Power supply device

Abstract

A power supply apparatus includes: a voltage conversion circuit including a switching device operating in response to a control signal, and receiving an input voltage and generating an output voltage higher or lower than the input voltage according to a duty cycle of the control signal; and a controller that changes a duty ratio of the control signal to adjust a level of the output voltage. The controller includes: a load sensor that detects a sensing current from the switching device; and a current compensation unit that applies a compensation current to a sensing current input to the load sensor during a transition period in which the output voltage changes from the first level to the second level.

Description

TECHNICAL FIELD

[0001] The present inventive concept relates to a power supply device. BACKGROUND

[0002] A semiconductor device can include a power supply device that generates a supply voltage required for its operation using an external supply voltage supplied from an external source. For example, the power supply device can use the external supply voltage as an input voltage to generate an output voltage at a level higher or lower than that of the input voltage. The power supply device can support a function of increasing or decreasing the output voltage in response to various applications, but during a period in which the output voltage is increased or decreased, it can be erroneously determined that a load connected to the power supply device has changed, thereby causing a malfunction of the power supply device. SUMMARY

[0003] An aspect of the present inventive concept is to reflect a compensation current in a sense current in a transition period in which an output voltage of a power supply device is increased or decreased, to effectively prevent a malfunction that can occur in the power supply device due to an increase or decrease in the sense current that can be caused by a change in the output voltage even if there is no change in the load in the transition period.

[0004] According to an aspect of the present inventive concept, a power supply device can include a voltage conversion circuit including a switching device operating in response to a control signal, and configured to receive an input voltage and generate an output voltage higher or lower than the input voltage according to a duty ratio of the control signal, and a controller configured to change the duty ratio of the control signal to adjust a level of the output voltage. The controller includes a load sensor detecting a sense current from the switching device included in the voltage conversion circuit, and a current compensation unit applying a compensation current to the sense current input to the load sensor during a transition period in which the output voltage is changed from a first level to a second level.

[0005] According to an aspect of the present inventive concept, a power supply device includes a voltage conversion circuit including an input terminal, an output terminal, and a switching device configured to operate in response to a control signal, and configured to receive an input voltage through the input terminal and output an output voltage through the output terminal, and a controller configured to generate the control signal and configured to detect a sense current from a load connected to the output terminal of the voltage conversion circuit. The controller generates a compensation current based on a slew rate of the output voltage and an effective capacitance of an output capacitor connected to the output terminal of the voltage conversion circuit, and applies the compensation current to the sense current during a transition period in which a level of the output voltage is adjusted.

[0006] According to an aspect of the present inventive concept, a power supply device includes a voltage conversion circuit including an inductor, at least one switching device, and an output capacitor, and a controller configured to activate the switching device in response to a control signal and configured to detect a sense current from the voltage conversion circuit to determine a change in a load receiving an output voltage of the voltage conversion circuit. The controller subtracts a first compensation current from the sense current when a current flowing through the inductor increases without a change in the load, and adds a second compensation current to the sense current when the current flowing through the inductor decreases without a change in the load. BRIEF DESCRIPTION OF DRAWINGS

[0007] The above and other aspects, features, and advantages of the present inventive concept will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which: Figure 1 is a block diagram illustrating a power supply device according to an embodiment.

[0008] Figure 2 and Figure 3 is a view illustrating an electronic device including a power supply device according to an embodiment.

[0009] Figures 4 to 6 is a circuit diagram illustrating a DC-DC converter included in a power supply device according to an embodiment.

[0010] Figure 7A and Figure 7B is an equivalent circuit diagram illustrating an operation of a DC-DC converter included in a power supply device according to an embodiment.

[0011] Figure 8 is a graph illustrating an operation of a DC-DC converter included in a power supply device according to an embodiment.

[0012] Figure 9A and Figure 9B is a view illustrating an operation of a power supply device according to an embodiment.

[0013] Figure 10A and Figure 10B is a view illustrating an operation of a power supply device according to an embodiment.

[0014] Figure 11 and Figure 12 is a view illustrating an operation of a power supply device according to an embodiment.

[0015] Figure 13 is a block diagram illustrating a power supply device according to an embodiment.

[0016] Figure 14 and Figure 16is a view showing an operation of the power supply device.

[0017] Figure 15 and Figures 17 to 19 is a view showing an operation of the power supply device according to an example embodiment.

[0018] Figure 20 is a view showing a power supply device according to an embodiment. DETAILED DESCRIPTION

[0019] Hereinafter, preferred embodiments of the inventive concept will be described with reference to the accompanying drawings.

[0020] Figure 1 is a block diagram showing a power supply device according to an embodiment.

[0021] Referring to Figure 1 The power supply device 100 according to an embodiment can include a DC-DC converter 110 as a voltage conversion circuit, and a controller 120, etc. The DC-DC converter 110 can include a circuit having at least one switching device, such as a step-down converter, a step-up converter, a step-down-step-up converter, etc. The DC-DC converter 110 can increase or decrease a level of an input voltage, which can be a direct current voltage, to output an output voltage. Depending on the embodiment, the power supply device 100 can include a low dropout (LDO) regulator as a voltage conversion circuit, instead of the DC-DC converter 110.

[0022] The controller 120 can output a control signal CNT that controls on / off switching of a switching device included in the DC-DC converter 110. In an embodiment, the control signal CNT can be a pulse width modulation (PWM) signal having a predetermined period.

[0023] The controller 120 can include a load sensor 121, a current compensation unit 123, etc. The load sensor 121 can detect a sense current ISENSE from an output terminal of the DC-DC converter 110, and can sense a change in a load connected to the output terminal of the DC-DC converter 110 based on the sense current ISENSE. For example, the controller 120 can detect a load connected to the DC-DC converter 110. For example, when it is determined that the load has increased based on the sense current ISENSE, the controller 120 can change an operation mode of the DC-DC converter 110, or can perform an overcurrent protection operation for protecting the DC-DC converter 110.

[0024] The power supply device 100 according to the embodiment can support a dynamic voltage scaling (DVS) function that can adjust a level of an output voltage. In an embodiment, when the DVS function is activated, the power supply device 100 can adjust the level of the output voltage regardless of a change in a load connected to the output terminal of the DC-DC converter 110. For example, the controller 120 can change a duty ratio and / or a frequency of a control signal CNT output to the DC-DC converter 110 to increase or decrease the level of the output voltage of the DC-DC converter 110.

