TW202110273A - Driving device - Google Patents

Abstract

A driving device for driving a lighting-emitting element includes a bridge rectifier, an automatic adjustment circuit, a first capacitor, a transformer, a power switch element, an output stage circuit, and a controller. The automatic adjustment circuit includes a buck circuit and a boost circuit, and generates a tuning voltage between a first threshold voltage and a second threshold voltage according to a rectified voltage. The first threshold voltage is higher than the minimum value of the rectified voltage. The second threshold voltage is lower than the maximum value of the rectified voltage. The transformer includes a main coil, a secondary coil, and an auxiliary coil. The main coil receives the tuning voltage. The secondary coil generates a transformation voltage. The output stage circuit generates an output voltage according to the transformation voltage, thereby controlling the light-emitting element.

Description

Drive device

The present invention relates to a driving device, and more particularly to a driving device that can drive a light-emitting element.

In the lighting application of light-emitting elements, the most common problem is flicker, which means that the brightness of light will periodically change over time. Generally speaking, when the switching frequency of light is below 60Hz, the human eye can easily perceive the flicker of the light source, and when the switching frequency of light is above 60Hz, although the human eye cannot easily detect it, it is still easy to cause eye fatigue And discomfort. In view of this, it is necessary to propose a new solution to overcome the shortcomings faced by the prior art.

In a preferred embodiment, the present invention provides a driving device for driving a light-emitting element, and includes: a bridge rectifier that generates a rectified potential according to a first input potential and a second input potential; and an automatic adjustment circuit , Including a step-down circuit and a step-up circuit, and according to the rectified potential to generate an adjusted potential between a first critical potential and a second critical potential, wherein the first critical potential is higher than the rectified potential The minimum value of the potential, and the second critical potential is lower than the maximum value of the rectified potential; a first capacitor storing the adjusted potential; a transformer including a main coil, a sub-coil, and an auxiliary coil, wherein the The main coil is used to receive the adjustment potential, and the auxiliary coil is used to generate a variable voltage potential; a power switch, wherein the main coil is coupled to a ground potential via the power switch, and the power switch The switching operation is performed based on a clock potential; an output stage circuit generates an output potential based on the variable voltage potential, wherein the light-emitting element determines whether to generate a light according to the output potential; and a controller generates the Clock potential.

In order to make the purpose, features and advantages of the present invention more comprehensible, specific embodiments of the present invention are listed below, with the accompanying drawings, and detailed descriptions are as follows.

In the specification and the scope of patent application, certain words are used to refer to specific elements. Those skilled in the art should understand that hardware manufacturers may use different terms to refer to the same component. This specification and the scope of patent application do not use differences in names as a way to distinguish elements, but use differences in functions of elements as a criterion for distinguishing. The terms "include" and "include" mentioned in the entire specification and the scope of the patent application are open-ended terms and should be interpreted as "including but not limited to". The term "approximately" means that within an acceptable error range, those skilled in the art can solve the technical problem within a certain error range and achieve the basic technical effect. In addition, the term "coupling" includes any direct and indirect electrical connection means in this specification. Therefore, if it is described in the text that a first device is coupled to a second device, it means that the first device can be directly electrically connected to the second device, or indirectly electrically connected to the second device through other devices or connection means. Two devices.

FIG. 1 is a schematic diagram of a driving device 100 according to an embodiment of the present invention. The driving device 100 is used to drive a light-emitting element 190. For example, the driving device 100 can be applied to a desktop computer, a notebook computer, or an integrated computer. As shown in Figure 1, the driving device 100 includes: a bridge rectifier 110, an automatic adjustment circuit 120, a first capacitor C1, a transformer 130, a power switch 140, an output stage circuit 150, and a controller 160 , Wherein the automatic adjustment circuit 120 includes a step-down circuit 124 and a step-up circuit 125. It should be noted that although not shown in Figure 1, the driving device 100 may further include other components, such as a voltage regulator or (and) a negative feedback circuit.

