Linear voltage regulator circuit and power supply chip

Abstract

The embodiments of the present disclosure provide a linear voltage stabilization circuit and a power chip. The linear voltage stabilization circuit includes a pre-start module, a voltage stabilization module and a reference module. During the power-on process of the power supply, when the pre-start module is enabled and the power supply voltage is less than a first preset voltage, the pre-start module starts the voltage stabilization module. During the startup process of the voltage stabilization module, the voltage stabilization module determines an analog power supply voltage according to the power supply voltage, and provides the analog power supply voltage to the reference module to start the reference module. When the power supply voltage is greater than or equal to the first preset voltage, the pre-start module stops working. The linear voltage stabilization circuit can reduce the complexity of the circuit structure, is conducive to the miniaturization of the circuit, and can also reduce the power consumption of the circuit. In addition, when the power supply voltage is high, the pre-start module stops working, which can further reduce the power consumption of the circuit.

Description

Technical Field

[0001] Embodiments of the present disclosure relate to the field of integrated circuit technology, and in particular to a linear voltage regulator circuit and a power supply chip. Background Art

[0002] Switching power supply systems are widely used in the field of automotive electronics. In automotive applications, the input voltage is getting lower and lower, and may even be less than 3V. In order for the switching power supply system to work normally under an input voltage of 3V, the voltage inside the switching power supply system is relatively high.

[0003] In the prior art, when the voltage detection circuit detects that the input voltage of the switching power supply system is low, the charge pump circuit generates a relatively high voltage to ensure that the bandgap reference source works normally, so as to ensure that the low dropout linear regulator (LDO) works normally. However, since the voltage detection circuit and the charge pump circuit need to work to ensure the normal operation of the LDO when the input voltage is low, the circuit structure is relatively complex, which is not conducive to the miniaturization of the circuit. Summary of the invention

[0004] The present disclosure provides a linear voltage stabilization circuit and a power supply chip, which can reduce the complexity of the circuit structure, facilitate the miniaturization of the circuit, and also reduce the power consumption of the circuit.

[0005] In a first aspect, the present disclosure provides a linear voltage stabilization circuit, comprising a pre-start module, a voltage stabilization module and a reference module, wherein an input end of the pre-start module and a power supply end of the voltage stabilization module are connected to a power supply, an output end of the pre-start module is connected to an input end of the voltage stabilization module, an output end of the voltage stabilization module is connected to a power supply end of the reference module, and a reference output end of the reference module is connected to a control end of the voltage stabilization module.

[0006] The pre-start module is configured to start the voltage stabilizing module during the power-on process of the power supply when the pre-start module is enabled and the power supply voltage is less than a first preset voltage, and stop working when the power supply voltage is greater than or equal to the first preset voltage; the first preset voltage is related to the minimum operating voltage of the reference module.

[0007] The voltage stabilizing module is configured to determine an analog power supply voltage according to the power supply voltage during the startup process of the voltage stabilizing module, and provide the analog power supply voltage to the reference module to start the reference module.

[0008] In some embodiments of the present disclosure, the pre-start module includes a control unit and a start unit, the input end of the control unit is connected to the power supply, the output end of the control unit is connected to the first input end of the start unit, the second input end of the start unit is connected to an enable signal, and the output end of the start unit is connected to the input end of the voltage stabilizing module.

[0009] The control unit is configured to generate a start-up control signal when the power supply voltage is less than the first preset voltage during the power-on process, and stop working when the power supply voltage is greater than or equal to the first preset voltage. The start-up unit is configured to generate a start-up signal according to the start-up control signal to start the voltage stabilizing module when the voltage of the enable signal is greater than a second preset voltage.

[0010] In some embodiments of the present disclosure, the control unit includes a first pull-up resistor, a second pull-up resistor, a first transistor, a second transistor and a pull-down component, the first end of the first pull-up resistor is connected to the power supply, the second end of the first pull-up resistor is connected to the first end of the second pull-up resistor and the second end of the second transistor, the second end of the second pull-up resistor is connected to the control end of the first transistor, the second end of the first transistor, the control end of the second transistor and the output end of the pull-down component, the first end of the first transistor and the input end of the pull-down component are grounded, the first end of the second transistor is connected to the first input end of the startup unit, and the control end of the pull-down component is connected to the output end of the reference module.