[0025] When the DVS function is activated, the controller 120 can increase or decrease the output current of the DC-DC converter 110 to increase or decrease the level of the output voltage. As the output current of the DC-DC converter 110 increases or decreases, a sense current ISENSE detected by the load sensor 121 can change. Even in the case where there is no change in the load connected to the output terminal of the DC-DC converter 110, the controller 120 can erroneously determine that the load connected to the DC-DC converter 110 increases or decreases based on the change in the sense current ISENSE, and can take subsequent actions accordingly. Thus, the power supply device 100 can experience unexpected malfunctions.

[0026] In an embodiment, during a transition time when the DVS function is activated and the level of the output voltage increases or decreases, the current compensation unit 123 of the controller 120 can provide a compensation current ICP to the load sensor 121. The compensation current ICP can be reflected to the sense current ISENSE detected by the load sensor 121 from the DC-DC converter 110. For example, a direction of the compensation current ICP, e.g., whether the current compensation unit 123 adds the compensation current ICP to the sense current ISENSE or draws a portion of the sense current ISENSE as the compensation current ICP, can be determined depending on the increase or decrease of the output voltage.

[0027] In this way, by reflecting the compensation current ICP to the sense current ISENSE in a transition period in which the level of the output voltage changes, it is possible to minimize a problem that the load sensor 121 incorrectly senses a change in the load connected to the DC-DC converter 110. Thus, it is possible to prevent malfunctions of the power supply device 100, and it is possible to improve reliability, power consumption, etc. of an electronic device including the power supply device 100.

[0028] Figure 2 and Figure 3 is a view illustrating an electronic device including a power supply device according to an embodiment.

[0029] Referring to Figure 2The electronic device according to the embodiments can be a display device 200. The display device 200 can include a display panel 210, a boost converter 220 and an inverting buck-boost converter 230 providing a power supply voltage required for the display panel 210, a controller 240, etc.

[0030] In Figure 2 the illustrated embodiment, the boost converter 220 can provide a first power supply voltage ELVDD to the display panel 210 using an input voltage supplied from a voltage source such as a battery, etc. The inverting buck-boost converter 230 can provide a second power supply voltage ELVSS to the display panel 210 using an input voltage supplied from the voltage source. For example, the first power supply voltage ELVDD from the boost converter 220 can be a positive voltage, and the second power supply voltage ELVSS output from the inverting buck-boost converter 230 can be a negative voltage.

[0031] The display panel 210 can include a plurality of pixels, and the plurality of pixels can be arranged along a plurality of scan lines and a plurality of data lines. Referring to Figure 3 , the plurality of pixels PX can each include an organic light emitting diode (OLED) device emitting light and a pixel circuit PC driving the OLED device. As Figure 3 indicated, the pixel circuit PC included in one pixel can be connected to one of the plurality of scan lines SL and one of the plurality of data lines DL.

[0032] Referring to Figure 3 , an anode of the OLED device can be connected to the pixel circuit PC, and the second power supply voltage ELVSS can be supplied to a cathode. In an embodiment, the cathode of the OLED device included in each of the plurality of pixels PX can be connected to an output terminal of the inverting buck-boost converter 230 to receive the second power supply voltage ELVSS.

[0033] The luminance of the OLED device in each of the plurality of pixels PX can vary depending on a driving current IDT applied to the OLED device by the pixel circuit PC. For example, the pixel circuit PC can control the driving current IDT flowing between the first power supply voltage ELVDD and the second power supply voltage ELVSS through the OLED device in response to a data voltage applied to the data line DL.

[0034] The pixel circuit PC can include a selection transistor ST, a driving transistor DT, and a storage capacitor Cst, etc. The selection transistor ST can be connected between the data line DL and a first node N1, and a gate of the selection transistor ST can be connected to the scan line SL. Accordingly, the selection transistor ST can be turned on or off by a voltage applied to the scan line SL.

[0035] The drive transistor DT receives the first power supply voltage ELVDD and can be connected to an anode of the OLED device at a second node N2. A gate of the drive transistor DT can be connected to the first node N1, and the storage capacitor Cst can be connected between the first node N1 and the second node N2. When the select transistor ST is turned on by a voltage applied to the scan line SL, a voltage of the first node N1 can be changed by a data voltage applied to the data line DL, and an amount of charge stored in the storage capacitor Cst can be changed. The drive transistor DT can provide a drive current IDT to the OLED device in response to the charge stored in the storage capacitor Cst.

[0036] In an embodiment, in order to adjust the luminance of the display panel 210, the level of the first power supply voltage ELVDD output by the boost converter 220 and / or the level of the second power supply voltage ELVSS output by the inverting buck-boost converter 230 can be adjusted. For example, in order to reduce the luminance of the display panel 210, the absolute value of the second power supply voltage ELVSS output from the inverting buck-boost converter 230 can be reduced.

[0037] In an embodiment, in order to adjust the level of the second power supply voltage ELVSS as described above, the inverting buck-boost converter 230 can provide a DVS function. The controller 240 can increase or decrease the level of the second power supply voltage ELVSS by adjusting a duty ratio and / or a frequency of a control signal provided to the inverting buck-boost converter 230. As described above, unlike the first power supply voltage ELVDD, the second power supply voltage ELVSS can be a negative voltage, and thus, it can be understood that as the level of the second power supply voltage ELVSS increases, the absolute value of the second power supply voltage ELVSS decreases, and as the level of the second power supply voltage ELVSS decreases, the absolute value of the second power supply voltage ELVSS increases.

[0038] As described above, when the DVS function is activated in the inverting buck-boost converter 230 and the level of the second power supply voltage ELVSS increases or decreases, a sense current of the inverting buck-boost converter 230 detected by the load sensor included in the controller 240 can change. Thus, the load sensor can erroneously diagnose that the size of a load connected to the inverting buck-boost converter 230 has changed, and the controller 240 can perform an erroneous control operation based on the erroneous diagnosis.

[0039] In an embodiment, in order to minimize a change in the sense current detected by the load sensor when the level of the second supply voltage ELVSS increases or decreases, the controller 240 can generate a compensation current. In an embodiment, the compensation current can correspond to a current added to or subtracted from the output terminal of the inverting buck-boost converter 230 when the level of the second supply voltage ELVSS changes, and can be reflected in the sense current. The compensation current can be reflected to the sense current, can effectively prevent the load sensor from misdiagnosing a change in the load when the level of the second supply voltage ELVSS increases or decreases, and can improve the operating efficiency, power consumption, etc. of the display device 200.

[0040] Figures 4 to 6 is a circuit diagram illustrating a DC-DC converter included in a power supply device according to an embodiment.

