Low dropout regulator, integrated circuit, power supply voltage stabilization system and chip system

Abstract

The application provides a low-dropout linear voltage regulator, characterized in that the low-dropout linear voltage regulator comprises an input voltage, an error amplifier, a power tube, a ground terminal and a voltage output terminal; the power tube comprises a first power tube and a second power tube, the first power tube and the second power tube are connected in parallel between the input voltage and the voltage output terminal; the output terminal of the error amplifier is connected to the gate of the first power tube, and the gate of the first power tube is provided with a control voltage; and the gate of the second power tube is connected to the ground terminal. The above-mentioned embodiment solves the self-starting problem under high voltage; secondly, the bandgap reference and the error amplifier are powered by the output voltage, the input power supplies power to the high-voltage device, the overall loop mode of input-output short connection and the self-feedback mechanism are utilized to realize the step-by-step rising of the output voltage until the predetermined output voltage is reached, and the low-voltage demand of output stability under the single, wide-range and high-voltage power supply mode is solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of integrated circuits, in particular to a low dropout regulator, an integrated circuit, a power supply voltage stabilizing system and a chip system. BACKGROUND

[0002] With the rapid development of electronic technology, especially the continuous popularity of portable and consumer electronics, power management chips play an increasingly important role in various portable electronic devices such as smart phones, tablet computers or other electronic products. Low dropout linear regulators (LDO) are widely used in power management chips due to their simple structure and excellent performance.

[0003] An LDO is a kind of linear regulator, which usually includes an error amplifier and a feedback resistor network. When the output load of the LDO changes, the output voltage will also change. The feedback resistor network collects the output voltage of the LDO and feeds it back to the input terminal of the error amplifier. The output terminal of the error amplifier is connected to the gate of the power adjustment tube. By adjusting the gate voltage of the power adjustment tube, the output of the LDO reaches a steady state.

[0004] If the power supply voltage of the LDO exceeds the voltage resistance of the MOS device as the power adjustment tube, for example, if the power supply voltage is 3.3V, and the voltage resistance of the power adjustment tube used is less than 3.3V (for example, 1.8V), it is easy to cause the MOS device to work in overvoltage and be damaged. SUMMARY

[0005] The present application provides a low dropout regulator, an integrated circuit, a power supply voltage stabilizing system and a chip system, which solves the problem of single, wide range, high voltage power supply mode and output stable low voltage demand.

[0006] To achieve the above purpose, in a first aspect, the embodiments of the present application provide a low dropout linear regulator, characterized in that it comprises an input voltage, an error amplifier, a power tube, a ground terminal and a voltage output terminal; the power tube comprises a first power tube and a second power tube, and the first power tube and the second power tube are connected in parallel between the input voltage and the voltage output terminal.

[0007] The output terminal of the error amplifier is connected to the gate of the first power tube to provide a control voltage to the gate of the first power tube.

[0008] The gate of the second power tube is connected to the ground terminal.

[0009] Optionally, the low dropout linear regulator further comprises a reference voltage generator for generating a reference voltage, and the reference voltage generator outputs a first input to the error amplifier.

[0010] Optionally, the low-dropout linear voltage regulator further comprises a resistor, the resistor being connected to the second input terminal of the error amplifier.

[0011] Optionally, when the gate-source voltage difference of the second power tube is greater than a preset value, the second power tube is turned on, and the output voltage is equal to the input voltage.

[0012] Optionally, when the gate-source voltage difference of the second power tube reaches the preset value, the second power tube is turned off, and the output voltage is constant.

[0013] Optionally, the output voltage of the output terminal is a supply voltage provided for the reference voltage generator and the error amplifier.

[0014] Optionally, the input voltage is a supply voltage provided for the first power tube, the second power tube, and the error amplifier.

[0015] In a second aspect, the embodiments of the present application provide an integrated circuit, characterized by comprising the low-dropout voltage regulator according to any one of claims 1 to 7 to provide a stable voltage for the integrated circuit.