[0011] The reference module is configured to generate a shutdown indication signal when the power supply voltage is greater than or equal to the first preset voltage, wherein the shutdown indication signal includes at least one of a reference signal, a working state signal, and a detection signal. The pull-down component is configured to turn off the second transistor according to the shutdown indication signal to stop the control unit from working.

[0012] In some embodiments of the present disclosure, the pull-down component includes a third transistor, a fourth transistor and a fifth transistor, the second end of the third transistor is connected to the control end of the second transistor, the first end of the third transistor is grounded through the fourth transistor and the fifth transistor in sequence, the control end of the third transistor is connected to the reference output end of the reference module, the control end of the fourth transistor is connected to the working status output end of the reference module, and the control end of the fifth transistor is connected to the detection output end of the reference module.

[0013] In some embodiments of the present disclosure, the reference module includes a bandgap reference source and a detection unit, the power supply end of the bandgap reference source and the power supply end of the detection unit are connected to the output end of the voltage stabilizing module, the reference output end of the bandgap reference source is connected to the first control end of the pull-down component and the first input end of the detection unit, the working status output end of the bandgap reference source is connected to the second control end of the pull-down component, the second input end of the detection unit is connected to the enable signal, and the detection output end of the detection unit is connected to the third control end of the pull-down component.

[0014] The bandgap reference source is configured to pull up the reference signal when the power supply voltage is greater than or equal to the first preset voltage, and to pull up the working state signal when the reference signal is stably output. The detection unit is configured to pull up the detection signal when the voltage of the enable signal is greater than the voltage of the reference signal.

[0015] In some embodiments of the present disclosure, the starting unit includes a sixth transistor and a seventh transistor, the control end of the sixth transistor is connected to the output end of the control unit, the second end of the sixth transistor is connected to the control end of the voltage stabilizing module, the first end of the sixth transistor is connected to ground through the seventh transistor, and the control end of the seventh transistor is connected to the enable signal.

[0016] In some embodiments of the present disclosure, the starting unit also includes an eleventh transistor, a first end of the eleventh transistor is grounded, a second end of the eleventh transistor is connected to the first input end of the starting unit, and a control end of the eleventh transistor is connected to the feedback end of the voltage stabilizing module.

[0017] The eleventh transistor is configured to stabilize the feedback voltage of the voltage stabilizing module at a third preset voltage, so as to stabilize the analog power supply voltage at a fourth preset voltage during the power-on process, and the fourth preset voltage is linearly related to the third preset voltage.

[0018] In some embodiments of the present disclosure, the pre-start module further includes a clamping unit, an input end of the clamping unit is connected to the first end of the first transistor, and an output end of the clamping unit is grounded.

[0019] The clamping unit is configured to limit the control voltage of the second transistor to a clamping voltage when the power supply voltage is greater than a fifth preset voltage.

[0020] In some embodiments of the present disclosure, the voltage stabilizing module includes an eighth transistor, a ninth transistor, a tenth transistor, a third pull-up resistor, a first feedback resistor, a second feedback resistor, an output capacitor and an operational amplifier, the control end of the eighth transistor is connected to the control end of the ninth transistor, the second end of the ninth transistor, the second end of the tenth transistor and the output end of the pre-start module, the first end of the eighth transistor is connected to the power supply, the first end of the ninth transistor is connected to the power supply through the third pull-up resistor, and the second end of the eighth transistor is connected to the first end of the first feedback resistor, the power supply end of the reference module and the first plate of the output capacitor.

[0021] The second end of the first feedback resistor is connected to the first end of the second feedback resistor and the inverting input end of the operational amplifier, the second end of the second feedback resistor, the first end of the tenth transistor and the second plate of the output capacitor are grounded, the output end of the operational amplifier is connected to the control end of the tenth transistor, and the non-inverting input end of the operational amplifier is connected to the reference output end of the reference module.

[0022] In a second aspect, the present disclosure provides a power chip, comprising any linear voltage regulator circuit provided in the first aspect.