[0041] Reference Figure 4 According to an embodiment, the power supply device 300 can include a DC-DC converter 310 as a voltage conversion circuit, and the DC-DC converter 310 can be an inverting buck-boost converter. For example, the DC-DC converter 310 can be the inverting buck-boost converter 230 of FIG. 1. Figure 2 The inverting buck-boost converter can include a first switching device SW1 and a second switching device SW2, an input capacitor CIN, an output capacitor COUT, an inductor L, etc. The first switching device SW1 can be connected between the input capacitor CIN and the inductor L, and the second switching device SW2 can be connected between the inductor L and the output capacitor COUT.

[0042] The controller 320 can output a first control signal CNT1 that controls the on / off switching of the first switching device SW1, and a second control signal CNT2 that controls the on / off switching of the second switching device SW2. The first control signal CNT1 and the second control signal CNT2 can have a complementary relationship with each other. Thus, when the first switching device SW1 is turned on, the second switching device SW2 can be turned off, and when the first switching device SW1 is turned off, the second switching device SW2 can be turned on.

[0043] The inverting buck-boost converter can generate an output voltage VOUT having a level higher or lower than that of the input voltage VIN, and the output voltage VOUT can have a sign opposite to that of the input voltage VIN. For example, during a time when the first switching device SW1 is on and the second switching device SW2 is off, energy can be stored in the inductor L through the input voltage VIN. During a time when the first switching device SW1 is off and the second switching device SW2 is on, the energy stored in the inductor L can be transferred to the output terminal.

[0044] Referring to Figure 5 , the power supply device 330 according to an embodiment can include a DC-DC converter 340 as a voltage conversion circuit, and the DC-DC converter 340 can be a boost converter. For example, the DC-DC converter 340 can be the boost converter 220 of FIG. 2. The boost converter can include a first switching device SW1 and a second switching device SW2, an inductor L, an output capacitor COUT, etc. The first switching device SW1 and the second switching device SW2 can be turned on / off by control signals CNT1 and CNT2 output from a controller 350. For example, when the first switching device SW1 is turned on, the second switching device SW2 can be turned off, and when the first switching device SW1 is turned off, the second switching device SW2 can be turned on. The boost converter can generate an output voltage VOUT having a level higher than that of an input voltage VIN. Figure 2

[0045] When the first switching device SW1 is turned on, a current generated by the input voltage VIN can flow through a loop including the inductor L and the first switching device SW1, and thus energy can be stored in the inductor L. When the first switching device SW1 is turned off and the second switching device SW2 is turned on, a current generated by the input voltage VIN can flow through a loop including the second switching device SW2 and the output capacitor COUT, and the energy stored in the inductor L can be transferred to an output terminal, an output voltage VOUT having a level higher than that of the input voltage VIN can be generated.

[0046] Referring to Figure 6 , the power supply device 360 according to an embodiment can include a DC-DC converter 370 as a voltage conversion circuit, and the DC-DC converter 370 can be a buck converter. For example, the DC-DC converter 370 can be the boost converter 220 of FIG. 2. The buck converter can include a first switching device SW1 and a second switching device SW2, an inductor L, an output capacitor COUT, etc. Unlike the boost converter described previously with reference to FIG. 2, in the buck converter, the first switching device SW1 can be directly connected to an input terminal. The first switching device SW1 and the second switching device SW2 can be turned on / off by control signals CNT1 and CNT2 output from a controller 380, and the buck converter can generate an output voltage VOUT having a level lower than that of an input voltage VIN. For example, when the first switching device SW1 is turned on, the second switching device SW2 can be turned off, and when the first switching device SW1 is turned off, the second switching device SW2 can be turned on. Figure 2 Figure 5

[0047] ​​​When the first switching device SW1 is turned on, a current generated by the input voltage VIN can flow through a loop including the first switching device SW1, the inductor L, and the output capacitor COUT, and thus energy can be stored in the inductor L. When the first switching device SW1 is turned off and the second switching device SW2 is turned on, the input terminal can be electrically separated from the inductor L and the output capacitor COUT, and a current can flow in a loop including the inductor L, the output capacitor COUT, and the second switching device SW2 by virtue of the energy stored in the inductor L. Then, an output voltage VOUT of a level lower than that of the input voltage VIN can be generated.

[0048] Figure 7A and Figure 7B is an equivalent circuit diagram illustrating an operation of a DC-DC converter included in a power supply device according to an embodiment. Figure 8 is a graph illustrating an operation of a DC-DC converter included in a power supply device according to an embodiment.

[0049] Figure 7A and Figure 7B may be an equivalent circuit diagram illustrating Figure 4 the operation of the inverting buck-boost converter shown in FIG. 8. Referring to Figure 4 , Figure 7A may be an equivalent circuit diagram during a time when the first switching device SW1 is turned on and the second switching device SW2 is turned off, and Figure 7B may be an equivalent circuit diagram during a time when the first switching device SW1 is turned off and the second switching device SW2 is turned on.

[0050] Referring to Figure 7A and Figure 8 , during a time when the first switching device SW1 is turned on, a current can be applied to the inductor L by virtue of the input voltage VIN, and the current flowing in the inductor L can linearly increase and energy can be stored in the inductor L. Referring to Figure 7B , during a time when the second switching device SW2 is turned on, the input terminal can be separated from the inductor L, and an output voltage VOUT can be generated by virtue of the energy stored in the inductor L. In this case, since the second switching device SW2 is turned on, the output voltage VOUT can be output as an inverted voltage compared to the input voltage VIN.

[0051] As Figure 8As illustrated, unlike the current flowing in the inductor L that increases and decreases according to the on / off switching of the switching devices SW1 and SW2, the load current ILOAD can be maintained constant. Even when the duty ratio and / or the frequency of the control signal applied to each of the switching devices SW1 and SW2 are adjusted to increase or decrease the level of the output voltage VOUT, the load current ILOAD can be maintained constant.

[0052] The controller that controls the switching devices SW1 and SW2 can include a load sensor that detects a sense current from the inverting buck-boost converter. For example, the load sensor can detect a sense current from the second switching device SW2 in the inverting buck-boost converter. When the inverting buck-boost converter performs an operation to increase the absolute value of the output voltage VOUT, an additional current can be added to the output capacitor COUT to increase the absolute value of the output voltage VOUT. Accordingly, even in the case where there is no change in the load actually connected to the output terminal of the inverting buck-boost converter, the sense current detected by the load sensor can increase.

[0053] When the sense current increases, the controller can determine that the load has increased and perform a control operation corresponding thereto. For example, the controller can respond to the change in the load by operating a different DC-DC converter connected to the load, or perform an overload protection (OLP) operation to prevent damage to the circuit due to the increase in the load. In fact, since there is no change in the load, when the controller performs the above-described control operation, problems such as unnecessary increase in power consumption or unnecessary protection operation can occur.