[0016] In a third aspect, the embodiments of the present application provide a power supply voltage stabilization system, characterized by comprising the low-dropout voltage regulator according to any one of claims 1 to 7.

[0017] In a fourth aspect, the embodiments of the present application provide a chip system, characterized by comprising the low-dropout voltage regulator according to any one of claims 1 to 7.

[0018] The low-dropout linear voltage regulator provided by the embodiments of the present application is characterized by comprising an input voltage, an error amplifier, a power tube, a ground terminal, and a voltage output terminal; the power tube comprises a first power tube and a second power tube, the first power tube and the second power tube are connected in parallel between the input voltage and the voltage output terminal; the output terminal of the error amplifier is connected to the gate of the first power tube to provide a control voltage for the gate of the first power tube; and the gate of the second power tube is connected to the ground terminal. The above embodiments solve the self-starting problem under high voltage; secondly, the output voltage is used to power the bandgap reference and the error amplifier, and the input power is used to power the power tube and other high-voltage devices; the overall loop mode of input-output short connection and the self-feedback mechanism are used to realize the gradual rise of the output voltage until the predetermined output voltage is reached, thereby solving the low-voltage demand for output stability under the single, wide-range, and high-voltage power supply mode. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 FIG. 1 is a schematic diagram of a low-dropout linear voltage regulator according to an embodiment of the present application;

[0020] Figure 2A The application provides a low-dropout linear voltage regulator in an ACDC circuit;

[0021] Figure 2B The application provides a low-dropout linear voltage regulator in a battery circuit;

[0022] Figure 2C The application provides a low-dropout linear voltage regulator in a switching voltage regulator circuit;

[0023] Figure 2D The application provides a low-dropout linear voltage regulator in a common battery circuit;

[0024] Figure 3 The application provides a low-dropout linear voltage regulator with a large input range;

[0025] Figure 4 The application provides a low-dropout linear voltage regulator with a large input range;

[0026] Figure 5 The application provides an integrated circuit for providing a stable voltage for an internal chip of an integrated circuit. DETAILED DESCRIPTION

[0027] In the following description, for the purposes of explanation and not limitation, specific details are set forth, such as particular sequences of steps, techniques, etc. in order to provide a thorough understanding of the embodiments of the application. However, it will be apparent to those skilled in the art that the embodiments of the present application can be practiced in other embodiments that depart from these specific details. In other instances, detailed descriptions of well-known methods, techniques, etc. are omitted so as not to obscure the description of the application with unnecessary detail.

[0028] The terminology used in the following description merely describes specific embodiments and is not intended to limit the application. As used in the specification and the appended claims, the singular forms "a," "an" and "the" are intended to include both singular and plural forms, unless the context clearly indicates otherwise.

[0029] The power supply voltage of portable electronic equipment will vary in a large range during operation, whether it is powered by AC mains through rectification (or AC adapter) or by battery pack. For example, the voltage of a single lithium-ion battery is 4.2V when fully charged and 2.3V when discharged, which varies greatly. The output voltage of various rectifiers is not only affected by the change of mains voltage, but also by the change of load. In order to ensure that the power supply voltage is stable and unchanged, almost all electronic equipment uses voltage stabilizer for power supply. Small and precise electronic equipment also requires a very clean power supply (no ripple, no noise) to avoid affecting the normal operation of electronic equipment. In order to meet the requirements of precise electronic equipment, a linear voltage regulator should be added to the input end of the power supply to ensure constant power supply voltage and realize active noise filtering.

[0030] Therefore, the deep image denoising method provided by the embodiments of the present application greatly reduces the calculation resources consumed by denoising by taking the number of mutations of a single pixel in its adjacent direction as the confidence weight. At the same time, the deep image denoising method does not need to be adjusted, which greatly improves the robustness of the denoising method. In addition, noise and edges are both regarded as a kind of mutation, and the number of mutations of a pixel in its adjacent direction is taken as the confidence weight, which achieves better noise filtering effect while retaining more texture details and other information. The calculation resources consumed are reduced, the robustness of the denoising method is enhanced, and the details such as texture and edges of the image are preserved and the denoising effect is improved.

