Voltage regulator, integrated circuit, motor drive system and electrical appliance

Abstract

The present invention provides a voltage regulator, an integrated circuit, a motor drive system, and an electrical appliance. The voltage regulator includes: a first switching transistor, the first end of the first switching transistor is used to receive a power supply signal; a voltage dividing circuit, the first end of the voltage dividing circuit is connected to the second end of the first switching transistor, the second end of the voltage dividing circuit is grounded, and the voltage dividing circuit has a feedback node; an error amplifier, the first input end of the error amplifier is used to receive a reference voltage, the second input end of the error amplifier is connected to the feedback node, and the output end of the error amplifier is connected to the control end of the first switching transistor to drive the first switching transistor to switch; a pre-driver circuit, the input end of the pre-driver circuit is used to receive a power supply signal, and the output end of the pre-driver circuit is connected to the power supply end of the error amplifier to supply power to the error amplifier; wherein, the second end of the first switching transistor is the output voltage node of the voltage regulator. The provided pre-driver circuit can improve the PSR of the error amplifier so as to meet the user's usage requirements for the voltage regulator.

Description

Technical Field

[0001] The present invention relates to the field of circuit technologies, and more particularly, to a voltage regulator, an integrated circuit, a motor drive system, and an electrical appliance. Background Art

[0002] PSR, an abbreviation of Primary Side Regulator, that is, power supply rejection. The power supply rejection of existing low dropout regulators (LDOs) at low frequencies is mainly determined by the loop gain.

[0003] The LDOs adopted by existing system-on-chips are usually of the capless structure. In this structure, the internal compensation capacitance in the LDO is relatively large, resulting in a relatively low loop bandwidth. It is relatively applicable at low frequencies. At high frequencies, due to the existence of parasitic capacitance, the PSR of existing LDOs will decrease significantly, making the LDO unable to meet the current usage requirements. Summary of the Invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art or related technologies.

[0005] To this end, in the first aspect of the present invention, a voltage regulator is provided.

[0006] In the second aspect of the present invention, an integrated circuit is provided.

[0007] In the third aspect of the present invention, a motor drive system is provided.

[0008] In the fourth aspect of the present invention, an electrical appliance is provided.

[0009] In view of this, according to the first aspect of the present invention, a voltage regulator is provided, including: a first switching transistor, the first end of the first switching transistor is configured to receive a power supply signal; a voltage dividing circuit, the first end of the voltage dividing circuit is connected to the second end of the first switching transistor, the second end of the voltage dividing circuit is grounded, and the voltage dividing circuit has a feedback node; an error amplifier, the first input terminal of the error amplifier is configured to receive a reference voltage, the second input terminal of the error amplifier is connected to the feedback node, and the output terminal of the error amplifier is connected to the control terminal of the first switching transistor to drive the first switching transistor to switch; a pre-driving circuit, the input terminal of the pre-driving circuit is configured to receive the power supply signal, and the output terminal of the pre-driving circuit is connected to the power supply terminal of the error amplifier to supply power to the error amplifier; wherein, the second end of the first switching transistor is the output voltage node of the voltage regulator.

[0010] The technical solution of this application proposes a voltage regulator. In this voltage regulator, in addition to including a first switching transistor, a voltage dividing circuit, and an error amplifier, it also includes a pre-driver circuit. Among them, the pre-driver circuit can supply power to the error amplifier. By setting the pre-driver circuit, the PSR of the error amplifier can be improved to reduce the influence of the power supply signal on the signal output by the output terminal of the error amplifier, thereby improving the PSR of the voltage regulator to meet the user's usage requirements for the voltage regulator.

[0011] The technical solution of this application is implemented based on the following principle. Specifically, the error amplifier and the first switching transistor are powered on and operate using the same power supply signal. The high-frequency interference of the power supply signal will be coupled to the error amplifier, thereby affecting the signal output by the output terminal of the error amplifier. In order to eliminate the influence of the high-frequency interference of the power supply signal on the error amplifier itself, the technical solution of this application sets a pre-driver circuit to process the power supply signal using the pre-driver circuit, thereby providing stable power supply to the error amplifier. During this process, the influence of the high-frequency interference of the power supply signal on the signal output by the output terminal of the error amplifier is eliminated or reduced, thereby improving the PSR of the voltage regulator to meet the user's usage requirements for the voltage regulator.

[0012] Among them, the first switching transistor and the voltage dividing circuit are located between the power supply signal and the ground. Therefore, by controlling the first switching transistor, the voltage output by the output voltage node can be controlled. The set error amplifier uses the feedback node on the voltage dividing circuit to feedback the voltage situation output by the output voltage node when the first switching transistor and the voltage dividing circuit are used in combination, and compares it with the reference voltage to know the voltage deviation situation of the voltage output by the voltage node. Combining the connection relationship between the output terminal of the error amplifier and the control terminal of the first switching transistor, the first switching transistor is controlled using the voltage deviation situation. During this process, the voltage regulator can achieve automatic adjustment of the output voltage, ensuring the stability of the output voltage.

