage generated in the current driver circuit.

[0022] The current driver device 100 of the first embodiment is, for example, as shown in... Figure 1 As shown, a preset drive current IX is supplied to the load X, including the capacitor CX, via the output terminal TX.

[0023] In addition, Figure 1 In the example shown, the load X includes a capacitor CX and an inductor LX connected in series with the capacitor CX. In this embodiment, it is assumed that the load X includes at least the capacitor CX.

[0024] The current driving device 100 of the first embodiment is, for example, as shown in the example... Figure 1 As shown, it includes a current driver circuit A, a charging circuit W, a drive current adjustment circuit Y, and a control circuit CNT.

[0025] Hereinafter, these structures of the current driver device 100 of the first embodiment will be described in detail.

[0026] [Current Driver Circuit]

[0027] The current driver circuit A has an output section A1 connected between the power supply and ground and connected to the output terminal TX. During operation, the current driver circuit A is driven by a power supply voltage VDD, and outputs an AC current I1 from the output section A1 according to the input AC voltage VAC.

[0028] The current driver circuit A has, for example, a general structure, with the general characteristics that the output AC current I1 is constant regardless of load deviation, temperature, or power supply, and that the phase of the output AC current I1 is constant regardless of load deviation.

[0029] [Charging Circuit]

[0030] The charging circuit W charges the capacitor CX of the load X and sets the voltage at the output terminal TX to the initial bias voltage.

[0031] The charging circuit W is, for example, as follows: Figure 1 As shown, it has a switching circuit SW controlled by the control circuit CNT.

[0032] The switching circuit SW is, for example, as follows: Figure 1 As shown, it is connected between the charging terminal TVC, which is subjected to the charging voltage VC, and the output terminal TX.

[0033] Furthermore, the switching circuit SW becomes conductive by connecting the charging terminal TVC and the output terminal TX, or becomes disconnected by disconnecting.

[0034] For example, the charging circuit W connects the charging terminal TVC and the output terminal TX to make them conductive, charging the capacitor CX of the load X, and setting the voltage of the output terminal TX to the initial bias voltage (here, the charging voltage VC).

[0035] In addition, the charging voltage VC is, for example, the voltage at the midpoint between the power supply voltage VDD and the ground voltage GND.

[0036] in addition, Figure 1 The structure of the charging circuit W shown is one example, but it can also be constructed from other structures that can perform the same function.

[0037] [Drive Current Adjustment Circuit]

[0038] The drive current adjustment circuit Y detects the AC voltage generated at the output section A1 of the current driver circuit A, i.e., the monitoring voltage V1. Based on the detection result of the monitoring voltage V1, the adjustment DC current IY is applied to the adjustment terminal Y2 between the output section A1 of the current driver circuit A and the output terminal TX.

[0039] Therefore, the drive current IX is the sum of the output AC current I1 from the current driver circuit A and the adjustment DC current IY from the drive current adjustment circuit Y. Furthermore, the adjustment DC current IY from the drive current adjustment circuit Y is set within a range of current values ​​from positive to negative.

[0040] The drive current adjustment circuit Y is, for example, as shown in... Figure 1 As shown, it includes a detection circuit D and a DC current adjustment circuit G.

[0041] [Detection Circuit]

[0042] The detection circuit D detects the waveform of the AC voltage (operating point voltage) generated at the output A1 of the current driver circuit A, i.e., the monitoring voltage V1, and outputs the detection result of the monitoring voltage V1 waveform (e.g., Figure 2 The peak detection voltage and valley detection voltage are shown.

[0043] Additionally, the waveform of the monitoring voltage (operating point voltage) V1, generated by the current driver circuit A based on the AC current output from the input AC voltage VAC, fluctuates. Therefore, for example, as... Figure 2 As shown, the detection circuit D performs peak detection processing and valley detection processing to detect voltage fluctuations.

[0044] That is, the detection circuit D is, for example, as follows: Figure 1 As shown, it has a peak detection circuit DP and a valley detection circuit DB.

[0045] The peak detection circuit DP detects the peak value of the monitoring voltage (operating point voltage) V1 output from the output A1 via the monitoring terminal Y1 connected to the output A1 of the current driver circuit A.

[0046] For example, the peak detection circuit DP detects the monitoring voltage (operating point voltage) V1 output from the output unit A1 via the monitoring terminal Y1, thereby detecting the peak detection voltage corresponding to the peak value of the waveform of the monitoring voltage V1. Figure 2 ).