The bridge rectifier 110 generates a rectified potential VR according to a first input potential VIN1 and a second input potential VIN2. Both the first input potential VIN1 and the second input potential VIN2 can come from an external power source, wherein an AC voltage having any frequency and any amplitude can be formed between the first input potential VIN1 and the second input potential VIN2. For example, the frequency of the AC voltage can be about 50Hz or 60Hz, and the root mean square value of the AC voltage can be about 110V or 220V, but it is not limited to this. The automatic adjustment circuit 120 generates an adjustment potential VT between a first threshold potential VTH1 and a second threshold potential VTH2 according to the rectification potential VR, wherein the first threshold potential VTH1 is higher than the minimum value VMIN of the rectification potential VR , And the second critical potential VTH2 is lower than the maximum value VMAX of the rectified potential VR. That is, the first threshold potential VTH1 may be substantially equal to a first predetermined ratio of the minimum value VMIN of the rectified potential VR, and the second threshold potential VTH2 may be substantially equal to a second predetermined ratio of the maximum value VMAX of the rectified potential VR. The first predetermined ratio can be greater than one, and the aforementioned second predetermined ratio can be less than one. The first capacitor C1 can be used to store the adjustment potential VT. The transformer 130 includes a main winding 131, a secondary winding 132, and an auxiliary winding 133. The primary winding 131 and the auxiliary winding 133 can be located on the same side of the transformer 130, and the secondary winding 132 can be located on the opposite side of the transformer 130. . The main coil 131 is used to receive the adjustment potential VT, and as a response to the adjustment potential VT, the auxiliary coil 132 can be used to generate a variable voltage potential VS. The auxiliary coil 133 is coupled to the controller 160. In addition, the main coil 131 is coupled to a ground potential VSS (for example, 0V) via the power switch 140. The power switch 140 performs a switching operation according to a clock potential VA, which can be turned on or off alternately. The output stage circuit 150 generates an output potential VOUT according to the variable voltage potential VS. The light emitting element 190 determines whether to generate a light according to the output potential VOUT. For example, if the output potential VOUT is at a high logic level, the light emitting element 190 will generate light, and if the output potential VOUT is at a low logic level, the light emitting element 190 will not generate any light. The controller 160 may be a control integrated circuit, where the controller 160 is used to generate the clock potential VA. The clock potential VA can be maintained at a fixed potential when the driving device 100 is initialized, and a periodic clock waveform can be provided after the driving device 100 enters the normal use stage. According to the actual measurement results, this circuit design method can reduce the non-ideal stroboscopic phenomenon, so the use of the light-emitting element 190 of the driving device 100 will not easily cause eye fatigue of the user.

The following embodiments will introduce the detailed structure and operation of the driving device 100. It must be understood that these drawings and descriptions are only examples, and are not used to limit the scope of the present invention.

FIG. 2 is a schematic diagram showing the driving device 200 according to an embodiment of the present invention. In the embodiment of FIG. 2, the driving device 200 has a first input node NIN1, a second input node NIN2, and an output node NOUT, and includes a bridge rectifier 210, an automatic adjustment circuit 220, and a first capacitor C1, a transformer 230, a power switch 240, an output stage circuit 250, and a controller 260. The first input node NIN1 and the second input node NIN2 of the driving device 200 can receive a first input potential VIN1 and a second input potential VIN2 respectively from an external power source, and the output node NOUT of the driving device 200 can be used to output an output potential VOUT to a light emitting element 290.

The bridge rectifier 210 includes a first diode D1, a second diode D2, a third diode D3, and a fourth diode D4. The anode of the first diode D1 is coupled to the first input node NIN1, and the cathode of the first diode D1 is coupled to a first node N1 to output a rectified potential VR. The second diode D2 has an anode and a cathode. The anode of the second diode D2 is coupled to the first input node NIN1, and the cathode of the second diode D2 is coupled to a ground potential VSS. The anode of the third diode D3 is coupled to the first node N1, and the cathode of the third diode D3 is coupled to the second input node NIN2. The anode of the fourth diode D4 is coupled to the ground potential VSS, and the cathode of the fourth diode D4 is coupled to the second input node NIN2.

The automatic adjustment circuit 220 includes: a second capacitor C2, a third capacitor C3, a fifth diode D5, a monitoring circuit 221, a first amplifier 222, a second amplifier 223, a step-down circuit 224, and A boost circuit 225. For example, the monitoring circuit 221 may include a voltage detector and an arithmetic circuit (not shown), and the first amplifier 222 and the second amplifier 223 may each be an error amplifier.