[0013] In addition, the voltage regulator proposed in this application also has the following additional technical features.

[0014] In the above technical solution, the voltage dividing circuit includes: a first resistor, the first end of the first resistor is connected to the second end of the first switching transistor; a second resistor, the first end of the second resistor is connected to the second end of the first resistor as the feedback node, and the second end of the second resistor is grounded.

[0015] In this technical solution, the detailed connection structure of the voltage dividing circuit is given. Among them, by defining that the voltage dividing circuit includes a first resistor and a second resistor, so that a series connection of resistors is formed between the first resistor and the second resistor, so as to select a feedback node from the resistors with series connection in the voltage dividing circuit, and further know the magnitude of the voltage that the output voltage node can output when the first switching transistor and the voltage dividing circuit are used.

[0016] In the above technical solution, the resistance values of the first resistor and the second resistor can be selected according to actual usage requirements, and their specific values are not limited herein.

[0017] In any of the above technical solutions, the pre-driver circuit includes: a second switching transistor, the first end of the second switching transistor is connected to the power supply terminal of the error amplifier; a filtering circuit, the first end of the filtering circuit is used to receive a power supply signal and is connected to the second end of the second switching transistor, the second end of the filtering circuit is grounded, and the output end of the filtering circuit is connected to the control end of the second switching transistor, and the filtering circuit is used to drive the second switching transistor.

[0018] In this technical solution, the detailed topological structure of the pre-driver circuit is specifically defined. Under this topological structure, the pre-driver circuit includes a second switching transistor and a filtering circuit. Among them, the first end of the filtering circuit can receive a power supply signal. Combining the connection relationship between the second switching transistor and the filtering circuit, the filtering circuit can control the second switching transistor, thereby controlling the magnitude of the power supply output from the first end of the second switching transistor.

[0019] In this process, the setting of the filtering circuit can eliminate the interference in the power supply signal. Therefore, the influence of the power supply signal on the voltage output from the first end of the second switching transistor is reduced, thereby providing a stable power supply to the error amplifier. In this process, the influence of the power supply signal on the signal output from the output end of the error amplifier is eliminated or reduced, so as to improve the PSR of the voltage regulator to meet the user's usage requirements for the voltage regulator.

[0020] In any of the above technical solutions, the filtering circuit includes: a third resistor, the first end of the third resistor is connected to the second end of the second switching transistor; a first capacitor, the first end of the first capacitor is connected to the second end of the third resistor, and the second end of the first capacitor is grounded; wherein, the connection point of the first end of the first capacitor and the second end of the third resistor is the output end of the filtering circuit.

[0021] In this technical solution, the detailed topological structure of the filtering circuit is specifically defined. Among them, the filtering circuit includes a third resistor and a first capacitor. Among them, the third resistor and the first capacitor constitute a low-pass filter network, and the interference on the power supply signal is filtered out under the action of the filtering circuit.

[0022] Based on the content recorded above, the filtering circuit is an RC filter. Among them, the larger the product of RC, the better the suppression effect on high-frequency interference.

[0023] In one of the technical solutions, the product of RC can be understood as the product of the resistance value of the third resistor and the capacitance value of the first capacitor.

[0024] In any of the above technical solutions, it further includes: a reference voltage output circuit, connected to the first input end of the error amplifier, for outputting a reference voltage.

[0025] In this technical solution, the source of the reference voltage is specifically given. By setting up a reference voltage output circuit, the reference voltage output circuit is used to provide the reference voltage.

[0026] In the above technical solution, the detailed circuit structure of the reference voltage output circuit will not be elaborated here.

[0027] In any of the above technical solutions, the output end of the pre-driver circuit is connected to the power supply end of the reference voltage output circuit for supplying power to the reference voltage output circuit.

[0028] In this technical solution, by defining the power supply connection between the pre-driver circuit and the reference voltage output circuit, the pre-driver circuit is used to supply power to the reference voltage output circuit. During this process, the interference in the power supply signal can be eliminated or weakened, thus improving the stability of the output voltage of the voltage regulator.

[0029] In any of the above technical solutions, it further includes: a second capacitor, the first end of the second capacitor is connected to the output end of the error amplifier, and the second end of the second capacitor is grounded.

[0030] In this technical solution, the interference that may be doped in the signal output from the output end of the error amplifier is eliminated. In the presence of this interference, the stability of the output voltage of the voltage regulator is affected.

[0031] The technical solution of this application sets the second capacitor to eliminate the interference that may be doped in the signal output from the output end of the error amplifier. Specifically, as a two-pole system, the low-dropout linear regulator needs to increase the compensation capacitor to make the low-dropout linear regulator stable.