[0023] The technical solution disclosed in the present invention provides a linear voltage stabilization circuit, including a pre-start module, a voltage stabilization module and a reference module. During the power-on process of the power supply, when the pre-start module is enabled and the power supply voltage is less than a first preset voltage, the pre-start module starts the voltage stabilization module. During the startup process of the voltage stabilization module, the voltage stabilization module determines the analog power supply voltage according to the power supply voltage, and provides the analog power supply voltage to the reference module to start the reference module. When the power supply voltage is greater than or equal to the first preset voltage, the pre-start module stops working. In this way, when the power supply voltage is low, the voltage stabilization module can establish an analog power supply voltage to ensure the normal operation of the reference module, thereby ensuring the normal operation of the linear voltage stabilization circuit. Since the linear voltage stabilization circuit does not require an additional voltage detection circuit and a charge pump circuit, it can reduce the complexity of the circuit structure, which is conducive to the miniaturization of the circuit and can also reduce the power consumption of the circuit. In addition, when the power supply voltage is high, the pre-start module stops working, which can further reduce the power consumption of the circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings required for describing the embodiments. It should be noted that the drawings described below only relate to some embodiments of the present disclosure, rather than limiting the present disclosure, wherein:

[0025] Figure 1 A circuit diagram of an LDO provided by the prior art;

[0026] Figure 2 A schematic diagram of the structure of a linear voltage stabilization circuit provided in an embodiment of the present disclosure;

[0027] Figure 3 A circuit diagram of a linear voltage stabilization circuit provided by an embodiment of the present disclosure;

[0028] Figure 4 A circuit diagram of another linear voltage stabilization circuit provided in an embodiment of the present disclosure. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solution and advantages of the embodiments of the present disclosure clearer, the technical solution of the embodiments of the present disclosure will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present disclosure, rather than all of the embodiments. Based on the described embodiments of the present disclosure, all other embodiments obtained by those skilled in the art without creative work also fall within the scope of protection of the present disclosure.

[0030] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by a person skilled in the art to which the subject matter of the present disclosure belongs. It will be further understood that terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the specification and the relevant art, and will not be interpreted in an idealized or overly formal form unless otherwise explicitly defined herein. As used herein, a statement that two or more parts are "connected" together shall mean that the parts are joined together directly or through one or more intermediate components.

[0031] Reference to "embodiments" in this disclosure means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase "embodiments" in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described in this disclosure may be combined with other embodiments.

[0032] In addition, the terms "first", "second", etc. in the specification and claims of the present disclosure or the above-mentioned drawings are used to distinguish different objects rather than to describe a specific order, and may explicitly or implicitly include one or more of the features.

[0033] The term "and / or" in this disclosure is only a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: A exists, A and B exist at the same time, and B exists. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0034] In the description of the present disclosure, unless otherwise specified, "plurality" and "at least two" mean more than two (including two). Similarly, "plurality groups" and "at least two groups" mean more than two groups (including two).

[0035] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings.

[0036] Figure 1 A schematic diagram of the structure of an LDO provided by the prior art, such as Figure 1 As shown, the LDO includes a voltage detection circuit 11 , a bandgap reference source 12 , a first enable detection circuit 13 , a second enable detection circuit 14 , a charge pump circuit 15 and an LDO circuit 16 .

[0037] When the power supply voltage Vin is normal, the power supply voltage Vin clamps the gate voltage of the first NMOS tube NM1 at about 5.8V through the resistor R and the Zener diode Dz, generating an internal power supply bias voltage Vstdby, and Vstdby=5.8V-Vth≈5V, where Vth is the threshold voltage of the first NMOS tube NM1.

[0038] The first enable detection circuit 13 can detect whether the voltage of the enable signal EN is higher than the threshold voltage of the NMOS. When the voltage of the enable signal EN is higher than the threshold voltage of the NMOS, the bandgap reference source 12 can work normally, generate the bandgap reference voltage Vbg and transmit it to the second enable detection circuit 14. The second enable detection circuit 14 can detect whether the voltage of the enable signal EN is higher than the bandgap reference voltage Vbg. When the voltage of the enable signal EN is higher than the bandgap reference voltage Vbg, the output signal EN_OK of the second enable detection circuit 14 is high, and the enable LDO circuit 16 generates the analog power supply voltage AVDD to power the internal modules.

[0039] When the power supply voltage Vin is low, the power supply voltage Vin is lower than the clamping voltage of the Zener diode Dz, 5.8V, and the internal power supply bias voltage Vstdby cannot be equal to 5V or cannot follow the power supply voltage Vin well, but is equal to the power supply voltage Vin minus the threshold voltage Vth of the first NMOS tube NM1. If the power supply voltage Vin is less than 3V, the internal power supply bias voltage Vstdby is less than 2.2V, and the bandgap reference source 12 cannot work normally. At this time, in order to maintain the internal power supply bias voltage Vstdby at 5V or equal to the input voltage Vin, the charge pump circuit 16 needs to generate a voltage Vcp to drive the second NMOS tube NM2, wherein the voltage Vcp is 5.8V.