[0031] The low-dropout linear voltage regulator in the prior art provided by the embodiments of the present application is described first. Referring to Figure 1 , Figure 1 The schematic diagram of a low-dropout linear voltage regulator in the prior art provided by the embodiments of the present application is as follows Figure 1As shown, the low dropout linear regulator can include: series regulating tube VT, sampling resistors R1 and R2, comparison amplifier A, current and C, and diode B. Among them, the sampling voltage is added to the non-inverting input terminal of the comparator A, and compared with the reference voltage Uref added to the inverting input terminal. The difference between the two is amplified by the amplifier A, and then controls the voltage drop of the series regulating tube, thereby stabilizing the output voltage. When the output voltage Uout decreases, the difference between the reference voltage and the sampling voltage increases, the drive current output by the comparison amplifier increases, and the voltage drop of the series regulating tube decreases, thereby increasing the output voltage. Conversely, if the output voltage Uout exceeds the required set value, the drive current output by the comparison amplifier decreases, thereby reducing the output voltage. During power supply, the output voltage correction is continuously performed, and the adjustment time is only limited by the reaction speed of the comparison amplifier and the output transistor loop. The low dropout linear regulator in the prior art can only provide a small range of input voltage range for voltage stabilization. For a large input voltage range, for example, the input voltage range is 2.5V-12V, the low dropout linear regulator in the prior art cannot stabilize the input voltage range of 2.5V-12V to a fixed output voltage. Therefore, it is an urgent technical problem to provide a low dropout linear regulator with a large input voltage range.

[0032] The application scenarios of the low dropout linear regulator provided by the embodiments of the present application are introduced below, and the low dropout linear regulator provided by the embodiments of the present application is applied to an AC / DC circuit. Figure 2A , Figure 2A The application scenarios of the low dropout linear regulator provided by the embodiments of the present application are introduced below, and the low dropout linear regulator provided by the embodiments of the present application is applied to an AC / DC circuit. Figure 2A The most common AC / DC power supply, the AC power supply voltage is converted into the required voltage after the transformer, and the voltage is converted into a direct current voltage after rectification. In this circuit, the role of the low dropout linear regulator is to stabilize the output voltage when the AC power supply voltage or the load changes, suppress the ripple voltage, and eliminate the AC noise generated by the power supply.

[0033] Further, the application scenarios of the low dropout linear regulator provided by the embodiments of the present application are introduced, and the low dropout linear regulator provided by the embodiments of the present application is applied to a battery circuit. Figure 2B , Figure 2B The application scenarios of the low dropout linear regulator provided by the embodiments of the present application are introduced below, and the low dropout linear regulator provided by the embodiments of the present application is applied to an AC / DC circuit. Figure 2BThe shown includes battery power supply 205, low dropout linear regulator 206 and output voltage 207. The working voltage of various storage batteries varies within a certain range, in order to ensure that the storage battery pack outputs constant voltage, usually should be connected to the low dropout linear regulator at the output of the battery pack. The power of the voltage difference linear regulator is low, so it can prolong the service life of the battery, and because the output voltage of the low dropout linear regulator is close to the input voltage, the output voltage can still be stable when the battery is close to the end of discharge.

[0034] Further, the application scenario of the low dropout linear regulator provided by the embodiment of the application is introduced, and the low dropout linear regulator is applied to the switching regulator power supply circuit. Figure 2C , Figure 2C The application schematic diagram of the low dropout linear regulator provided by the embodiment of the application in the switching regulator power supply circuit is shown in FIG. 2. Figure 2C The shown includes power supply 208, DCDC converter 209, low dropout linear regulator 210 and output voltage 211. The switching regulator power supply has high efficiency, but the output ripple voltage is high, the noise is large, and the voltage regulation rate and other performances are poor, especially when supplying power to an analog circuit, which will have a greater impact. The low dropout linear regulator connected at the output of the switching regulator can realize active filtering, greatly improve the stability precision of the output voltage, and the efficiency of the power supply system will not be significantly reduced.