[0054] In an embodiment, when the level of the output voltage VOUT changes, the controller can reflect a separate compensation current to the sense current. Accordingly, even during a transient period when the level of the output voltage VOUT increases or decreases, the change in the magnitude of the sense current detected by the load sensor of the controller can be minimized, and the controller can prevent the controller's control operation from being performed due to a false diagnosis of an increase in the load.

[0055] Figure 9A and Figure 9B is a view illustrating an operation of a power supply device according to an embodiment.

[0056] Referring to Figure 9A , the power supply device 400 according to an embodiment can include a DC-DC converter 410 and a controller 420, and the DC-DC converter 410 can be an inverting buck-boost converter. For example, the DC-DC converter 410 can be an inverting buck-boost converter that converts a DC voltage to a DC voltage having a different level. Figure 2The controller 420 can output a first control signal CNT1 that controls the on / off switching of the first switching device SW1, and a second control signal CNT2 that controls the on / off switching of the second switching device SW2. In addition, the controller 420 can detect the sense current ISENSE, and can generate a compensation current ICP.

[0057] Figure 9B is a view illustrating an operation in which the level of the output voltage VOUT generated from the DC-DC converter 410 decreases from a first level LV1 to a second level LV2. The output voltage VOUT generated from the DC-DC converter 410, which can be an inverting buck-boost converter, can be a negative voltage having a sign opposite to that of the input voltage VIN. Accordingly, the decrease in the level of the output voltage VOUT can be understood as an increase in the absolute value of the output voltage VOUT.

[0058] As shown in Figure 9B , during a transition period between the first time point t1 and the second time point t2, the level of the output voltage VOUT decreases from the first level LV1 to the second level LV2. During the transition period, a current (e.g., ΔISENSE) can be added to the output capacitor COUT in addition to the load current ILOAD applied before the first time point t1, and thus the absolute value of the output voltage VOUT can increase. For example, when the DVS function is activated, the controller 420 can increase the output current of the DC-DC converter 410 to increase the absolute value of the level of the output voltage VOUT.

[0059] Although the load connected to the output terminal of the DC-DC converter 410 is unchanged, a current for increasing the absolute value of the output voltage VOUT can be added to the load current ILOAD, as shown in Figure 9B . For example, the sense current ISENSE can increase an additional current ΔISENSE during the transition period. For example, the absolute value of the output voltage VOUT can increase due to the additional current ΔISENSE added to the sense current ISENSE during the transition period.

[0060] The controller 420 can include a load sensor 421 that detects the sense current ISENSE, and can control the DC-DC converter 410 with reference to the sense current ISENSE detected by the load sensor 421. As shown in Figure 9BAs illustrated, when the sense current ISENSE detected by the load sensor 421 increases during the transition period, the controller 420 can misdiagnose that the load connected to the DC-DC converter 410 has increased. In response to this misdiagnosis, the controller 420 can also activate a different DC-DC converter connected to the load outside the DC-DC converter 410 or perform an OLP operation. Accordingly, power consumption can be unnecessarily increased or a meaningless protection operation can be performed.

[0061] Referring to Figure 9A and Figure 9B , the current compensation unit 423 can generate a compensation current ICP during the transition period, and the size of the compensation current ICP can be equal to the size of the additional current ΔISENSE added during the transition period.

[0062] In the embodiments described with reference to Figure 9A and Figure 9B , when the DVS function is activated, an additional current ΔISENSE can be added to the output capacitor COUT of the DC-DC converter 410 to increase the absolute value of the output voltage VOUT. Accordingly, the controller 420 can subtract the compensation current ICP from the sense current ISENSE detected from the DC-DC converter 410. In the embodiments illustrated in Figure 9A and Figure 9B , the compensation current ICP having substantially the same size as the additional current ΔISENSE can be subtracted from the sense current ISENSE by the current compensation unit 423.

[0063] Accordingly, the current input to the load sensor 421 can have the same or similar size as the load current ILOAD, and the load sensor 421 can detect a current having approximately the same size as before the first time point t1 even during the transition period. Accordingly, the controller 420 can not perform unnecessary control operations.

[0064] Figure 10A and Figure 10B are views illustrating the operation of a power supply device according to an embodiment.

[0065] Referring to Figure 10AAccording to the power supply device 400 of the embodiment, the DC-DC converter 410 can be a reverse buck-boost converter. The controller 420 can output a first control signal CNT1 that controls on / off switching of the first switching device SW1, and a second control signal CNT2 that controls on / off switching of the second switching device SW2. In addition, the controller 420 can include a load sensor 421 that detects the sense current ISENSE, a current compensation unit 423 that generates a compensation current ICP, and the like.

[0066] Figure 10B is a view illustrating an operation in which the level of the output voltage VOUT generated by the DC-DC converter 410 increases from the second level LV2 to the first level LV1. Both the first level LV1 and the second level LV2 can be negative voltages, and thus, as the level of the output voltage VOUT increases, the absolute value of the output voltage VOUT can decrease. For example, the DVS function is activated, the controller 420 can decrease the output current of the DC-DC converter 410 to decrease the absolute value of the level of the output voltage VOUT.

[0067] As shown in Figure 10B , during the transition period between the first time point t1 and the second time point t2, the output capacitor COUT can subtract the additional current from the load current ILOAD applied before the first time point t1. Thus, the absolute value of the output voltage VOUT can decrease. Even in the case where the load connected to the output terminal of the DC-DC converter 410 is not changed, since the additional current for decreasing the absolute value of the output voltage VOUT is subtracted from the load current ILOAD, as shown in Figure 10B , the sense current ISENSE can decrease the additional current ΔISENSE.

[0068] Because the sense current ISENSE decreases the additional current ΔISENSE, the controller 420 that controls the DC-DC converter 410 based on the detection result of the load sensor 421 can misdiagnose that the load connected to the DC-DC converter 410 has decreased during the transition period. The controller 420 can perform an incorrect control operation in response to such a misdiagnosis.

[0069] Referring to Figure 10B , the current compensation unit 423 can generate the compensation current ICP during the transition period, and the compensation current ICP can have the same magnitude as the additional current ΔISENSE subtracted during the transition period.