[0040] At this time, it can be known from the working state of the second NMOS transistor NM2 that when the power supply voltage Vin is greater than 5V, the internal power supply bias voltage Vstdby is equal to 5V, and when the power supply voltage Vin is less than 5V, the internal power supply bias voltage Vstdby is equal to the power supply voltage Vin. In this way, when the power supply voltage Vin is less than 3V, it can ensure that the internal power supply bias voltage Vstdby is substantially equal to the power supply voltage Vin, so as to ensure the normal operation of the bandgap reference source 12, thereby ensuring the normal operation of the LDO.

[0041] In the existing technical solution, when the power supply voltage Vin is low, an internal charge pump circuit 16 is usually required to generate a relatively high voltage Vcp, and an additional voltage detection circuit 11 is also required. When the voltage detection circuit 11 detects that the input voltage Vin is low, the charge pump circuit 16 will be turned on. The charge pump circuit 16 generates a relatively high voltage to ensure that the bandgap reference source 12 works normally, so as to ensure that the LDO works normally. However, since the voltage detection circuit 11 and the charge pump circuit 16 need to work to ensure the normal operation of the LDO when the power supply voltage Vin is low, the circuit structure of the LDO is relatively complex, which is not conducive to the miniaturization of the circuit. In addition, the voltage detection circuit 11 and the charge pump circuit 16 consume power, resulting in high energy consumption of the circuit.

[0042] In order to solve the above technical problems, the present invention provides a linear voltage stabilization circuit, including a pre-start module, a voltage stabilization module and a reference module. During the power-on process of the power supply, when the pre-start module is enabled and the power supply voltage is less than a first preset voltage, the pre-start module starts the voltage stabilization module. During the startup process of the voltage stabilization module, the voltage stabilization module determines the analog power supply voltage according to the power supply voltage, and provides the analog power supply voltage to the reference module to start the reference module. When the power supply voltage is greater than or equal to the first preset voltage, the pre-start module stops working. In this way, when the power supply voltage is low, the voltage stabilization module can establish an analog power supply voltage to ensure the normal operation of the reference module, thereby ensuring the normal operation of the linear voltage stabilization circuit. Since the linear voltage stabilization circuit does not require an additional voltage detection circuit and a charge pump circuit, it can reduce the complexity of the circuit structure, which is conducive to the miniaturization of the circuit and can also reduce the power consumption of the circuit. In addition, when the power supply voltage is high, the pre-start module stops working, which can further reduce the power consumption of the circuit.

[0043] The technical solution provided by the present disclosure is described in detail below with reference to several specific embodiments.

[0044] Figure 2 A schematic diagram of a linear voltage stabilization circuit provided in an embodiment of the present disclosure is shown in FIG. Figure 2 As shown, the linear voltage stabilization circuit 100 includes a pre-start module 110, a voltage stabilization module 120 and a reference module 130, the input end of the pre-start module 110 and the power supply end of the voltage stabilization module 120 are connected to the power supply, the output end of the pre-start module 110 is connected to the input end of the voltage stabilization module 120, the output end of the voltage stabilization module 120 is connected to the power supply end of the reference module 130, and the reference output end of the reference module 130 is connected to the control end of the voltage stabilization module 120.

[0045] The pre-start module 110 is configured to, during the power-on process of the power supply, start the voltage stabilizing module 120 when the pre-start module 110 is enabled and the power supply voltage Vin is less than the first preset voltage Vth1, and stop working when the power supply voltage Vin is greater than or equal to the first preset voltage Vth1. The first preset voltage Vth1 is related to the minimum operating voltage of the reference module 130.

[0046] The voltage regulating module 120 is configured to determine the analog power supply voltage AVDD according to the power supply voltage Vin during the startup process of the voltage regulating module 120 , and provide the analog power supply voltage AVDD to the reference module 130 to start the reference module 130 .