[0047] The valley detection circuit DB detects the valley value of the monitoring voltage (operating point voltage) V1 output from the output A1 via the monitoring terminal Y1 connected to the output A1 of the current driver circuit A.

[0048] For example, the valley detection circuit DB detects the monitoring voltage (operating point voltage) V1 output from the output unit A1 via the monitoring terminal Y1, thereby detecting the valley detection voltage corresponding to the valley value of the waveform of the monitoring voltage V1. Figure 2 ).

[0049] [DC Current Adjustment Circuit]

[0050] The DC current adjustment circuit G applies a positive or negative adjustment DC current IY to the adjustment terminal Y2 between the output section A1 of the current driver circuit A and the output terminal TX, based on the comparison result of comparing the waveform of the monitoring voltage V1 output by the detection circuit D with the power supply voltage VDD and / or the ground voltage GND.

[0051] In this first embodiment, the DC current adjustment circuit G is, for example, as shown in the example below. Figure 1 As shown, it includes a first differential voltage detection circuit GP, a second differential voltage detection circuit GB, and a DC current output circuit DGC1.

[0052] [First Differential Voltage Detection Circuit]

[0053] The first differential voltage detection circuit GP receives information about the peak detection voltage and the power supply voltage VDD detected by the peak detection circuit DP (e.g., the peak detection voltage and the power supply voltage VDD).

[0054] Furthermore, the first differential voltage detection circuit GP detects the difference between the peak detection voltage detected by the peak detection circuit DP and the power supply voltage VDD, which is the first differential voltage, and outputs information related to the first differential voltage (e.g., the voltage corresponding to the first differential voltage).

[0055] [Second Differential Voltage Detection Circuit]

[0056] The second differential voltage detection circuit GB receives information about the valley detection voltage and ground voltage GND detected by the valley detection circuit DB (e.g., the valley detection voltage and ground voltage GND).

[0057] Furthermore, the second differential voltage detection circuit GB detects the difference between the valley detection voltage detected by the valley detection circuit DB and the ground voltage GND, which is the second differential voltage, and outputs information related to the second differential voltage (e.g., the voltage corresponding to the second differential voltage).

[0058] [DC Current Output Circuit]

[0059] The DC current output circuit DGC1 controls the adjustment DC current IY and outputs it to the adjustment terminal Y2 in a manner that makes the difference between the first differential voltage and the second differential voltage close to a preset reference value.

[0060] Furthermore, for example, the reference value can also be zero. In this case, the DC current output circuit DCG1 controls and outputs an adjustment DC current IY in a manner that makes the first differential voltage equal to the second differential voltage.

[0061] In addition, the above-mentioned Figure 1 The structure of the drive current adjustment circuit Y shown is one example, but it can also be constructed from other structures that can perform the same function.

[0062] [Control Circuit]

[0063] In addition, the control circuit CNT controls the current driver circuit A, the charging circuit W, and the drive current adjustment circuit Y.

[0064] For example, during the stop period before the start of the current driver circuit A, the control circuit CNT turns on the switching circuit SW, causing the capacitor CX of the load X to be charged to the initial bias voltage by the charging voltage VC.

[0065] Furthermore, as mentioned above, the charging voltage VC is the voltage at the midpoint between the power supply voltage VDD and the ground voltage GND.

[0066] After the control circuit CNT charges the capacitor CX of the load X to the initial bias voltage with the charging voltage VC, and after the switching circuit SW is turned off, the current driver circuit A is started to drive during the drive.

[0067] [Operation of the current driver device]

[0068] Next, an example of the operation of the current driver device 100 having the above structure will be described.

[0069] For example, during the stop period before the current driver circuit A starts driving, the control circuit CNT turns on the switching circuit SW, so that the capacitor CX of the load X is charged to the initial bias voltage by the charging voltage VC.

[0070] Furthermore, after the control circuit CNT charges the capacitor CX of the load X to the initial bias voltage with the charging voltage VC, and after disconnecting the switching circuit SW, it starts the drive of the current driver circuit A during the drive period.

[0071] During this driving period, the drive current adjustment circuit Y detects the AC voltage generated at the output A1 of the current driver circuit A, i.e., the monitoring voltage V1. Based on the detection result of the monitoring voltage V1, the adjustment DC current IY is applied to the adjustment terminal Y2 between the output A1 of the current driver circuit A and the output terminal TX.