[0070] In reference to Figure 10A and Figure 10BIn the described embodiment, a compensation current ICP having substantially the same magnitude as the additional current ΔISENSE can be added to the sense current ISENSE by the current compensation unit 423. In this case, the compensation current ICP can be reflected to the sense current ISENSE detected by the load sensor 421 from the DC-DC converter 410 to reduce the absolute value of the output voltage VOUT. Accordingly, even in the case where the sense current ISENSE input to the controller 420 is changed by the additional current ΔISENSE during the transition period, the current input to the load sensor 421 can be maintained to be approximately the same magnitude as before the first point in time t1. Accordingly, the controller 420 can determine that the load connected to the DC-DC converter 410 is not changed, and can not perform unnecessary control operations.

[0071] Figure 11 and Figure 12 are views illustrating operations of a power supply device according to an embodiment.

[0072] Figure 11 and Figure 12 are views illustrating how a controller controlling a DC-DC converter generates a compensation current ICP during a transition period in which an output voltage of the DC-DC converter is increased or decreased. In reference to Figure 11 and Figure 12 In the described embodiment, the DC-DC converter can include an inverting buck-boost converter, a buck converter, a boost converter, etc.

[0073] Referring to Figure 11 , the compensation current ICP can be generated during a transition period in which the output voltage is decreased from a first level LV1 to a second level LV2. In the described embodiment, since the output voltage is decreased from the first level LV1 to the second level LV2, a current can be added to the output capacitor during the transition period. In order to effectively prevent a malfunction of the controller, it is necessary to calculate an amount of the additional current added to the output capacitor, and generate the compensation current ICP based on this. For example, the additional current reflected in the output capacitor during the transition period can be defined as Equation 1 below: Figure 11 [Equation 1]

[0074] As shown in Equation 1, the additional current IADD reflected in the output capacitor can be determined as a product between a slew rate during the transition period and an effective capacitance COUT of the output capacitor. Accordingly, the first level LV1, the second level LV2, a length of the transition period tTRANS, and the slew rate can be used to calculate the compensation current ICP. ADD EFF ​​​to calculate the conversion rate, an effective capacitance C of the output capacitor can be used EFF to calculate the additional current I ADD , and the compensation current ICP can be generated based on this. For example, the effective capacitance C EFF may be determined as a median value of the output voltage during each of the sub-periods TP1 to TP4.

[0075] In an embodiment, the output capacitor connected to the output terminal of the DC-DC converter can be a multilayer ceramic capacitor (MLCC), and the effective capacitance of the multilayer ceramic capacitor can change depending on the voltage applied across both ends. Due to this characteristic, when the same compensation current ICP is applied to all periods of the transition period in which the output voltage of the DC-DC converter including the multilayer ceramic capacitor as the output capacitor changes, the load sensor included in the controller can malfunction.

[0076] In an embodiment, as Figure 11 shown, the transition period can be divided into predetermined sub-periods TP1 to TP4, and the controller can generate the compensation current ICP having different sizes in at least some of the sub-periods TP1 to TP4. In an embodiment as Figure 11 shown, the conversion rate of each of the sub-periods TP1 to TP4 can be constant, and as previously explained with reference to Equation 1, the size of the additional current added to the output capacitor can be determined by the effective capacitance of the output capacitor. Accordingly, the size of the compensation current ICP determined from the additional current can be differently determined in each of the sub-periods TP1 to TP4.

[0077] In an embodiment as Figure 11 shown, the controller generates a first compensation current ICP1 during a first sub-period TP1, a second compensation current ICP2 during a second sub-period TP2, a third compensation current ICP3 during a third sub-period TP3, and a fourth compensation current ICP4 during a fourth sub-period TP4. The effective capacitance of the output capacitor can be maximum within the first sub-period TP1 in which the level of the output voltage is highest, and can be minimum within the fourth sub-period TP4 in which the level of the output voltage is lowest. Accordingly, among the first compensation current ICP1 to the fourth compensation current ICP4, the first compensation current ICP1 can be generated as maximum, and the fourth compensation current ICP4 can be generated as minimum.

[0078] Referring to Figure 12 , the compensation current ICP can be generated during a transition period in which the output voltage increases from a second level LV2 to a first level LV1. In Figure 12In the illustrated embodiment, the output voltage can increase from the first level LV1 to the second level LV2 because the current flowing in the output capacitor during the transition period can decrease. To effectively prevent malfunction of the controller, a compensation current ICP corresponding to the decreased current in the output capacitor can be generated and reflected to the sensed current detected by the load sensor of the controller.

[0079] The method of determining the compensation current can be similar to that described previously with reference to Figure 11 For example, the magnitude of the current drawn from the output capacitor to increase the output voltage can be defined as in Equation 1 above, and, for example, can be determined by the slew rate of the output voltage and the effective capacitance of the output capacitor.

[0080] In an embodiment, when the output capacitor connected to the output terminal of the DC-DC converter is a multilayer ceramic capacitor, the effective capacitance of the output capacitor can change depending on the voltage applied across the two terminals. Accordingly, in an embodiment, as Figure 11 illustrated, the transition period can be divided into predetermined sub-periods TP1 to TP4, and the controller can generate compensation currents ICP having different magnitudes in at least some of the sub-periods TP1 to TP4, and can reflect them to the sensed current. In Figure 12 the illustrated embodiment, the slew rate of each of the sub-periods TP1 to TP4 can be constant, and the magnitude of the compensation current ICP generated in each of the sub-periods TP1 to TP4 can be determined according to the effective capacitance of the output capacitor.

[0081] In Figure 12 the illustrated embodiment, the effective capacitance of the output capacitor can be smallest in the first sub-period TP1 in which the level of the output voltage is lowest, and can be largest in the fourth sub-period TP4 in which the level of the output voltage is highest. Accordingly, the controller can generate the first compensation current ICP1, which is the smallest among the first to fourth compensation currents ICP1 to ICP4, and the fourth compensation current ICP4, which is the largest.

[0082] Figure 13 is a block diagram illustrating a power supply device according to an embodiment.

[0083] Reference Figure 13According to an embodiment, the power supply device 500 can include a DC-DC converter 510, a controller 520, and the like. The DC-DC converter 510 can include a circuit having at least one switching device, such as a step-down converter, a step-up converter, a step-down-step-up converter, and the like. The DC-DC converter 510 can output an output voltage having a level higher or lower than that of an input voltage, which can be a direct current voltage. The DC-DC converter 510 can include a first DC-DC converter 511 and a second DC-DC converter 512, and the first DC-DC converter 511 and the second DC-DC converter 512 can be connected to the same load. The first DC-DC converter 511 can be a master converter, and the second DC-DC converter 512 can be a slave converter.

[0084] The controller 520 can output a control signal CNT that controls on / off switching of a switching device included in the DC-DC converter 510. The control signal CNT can be a pulse width modulation signal, and a level of an output voltage generated by the DC-DC converter 510 can vary depending on a duty ratio, a frequency, and the like of the control signal CNT.