[0032] Since the second end of the second capacitor is grounded instead of being connected to the second end of the first switching transistor, the high-frequency interference in the power supply signal will not be coupled to the error amplifier through the compensation capacitor to interfere with the output of the error amplifier. Compared with the related technical solution, the compensation capacitor can be connected across the gate and drain of the first switching transistor. Under the Miller effect, it is equivalent to a large capacitor of the gate to the power supply signal, and the high-frequency interference on the power supply signal is more likely to be coupled to the gate, that is, the output of the error amplifier.

[0033] In addition, the second capacitor is grounded, that is, it belongs to a capacitor to the ground, making the voltage output from the output end of the error amplifier more stable, which is also beneficial to the voltage stability of the final output voltage node. That is, the interference that may be doped in the signal output from the output end of the error amplifier will not act on the voltage dividing circuit either, thus ensuring the stability of the output voltage of the voltage regulator.

[0034] In addition, adopting the above connection method improves the stability of the output voltage of the voltage regulator.

[0035] In any of the above technical solutions, the first switching transistor is an NMOS transistor.

[0036] In this technical solution, the type of the first switching transistor is specifically defined. Among them, NMOS (N-Mental-Oxide-Semiconductor, N-type metal-oxide-semiconductor), and a transistor with the above structure is called an NMOS transistor, that is, an NMOS tube.

[0037] Among them, two N+ regions with high doping concentrations are fabricated on a P-type silicon substrate with a relatively low doping concentration, and two electrodes are led out with metallic aluminum, serving as the drain and source respectively. Then, a very thin silicon dioxide insulating layer is covered on the semiconductor surface, and an aluminum electrode is further encapsulated on the insulating layer between the drain-source electrodes as the gate, and an electrode is also led out on the substrate, thereby forming an N-channel enhancement-mode MOS transistor.

[0038] In the technical solution of the present application, the NMOS transistor has better PSR. When used as a power transistor or a switching transistor, the power supply signal acts on the drain, and the influence on the source is relatively small. As can be seen from the above, the PSR can be improved by selecting the type of the first switching transistor, thereby ensuring the stability of the output voltage of the voltage regulator.

[0039] In one of the technical solutions, the second switching transistor is an NMOS transistor.

[0040] In this technical solution, by defining the second switching transistor as an NMOS transistor, the influence of the high-frequency interference of the power supply signal on the power supply of the error amplifier can be minimized, thereby ensuring the stability of the output voltage of the voltage regulator.

[0041] In any of the above technical solutions, the second end of the first switching transistor is the source of the NMOS transistor.

[0042] In this technical solution, considering that the second end of the first switching transistor outputs voltage as the output voltage node, therefore, the voltage at the output voltage node needs to be the most stable. Since the influence of the power supply signal on the source in the NMOS transistor is relatively small, the source of the NMOS transistor is selected as the second end of the first switching transistor, thereby ensuring the stability of the output voltage of the voltage regulator.

[0043] In any of the above technical solutions, the NMOS transistor is a native NMOS transistor.

[0044] In this technical solution, compared with a general NMOS device, the threshold voltage of the native NMOS transistor is reduced from several hundred millivolts to about 0 volts, reducing the dropout voltage, thereby improving the efficiency of the NMOS transistor and also reducing the minimum operating voltage of the power supply signal.

[0045] In any of the above technical solutions, the voltage regulator is a linear voltage regulator.

[0046] According to the second aspect of the present invention, the present invention provides an integrated circuit, including: a voltage regulator as described in any one of the above.

[0047] In this technical solution, the above voltage regulator can be integrated into an existing integrated circuit to supply power to other circuit components in the integrated circuit, so as to improve the reliability during the operation of the integrated circuit.

[0048] In the above technical solution, the integrated circuit is a system-on-chip.

[0049] According to the third aspect of the present invention, the present invention provides a motor drive system, including: a voltage regulator as described in any one of the above; and / or an integrated circuit as described in any one of the above.

[0050] In this technical solution, a specific usage scenario of the above voltage regulator and / or integrated circuit is given. Among them, the motor drive system further includes a control board, and the above motor drive system is integrated on the control board to supply power to the control board.

[0051] According to the fourth aspect of the present invention, the present invention provides an electrical appliance, including: a voltage regulator as described in any one of the above; and / or an integrated circuit as described in any one of the above.

[0052] In the above technical solution, the electrical appliance can be a household appliance, such as a refrigerator, a television, a washing machine, etc.

[0053] Additional aspects and advantages of the present invention will be partially given in the following description, partially become apparent from the following description, or be understood through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] The above and / or additional aspects and advantages of the present invention will become apparent and be readily understood from the description of the embodiments in conjunction with the following drawings, where:

[0055] Figure 1 One of the topological schematic diagrams of the voltage regulator in the embodiment of the present invention is shown;

[0056] Figure 2 The topological schematic diagram of the pre-driver circuit in the embodiment of the present invention is shown;

[0057] Figure 3Shows the second topological schematic diagram of the voltage regulator in the embodiment of the present invention;

[0058] Figure 4 Shows the simulation result of the voltage regulator in the embodiment of the present invention.