The first terminal of the second capacitor C2 is coupled to the first node N1 to receive and store the rectified potential VR, and the second terminal of the second capacitor C2 is coupled to the ground potential VSS. The monitoring circuit 221 is used to detect the rectified potential VR. The monitoring circuit 221 further generates a second threshold potential VTH2 at a second node N2 according to the maximum value VMAX of the rectified potential VR, and according to the minimum value VMIN of the rectified potential VR A first threshold potential VTH1 is generated from a third node N3. The first threshold potential VTH1 is higher than the minimum value VMIN of the rectification potential VR, and the second threshold potential VTH2 is lower than the maximum value VMAX of the rectification potential VR. For example, the first threshold potential VTH1 may be approximately equal to 120% of the minimum value VMIN of the rectified potential VR, and the second threshold potential VTH2 may be approximately equal to 80% of the maximum value VMAX of the rectified potential VR, but it is not limited to this. The anode of the fifth diode D5 is coupled to the first node N1, and the cathode of the fifth diode D5 is coupled to the monitoring circuit 221. The monitoring circuit 221 can detect the rectified potential VR at the first node N1 through the fifth diode D5, where the fifth diode D5 can be used to prevent one of the operating currents of the monitoring circuit 221 from flowing back to the first node N1.

The positive input terminal of the first amplifier 222 is coupled to the first node N1, the negative input terminal of the first amplifier 222 is coupled to the second node N2, and the output terminal of the first amplifier 222 is used to output a first control Potential VC1. If the rectified potential VR is higher than or equal to the second threshold potential VTH2, the first control potential VC1 will be a high logic level, and if the rectified potential VR is lower than the second threshold potential VTH2, the first control potential VC1 will be a low logic level Level. The positive input terminal of the second amplifier 223 is coupled to the third node N3, the negative input terminal of the second amplifier 223 is coupled to the first node N1, and the output terminal of the second amplifier 223 is used to output a second control Potential VC2. If the rectified potential VR is lower than or equal to the first threshold potential VTH1, the second control potential VC2 will be a high logic level, and if the rectified potential VR is higher than the first threshold potential VTH1, the second control potential VC2 will be a low logic level Level. The step-down circuit 224 and the step-up circuit 225 generate and output an adjustment potential VT at a fourth node N4 according to the rectified potential VR, the first control potential VC1, and the second control potential VC2. The third capacitor C3 is coupled between the step-down circuit 224 and the step-up circuit 225, wherein the third capacitor C3 can be used to reduce the step-down circuit 224 and the step-up circuit when the maximum value VMAX and the minimum value VMIN of the rectified potential VR are too close. The probability of misjudgment of the circuit 225.

In some embodiments, the automatic adjustment circuit 220 further includes a fourth capacitor C4 and a fifth capacitor C5. The first end of the fourth capacitor C4 is coupled to the second node N2, and the second end of the fourth capacitor C4 is coupled to the ground potential VSS. The first terminal of the fifth capacitor C5 is coupled to the third node N3, and the second terminal of the fifth capacitor C5 is coupled to the ground potential VSS. The fourth capacitor C4 and the fifth capacitor C5 can be used to filter high frequency noise at the second node N2 and the third node N3.

The first terminal of the first capacitor C1 is coupled to the fourth node N4 to receive and store the adjustment potential VT, and the second terminal of the first capacitor C1 is coupled to the ground potential VSS.

The transformer 230 includes a main coil 231, a secondary coil 232, and an auxiliary coil 233. The first end of the main coil 231 is coupled to the fourth node N4 to receive the adjustment potential VT, and the second end of the main coil 231 is coupled to a fifth node N5. The first end of the auxiliary coil 232 is coupled to a sixth node N6 to output a variable voltage potential VS, and the second end of the auxiliary coil 232 is coupled to the ground potential VSS. The first end of the auxiliary coil 233 is coupled to the controller 260 to receive a supply potential VCC, and the second end of the auxiliary coil 233 is coupled to the ground potential VSS. For example, the supply potential VCC can be a fixed potential.