[0085] The controller 520 can include a load sensor 521, a current compensation unit 523, and the like. The load sensor 521 can detect a sense current ISENSE from a switching device connected to an output terminal of the DC-DC converter 510, and can sense a change in a load connected to the output terminal of the DC-DC converter 510 based on the sense current ISENSE. For example, when it is determined that the load is changed based on the sense current ISENSE, the controller 520 can perform a control operation corresponding thereto.

[0086] In an embodiment, the controller 520 can activate the first DC-DC converter 511 and deactivate the second DC-DC converter 512 in a case where a change in the load is not detected. When only the first DC-DC converter 511 is activated and an increase in the load is sensed based on the sense current ISENSE, the controller 520 can additionally activate the second DC-DC converter 512 to increase an amount of current supplied to the load and maintain a level of an output voltage applied to the load. Alternatively, the controller 520 can perform an OLP operation in response to an increase in the load.

[0087] The power supply device 500 can support a DVS function that can adjust a level of an output voltage regardless of a change in a load. For example, the controller 520 can change a duty ratio and / or a frequency of the control signal CNT to increase or decrease a level of an output voltage of the DC-DC converter 510.

[0088] When the DVS function is activated, the output current of the DC-DC converter 510 can increase or decrease. As the output current of the DC-DC converter 510 increases or decreases, the sense current ISENSE detected by the load sensor 521 can change, and thus the controller 520 can misdiagnose that the load has changed based on the sense current ISENSE even if there is no change in the load connected to the DC-DC converter 510. Accordingly, an unexpected malfunction can occur in the power supply device 500.

[0089] In an embodiment, during a transition time when the DVS function is activated and the level of the output voltage increases or decreases, the current compensation unit 523 of the controller 520 can provide the load sensor 521 with the compensation current ICP by adding the compensation current ICP to the sense current ISENSE or subtracting the compensation current ICP from the sense current ISENSE. For example, when the DVS function is activated while both the first DC-DC converter 511 and the second DC-DC converter 512 are activated, the current compensation unit 523 can provide the load sensor 521 with the compensation current ICP for the sense current ISENSE detected in the first DC-DC converter 511 and the second DC-DC converter 512, respectively.

[0090] The compensation current ICP can be reflected in the sense current ISENSE detected by the load sensor 521 from the DC-DC converter 510, and can compensate for the sense current ISENSE that increases or decreases during the DVS function. For example, whether the current compensation unit 523 adds the compensation current ICP to the sense current ISENSE or draws a portion of the sense current ISENSE as the compensation current ICP can be determined depending on the increase or decrease of the output voltage of the DC-DC converter 510.

[0091] Figure 14 and Figure 16 are views illustrating an operation of a power supply device, and Figures 17 to 19 and Figure 14 are views illustrating an operation of a power supply device according to an example embodiment.

[0092] Figure 15 and Figure 14 are views illustrating a DVS operation of a power supply device when an output voltage VOUT decreases from a first level LV1 to a second level LV2. The power supply device can include a DC-DC converter, a controller, etc., and the DC-DC converter can include an inverting buck-boost converter. In this case, the output voltage VOUT of the DC-DC converter can be a negative voltage.

[0093] Referring to Figure 15 and Figure 14During a transition period between the first time point t1 and the second time point t2, the output voltage VOUT of the DC-DC converter can be adjusted from the first level LV1 to the second level LV2. Since the output voltage VOUT is a negative voltage, the absolute value of the first level LV1 can be smaller than the absolute value of the second level LV2, and thus, in the case where the load connected to the output terminal of the DC-DC converter is not changed during the transition period, the inductor current IL flowing in the inductor included in the DC-DC converter can increase. Since the reference Figure 15 and Figure 14 The operation described above is an operation of reducing only the level of the output voltage VOUT without changing the load, and thus, the load current ILOAD can be maintained constant before and after the transition period.

[0094] As described above, the controller can include a load sensor, and the load sensor can detect a sense current from the DC-DC converter to determine whether the load is changed. Referring first to Figure 14 In the comparative example shown, at the first time point t1 at which the DVS operation is performed, a sense voltage VSENSE corresponding to the sense current can increase. This can be a phenomenon that occurs when a current is added to the output capacitor in the DVS operation to reduce the output voltage VOUT from the first level LV1 to the second level LV2.

[0095] The output voltage VOUT can be a negative voltage, which is reduced from the first level LV1 to the second level LV2 to increase the absolute value of the output voltage VOUT, and a current can be added to the output capacitor to increase the absolute value of the output voltage VOUT. The added current can be reflected to the sense current to increase the sense current detected by the load sensor, and the sense voltage VSENSE can accordingly increase. The sense voltage VSENSE can return to its original value near the second time point t2 at which the DVS operation ends.

[0096] As a result, even in the case where the actual load connected to the DC-DC converter is not changed, the controller can determine that the load has been added between the first time t1 and the second time t2. Thus, as Figure 11 shown, an unnecessary protection operation can be performed between the first time t1 and the second time t2, or the power consumption of the power supply device can increase.

[0097] In an embodiment, during the transition period in which the DVS operation is performed, a compensation current can be subtracted from the sense current input to the load sensor of the controller. The compensation current can be determined by a current (e.g., ΔISENSE) added to the output capacitor to increase the absolute value of the output voltage VOUT, and for example, can be as described above with reference to Figure 15The compensation current can be reflected to the sense current to minimize a change of the sense current before and after the transition period, and can prevent unnecessary OLP operation (or OLP enable) from being performed, etc.

[0098] Referring to a view illustrating an operation according to an embodiment Figure 16 , the sense voltage VSENSE can fluctuate at the first time point t1 and the second time point t2, respectively. This can be a change of the sense voltage VSENSE that occurs when the compensation current is reflected in the sense current at the start and end of the DVS operation. In addition to the phenomenon that the sense voltage VSENSE fluctuates at the first time point t1 and the second time point t2, respectively, the sense voltage VSENSE can be maintained at a constant value regardless of the activation of the DVS operation. Therefore, even in the transition period, it is possible to prevent unnecessary protection operation from being performed to reasonably control the protection operation, and it is possible to effectively manage the power consumption of the power supply device.