[0059] Wherein, Figures 1 to 3 The corresponding relationship between the reference numerals and the component names in

[0060] Q1 is the first switching transistor, Q2 is the second switching transistor, A is the error amplifier, P1 is the pre-driver circuit, R1 is the first resistor, R2 is the second resistor, R3 is the third resistor, C1 is the first capacitor, C2 is the second capacitor, P2 is the reference voltage output circuit, VDD is the power supply signal, and VOUT is the output voltage node. Detailed implementation manners

[0061] In order to be able to more clearly understand the above aspects, features and advantages of the present invention, the present invention will be further described in detail below with reference to the drawings and specific implementation manners. It should be noted that, without conflict, the embodiments of the present application and the features in the embodiments may be combined with each other.

[0062] Many specific details are set forth in the following description in order to fully understand the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the protection scope of the present invention is not limited by the specific embodiments disclosed below.

[0063] As Figure 1 、 Figure 2 、 Figure 3 shown, according to an embodiment of the present invention, a voltage regulator is provided, including: a first switching transistor Q1, a first end of the first switching transistor Q1 is used to receive a power supply signal VDD; a voltage dividing circuit, a first end of the voltage dividing circuit is connected to a second end of the first switching transistor Q1, a second end of the voltage dividing circuit is grounded, and the voltage dividing circuit has a feedback node; an error amplifier A, a first input end of the error amplifier A is used to receive a reference voltage, a second input end of the error amplifier A is connected to the feedback node, and an output end of the error amplifier A is connected to a control end of the first switching transistor Q1 to drive the first switching transistor Q1 to switch; a pre-driver circuit P1, an input end of the pre-driver circuit P1 is used to receive the power supply signal VDD, and an output end of the pre-driver circuit P1 is connected to a power supply end of the error amplifier A to supply power to the error amplifier A; wherein, the second end of the first switching transistor Q1 is the output voltage node VOUT of the voltage regulator.

[0064] An embodiment of the present application provides a voltage regulator. In addition to including a first switching transistor Q1, a voltage dividing circuit, and an error amplifier A, the voltage regulator further includes a pre-driver circuit P1. The pre-driver circuit P1 can supply power to the error amplifier A. By setting the pre-driver circuit P1, the PSR of the error amplifier A can be improved to reduce the influence of high-frequency interference of the power supply signal VDD on the signal output from the output terminal of the error amplifier A, thereby improving the PSR of the voltage regulator. The comparison results are as Figure 4 shown, where Figure 4 the abscissa is the frequency and the ordinate is the PSR to meet the user's requirements for using the voltage regulator.

[0065] Among them, using a NativeNMOS device as the power transistor, the PSR is significantly improved at high frequencies; after adding the pre-driver circuit P1 additionally, the PSR is further improved. Whether to add the pre-driver circuit P1 can be flexibly selected according to specific application scenarios.

[0066] The embodiment of the present application is implemented based on the following principle. Specifically, the error amplifier A and the first switching transistor Q1 are powered on and operated using the same power supply signal VDD. High-frequency interference of the power supply signal VDD will be coupled to the error amplifier A, thereby affecting the signal output from the output terminal of the error amplifier A. To eliminate the influence of high-frequency interference of the power supply signal VDD on the error amplifier A itself, the embodiment of the present application sets the pre-driver circuit P1 to process the power supply signal VDD using the pre-driver circuit P1, so as to provide stable power supply to the error amplifier A. During this process, the influence of high-frequency interference of the power supply signal VDD on the signal output from the output terminal of the error amplifier A is eliminated or reduced, thereby improving the PSR of the voltage regulator to meet the user's requirements for using the voltage regulator.

[0067] Among them, the first switching transistor Q1 and the voltage dividing circuit are located between the power supply signal VDD and the ground. Therefore, by controlling the first switching transistor Q1, the voltage output from the output voltage node VOUT can be controlled. The set error amplifier A uses the feedback node on the voltage dividing circuit to feedback the voltage situation output from the output voltage node VOUT when the first switching transistor Q1 and the voltage dividing circuit are used in combination, and compares it with the reference voltage to know the voltage deviation situation output from the voltage node. Combining the connection relationship between the output terminal of the error amplifier A and the control terminal of the first switching transistor Q1, the first switching transistor Q1 is controlled using the voltage deviation situation. During this process, the voltage regulator can realize automatic adjustment of the output voltage, ensuring the stability of the output voltage.