[0072] For example, the detection circuit D of the drive current adjustment circuit Y detects the waveform of the AC voltage (operating point voltage) generated at the output A1 of the current driver circuit A, i.e., the monitoring voltage V1, and outputs the detection result of the monitoring voltage V1 waveform (e.g., Figure 2 The peak detection voltage and valley detection voltage are shown.

[0073] In this case, the peak detection circuit DP of the detection circuit D detects the peak value of the monitoring voltage (operating point voltage) V1 output from the output A1 via the monitoring terminal Y1 connected to the output A1 of the current driver circuit A.

[0074] For example, the peak detection circuit DP detects the monitoring voltage (operating point voltage) V1 output from the output unit A1 via the monitoring terminal Y1, thereby detecting the peak detection voltage corresponding to the peak value of the waveform of the monitoring voltage V1. Figure 2 ).

[0075] Furthermore, the valley detection circuit DB of the detection circuit D detects the valley value of the monitoring voltage (operating point voltage) V1 output from the output A1 via the monitoring terminal Y1 connected to the output A1 of the current driver circuit A.

[0076] For example, the valley detection circuit DB detects the monitoring voltage (operating point voltage) V1 output from the output unit A1 via the monitoring terminal Y1, thereby detecting the valley detection voltage corresponding to the valley value of the waveform of the monitoring voltage V1. Figure 2 ).

[0077] Furthermore, the DC current adjustment circuit G of the drive current adjustment circuit Y applies a positive or negative adjustment DC current IY to the adjustment terminal Y2 between the output section A1 of the current driver circuit A and the output terminal TX based on the comparison result of the detection result of the waveform of the monitoring voltage V1 output by the detection circuit D and the power supply voltage VDD and / or ground voltage GND.

[0078] For example, the first differential voltage detection circuit GP of the DC current adjustment circuit G detects the difference between the peak detection voltage detected by the peak detection circuit DP and the power supply voltage VDD, which is the first differential voltage, and outputs information related to the first differential voltage (e.g., the voltage corresponding to the first differential voltage).

[0079] Furthermore, the second differential voltage detection circuit GB of the DC current adjustment circuit G detects the difference between the valley detection voltage detected by the valley detection circuit DB and the ground voltage GND, which is the second differential voltage, and outputs information related to the second differential voltage (e.g., the voltage corresponding to the second differential voltage).

[0080] Furthermore, the DC current output circuit DGC1 of the DC current adjustment circuit G makes the difference between the first differential voltage and the second differential voltage close to a preset reference value. Figure 3 In this manner, the DC current IY for adjustment is controlled and output to the adjustment terminal Y2.

[0081] Furthermore, for example, the reference value can also be zero. In this case, the DC current output circuit DCG1 controls and outputs an adjustment DC current IY in a manner that makes the first differential voltage equal to the second differential voltage.

[0082] Through the operation of the current driver device 100 during the aforementioned driving period, for example, Figure 3 As shown, the operating point voltage of the current driver circuit A of the current driver device 100 can be controlled within a specified operating range (normal operating range), and the reduction of the drive current for driving loads including capacitors can be suppressed.

[0083] That is, the current driver device according to the first embodiment can control the operating point voltage of the current driver circuit within a specified operating range (normal operating range) and can suppress the reduction of the drive current driving the load including the capacitor.

[0084] (Second Implementation)

[0085] Here, in the first embodiment already described, an example of the structure of a current driver device performing analog signal processing was given. However, the structure of this current driver device is not limited to this. Therefore, in this second embodiment, an example of the structure of a current driver device performing digital signal processing will be given.

[0086] Figure 4 This is a diagram illustrating an example of the structure of the current driver device according to the second embodiment. Additionally, Figure 5 It means Figure 4 The diagram illustrates an example of the relationship between the driving period and the stopping period of the current driver circuit in the shown current driver device and the operation of the drive current adjustment circuit. Additionally, Figure 6 It means Figure 5 The figure shows an example of the relationship between the monitoring voltage V1 and the reference voltage and the voltage comparison result information during the driving period of the current driver circuit of the current driver device shown.

[0087] Furthermore, in the following description of the current driver device of the second embodiment, the description of structures marked with the same reference numerals as in the first embodiment will be omitted.