The power switch 240 includes a first transistor M1. The first transistor M1 can be an N-type MOSFET. The control terminal of the first transistor M1 is used to receive a clock potential VA, the first terminal of the first transistor M1 is coupled to the ground potential VSS, and the second terminal of the first transistor M1 is coupled to the fifth Node N5. The controller 260 is used to generate the clock potential VA. The clock potential VA can be maintained at a fixed potential (for example, the ground potential VSS) when the driving device 200 is initialized, and a periodic clock waveform can be provided after the driving device 200 enters the normal use phase.

The output stage circuit 250 includes a sixth diode D6, a sixth capacitor C5, and a resistor R1. The anode of the sixth diode D6 is coupled to the sixth node N6 to receive the variable voltage potential VS, and the cathode of the sixth diode D6 is coupled to a seventh node N7. The first terminal of the sixth capacitor C6 is coupled to the seventh node N7, and the second terminal of the sixth capacitor C6 is coupled to the ground potential VSS. The first end of the resistor R1 is coupled to the seventh node N7, and the second end of the resistor R1 is coupled to the output node NOUT.

The light emitting element 290 may include one or a plurality of light emitting diodes connected in series between the output node NOUT and the ground potential VSS. The total number of light-emitting diodes is not particularly limited in the present invention. In other embodiments, the aforementioned light-emitting diodes can also be changed to sub-millimeter light-emitting diodes (Mini LED), micro-light-emitting diodes (Micro LED), or organic light-emitting diodes (Organic LED, OLED) , But it's not limited to this. For example, if the output potential VOUT is at a high logic level, the light emitting element 290 will generate a light, and if the output potential VOUT is at a low logic level, the light emitting element 290 will not generate any light.

FIG. 3 is a schematic diagram showing the step-down circuit 224 and the step-up circuit 225 according to an embodiment of the present invention. In the embodiment of FIG. 3, the step-down circuit 224 includes a second transistor M2, a first inductor L1, and a seventh diode D7, and the step-up circuit 225 includes a third transistor M3, A second inductor L2, and an eighth diode D8. The second transistor M2 and the third transistor M3 can each be an N-type MOSFET. The anode of the seventh diode D7 is coupled to an eighth node N8, and the cathode of the seventh diode D7 is coupled to the first node N1 and the fourth node N4. The control terminal of the second transistor M2 is used to receive the first control potential VC1, the first terminal of the two transistors M2 is coupled to the ground potential VSS, and the second terminal of the second transistor M2 is coupled to the first Eight nodes N8. The first end of the first inductor L1 is coupled to an eighth node N8, and the second end of the first inductor L1 is coupled to a ninth node N9. The third capacitor C3 is coupled between the ninth node N9 and the ground potential VSS. The first end of the second inductor L2 is coupled to the first node N1, and the second end of the second inductor L2 is coupled to a tenth node N10. The control terminal of the third transistor M3 is used to receive the second control potential VC2, the first terminal of the third transistor M3 is coupled to the ground potential VSS, and the second terminal of the third transistor M3 is coupled to the first Ten nodes N10. The anode of the eighth diode D8 is coupled to the tenth node N10, and the cathode of the eighth diode D7 is coupled to the fourth node N4. It must be understood that the step-down circuit 224 and the step-up circuit 225 in FIG. 3 are only examples. In other embodiments, they can also be implemented with different circuit structures.

Fig. 4 shows a waveform diagram of the rectified potential VR according to an embodiment of the present invention. Fig. 5 shows a waveform diagram of the adjustment potential VT according to an embodiment of the present invention. According to the measurement results in Figures 4 and 5, the maximum value of the adjustment potential VT can be equal to the second threshold potential VTH2, which is lower than the maximum value VMAX of the rectification potential VR, and the minimum value of the adjustment potential VT can be equal to the first threshold The potential VTH1 is higher than the minimum value VMIN of the rectified potential VR. That is, the adjustment potential VT can be regarded as a compressed version of the rectified potential VR, which has a lower peak value and a higher valley value. Generally, the flicker percentage of the light-emitting element 290 can be as described in the following equation (1):

…………………………………………….(1) 其中「P」代表發光元件290之閃爍百分比，「A」代表輸出電位VOUT之極大值，而「B」代表輸出電位VOUT之極小值。

………………………………………. (1) where "P" represents the flicker percentage of the light-emitting element 290, "A" represents the maximum value of the output potential VOUT, and "B" represents the output The minimum value of the potential VOUT.