[0068] In the above embodiment, the voltage dividing circuit includes: a first resistor R1, the first end of the first resistor R1 is connected to the second end of the first switching transistor Q1; a second resistor R2, the first end of the second resistor R2 is connected to the second end of the first resistor R1 to serve as a feedback node, and the second end of the second resistor R2 is grounded.

[0069] In this embodiment, the detailed connection structure of the voltage dividing circuit is given. Among them, by defining that the voltage dividing circuit includes the first resistor R1 and the second resistor R2, so that a series connection of resistors is formed between the first resistor R1 and the second resistor R2, so as to select a feedback node from the resistors with series connection in the voltage dividing circuit, and further know the magnitude of the voltage that the output voltage node VOUT can output when the first switching transistor Q1 and the voltage dividing circuit are used.

[0070] In the above embodiment, the resistance values of the first resistor R1 and the second resistor R2 can be selected according to actual usage requirements, and their specific values are not limited herein.

[0071] In any of the above embodiments, the pre-driver circuit P1 includes: a second switching transistor Q2, the first end of the second switching transistor Q2 is connected to the power supply terminal of the error amplifier A; a filtering circuit, the first end of the filtering circuit is used to receive the power supply signal VDD and is connected to the second end of the second switching transistor Q2, the second end of the filtering circuit is grounded, and the output end of the filtering circuit is connected to the control end of the second switching transistor Q2, and the filtering circuit is used to drive the second switching transistor Q2.

[0072] In this embodiment, the detailed topological structure of the pre-driver circuit P1 is specifically defined. Under this topological structure, the pre-driver circuit P1 includes the second switching transistor Q2 and the filtering circuit. Among them, the first end of the filtering circuit can receive the power supply signal VDD. Combining the connection relationship between the second switching transistor Q2 and the filtering circuit, the filtering circuit can control the second switching transistor Q2, so as to control the magnitude of the power supply output by the first end of the second switching transistor.

[0073] In this process, the setting of the filtering circuit can eliminate the interference in the power supply signal VDD. Therefore, the influence of the power supply signal VDD on the voltage output by the first end of the second switching transistor Q2 is reduced, so as to provide a stable power supply to the error amplifier A. In this process, the influence of the power supply signal VDD on the signal output by the output end of the error amplifier A is eliminated or reduced, so as to improve the PSR of the voltage regulator to meet the user's usage requirements for the voltage regulator.

[0074] In any of the above embodiments, the filter circuit includes: a third resistor R3, with the first end of the third resistor R3 connected to the second end of the second switching transistor Q2; a first capacitor C1, with the first end of the first capacitor C1 connected to the second end of the third resistor R3, and the second end of the first capacitor C1 grounded; wherein, the connection point of the first end of the first capacitor C1 and the second end of the third resistor R3 is the output end of the filter circuit.

[0075] In this embodiment, the detailed topological structure of the filter circuit is specifically defined. Among them, the filter circuit includes a third resistor R3 and a first capacitor C1. Among them, the third resistor R3 and the first capacitor C1 constitute a low-pass filter network, and the interference on the power supply signal VDD is filtered out under the action of the filter circuit.

[0076] Based on the content recorded above, it can be known that the filter circuit is an RC filter. Among them, the larger the product of RC, the better the suppression effect on high-frequency interference, but a trade-off needs to be made between the area and frequency of the switching transistor.

[0077] In one of the embodiments, the product of RC can be understood as the product of the resistance value of the third resistor R3 and the capacitance value of the first capacitor C1.

[0078] In one of the embodiments, the value of the first capacitor C1 can be selected according to the product of RC. For example, when the product of RC is a fixed value, as the value of the first capacitor C1 increases, the value of the third resistor R3 decreases; conversely, as the value of the first capacitor C1 decreases, the value of the third resistor R3 increases.

[0079] In any of the above embodiments, it further includes: a reference voltage output circuit P2, connected to the first input end of the error amplifier A, for outputting a reference voltage.

[0080] In this embodiment, the source of the reference voltage is specifically given. By setting the reference voltage output circuit P2, the reference voltage output circuit P2 is used to provide the reference voltage.

[0081] In the above embodiments, the detailed circuit structure of the reference voltage output circuit P2 will not be elaborated here.

[0082] In any of the above embodiments, the output end of the pre-driver circuit P1 is connected to the power supply end of the reference voltage output circuit P2, for supplying power to the reference voltage output circuit P2.

[0083] In this embodiment, by defining the power supply connection between the pre-driver circuit P1 and the reference voltage output circuit P2, the pre-driver circuit P1 is used to supply power to the reference voltage output circuit P2. In this process, the influence of the interference in the power supply signal VDD on the reference voltage can be eliminated or weakened, thereby improving the stability of the output voltage of the voltage regulator.

[0084] As Figure 3 shown, in any of the above embodiments, it further includes: a second capacitor C2, the first end of the second capacitor C2 is connected to the output end of the error amplifier A, and the second end of the second capacitor C2 is grounded.