[0088] For example, Figure 4 As shown, the current driver device 200 of the second embodiment supplies a preset drive current IX to a load X including a capacitor CX via the output terminal TX.

[0089] The current driver device 200 of the second embodiment is, for example, as shown in... Figure 1 As shown, it includes a current driver circuit A, a charging circuit W, a drive current adjustment circuit Y200, and a control circuit CNT.

[0090] The structure of the current driver device 200 according to the second embodiment will be described in detail below.

[0091] [Drive Current Adjustment Circuit]

[0092] The drive current adjustment circuit 200Y detects the AC voltage generated in the output section A1 of the current driver circuit A, i.e., the monitoring voltage V1. Based on the detection result of the monitoring voltage V1, the adjustment DC current IY is applied to the adjustment terminal Y2 between the output section A1 of the current driver circuit A and the output terminal TX.

[0093] Therefore, the drive current IX is the sum of the output AC current I1 from the current driver circuit A and the adjustment DC current IY from the drive current adjustment circuit Y. Furthermore, the adjustment DC current IY from the drive current adjustment circuit Y is set within a range of current values ​​from positive to negative.

[0094] The drive current adjustment circuit Y200 is, for example, as follows: Figure 4 As shown, it includes a detection circuit D200, a DC current adjustment circuit G200, and a logic circuit Z.

[0095] Thus, the drive current adjustment circuit Y200 of the current driver device 200 of the second embodiment, compared with the drive current adjustment circuit Y of the current driver device 100 of the first embodiment, also includes a logic circuit Z for performing digital signal processing.

[0096] That is, the structure of the drive current adjustment circuit Y200 is different from that of the drive current adjustment circuit Y in the first embodiment that performs analog signal processing in terms of performing digital signal processing.

[0097] [Detection Circuit]

[0098] The detection circuit D200 detects the waveform of the AC voltage generated at the output A1 of the current driver circuit A, i.e., the monitoring voltage V1, and outputs the detection result of the monitoring voltage V1 waveform.

[0099] The detection circuit D200 is, for example, as follows: Figure 4 As shown, it includes a reference voltage setting circuit DREF, a comparator DT, and a first memory DM1.

[0100] [Reference Voltage Setting Circuit]

[0101] The reference voltage setting circuit DREF sets and outputs any one of multiple reference voltages VREF.

[0102] For example, the reference voltage setting circuit DREF outputs the reference voltage VREF in a way that causes the value to change in stages.

[0103] In particular, the reference voltage setting circuit DREF generates and outputs the value of the reference voltage VREF in stages at time intervals longer than the period of the monitored voltage (operating point voltage) V1. Figure 6 ).

[0104] [Comparator]

[0105] The comparator DT sequentially compares the reference voltage VREF output by the reference voltage setting circuit DREF with the monitoring voltage V1, and outputs the voltage comparison result information corresponding to the comparison result. Figure 6 ).

[0106] [First Memory]

[0107] The first memory DM1 stores and outputs the voltage comparison result information output from the comparator DT.

[0108] The detection circuit D200 outputs (transmits) the voltage comparison result information stored in the first memory DM1 as the detection result of the waveform of the monitoring voltage V1 to the DC current adjustment circuit G200.

[0109] [DC Current Adjustment Circuit]

[0110] The DC current adjustment circuit G200 applies a positive or negative adjustment DC current IY to the adjustment terminal Y2 between the output section A1 of the current driver circuit A and the output terminal TX, based on the voltage comparison result information output by the detection circuit D.

[0111] In this second embodiment, the DC current adjustment circuit G200 is, for example, as shown in the example... Figure 4 As shown, it has a second memory GM2, a decoder GDE, and a DC current output circuit DGC2.

[0112] [Second Memory]

[0113] The second memory GM2 stores the voltage comparison result information transferred from the first memory DM1.

[0114] [Decoder]

[0115] The decoder GDE decodes the voltage comparison results stored in the second memory GM2, obtains and outputs the setting data for setting the value of the DC current IY used for adjustment.

[0116] [DC Current Output Circuit]

[0117] The DC current output circuit DGC2 sets the value of the adjustment DC current IY based on the set data, and outputs the set value of the adjustment DC current IY to the adjustment terminal Y2.

[0118] [Logic Circuits]

[0119] Logic circuit Z, for example Figure 4 As shown, the operation of the control detection circuit D200 and the DC current adjustment circuit G200 is controlled.