According to equation (1), if the maximum value of the output potential VOUT can be reduced or (and) the minimum value of the output potential VOUT can be increased, the flicker percentage of the light-emitting element 290 can be greatly reduced. After the driving device 200 uses the automatic adjustment circuit 220, its output potential VOUT can be roughly proportional to the adjustment potential VT, rather than the original rectified potential VR. Under this design, the adjustment potential VT between the first threshold potential VTH1 and the second threshold potential VTH2 can effectively suppress the stroboscopic phenomenon of the light-emitting element 290. For example, if the first threshold potential VTH1 is higher than the minimum value VMIN of the rectification potential VR by about 20%, and the second threshold potential VTH2 is lower than the maximum value VMAN of the rectification potential VR by about 20%, the flicker percentage of the light-emitting element 290 can be greatly reduced Up to about 40%.

In some embodiments, the component parameters of the driving device 200 may be as described below. The resistance value of the resistor R1 can be between 423Ω and 517Ω, preferably 470Ω. The capacitance value of the first capacitor C1 can be between 96 μF and 144 μF, preferably 120 μF. The capacitance value of the second capacitor C2 can be between 80 nF and 120 nF, preferably 100 nF. The capacitance value of the third capacitor C3 may be between 37.6 μF and 56.4 μF, preferably 47 μF. The capacitance value of the fourth capacitor C4 can be between 3.76 μF and 5.64 μF, preferably 4.7 μF. The capacitance value of the fifth capacitor C5 may be between 3.76 μF and 5.64 μF, preferably 4.7 μF. The capacitance value of the sixth capacitor C6 can be between 1200 μF and 1800 μF, preferably 1500 μF. The ratio of the number of turns of the primary coil 231 to the secondary coil 232 can be between 1 and 40, preferably 20. The turns ratio of the auxiliary coil 232 to the auxiliary coil 233 can be between 1 and 3, preferably 1.33. The above parameter range is obtained based on the results of many experiments, which helps to optimize the conversion efficiency of the driving device 200 and effectively suppress the stroboscopic phenomenon.

The present invention provides a novel driving device, which includes an automatic adjustment circuit that can reduce the flicker percentage of the light-emitting element. According to the actual measurement results, the use of the aforementioned automatic adjustment circuit can suppress the non-ideal flicker of the corresponding light-emitting element, thereby reducing the user's eye fatigue and discomfort. Generally speaking, the driving device of the present invention is not susceptible to the negative effects of general low-frequency noise from the mains, so it is very suitable for use in various types of electronic devices.

It is worth noting that the above-mentioned potential, current, resistance value, inductance value, capacitance value, and other component parameters are not the limiting conditions of the present invention. The designer can adjust these settings according to different needs. The driving device of the present invention is not limited to the state illustrated in Figs. 1-5. The present invention may only include any one or more of the features of any one or more of the embodiments in FIGS. 1-5. In other words, not all the features shown in the figures need to be implemented in the driving device of the present invention at the same time. Although the embodiment of the present invention uses metal oxide half field effect transistors as an example, the present invention is not limited to this. Those skilled in the art can use other types of transistors, such as junction field effect transistors or fins. Type field effect transistors, etc., without affecting the effect of the present invention.

The ordinal numbers in this specification and the scope of the patent application, such as "first", "second", "third", etc., do not have a sequential relationship with each other, and they are only used to distinguish two having the same Different components of the name.

Although the present invention is disclosed as above in the preferred embodiment, it is not intended to limit the scope of the present invention. Anyone who is familiar with the art can make some changes and modifications without departing from the spirit and scope of the present invention. Therefore, The scope of protection of the present invention shall be subject to those defined by the attached patent scope.