[0085] In this embodiment, the interference that may be doped in the signal output from the output end of the error amplifier A is eliminated. In the presence of this interference, the stability of the output voltage of the voltage regulator is affected.

[0086] The embodiment of the present application sets the second capacitor C2 to eliminate the interference that may be doped in the signal output from the output end of the error amplifier A by using the second capacitor C2. Specifically, the low dropout linear regulator is a two-pole system and needs to increase the compensation capacitor to make the low dropout linear regulator stable.

[0087] Since the second end of the second capacitor C2 is grounded instead of being connected to the second end of the first switching transistor Q1, the high-frequency interference in the power supply signal will not be coupled to the error amplifier A through the compensation capacitor to interfere with the output of the error amplifier A. Compared with the related technical solutions, the compensation capacitor can be connected across the gate and drain of the first switching transistor Q1. Under the Miller effect, it is equivalent to a large capacitor of the gate to the power supply signal, and the high-frequency interference on the power supply signal is more likely to be coupled to the gate, that is, the output of the error amplifier A.

[0088] In addition, the second capacitor C2 is grounded, that is, it belongs to a capacitor to the ground, making the voltage output from the output end of the error amplifier A more stable, which is also beneficial to the voltage stability of the final output voltage node. That is, the interference that may be doped in the signal output from the output end of the error amplifier A will not act on the voltage dividing circuit either, thus ensuring the stability of the output voltage of the voltage regulator.

[0089] In addition, adopting the above connection method improves the stability of the output voltage of the voltage regulator.

[0090] In any of the above embodiments, the first switching transistor Q1 is an NMOS transistor.

[0091] In this embodiment, the type of the first switching transistor Q1 is specifically defined. Among them, NMOS (N-Mental-Oxide-Semiconductor, N-type metal-oxide-semiconductor), and the transistor with the above structure is called an NMOS transistor, that is, an NMOS tube.

[0092] Among them, two N+ regions with high doping concentrations are fabricated on a P-type silicon substrate with a relatively low doping concentration, and two electrodes are led out with metallic aluminum to serve as the drain and source respectively. Then, a very thin silicon dioxide insulating layer is covered on the semiconductor surface, and an aluminum electrode is further encapsulated on the insulating layer between the drain and source as the gate, and an electrode is also led out on the substrate, thus forming an N-channel enhancement-mode MOS transistor.

[0093] In the embodiments of the present application, the NMOS transistor has a better PSR. When used as a power transistor or a switching transistor, the power supply signal VDD acts on the drain, and has a relatively small influence on the source. As can be seen from the above, the PSR can be improved by selecting the first switching transistor Q1, thereby ensuring the stability of the output voltage of the voltage regulator.

[0094] In one of the embodiments, the second switching transistor Q2 is an NMOS transistor.

[0095] In this embodiment, by defining the second switching transistor Q2 as an NMOS transistor, the influence of the high-frequency interference of the power supply signal VDD on the power supply of the error amplifier A can be minimized to the greatest extent, thereby ensuring the stability of the output voltage of the voltage regulator.

[0096] In any of the above embodiments, the second end of the first switching transistor Q1 is the source of the NMOS transistor.

[0097] In this embodiment, considering that the second end of the first switching transistor Q1 outputs voltage as the output voltage node VOUT, therefore, the voltage at the output voltage node VOUT needs to be the most stable. Since the influence of the power supply signal VDD on the source in the NMOS transistor is relatively small, the source of the NMOS transistor is selected as the second end of the first switching transistor Q1, thereby ensuring the stability of the output voltage of the voltage regulator.

[0098] In any of the above embodiments, the NMOS transistor is a native NMOS transistor.

[0099] In this embodiment, compared with a common NMOS device, the threshold voltage of the native NMOS transistor is reduced from several hundred millivolts to about 0 V, reducing the dropout voltage, thereby improving the efficiency of the NMOS transistor and also reducing the minimum operating voltage of the power supply signal VDD.

[0100] In any of the above embodiments, the voltage regulator is a linear voltage regulator.

[0101] In one embodiment, the non-inverting input terminal of the error amplifier A is connected to a reference voltage, the inverting input terminal is connected to the feedback voltage VF, and the output terminal VG is connected to the gate of the power native NMOS transistor. The drain of the transistor is connected to the power supply signal VDD, and the pre-driver circuit P1 provides the voltage VREG for the error amplifier A. The control terminal of the second switching transistor in the pre-driver circuit P1 is controlled under VC.

[0102] In the embodiment of the present application, a P1+NMOS linear voltage regulator with high power supply rejection is adopted. It has the following advantages: 1. Smaller area overhead; 2. Smaller dropout voltage, and the minimum operating voltage can be lower.