[0047] For example, Figure 3 A circuit diagram of a linear voltage stabilizing circuit provided by an embodiment of the present disclosure, combined with Figure 2 and Figure 3As shown, the pre-start module 110 includes a control unit 111 and a start unit 112, the input end of the control unit 111 is connected to the power supply, the output end of the control unit 111 is connected to the first input end of the start unit 112, the second input end of the start unit 112 is connected to the enable signal EN, and the output end of the start unit 112 is connected to the input end of the voltage stabilizing module 120.

[0048] The control unit 111 includes a first pull-up resistor Ru1, a second pull-up resistor Ru2, a first transistor M1, a second transistor M2 and a pull-down component 1111, wherein the first end of the first pull-up resistor Ru1 is connected to a power supply, the second end of the first pull-up resistor Ru1 is connected to the first end of the second pull-up resistor Ru2 and the second end of the second transistor M2, the second end of the second pull-up resistor Ru2 is connected to the control end of the first transistor M1, the second end of the first transistor M1, the control end of the second transistor M2 and the output end of the pull-down component 1111, the first end of the first transistor M1 and the input end of the pull-down component 1111 are grounded, the first end of the second transistor M2 is connected to the first input end of the start unit 112, and the control end of the pull-down component 1111 is connected to the output end of the reference module 130.

[0049] Exemplarily, the first transistor M1 and the second transistor M2 are NMOS, the drain of the first transistor M1 is connected to the gate of the first transistor M1, the gate of the second transistor M2 and the second end of the second pull-up resistor Ru2, the source of the first transistor M1 is connected to the input end of the pull-down component 1111, the drain of the second transistor M2 is connected to the first end of the second pull-up resistor Ru2, and the source of the second transistor M2 is connected to the first input end of the start unit 112.

[0050] The start-up unit 112 includes a sixth transistor M6 and a seventh transistor M7, wherein the control end of the sixth transistor M6 is connected to the output end of the control unit 111, the second end of the sixth transistor M6 is connected to the control end of the voltage stabilizing module 120, the first end of the sixth transistor M6 is connected to the ground through the seventh transistor M7, and the control end of the seventh transistor M7 is connected to the enable signal EN.

[0051] Exemplarily, the sixth transistor M6 and the seventh transistor M7 are NMOS, the gate of the sixth transistor M6 is connected to the source of the second transistor M2, the drain of the sixth transistor M6 is connected to the control end of the voltage stabilizing module 120, the source of the sixth transistor M6 is connected to the ground through the seventh transistor M7, and the gate of the seventh transistor M7 is connected to the enable signal EN.

[0052] During the power-on process, when the power supply voltage Vin is less than the first preset voltage Vth1, the pre-start module 110 starts working, the gate voltage of the first transistor M1 is approximately equal to the power supply voltage Vin, and the source voltage of the second transistor M2 is equal to Vin-Vgs_2, wherein Vgs_2 is the gate-source voltage of the second transistor M2, and the source voltage Vin-Vgs_2 of the second transistor M2 is the control signal generated by the control unit 111.

[0053] When the control signal Vin-Vgs_2 is greater than the gate-source voltage Vgs_6 of the sixth transistor M6, the input voltage Vin is greater than Vgs_2+Vgs_6, the control signal Vin-Vgs_2 generated by the control unit 111 is a start control signal, and the sixth transistor M6 is turned on. When the control signal Vin-Vgs_2 is less than or equal to the gate-source voltage Vgs_6 of the sixth transistor M6, the input voltage Vin is less than or equal to Vgs_2+Vgs_6, the control signal Vin-Vgs_2 generated by the control unit 111 is a shutdown control signal, and the sixth transistor M6 is turned off.

[0054] When the voltage of the enable signal EN is greater than the threshold voltage of the seventh transistor M7, that is, the voltage of the enable signal EN is greater than the second preset voltage Vth2, the seventh transistor M7 is turned on, and the turned-on sixth transistor M6 and seventh transistor M7 can pull down the control voltage of the voltage stabilizing module 120 to start the voltage stabilizing module 120. Therefore, when the voltage of the enable signal EN is greater than the second preset voltage, the start unit 112 can generate a start signal according to the start control signal to start the voltage stabilizing module 120.