[0120] The logic circuit Z controls, for example, the reference voltage setting circuit DREF, the comparator DT, the first memory DM1, and the second memory GM2 according to the control signal output from the control circuit CNT.

[0121] For example, during the driving period of current driver circuit A, H1 ( Figure 5 , Figure 6 The logic circuit Z causes the decoder GDE to decode the voltage comparison result information stored in the second memory GM2 during the last stop period T1, thereby obtaining and outputting the setting data for setting the value of the DC current IY for adjustment.

[0122] Furthermore, during this drive, H1 ( Figure 5 , Figure 6The logic circuit Z causes the DC current output circuit DGC2 to set the value of the adjustment DC current IY based on the set data, and outputs the set value of the adjustment DC current IY to the adjustment terminal Y2.

[0123] For example, Figure 5 , Figure 6 As shown, during the driving period H1, the logic circuit Z outputs the reference voltage VREF by changing the value of the reference voltage VREF in stages through the reference voltage setting circuit DREF.

[0124] And, for example, Figure 5 , Figure 6 As shown, during the driving period H1, the logic circuit Z compares the reference voltage VREF output by the reference voltage setting circuit DREF with the monitoring voltage V1 through the comparator DT, and outputs the voltage comparison result information (L: low level / H: high level) corresponding to the comparison result.

[0125] For example, the comparator DT compares the reference voltage VREF with the monitoring voltage V1. When the monitoring voltage V1 crosses the reference voltage VREF (V1 crosses VREF from low voltage to high voltage or from high voltage to low voltage), it outputs the voltage comparison result information (H: high level) corresponding to the comparison result.

[0126] On the other hand, the comparator DT compares the reference voltage VREF with the monitoring voltage V1. If the monitoring voltage V1 is always higher or lower than the reference voltage VREF during the detection period, it outputs the voltage comparison result information (L: low level) corresponding to the comparison result.

[0127] Here, in Figure 6 In the example, ○ represents the detection period of comparator DT, and △ represents the latching and reset period of comparator DT and the period of reference voltage change. The normal operating range of current driver circuit A is defined by preset upper and lower limits.

[0128] For example, Figure 6 As shown, during the driving period H1, the reference voltage VREF is output by means of the reference voltage setting circuit DREF, so that the value of the reference voltage VREF increases in stages.

[0129] Moreover, in Figure 6In the example, comparator DT confirms the range of the operating point voltage on the valley side. Since the monitored voltage V1 is always higher than the reference voltage VREF during the drive period H1, it outputs voltage comparison result information (L, L, L, L). Furthermore, comparator DT confirms the range of the operating point voltage on the peak side. Since the monitored voltage V1 changes from a state higher than the reference voltage VREF to a state lower than the reference voltage VREF during the drive period H1, it outputs voltage comparison result information (H, H, H, L). Based on the voltage comparison result information (L, L, L, L) confirming the operating point voltage on the valley side and the voltage comparison result information (H, H, H, L) confirming the range of the operating point voltage on the peak side, the operating point state of the monitored voltage V1 can be determined.

[0130] Moreover, for example, Figure 5 , Figure 6 As shown, during the driving period H1, the logic circuit Z stores the voltage comparison result information output from the comparator DT through the first memory DM1.

[0131] For example, Figure 5 As shown, during the stop period T2 when the current driver circuit A stops following the drive period H1, the logic circuit Z transmits the voltage comparison result information stored in the first memory DM1 to the second memory GM2, as voltage comparison result information to be used in the next drive period H2 following the stop period T2.

[0132] Furthermore, driving the current driver circuit A is not limited to supplying drive current IX to the load X; it can also be that the logic circuit Z specifically operates the current driver circuit A to set the value of the adjustment DC current IY.

[0133] Furthermore, when the current driver circuit A is first started, the drive current adjustment circuit Y200 (logic circuit Z) can also set the adjustment DC current IY to an initial current value (e.g., zero) (setting the voltage comparison result information recorded in the second memory GM2 to a preset initial value).

[0134] [Operation of the current driver device]

[0135] Next, an example of the operation of the current driver device 200 having the above structure will be described.

[0136] For example, Figure 5 As shown, the control circuit CNT, for example, during the stop period T1 before the start of the current driver circuit A, turns on the switching circuit SW, so that the capacitor CX of the load X is charged to the initial bias voltage by the charging voltage VC.