[0103] Among them, the NMOS transistor is implemented with a native device, the threshold voltage is about 0V, and the output voltage of VREG is close to the VDD voltage. Since the current of the reference voltage and the error amplifier A as the load is small, the required area of the power transistor is small, and the voltage drop can be almost ignored, which has little impact on the minimum operating voltage of the system.

[0104] In one embodiment, the power supply signal VDD can be a fixed power supply, such as a DC source, etc.

[0105] In one embodiment, the present invention provides an integrated circuit, including: a voltage regulator as described in any one of the above.

[0106] The technical solution of the present application proposes an integrated circuit including a voltage regulator. In addition to including a first switching transistor, a voltage dividing circuit, and an error amplifier, the voltage regulator further includes a pre-driver circuit. Among them, the pre-driver circuit can supply power to the error amplifier. By setting the pre-driver circuit, the PSR of the error amplifier can be improved to reduce the influence of the power supply signal on the signal output by the output terminal of the error amplifier, so as to improve the PSR of the voltage regulator to meet the user's usage requirements for the voltage regulator.

[0107] The technical solution of the present application is implemented based on the following principle. Specifically, the error amplifier and the first switching transistor are powered on and operated with the same power supply signal. Therefore, the power supply signal will be coupled to the error amplifier, and further affect the signal output by the output terminal of the error amplifier. In order to eliminate the influence of the power supply signal on the error amplifier itself, the technical solution of the present application sets a pre-driver circuit to process the power supply signal by using the pre-driver circuit, so as to provide stable power supply to the error amplifier. During this process, the influence of the power supply signal on the signal output by the output terminal of the error amplifier is eliminated or reduced, so as to improve the PSR of the voltage regulator to meet the user's usage requirements for the voltage regulator. In this embodiment, the above voltage regulator can be integrated into an existing integrated circuit to supply power to other circuit components in the integrated circuit, so as to improve the reliability during the operation of the integrated circuit.

[0108] In the above embodiments, the integrated circuit is a system-on-chip.

[0109] In one of the embodiments, the present invention provides a motor drive system, comprising: a voltage regulator as described in any one of the above; and / or an integrated circuit as described in any one of the above.

[0110] In this embodiment, a motor drive system including the voltage regulator in any one of the above embodiments or including the integrated circuit in any one of the above embodiments is proposed. Therefore, the motor drive system has the advantages of the voltage regulator in any one of the above embodiments, or has the advantages of the integrated circuit in any one of the above embodiments. Correspondingly, it can achieve the technical effects that the voltage regulator in any one of the above embodiments can achieve, or can achieve the technical effects that the integrated circuit in any one of the above embodiments can achieve, which will not be elaborated here.

[0111] In this embodiment, a use scenario of the above voltage regulator and / or integrated circuit is specifically given. Among them, the motor drive system further includes a control board, and the above motor drive system is integrated on the control board to provide power supply for the control board.

[0112] In the above embodiments, the motor drive system further includes a motor connected to the control board to control the operation of the motor by using the control board.

[0113] In one of the embodiments, the motor in the above can be a drive motor that drives a load to operate.

[0114] In one of the embodiments, the present invention provides an electrical appliance, comprising: a voltage regulator as described in any one of the above; and / or an integrated circuit as described in any one of the above.

[0115] In this embodiment, a voltage regulator including any one of the above embodiments or an integrated circuit including any one of the above embodiments is proposed. Therefore, the electrical appliance has the advantages of the voltage regulator in any one of the above embodiments, or has the advantages of the integrated circuit in any one of the above embodiments. Correspondingly, it can achieve the technical effects that the voltage regulator in any one of the above embodiments can achieve, or can achieve the technical effects that the integrated circuit in any one of the above embodiments can achieve. To avoid repetition, it will not be elaborated here.

[0116] In the above embodiments, the provided voltage regulator and / or integrated circuit is used to provide stable power supply to ensure the stable operation of the electrical appliance.

[0117] Among them, the electrical appliance can be a household electrical appliance, such as a refrigerator, a television, a washing machine, etc.

[0118] The terms "first", "second", etc. in the description and claims of this application may explicitly or implicitly include one or more of such features. In the written description of the present invention, unless otherwise specified, the meaning of "a plurality of" is two or more. In addition, "and / or" in the description and claims means at least one of the connected objects, and the character " / ", generally represents an "or" relationship between the associated objects before and after.

[0119] In the written description of the present invention, it can be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the technical solution of the present invention and simplifying the description of the technical solution of the present invention, rather than indicating or implying that the structure, device, or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, these descriptions cannot be understood as limitations on the present invention.