[0035] Further, the application scenario of the low dropout linear regulator provided by the embodiment of the application is introduced, and the low dropout linear regulator is applied to the switching regulator power supply circuit. Figure 2D , Figure 2D The application schematic diagram of the low dropout linear regulator provided by the embodiment of the application in the common battery circuit is shown in FIG. 3. Figure 2D The shown includes power supply 212, one end of power supply 212 is grounded, and the other end is connected with LDO1, LDO2, LDO3……LDOn respectively, wherein LDO1, LDO2, LDO3……LDOn have enable end 1, enable end 2, enable end 3……LDOn respectively. In some applications, such as wireless communication equipment, only one battery is usually used for power supply, but different voltages are often used in the isolated circuits, so multiple voltage stabilizers must be used for power supply. In order to save the weight of the common battery, the low dropout linear regulator is usually in sleep state when the equipment is not working, and therefore the linear regulator has an enable control end. The power supply system has the functions of multiple output and on-off control with a single storage battery.

[0036] The schematic diagram of the low dropout linear regulator with a large input voltage range provided by the embodiment of the application is introduced below, and the low dropout linear regulator is applied to the switching regulator power supply circuit. Figure 3 , Figure 3 The schematic diagram of the low dropout linear regulator with a large input voltage range provided by the embodiment of the application is shown in FIG. 4. Figure 3The low dropout linear regulator shown includes a reference voltage generator 301, an error amplifier 302, a power tube 303 and a voltage dividing resistor 304. As shown Figure 3 , one end of the reference voltage generator 301 is connected to the output voltage terminal, and the other end is connected to the error amplifier 302; the error amplifier 302 is connected to the input voltage, the voltage output terminal and the power tube 303 respectively; the power tube 303 is connected to the input voltage and the other end of the power tube 303 is grounded; one end of the error amplifier 302 is connected to the voltage dividing resistor 304, and the voltage dividing resistor 304 is connected to the power tube 303 and the voltage output terminal respectively, and one end of the voltage dividing resistor 304 is grounded. Among them, the reference voltage generator 301 can be a bandgap reference to generate the required reference voltage for LDO; the error amplifier 302 is mainly used to provide sufficient gain. When the output load changes, the voltage at the node of the voltage dividing resistor 304 changes, and the error amplifier amplifies the input voltage difference and outputs it to the power tube 303, thereby achieving the purpose of adjusting the output voltage by controlling the power tube voltage.

[0037] The following describes the connection diagram of the low dropout linear regulator circuit with a large input voltage range provided by the embodiment of the application, referring to Figure 4 , Figure 4 The connection diagram of the low dropout linear regulator circuit with a large input voltage range provided by the embodiment of the application is shown in the figure. Figure 4 As shown, one end of the bandgap reference 401 is connected to the output voltage (V out ), and the reference voltage (V ref ) generated by the bandgap reference 401 is input to the non-inverting input terminal of the error amplifier 402, and the error amplifier 402 is connected to the output voltage (V out ) and the input voltage (avdd) respectively, and the output terminal v g of the error amplifier is connected to the gate of the first power tube 403 (M p ), the source of the first power tube 403 is connected to the input voltage (avdd), and the drain of the first power tube 403 is connected to the first resistor R1, the output voltage (V out ) and the source of the second power tube 404, the drain of the second power tube 404 is connected to the input voltage (avdd), and the gate of the second power tube 404 is grounded; one end of the second resistor R2 is connected to the first resistor R1 and the inverting input terminal of the error amplifier 402, and the other end of the second resistor R2 is grounded. Among them, the first power tube can be a MOS tube, and the second power tube can be a field effect tube.