[0055] Continue to see Figure 3 The voltage stabilizing module 120 includes an eighth transistor M8, a ninth transistor M9, a tenth transistor M10, a third pull-up resistor Ru3, a first feedback resistor Rfb1, a second feedback resistor Rfb2, an output capacitor Cout, and an operational amplifier OP. The control end of the eighth transistor M8 is connected to the control end of the ninth transistor M9, the second end of the ninth transistor M9, the second end of the tenth transistor M10, and the output end of the pre-starting module 110, the first end of the eighth transistor M8 is connected to the power supply, the first end of the ninth transistor M9 is connected to the power supply through the third pull-up resistor Ru3, and the second end of the eighth transistor M8 is connected to the first end of the first feedback resistor Rfb1, the power supply end of the reference module 130, and the first plate of the output capacitor Cout.

[0056] The second end of the first feedback resistor Rfb1 is connected to the first end of the second feedback resistor Rfb2 and the inverting input end of the operational amplifier OP, the second end of the second feedback resistor Rfb2, the first end of the tenth transistor M10 and the second plate of the output capacitor Cout are grounded, the output end of the operational amplifier OP is connected to the control end of the tenth transistor M10, and the non-inverting input end of the operational amplifier OP is connected to the reference output end of the reference module 130.

[0057] Exemplarily, the eighth transistor M8 and the ninth transistor M9 are PMOS, the tenth transistor M10 is NMOS, the gate of the eighth transistor M8 is connected to the gate of the ninth transistor M9, the drain of the ninth transistor M9, the drain of the tenth transistor M10 and the output end of the pre-start module 110, the source of the eighth transistor M8 is connected to the power supply, the source of the ninth transistor M9 is connected to the power supply through the third pull-up resistor Ru3, the drain of the eighth transistor M8 is connected to the first end of the first feedback resistor Rfb1, the source of the tenth transistor M10 is grounded, and the output end of the operational amplifier OP is connected to the gate of the tenth transistor M10.

[0058] During the startup of the voltage stabilizing module 120, the gate voltage of the eighth transistor M8 and the gate voltage of the ninth transistor M9 are pulled down to ground, and the input voltage Vin charges the output capacitor Cout. For example, the output capacitor Cout can be an off-chip capacitor or an on-chip capacitor, and the capacitance value of the output capacitor Cout is 1 μF to stabilize the analog power supply voltage AVDD output by the voltage stabilizing module 120. The reference module 130 works normally and outputs the reference voltage Vref.

[0059] At this time, the analog power supply voltage AVDD output by the voltage stabilizing module 120 is close to the input voltage Vin. When the power supply voltage Vin rises to a value greater than or equal to the first preset voltage Vth1, the power supply voltage Vin reaches the minimum operating voltage of the reference module 130, and the reference module 130 can work normally and generate a shutdown indication signal. The shutdown indication signal includes at least one of the reference signal VBG, the working state signal BG_OK, and the detection signal EN_OK.

[0060] After the voltage stabilizing module 120 is started, the voltage stabilizing module 120 operates normally, the pre-starting module 110 stops operating, and the analog power supply voltage AVDD output by the voltage stabilizing module 120 is stabilized at a set voltage by a loop consisting of the operational amplifier OP, the first feedback resistor Rfb1, the second feedback resistor Rfb2, the eighth transistor M8, the ninth transistor M9 and the tenth transistor M10, that is, AVDD=(R1+R2) / R2*Vref, wherein R1 is the resistance value of the first feedback resistor Rfb1, and R2 is the resistance value of the second feedback resistor Rfb2.

[0061] For example, see Figure 3The shutdown indication signal includes a reference signal VBG, a working state signal BG_OK and a detection signal EN_OK. The pull-down component 1111 includes a third transistor M3, a fourth transistor M4 and a fifth transistor M5. The second end of the third transistor M3 is connected to the control end of the second transistor M2. The first end of the third transistor M3 is grounded through the fourth transistor M4 and the fifth transistor M5 in sequence. The control end of the third transistor M3 is connected to the reference output end of the reference module 130. The control end of the fourth transistor M4 is connected to the working state output end of the reference module 130. The control end of the fifth transistor M5 is connected to the detection output end of the reference module 130.

[0062] The reference module 130 includes a bandgap reference source 131 and a detection unit 132, wherein the power supply end of the bandgap reference source 131 and the power supply end of the detection unit 132 are connected to the output end of the voltage stabilizing module 120, the reference output end of the bandgap reference source 131 is connected to the first control end of the pull-down component 1111 and the first input end of the detection unit 132, the working status output end of the bandgap reference source 131 is connected to the second control end of the pull-down component 1111, the second input end of the detection unit 132 is connected to the enable signal EN, and the detection output end of the detection unit 132 is connected to the third control end of the pull-down component 1111.