100, 200: drive device 110, 210: Bridge rectifier 120, 220: automatic adjustment circuit 124, 224: step-down circuit 125, 225: boost circuit 130, 230: Transformer 131, 231: main coil 132, 232: secondary coil 133, 233: auxiliary coil 140, 240: power switch 150, 250: output stage circuit 160, 260: Controller 190, 290: light-emitting element 221: monitoring circuit 222: first amplifier 223: second amplifier 224: Buck circuit 225: Boost circuit C1: The first capacitor C2: second capacitor C3: third capacitor C4: Fourth capacitor C5: Fifth capacitor C6: The sixth capacitor D1: The first diode D2: The second diode D3: The third diode D4: The fourth diode D5: Fifth diode D6: The sixth diode D7: seventh diode D8: The sixth diode L1: first inductor L2: second inductor M1: The first transistor M2: second transistor M3: third transistor N1: the first node N2: second node N3: third node N4: Fourth node N5: fifth node N6: sixth node N7: seventh node N8: The eighth node N9: Ninth node N10: Tenth node NIN1: the first input node NIN2: second input node NOUT: output node R1: resistor VA: clock potential VC1: The first control potential VC2: second control potential VCC: supply potential VIN1: the first input potential VIN2: second input potential VMAX: Maximum value VMIN: minimum value VOUT: output potential VR: Rectified potential VS: Variable voltage potential VSS: Ground potential VT: Adjust the potential VTH1: the first critical potential VTH2: second critical potential

Fig. 1 is a schematic diagram showing a driving device according to an embodiment of the present invention. Fig. 2 is a schematic diagram showing the driving device according to an embodiment of the present invention. FIG. 3 is a schematic diagram showing the step-down circuit and the step-up circuit according to an embodiment of the present invention. Fig. 4 shows a waveform diagram of the rectified potential according to an embodiment of the present invention. Fig. 5 shows a waveform diagram of the adjustment potential according to an embodiment of the present invention.

100: drive device

110: Bridge rectifier

120: automatic adjustment circuit

124: Buck circuit

125: Boost circuit

130: Transformer

131: main coil

132: Secondary coil

133: auxiliary coil

140: power switch

150: output stage circuit

160: Controller

190: Light-emitting element

C1: The first capacitor

VA: clock potential

VIN1: the first input potential

VIN2: second input potential

VOUT: output potential

VR: Rectified potential

VS: Variable voltage potential

VSS: Ground potential

VT: Adjust the potential

Claims (10)