[0099] Figure 17 and Figure 14 is a view illustrating the DVS operation of the power supply device when the output voltage VOUT is increased from the second level LV2 to the first level LV1. As previously described with reference to Figure 15 and Figure 16 , the output voltage VOUT can be a negative voltage, and the absolute value of the second level LV2 can be greater than the absolute value of the first level LV1. Therefore, in the case where the load connected to the output terminal of the DC-DC converter does not change during the transition period, the inductor current IL flowing in the inductor included in the DC-DC converter can decrease. In addition, since the operation described with reference to Figure 17 and Figure 16 is an operation of only increasing the level of the output voltage VOUT without changing the load, the load current ILOAD can be maintained constant before and after the transition period.

[0100] As described above, the controller can include a load sensor that detects the sense current from the DC-DC converter and determines whether the load is changed. Referring first to a comparative example shown in Figure 14 , at the first time point t1 at which the DVS operation can be performed, the sense voltage VSENSE corresponding to the sense current can decrease. This can be a phenomenon that occurs when the current flowing through the output capacitor is decreased in the DVS operation to increase the output voltage VOUT from the second level LV2 to the first level LV1.

[0101] Due to the decreased current, the sense current detected by the load sensor decreases, and the sense voltage VSENSE can correspondingly decrease. The sense voltage VSENSE can return to its original value around the second time point t2 at which the DVS operation ends.

[0102] Even in a case where an actual load connected to the DC-DC converter does not change, the controller can determine that the load has decreased between the first time t1 and the second time t2. Thus, as shown in Figure 12 unnecessary phase split (PSE) operation, etc. can be performed between the first time point t1 and the second time point t2, and a problem can occur in the operation of the electronic device using the output voltage VOUT of the power supply device.

[0103] In an embodiment, during the transition period in which the DVS operation is performed, a compensation current can be reflected in a sense current input to a load sensor of the controller. The compensation current can be determined by a current subtracted from the output capacitor to decrease an absolute value of the output voltage VOUT, and for example, can be determined as in the embodiment described above with reference to Figure 17 The compensation current can be added to the sense current, a change in the sense current before and after the transition period can be minimized, and an unnecessary phase split operation, etc. can be prevented from being performed.

[0104] Referring to a view illustrating an operation according to an embodiment, Figure 18 The sense voltage VSENSE can fluctuate at the first time point t1 and the second time point t2, respectively. This can be a change in the sense voltage VSENSE that occurs when the compensation current is reflected in the sense current at the start and the end of the DVS operation. In addition to the phenomenon that the sense voltage VSENSE fluctuates at the first time point t1 and the second time point t2, respectively, the sense voltage VSENSE can be maintained at a constant value regardless of the activation of the DVS operation. Thus, the controller does not erroneously recognize that the load has changed in the transition period, and does not perform a phase split operation during the transition period.

[0105] Figure 19 and Figure 18 are views illustrating a DVS operation of a power supply device when an output voltage VOUT is decreased from a first level LV1 to a second level LV2. The power supply device can include a DC-DC converter, a controller, etc., and the DC-DC converter can include an inverting buck-boost converter. Thus, the output voltage VOUT can be a negative voltage.

[0106] Referring to Figure 19 and Figure 18 During a transition period between the first time point t1 and the second time point t2, the output voltage VOUT of the DC-DC converter can be adjusted from the first level LV1 to the second level LV2. Since the output voltage VOUT is a negative voltage, an absolute value of the first level LV1 can be smaller than an absolute value of the second level LV2, and thus, an inductor current IL flowing in an inductor included in the DC-DC converter can increase. The load current ILOAD can be maintained constant before and after the transition period.

[0107] Figure 11 is a view illustrating operations of the controller generating a constant compensation current and reflecting it to the sense current during the transition period. As in the previous reference to Figure 12 and Figure 19 described in the embodiments, Figure 18 is a view illustrating operations of the transition period being divided into a plurality of sub-periods and a compensation current having different sizes being generated in at least some of the sub-periods to be reflected to the sense current.

[0108] When a certain amount of compensation current is reflected to the sense current throughout the transition period, in an initial period of the transition period in which the effective capacitance of the output capacitor has a relatively large value, the increase of the sense current can not be fully compensated. Therefore, in the initial period of the transition period, even in the case where the compensation current is reflected to the sense current, the sense current detected by the load sensor can be larger than before the first time point t1, and thus, as Figure 19 illustrated, the sense voltage VSENSE can increase to unnecessarily perform the OLP operation (or OLP enablement) or the like.

[0109] When the transition period is divided into two or more sub-periods and a compensation current having different sizes in each of the sub-periods is reflected to the sense current, as Figure 18 illustrated, the change range of the sense voltage VSENSE can be reduced compared to the embodiment illustrated in Figure 20 . Therefore, even when the transition period for performing the DVS operation is long or the difference between the first level LV1 and the second level LV2 is large, the transition period can be segmented, and a compensation current having different sizes can be reflected to the sense current to effectively prevent unnecessary OLP operation or the like from being performed.

[0110] Figure 20 is a view illustrating a power supply device according to an embodiment.

[0111] The power supply device 600 according to the embodiment illustrated in ​ may include a low dropout (LDO) regulator 610 as a voltage conversion circuit. The power supply device 600 can include the LDO regulator 610 and a controller 620. The controller 620 can include resistor devices R1 and R2 connected to output terminals of the LDO regulator 610, a load sensor 621, a current compensation unit 623, an error amplifier 625, a driver 627, and the like. The LDO regulator 610 can include an input capacitor CIN, a switching device SW, and an output capacitor COUT, and on / off switching of the switching device SW can be controlled by the driver 627 of the controller 620.

[0112] The LDO regulator 610 can generate an output voltage VOUT of a level lower than a level of an input voltage VIN. The resistive devices R1 and R2 can transmit a feedback voltage distributed by the output voltage VOUT of the LDO regulator 610 to the error amplifier 625, and the error amplifier 625 can amplify a difference between the feedback voltage and a reference voltage VREF, and the driver 627 can control the switching device SW according to an output of the error amplifier 625.

[0113] For example, when the input voltage VIN input to the LDO regulator 610 is inadvertently increased, the output of the error amplifier 625 can be increased. The driver 627 can control the switching device SW in response to the increase of the output of the LDO regulator 610 to minimize the increase of the output voltage VOUT and stabilize the output voltage VOUT.

[0114] The controller 620 can include a load sensor 621 that detects a sense current from the switching device SW, and can support a DVS function that adjusts a level of the output voltage VOUT. When the DVS function is activated, the magnitude of the sense current detected by the load sensor 621 can change even in a case where a load connected to the output terminal of the LDO regulator 610 does not change. Accordingly, the controller 620 can erroneously determine that the load has changed to additionally perform unnecessary operations.