[0063] For example, the third transistor M3, the fourth transistor M4 and the fifth transistor M5 are NMOS, the gate of the third transistor M3 is connected to the reference output terminal of the bandgap reference source 131, the gate of the fourth transistor M4 is connected to the working state output terminal of the bandgap reference source 131, and the gate of the fifth transistor M5 is connected to the detection output terminal of the detection unit 132. The drain of the third transistor M3 is connected to the gate of the second transistor M2, the source of the third transistor M3 is connected to the drain of the fourth transistor M4, the source of the fourth transistor M4 is connected to the drain of the fifth transistor M5, and the source of the fifth transistor M5 is grounded.

[0064] When the power supply voltage Vin rises to a value greater than or equal to the first preset voltage Vth1, the bandgap reference source 131 can work normally, pull up the reference signal VBG, and provide it to the gate of the third transistor M3 to turn on the third transistor M3. When the bandgap reference source 131 works stably, it can stably output the reference signal VBG, pull up the working state signal BG_OK, and provide it to the gate of the fourth transistor M4 to turn on the fourth transistor M4.

[0065] The detection unit 132 can receive the enable signal EN and the reference signal VBG, and compare the voltage of the enable signal EN with the voltage of the reference signal VBG, and when the voltage of the enable signal EN is greater than the voltage of the reference signal VBG, pull up the detection signal EN_OK, and provide it to the gate of the fifth transistor M5 to turn on the fifth transistor M5. The turned-on third transistor M3, fourth transistor M4, and fifth transistor M5 can pull down the gate voltage of the second transistor M2, turn off the second transistor M2, so that the control unit 111 stops working, thereby controlling the pre-start module 110 to stop working.

[0066] In other embodiments, the shutdown indication signal includes a reference signal VBG, and the corresponding pull-down component 1111 includes a third transistor M3, or the shutdown indication signal includes a working status signal BG_OK, and the corresponding pull-down component 1111 includes a fourth transistor M4, or the shutdown indication signal includes a detection signal EN_OK, and the corresponding pull-down component 1111 includes a fifth transistor M5.

[0067] In some other embodiments, the shutdown indication signal includes a reference signal VBG and a working status signal BG_OK, and the corresponding pull-down component 1111 includes a third transistor M3 and a fourth transistor M4, or, the shutdown indication signal includes a reference signal VBG and a detection signal EN_OK, and the corresponding pull-down component 1111 includes a third transistor M3 and a fifth transistor M5, or, the shutdown indication signal includes detection signals working status signals BG_OK and EN_OK, and the corresponding pull-down component 1111 includes a fourth transistor M4 and a fifth transistor M5.

[0068] Thus, the pull-down component 1111 turns off the second transistor M2 according to the shutdown indication signal, that is, controls the second transistor M2 to stop working, so that the control unit 111 stops working, thereby controlling the pre-start module 110 to stop working after the voltage stabilizing module 120 starts, which can reduce unnecessary energy consumption.

[0069] In summary, when the power supply voltage Vin is low, the pre-start module 110 is enabled to start the voltage regulator module 120. During its startup process, the voltage regulator module 120 can determine the analog power supply voltage AVDD according to the power supply voltage Vin, and provide the analog power supply voltage AVDD to the reference module 130 to start the reference module 130. In this way, when the power supply voltage Vin is low, the voltage regulator module 120 can establish the analog power supply voltage AVDD to ensure that the reference module 130 works normally, thereby ensuring that the linear voltage regulator circuit 100 works normally. Since the linear voltage regulator circuit 100 does not require an additional voltage detection circuit and a charge pump circuit, the complexity of the circuit structure can be reduced, which is conducive to the miniaturization of the circuit and can also reduce the power consumption of the circuit. In addition, when the power supply voltage Vin is high, the pre-start module 110 stops working, which can further reduce the power consumption of the circuit.

[0070] In some embodiments, Figure 4 A circuit diagram of another linear voltage stabilization circuit provided by an embodiment of the present disclosure is shown in FIG. Figure 4 As shown, the start-up unit 112 further includes an eleventh transistor M11, a first end of the eleventh transistor M11 is grounded, a second end of the eleventh transistor M11 is connected to the first input end of the start-up unit 112, and a control end of the eleventh transistor M11 is connected to the feedback end of the voltage stabilizing module 120.