[0137] Furthermore, after the control circuit CNT charges the capacitor CX of the load X to the initial bias voltage with the charging voltage VC, and after the switching circuit SW is disconnected, the current driver circuit A is started to drive during the drive period by the control circuit CNT.

[0138] Furthermore, the logic circuit Z controls, for example, the reference voltage setting circuit DREF, the comparator DT, the first memory DM1, and the second memory GM2 according to the control signal output from the control circuit CNT.

[0139] For example, during the driving period of current driver circuit A, H1 ( Figure 5 , Figure 6 The logic circuit Z causes the decoder GDE to decode the voltage comparison result information stored in the second memory GM2 during the last stop period T1, thereby obtaining and outputting the setting data for setting the value of the DC current IY for adjustment.

[0140] Furthermore, during this drive, H1 ( Figure 5 , Figure 6 The logic circuit Z causes the DC current output circuit DGC2 to set the value of the adjustment DC current IY based on the set data, and outputs the set value of the adjustment DC current IY to the adjustment terminal Y2.

[0141] For example, Figure 5 , Figure 6 As shown, during the driving period H1, the logic circuit Z outputs the reference voltage VREF by changing the value of the reference voltage VREF in stages through the reference voltage setting circuit DREF.

[0142] And, for example, Figure 5 , Figure 6 As shown, during the driving period H1, the logic circuit Z compares the reference voltage VREF output by the reference voltage setting circuit DREF with the monitoring voltage V1 through the comparator DT, and outputs the voltage comparison result information (L: low level / H: high level) corresponding to the comparison result.

[0143] Moreover, for example, Figure 5 , Figure 6 As shown, during the driving period H1, the logic circuit Z stores the voltage comparison result information output from the comparator DT through the first memory DM1.

[0144] For example, Figure 5As shown, during the stop period T2 after the drive period H1, when the current driver circuit A stops, the logic circuit Z transmits the voltage comparison result information stored in the first memory DM1 to the second memory GM2, as voltage comparison result information to be used in the next drive period H2 after the stop period T2.

[0145] Furthermore, the second memory GM2, for example, Figure 5 As shown, the voltage comparison result information transmitted from the first memory DM1 is stored.

[0146] Furthermore, the decoder GDE decodes the voltage comparison result information stored in the second memory GM2, obtains and outputs the setting data for setting the value of the DC current IY for adjustment.

[0147] Furthermore, the DC current output circuit DGC2, for example, Figure 5 As shown, the value of the adjustment DC current IY is set based on the set data, and the set value of the adjustment DC current IY is output to the adjustment terminal Y2.

[0148] In this case, for example, the DC current output circuit DCG2 controls and outputs the adjustment DC current IY based on setting data representing the relationship between the reference voltage VREF and the monitoring voltage V1, so that the monitoring voltage V1 converges within the range of the normal operating range of the current driver circuit A as defined by the preset upper and lower limits.

[0149] By operating the current driver device 200 during the aforementioned driving period, the operating point voltage of the current driver circuit A of the current driver device 200 can be controlled within a specified operating range (normal operating range), and the reduction of the driving current for driving loads including capacitors can be suppressed.

[0150] That is, the current driver device according to the second embodiment can control the operating point voltage within a specified operating range (the range of normal operation) and can suppress the reduction of the drive current driving the load including the capacitor.

[0151] Several embodiments of the present invention have been described, but these embodiments are merely illustrative and not intended to limit the scope of the invention. These new embodiments can be implemented in various other ways, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included within the scope and spirit of the invention, and are also included within the scope of the invention as described in the claims and its equivalents.

Claims

1. A current driver device for supplying a preset drive current to a load including a capacitor via an output terminal, characterized in that, have: The current driver circuit has an output section connected to the output terminal, is driven by a power supply voltage, and outputs an AC current from the output section according to the input AC voltage. The charging circuit charges the capacitor of the load and sets the voltage of the output terminal to the initial bias voltage. The drive current adjustment circuit detects the AC voltage generated at the output of the current driver circuit, i.e., the monitoring voltage, and applies an adjustment DC current to the adjustment terminal between the output of the current driver circuit and the output terminal based on the detection result of the monitoring voltage. as well as The control circuit controls the current driver circuit, the charging circuit, and the drive current adjustment circuit.

2. The current driver device according to claim 1, characterized in that, The charging circuit includes a switching circuit connected between the charging terminal to which a charging voltage is applied and the output terminal. The switching circuit is in a conducting state by connecting the charging terminal and the output terminal, or in a cutting state by disconnecting the charging terminal and the output terminal.