[0115] In an embodiment, during a transition period in which the level of the output voltage VOUT is increased or decreased when the DVS function is activated, the current compensation unit 623 can generate a compensation current ICP to be reflected to the sense current ISENSE. For example, when the DVS function is activated and the sense current ISENSE is increased, the compensation current ICP can be subtracted from the sense current ISENSE, and when the DVS function is activated and the sense current ISENSE is decreased, the compensation current ICP can be added to the sense current ISENSE. Accordingly, it is possible to prevent the controller 620 from erroneously detecting that the load has changed during the transition period, and to prevent unnecessary protection operations from being performed or to prevent the power consumption of the power supply device 600 from being increased.

[0116] According to an embodiment, during a transition period in which an output voltage of a voltage conversion circuit included in a power supply device is increased or decreased, a compensation current can be reflected to a sense current detected by a load sensor of a controller that controls the voltage conversion circuit. Accordingly, it is possible to effectively prevent a malfunction of the power supply device that can occur due to the load sensor erroneously detecting a load change in the transition period in which the output voltage is increased or decreased without an actual load change.

[0117] Various advantages and effects of the present inventive concept are not limited to the above-described content and can be more easily understood by the description of specific embodiments of the present inventive concept.

[0118] While example embodiments have been shown and described above, it will be apparent to those skilled in the art that modifications and changes can be made without departing from the scope of the application as defined in the appended claims.

Claims

1. A power supply device, the power supply device comprising: a voltage conversion circuit including a switching device configured to operate in response to a control signal, and the voltage conversion circuit is configured to: receive an input voltage, and generate an output voltage higher or lower than the input voltage in dependence on a duty cycle of the control signal; and a controller configured to change the duty cycle of the control signal to regulate a level of the output voltage, the controller including: a load sensor configured to detect a sense current from the switching device, and a current compensation unit configured to apply a compensation current to the sense current input to the load sensor during a transition period in which the output voltage changes from a first level to a second level.

2. The power supply device of claim 1, wherein, the voltage conversion circuit includes: a first DC-DC converter configured to operate as a master device, and a second DC-DC converter configured to operate as a slave device, and wherein an activation state of the first DC-DC converter at a time of outputting the output voltage at the first level is equal to an activation state of the first DC-DC converter during the transition period, and an activation state of the second DC-DC converter at a time of outputting the output voltage at the first level is equal to an activation state of the second DC-DC converter during the transition period.

3. The power supply device of claim 1, wherein, the power supply device is configured such that, when an absolute value of the first level is smaller than an absolute value of the second level, the controller is caused to subtract the compensation current from the sense current during the transition period.

4. The power supply device of claim 1, wherein, the power supply device is configured such that, when the absolute value of the first level is greater than the absolute value of the second level, the controller is caused to add the compensation current to the sense current during the transition period.

5. The power supply device of claim 1, wherein, the voltage conversion circuit includes: an output capacitor connected to an output terminal of the voltage conversion circuit, and the output capacitor includes a multilayer ceramic capacitor.

6. The power supply device of claim 5, wherein, the transition period includes a plurality of sub-periods, and wherein the power supply device is configured such that the controller: applies a first compensation current to the sense current in a first sub-period of the plurality of sub-periods, and applies a second compensation current having a different magnitude from that of the first compensation current to the sense current in a second sub-period following the first sub-period of the plurality of sub-periods.

7. The power supply device of claim 6, wherein, the power supply device is configured such that, when the absolute value of the first level is smaller than the absolute value of the second level, the controller is caused to set the magnitude of the first compensation current to be greater than the magnitude of the second compensation current.

8. The power supply device of claim 6, wherein, the power supply device is configured such that, when the absolute value of the first level is greater than the absolute value of the second level, the controller is caused to set the magnitude of the first compensation current to be smaller than the magnitude of the second compensation current.

9. A power supply device, the power supply device comprising: a voltage conversion circuit comprising an input terminal, an output terminal, and a switching device configured to operate in response to a control signal, and configured to: receive an input voltage through the input terminal, and output an output voltage through the output terminal; and a controller configured to: generate the control signal, and detect a sense current from a load connected to the output terminal of the voltage conversion circuit, wherein the power supply is configured so that the controller: generates a compensation current based on a slew rate of the output voltage and an effective capacitance of an output capacitor connected to the output terminal of the voltage conversion circuit during a transition period in which a level of the output voltage is adjusted, and applies the compensation current to the sense current.

10. The power supply device of claim 9, wherein, the power supply is configured so that the controller subtracts the compensation current from the sense current when an absolute value of the output voltage increases during the transition period.

11. The power supply device of claim 9, wherein, the power supply is configured so that the controller adds the compensation current to the sense current when the absolute value of the output voltage decreases during the transition period.

12. The power supply device of claim 9, wherein, a magnitude of the compensation current is proportional to the effective capacitance of the output capacitor.

13. The power supply device of claim 9, wherein, the transition period comprises two or more sub-periods, and wherein the power supply is configured so that the controller generates compensation currents having different magnitudes in the two or more sub-periods.

14. The power supply device of claim 13, wherein, the magnitude of the compensation current is determined based on the effective capacitance of the output capacitor in each of the sub-periods and a slew rate of the output voltage in each of the sub-periods.

15. The power supply device of claim 14, wherein, the effective capacitance of the output capacitor is determined based on a level of the output voltage at a mid-point in each of the sub-periods.

16. The power supply device of claim 13, wherein, the effective capacitance of the output capacitor changes depending on an absolute value of the output voltage.

17. A power supply comprising: a voltage conversion circuit comprising an inductor, a switching device, and an output capacitor; and a controller configured to: activate the switching device in response to a control signal, and detect a sense current from the voltage conversion circuit to determine a change in a load receiving an output voltage of the voltage conversion circuit, wherein the power supply is configured so that the controller: subtracts a first compensation current from the sense current when a current flowing through the inductor increases without a change in the load, and adds a second compensation current to the sense current when the current flowing through the inductor decreases without a change in the load.

18. The power supply device of claim 17, wherein, a magnitude of the first compensation current and a magnitude of the second compensation current are determined based on an effective capacitance of the output capacitor.

19. The power supply device of claim 18, wherein, each of the magnitude of the first compensation current and the magnitude of the second compensation current is proportional to the effective capacitance of the output capacitor.

20. The power supply device of claim 17, wherein, the power supply is configured so that the controller performs a dynamic voltage scaling operation, the dynamic voltage scaling operation: to increase the absolute value of the output voltage of the voltage conversion circuit by increasing the current through the inductor without a change in load, and to decrease the absolute value of the output voltage of the voltage conversion circuit by decreasing the current through the inductor without a change in load.

Images