[0120] In the written description of the present invention, it can be understood that, except for explicit regulations and limitations, the terms "mounted", "connected", "joined" should be understood in a broad sense. For example, it can be fixedly connected, detachably connected, or integrally connected; it can be a mechanical connection, or an electrical connection; it can be a direct connection between the two, or an indirect connection between the two through an intermediate medium, and it can be the communication inside the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0121] In the claims, description, and description drawings of the present invention, the term "a plurality of" means two or more. Unless there are additional explicit limitations, the orientation or positional relationship indicated by the terms "upper", "lower", etc. is based on the orientation or positional relationship shown in the drawings. It is only for more conveniently describing the present invention and making the description process simpler, rather than indicating or implying that the device or element referred to must have the specific orientation described, be constructed and operated in a specific orientation. Therefore, these descriptions cannot be understood as limitations on the present invention; the terms "connected", "mounted", "fixed", etc. should all be understood in a broad sense. For example, "connected" can be a fixed connection between multiple objects, a detachable connection between multiple objects, or an integral connection; it can be a direct connection between multiple objects, or an indirect connection between multiple objects through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances of the above data.

[0122] In the claims, description of the specification and the drawings of the present invention, the descriptions of terms such as "one embodiment", "some embodiments", "specific embodiments", etc. mean that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In the claims, description of the specification and the drawings of the present invention, the schematic representations of the above terms do not necessarily refer to the same embodiment or instance. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0123] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A voltage regulator, characterized in that, Comprising: A first switching transistor, a first end of the first switching transistor is configured to receive a power supply signal; A voltage dividing circuit, a first end of the voltage dividing circuit is connected to a second end of the first switching transistor, a second end of the voltage dividing circuit is grounded, and the voltage dividing circuit has a feedback node; An error amplifier, a first input terminal of the error amplifier is configured to receive a reference voltage, a second input terminal of the error amplifier is connected to the feedback node, and an output terminal of the error amplifier is connected to a control terminal of the first switching transistor to drive the first switching transistor to switch; A pre-driving circuit, an input terminal of the pre-driving circuit is configured to receive the power supply signal, and an output terminal of the pre-driving circuit is connected to a power supply terminal of the error amplifier to supply power to the error amplifier; Wherein, the second end of the first switching transistor is an output voltage node of the voltage regulator; The pre-driving circuit includes: A second switching transistor, a first end of the second switching transistor is connected to the power supply terminal of the error amplifier; A filtering circuit, a first end of the filtering circuit is configured to receive the power supply signal and is connected to a second end of the second switching transistor, a second end of the filtering circuit is grounded, and an output terminal of the filtering circuit is connected to a control terminal of the second switching transistor, and the filtering circuit is configured to drive the second switching transistor to control the magnitude of the power supply output by the first end of the second switching transistor; The filtering circuit includes: A third resistor, a first end of the third resistor is connected to the second end of the second switching transistor; A first capacitor, a first end of the first capacitor is connected to a second end of the third resistor, and a second end of the first capacitor is grounded; Wherein, a connection point of the first end of the first capacitor and the second end of the third resistor is the output terminal of the filtering circuit; the filtering circuit is an RC filtering circuit, and the value of the first capacitor is selected according to the product of the resistance value of the third resistor and the capacitance value of the first capacitor.

2. The voltage regulator according to claim 1, characterized in that, The voltage dividing circuit includes: A first resistor, a first end of the first resistor is connected to the second end of the first switching transistor; A second resistor, a first end of the second resistor is connected to a second end of the first resistor as the feedback node, and a second end of the second resistor is grounded.

3. The voltage regulator according to claim 1, characterized in that, Further comprising: A reference voltage output circuit, connected to the first input terminal of the error amplifier, for outputting the reference voltage.

4. The voltage regulator according to claim 3, characterized in that, The output terminal of the pre-driving circuit is connected to the power supply terminal of the reference voltage output circuit to supply power to the reference voltage output circuit.

5. The voltage regulator according to claim 1, characterized in that, Further comprising: A second capacitor, a first end of the second capacitor is connected to the output terminal of the error amplifier, and a second end of the second capacitor is grounded.

6. The voltage regulator according to any one of claims 1 to 5, characterized in that, The first switching transistor is an NMOS transistor.

7. The voltage regulator according to claim 6, wherein The second end of the first switching transistor is the source of the NMOS transistor.

8. The voltage regulator according to claim 6, characterized in that, The NMOS transistor is a native NMOS transistor.

9. The voltage regulator according to any one of claims 1 to 5, characterized in that, The voltage regulator is a linear voltage regulator.

10. An integrated circuit, characterized in that, Comprising: The voltage regulator according to any one of claims 1 to 9.

11. The integrated circuit according to claim 10, wherein The integrated circuit is a system-on-chip.

12. A motor drive system, characterized in that, Comprising: The voltage regulator according to any one of claims 1 to 9; And / or The integrated circuit according to claim 10 or 11.

13. An electrical appliance, characterized in that, Comprising: A voltage regulator according to any one of claims 1 to 9; and / or an integrated circuit according to claim 10 or 11.

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