[0038] In the embodiment of the present application, the input voltage (avdd) can be 2.5V-12V, and the output voltage can be stabilized at 2.2V-5V by the low-dropout linear regulator provided by the embodiment of the present application. The range of the input voltage and the range of the output voltage are only for illustrative purposes, and the present application is not limited in this regard. Figure 4 In the low-dropout linear regulator circuit shown, the circuit is first self-started by the second power tube 404. When the gate-source voltage difference of the second power tube 404 (the difference between the gate voltage and the source voltage) is greater than -5V, the second power tube is in an open state, at which time the output voltage is equal to the input voltage avdd, and at this time the load current is mainly provided by the second power tube. As the output voltage increases, the gate-source voltage difference of the second power tube 404 is closer to -5V. When the gate-source voltage difference of the second power tube 404 is around -5V, the second power tube 404 is closed, at which time the load current is mainly provided by the first power tube 403. The LDO relies on its own negative feedback mechanism to achieve voltage stabilization. When the output load of the LDO changes, the output voltage will also change. The feedback resistors R1 and R2 collect the output voltage of the LDO and feed it back to the input terminal of the error amplifier. The output terminal of the error amplifier is connected to the gate of the power adjustment tube. By adjusting the gate voltage of the power adjustment tube, the output of the LDO reaches a steady state (the steady state voltage of the embodiment of the present application is set to 5V, but this is only for illustrative purposes and is not limited in this regard). The above method solves the problem of self-starting at high voltage. Secondly, the output voltage (V out ) is used to power the bandgap reference 401 and the error amplifier 402, and the input power avdd is used to power the first power tube, the second power tube, and other high-voltage devices, such as the high-voltage devices in the error amplifier. The overall loop mode of input-output shorting and the self-feedback mechanism are used to achieve gradual increase of the output voltage until the predetermined output voltage is reached, solving the problem of low-voltage output stabilization in a single, wide-range, high-voltage power supply mode. Therefore, when V out increases from 0V, the JFET tube provides an initial voltage. As V out increases to the point where the bandgap reference and the error amplifier can work, the self-feedback mechanism begins to take effect, and the output voltage begins to stabilize, i.e., when avdd≤5V, Vout≈avdd; when 5V<avdd≤12V, Vout=5V.

[0039] The integrated circuit provided by the embodiment of the present application is described below. Referring to Figure 5 , Figure 5 is a schematic diagram of an integrated circuit provided by the embodiment of the present application for providing a stable voltage to the internal chip of the integrated circuit. As Figure 5The integrated circuit diagram shows an integrated circuit 50, wherein the integrated circuit 50 comprises a voltage source 501, a low-dropout linear regulator 502 and a chip circuit 503. The voltage source 501 can provide a wide range of voltage, for example, 2.5V-12V, and the voltage source can provide a stable voltage for the chip circuit 503 after the voltage is processed by the low-dropout linear regulator 502. The low-dropout linear regulator 502 can use the above-mentioned embodiments to provide a stable voltage.

[0040] The application provides a power supply voltage stabilizing system, which comprises the low-dropout linear regulator provided in the above-mentioned embodiments.

[0041] The LDO provided by the embodiments of the application can be applied to the field of analog chip power supply, and the specific application is not limited herein.

[0042] In the above-mentioned embodiments, the description of each embodiment has its own focus, and the parts not described or recorded in a certain embodiment can be referred to the related description of other embodiments.

[0043] Those skilled in the art can understand that the units and algorithm steps of each example described in combination with the embodiments disclosed herein can be realized by electronic hardware or a combination of computer software and electronic hardware. Whether the functions are realized in hardware or software mode depends on the specific application and design constraints of the technical solution. The skilled person can use different methods to realize the described functions for each specific application, but such implementation should not be considered beyond the scope of the application.

[0044] In the embodiments provided in the application, it should be understood that the disclosed devices / apparatuses and methods can be implemented in other ways. For example, the above-described device / apparatus embodiment is only schematic, for example, the division of the modules or units is only a logical function division, and there can be another division manner in actual implementation, for example, a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the shown or discussed mutual elements can be indirect coupling or communication connection through some interfaces, devices or units, and can be electrical, mechanical or other forms.

[0045] It should be understood that when used in the specification and the appended claims of the application, the term "comprising" indicates the presence of the described features, integers, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or sets thereof.