A driving device is used to drive a light-emitting element and includes: A bridge rectifier that generates a rectified potential according to a first input potential and a second input potential; An automatic adjustment circuit includes a step-down circuit and a step-up circuit, and generates an adjustment potential between a first critical potential and a second critical potential according to the rectified potential, wherein the first critical potential is Higher than the minimum value of the rectified potential, and the second critical potential is lower than the maximum value of the rectified potential; A first capacitor storing the adjusted potential; A transformer, including a main coil, a secondary coil, and an auxiliary coil, wherein the main coil is used to receive the adjustment potential, and the secondary coil is used to generate a variable voltage potential; A power switch, wherein the main coil is coupled to a ground potential via the power switch, and the power switch performs switching operations according to a clock potential; An output stage circuit generates an output potential according to the variable voltage potential, wherein the light-emitting element determines whether to generate a light according to the output potential; and A controller generates the clock potential. The driving device described in item 1 of the scope of patent application, wherein the bridge rectifier includes: A first diode has an anode and a cathode, wherein the anode of the first diode is coupled to a first input node to receive the first input potential, and the first diode of the The cathode is coupled to a first node to output the rectified potential; A second diode having an anode and a cathode, wherein the anode of the second diode is coupled to the first input node, and the cathode of the second diode is coupled to the ground Potential A third diode has an anode and a cathode, wherein the anode of the third diode is coupled to the first node, and the cathode of the third diode is coupled to a second Input node to receive the second input potential; and A fourth diode having an anode and a cathode, wherein the anode of the fourth diode is coupled to the ground potential, and the cathode of the fourth diode is coupled to the second input node. For the driving device described in item 2 of the scope of patent application, the automatic adjustment circuit further includes: A second capacitor has a first terminal and a second terminal, wherein the first terminal of the second capacitor is coupled to the first node to receive the rectified potential, and the second terminal of the second capacitor Is coupled to the ground potential; A monitoring circuit detects the rectified potential, wherein the monitoring circuit generates the second critical potential at a second node based on the maximum value of the rectified potential, and generates the second critical potential at a second node based on the minimum value of the rectified potential. The first critical potential is generated at the three nodes; and A fifth diode having an anode and a cathode, wherein the anode of the fifth diode is coupled to the first node, and the cathode of the fifth diode is coupled to the monitoring circuit . For the driving device described in item 3 of the scope of patent application, the automatic adjustment circuit further includes: A first amplifier has a positive input terminal, a negative input terminal, and an output terminal, wherein the positive input terminal of the first amplifier is coupled to the first node, and the negative input terminal of the first amplifier is Coupled to the second node, and the output terminal of the first amplifier is used to output a first control potential; A second amplifier has a positive input terminal, a negative input terminal, and an output terminal, wherein the positive input terminal of the second amplifier is coupled to the third node, and the negative input terminal of the second amplifier is Coupled to the first node, and the output terminal of the second amplifier is used to output a second control potential; and A third capacitor, coupled between the step-down circuit and the step-up circuit; The step-down circuit and the step-up circuit generate the adjusted potential at a fourth node according to the rectified potential, the first control potential, and the second control potential. For the driving device described in item 3 of the scope of patent application, the automatic adjustment circuit further includes: A fourth capacitor has a first terminal and a second terminal, wherein the first terminal of the fourth capacitor is coupled to the second node, and the second terminal of the fourth capacitor is coupled to the Ground potential; and A fifth capacitor has a first terminal and a second terminal, wherein the first terminal of the fifth capacitor is coupled to the third node, and the second terminal of the fifth capacitor is coupled to the Ground potential The first capacitor has a first terminal and a second terminal, the first terminal of the first capacitor is coupled to the fourth node to receive the adjustment potential, and the second terminal of the first capacitor is Coupled to the ground potential. The driving device described in item 4 of the scope of patent application, wherein the main coil has a first end and a second end, and the first end of the main coil is coupled to the fourth node to receive the adjustment potential, The second end of the main coil is coupled to a fifth node, the auxiliary coil has a first end and a second end, and the first end of the auxiliary coil is coupled to a sixth node to output the Variable voltage, the second end of the auxiliary coil is coupled to the ground potential, the auxiliary coil has a first end and a second end, and the first end of the auxiliary coil is received by the controller A potential is supplied, and the second end of the auxiliary coil is coupled to the ground potential. The driving device described in item 6 of the scope of patent application, wherein the power switch includes: A first transistor has a control terminal, a first terminal, and a second terminal, wherein the control terminal of the first transistor is used to receive the clock potential, and the first transistor of the first transistor The terminal is coupled to the ground potential, and the second terminal of the first transistor is coupled to the fifth node. The driving device described in item 6 of the scope of patent application, wherein the output stage circuit includes: A sixth diode has an anode and a cathode, wherein the anode of the sixth diode is coupled to the sixth node to receive the variable voltage potential, and the cathode of the sixth diode is Coupled to a seventh node; A sixth capacitor having a first terminal and a second terminal, wherein the first terminal of the sixth capacitor is coupled to the seventh node, and the second terminal of the sixth capacitor is coupled to the Ground potential; and A resistor has a first end and a second end, wherein the first end of the resistor is coupled to the seventh node, and the second end of the resistor is coupled to an output node to The output potential is output. The driving device described in item 4 of the scope of patent application, wherein the step-down circuit includes: A seventh diode having an anode and a cathode, wherein the anode of the seventh diode is coupled to an eighth node, and the cathode of the seventh diode is coupled to the first Node and the fourth node; A second transistor has a control terminal, a first terminal, and a second terminal, wherein the control terminal of the second transistor is used to receive the first control potential, and the first terminal of the second transistor One end is coupled to the ground potential, and the second end of the second transistor is coupled to the eighth node; and A first inductor has a first end and a second end, wherein the first end of the first inductor is coupled to the eighth node, and the second end of the first inductor is coupled Connected to a ninth node; The third capacitor is coupled between the ninth node and the ground potential. The driving device described in item 9 of the scope of patent application, wherein the booster circuit includes: A second inductor has a first end and a second end, wherein the first end of the second inductor is coupled to the first node, and the second end of the second inductor is coupled Connected to a tenth node; A third transistor has a control terminal, a first terminal, and a second terminal, wherein the control terminal of the third transistor is used to receive the second control potential, and the second terminal of the third transistor One end is coupled to the ground potential, and the second end of the third transistor is coupled to the tenth node; and An eighth diode having an anode and a cathode, wherein the anode of the eighth diode is coupled to the tenth node, and the cathode of the eighth diode is coupled to the fourth node node.

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