3. The current driver device according to claim 2, characterized in that, The control circuit is, During the stop period before the current driver circuit starts driving, the switching circuit is turned on to charge the capacitor of the load to the initial bias voltage using the charging voltage. Subsequently, after the switching circuit is turned off, the current driver circuit is driven during the driving process.

4. The current driver device according to claim 2, characterized in that, The charging voltage is the voltage at the midpoint between the power supply voltage and the ground voltage.

5. The current driver device according to claim 2, characterized in that, The drive current adjustment circuit includes: The detection circuit detects the waveform of the AC voltage generated at the output of the current driver circuit, i.e., the monitoring voltage, and outputs the detection result of the monitoring voltage waveform. as well as The DC current adjustment circuit applies an adjustment DC current to the adjustment terminal between the output section of the current driver circuit and the output terminal, based on the detection result of the waveform of the monitoring voltage output by the detection circuit.

6. The current driver device according to claim 3, characterized in that, The drive current adjustment circuit includes: The detection circuit detects the waveform of the AC voltage generated at the output of the current driver circuit, i.e., the monitoring voltage, and outputs the detection result of the monitoring voltage waveform. as well as The DC current adjustment circuit applies an adjustment DC current to the adjustment terminal between the output section of the current driver circuit and the output terminal, based on the detection result of the waveform of the monitoring voltage output by the detection circuit.

7. The current driver device according to claim 4, characterized in that, The drive current adjustment circuit includes: The detection circuit detects the waveform of the AC voltage generated at the output of the current driver circuit, i.e., the monitoring voltage, and outputs the detection result of the monitoring voltage waveform. as well as The DC current adjustment circuit applies an adjustment DC current to the adjustment terminal between the output section of the current driver circuit and the output terminal, based on the detection result of the waveform of the monitoring voltage output by the detection circuit.

8. The current driver device according to claim 5, characterized in that, The detection circuit includes: A peak detection circuit detects a peak detection voltage corresponding to the peak value of the waveform of the monitored voltage; and The valley detection circuit detects the valley detection voltage corresponding to the valley value of the waveform of the monitored voltage. The DC current adjustment circuit includes: The first differential voltage detection circuit detects the difference between the peak detection voltage detected by the peak detection circuit and the power supply voltage, which is the first differential voltage. The second differential voltage detection circuit detects the difference between the valley detection voltage detected by the valley detection circuit and the ground voltage, which is the second differential voltage. as well as A DC current output circuit controls the adjustment DC current and outputs it to the adjustment terminal in such a way that the difference between the first differential voltage and the second differential voltage is close to a preset reference value.

9. The current driver device according to claim 6, characterized in that, The detection circuit includes: A peak detection circuit detects a peak detection voltage corresponding to the peak value of the waveform of the monitored voltage; and The valley detection circuit detects the valley detection voltage corresponding to the valley value of the waveform of the monitored voltage. The DC current adjustment circuit includes: The first differential voltage detection circuit detects the difference between the peak detection voltage detected by the peak detection circuit and the power supply voltage, which is the first differential voltage. The second differential voltage detection circuit detects the difference between the valley detection voltage detected by the valley detection circuit and the ground voltage, which is the second differential voltage. as well as A DC current output circuit controls the adjustment DC current and outputs it to the adjustment terminal in such a way that the difference between the first differential voltage and the second differential voltage is close to a preset reference value.

10. The current driver device according to claim 7, characterized in that, The detection circuit includes: A peak detection circuit detects a peak detection voltage corresponding to the peak value of the waveform of the monitored voltage; and The valley detection circuit detects the valley detection voltage corresponding to the valley value of the waveform of the monitored voltage. The DC current adjustment circuit includes: The first differential voltage detection circuit detects the difference between the peak detection voltage detected by the peak detection circuit and the power supply voltage, which is the first differential voltage. The second differential voltage detection circuit detects the difference between the valley detection voltage detected by the valley detection circuit and the ground voltage, which is the second differential voltage. as well as A DC current output circuit controls the adjustment DC current and outputs it to the adjustment terminal in such a way that the difference between the first differential voltage and the second differential voltage is close to a preset reference value.

11. The current driver device according to claim 8, characterized in that, The DC current output circuit controls and outputs the adjustment DC current in such a way that the first differential voltage is equal to the second differential voltage.