[0046] It should also be understood that, in the description of the application and the appended claims, the term "and / or" is used to mean one or more of the associated listed items, as well as the sum of all possible combinations of the associated listed items. It should also be understood that, in the description of the application and the appended claims, the term "comprises / comprising" or "includes / including" is used to mean one or more of the associated listed items, as well as the sum of all possible combinations of the associated listed items.

[0047] As used in the description of the application and the appended claims, the term "if' can be interpreted to mean "when" or "upon" or "in response to determining" or "in response to detecting," depending on the context. Similarly, the phrase "if it is determined" or "if [a described condition or event] is detected" can be interpreted to mean "upon determining" or "in response to determining" or "upon detecting [the described condition or event]" or "in response to detecting [the described condition or event]," depending on the context.

[0048] In addition, the terms "first", "second", "third", etc. as used in the description of the application and the appended claims are merely to distinguish descriptions and cannot be understood as indicating or implying relative importance.

[0049] Reference in the specification to "one embodiment" or "some embodiments" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the application. The appearances of the phrase "in one embodiment" or "in some embodiments" in various places in the specification are not necessarily all referring to the same embodiment, although it can. The terms "including," "comprising," "having" and variations thereof are meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless otherwise noted, terms such as "first" and "second" are used herein, as are "third" and "fourth," merely to distinguish between similar elements, and do not imply relative importance.

[0050] Finally, it should be noted that the above-described embodiments are merely intended to illustrate the technical solutions of the present application, but not to limit the same; even though the present application has been described in detail with reference to the above-described embodiments, those skilled in the art should understand that they can still make modifications to the technical solutions recorded in the above-described embodiments, or make equivalent replacements to some or all of the technical features thereof; and such modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A low-dropout linear voltage regulator, characterized by, The low-dropout linear voltage regulator comprises: an input voltage, an error amplifier, power tubes, a ground terminal and a voltage output terminal; the power tubes comprise first and second power tubes, which are connected in parallel between the input voltage and the voltage output terminal; an output terminal of the error amplifier is connected to a gate of the first power tube to provide a control voltage to the gate of the first power tube; a source of the first power tube is connected to the input voltage, a drain of the first power tube is connected to a first resistor, the voltage output terminal and a source of the second power tube respectively, a drain of the second power tube is connected to the input voltage, and a gate of the second power tube is grounded; one end of a second resistor is connected to the first resistor and a reverse input terminal of the error amplifier, and the other end of the second resistor is grounded; when an output voltage of the voltage output terminal starts to increase from 0V, the second power tube provides an initial voltage, and as the output voltage of the voltage output terminal increases to a voltage at which the error amplifier can work, the output voltage of the voltage output terminal starts to stabilize; the output voltage of the voltage output terminal provides a power supply voltage for the error amplifier.

2. The low dropout linear regulator of claim 1, wherein, The low-dropout linear voltage regulator further comprises a reference voltage generator for generating a reference voltage, and the reference voltage generator outputs a positive input terminal of the error amplifier.

3. The low dropout linear regulator of claim 1, wherein, When a gate-source voltage difference of the second power tube is greater than a preset value, the second power tube is turned on, and the output voltage of the voltage output terminal is equal to the input voltage.

4. The low dropout linear regulator of claim 1, wherein, When the gate-source voltage difference of the second power tube reaches the preset value, the second power tube is turned off, and the output voltage of the voltage output terminal is constant.

5. The low dropout linear regulator of claim 2, wherein, The output voltage of the voltage output terminal provides a power supply voltage for the reference voltage generator.

6. The low dropout linear regulator of claim 1, wherein, The input voltage provides a power supply voltage for the first power tube, the second power tube and the error amplifier.

7. An integrated circuit, characterized by The integrated circuit comprises the low-dropout linear voltage regulator as claimed in any one of claims 1 to 6, and the low-dropout linear voltage regulator provides a stable voltage for the integrated circuit.

8. A power supply regulation system, characterized by, The integrated circuit comprises the low-dropout linear voltage regulator as claimed in any one of claims 1 to 6.

9. A chip system, characterized by The integrated circuit comprises the low-dropout linear voltage regulator as claimed in any one of claims 1 to 6.

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