12. The current driver device according to claim 9, characterized in that, The DC current output circuit controls and outputs the adjustment DC current in such a way that the first differential voltage is equal to the second differential voltage.

13. The current driver device according to claim 5, characterized in that, The current driver device also includes: The logic circuit controls the operation of the detection circuit and the DC current adjustment circuit. The detection circuit includes: A reference voltage setting circuit sets and outputs any one of a plurality of reference voltages, and outputs the reference voltage in a manner that causes the value of the reference voltage to change in stages; The comparator compares the reference voltage output by the reference voltage setting circuit with the monitoring voltage in sequence, and outputs voltage comparison result information corresponding to the comparison result. as well as A first memory stores the voltage comparison result information output from the comparator; The DC current adjustment circuit includes: The second memory stores the voltage comparison result information transmitted from the first memory; The decoder decodes the voltage comparison result information stored in the second memory to obtain and output setting data for setting the value of the adjustment DC current; as well as A DC current output circuit sets the value of the adjustment DC current based on the set data and outputs the set value of the adjustment DC current to the adjustment terminal.

14. The current driver device according to claim 6, characterized in that, The current driver device also includes: The logic circuit controls the operation of the detection circuit and the DC current adjustment circuit. The detection circuit includes: A reference voltage setting circuit sets and outputs any one of a plurality of reference voltages, and outputs the reference voltage in a manner that causes the value of the reference voltage to change in stages; The comparator compares the reference voltage output by the reference voltage setting circuit with the monitoring voltage in sequence, and outputs voltage comparison result information corresponding to the comparison result. as well as A first memory stores the voltage comparison result information output from the comparator; The DC current adjustment circuit includes: The second memory stores the voltage comparison result information transmitted from the first memory; The decoder decodes the voltage comparison result information stored in the second memory to obtain and output setting data for setting the value of the adjustment DC current; as well as A DC current output circuit sets the value of the adjustment DC current based on the set data and outputs the set value of the adjustment DC current to the adjustment terminal.

15. The current driver device according to claim 13, characterized in that, The logic circuit controls the reference voltage setting circuit, the comparator, the first memory, and the second memory. During the drive period driven by the current driver circuit, The logic circuit causes the decoder to decode the voltage comparison result information stored in the second memory during the last stop, thereby obtaining and outputting setting data for setting the value of the adjustment DC current, and causes the DC current output circuit to set the value of the adjustment DC current based on the setting data, and output the set value of the adjustment DC current to the adjustment terminal.

16. The current driver device according to claim 14, characterized in that, The logic circuit controls the reference voltage setting circuit, the comparator, the first memory, and the second memory. During the drive period driven by the current driver circuit, The logic circuit causes the decoder to decode the voltage comparison result information stored in the second memory during the last stop, thereby obtaining and outputting setting data for setting the value of the adjustment DC current, and causes the DC current output circuit to set the value of the adjustment DC current based on the setting data, and output the set value of the adjustment DC current to the adjustment terminal.

17. The current driver device according to claim 15, characterized in that, During the drive, The logic circuit is, The reference voltage is output in a manner that causes the value of the reference voltage to change in stages, through the reference voltage setting circuit. The comparator sequentially compares the reference voltage output by the reference voltage setting circuit with the monitoring voltage, and outputs voltage comparison result information corresponding to the comparison result. The first memory stores the voltage comparison result information output from the comparator.

18. The current driver device according to claim 16, characterized in that, During the drive, The logic circuit is, The reference voltage is output in a manner that causes the value of the reference voltage to change in stages, through the reference voltage setting circuit. The comparator sequentially compares the reference voltage output by the reference voltage setting circuit with the monitoring voltage, and outputs voltage comparison result information corresponding to the comparison result. The first memory stores the voltage comparison result information output from the comparator.

19. The current driver device according to claim 17, characterized in that, During the stop period following the driving period, when the current driver circuit stops, The logic circuit transmits the voltage comparison result information stored in the first memory to the second memory, and stores it in the second memory as voltage comparison result information to be used in the next drive period following the stop period.

20. The current driver device according to claim 18, characterized in that, During the stop period following the driving period, when the current driver circuit stops, The logic circuit transmits the voltage comparison result information stored in the first memory to the second memory, and stores it in the second memory as voltage comparison result information to be used in the next drive period following the stop period.

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