[0071] The eleventh transistor M11 is configured to stabilize the feedback voltage of the voltage stabilizing module 120 at the third preset voltage Vth3, so as to stabilize the analog power supply voltage AVDD at a fourth preset voltage Vth4 during the power-on process, and the fourth preset voltage Vth4 is linearly related to the third preset voltage Vth3.

[0072] Exemplarily, the loop composed of the first feedback resistor Rfb1, the second feedback resistor Rfb2, the sixth transistor M6, the eighth transistor M8, the ninth transistor M9 and the eleventh transistor M11 can stabilize the analog power supply voltage AVDD at a fourth preset voltage Vth4, AVDD=Vth4=(R1+R2) / R2*Vth3, wherein Vth3 is the feedback voltage of the voltage stabilization module 120, and Vth3 is equal to the gate-source voltage Vgs_11 of the eleventh transistor M11.

[0073] In this way, when the input voltage Vin is rising, if the reference module 130 is not established in time, that is, the reference signal VBG is at a low level, or the working status signal BG_OK is at a low level, or the check signal EN_OK is at a low level, the analog power supply voltage AVDD will not increase indefinitely with the input voltage Vin, but will be stabilized at the fourth preset voltage Vth4, ensuring that the analog power supply voltage AVDD will not be too high, avoiding the circuit under the power domain of the analog power supply voltage AVDD from burning due to overvoltage, thereby improving the stability of the circuit.

[0074] In some embodiments, Figure 4 As shown, the pre-start module 110 further includes a clamp unit 113 , an input end of the clamp unit 113 is connected to the first end of the first transistor M1 , and an output end of the clamp unit 113 is grounded.

[0075] The clamping unit 113 is configured to limit the control voltage of the second transistor M2 to the clamping voltage Vclp when the power voltage Vin is greater than the fifth preset voltage Vth5.

[0076] For example, Figure 4 As shown, the clamping unit 113 includes one or more diode-connected transistors. Figure 3 As shown, the clamping unit 113 includes a twelfth transistor M12, a thirteenth transistor M13 and a fourteenth transistor M14, the source of the first transistor M1 is connected to the drain of the twelfth transistor M12 and the gate of the twelfth transistor M12, the source of the twelfth transistor M12 is connected to the drain of the thirteenth transistor M13 and the gate of the thirteenth transistor M13, the source of the thirteenth transistor M13 is connected to the drain of the fourteenth transistor M14 and the gate of the fourteenth transistor M14, and the source of the fourteenth transistor M14 is grounded.

[0077] When the power supply voltage Vin is greater than the fifth preset voltage Vth5, the first transistor M1 and the second transistor M2 are both turned on, and the gate voltage of the second transistor M2 changes with the power supply voltage Vin. At this time, the twelfth transistor M12, the thirteenth transistor M13 and the fourteenth transistor M14 can limit the gate voltage of the second transistor M2 to the clamping voltage Vclp to avoid the problem of the second transistor M2 burning due to the gate voltage of the second transistor M2 being too high, so as to improve the stability of the circuit.

[0078] In other embodiments, the number of transistors in the clamping unit 113 may be one, two, or more than three. The transistors in the clamping unit 113 may be MOS or a Zener diode, etc. The number and type of transistors determine the clamping voltage Vclp, and the clamping voltage Vclp depends on the minimum operating voltage of the linear voltage regulator circuit 100.

[0079] The present disclosure further provides a power chip, comprising the linear voltage regulator circuit 100 provided in any one of the above embodiments.

[0080] The power chip provided in the embodiment of the present disclosure includes the linear voltage regulator circuit 100 provided in any of the above embodiments, and has the same functional modules and beneficial effects as the linear voltage regulator circuit 100, which will not be repeated here.

[0081] The present disclosure further provides an electronic device, comprising the linear voltage stabilization circuit 100 provided by any of the above embodiments.

[0082] Exemplarily, the electronic device may be a charger or a transformer, or other device capable of voltage conversion, and the embodiments of the present disclosure do not impose specific limitations on this.

[0083] The electronic device provided by the embodiment of the present disclosure includes the linear voltage regulator circuit 100 provided by any of the above embodiments, and has the same functional modules and beneficial effects as the linear voltage regulator circuit 100, which will not be repeated here.

[0084] Unless the context clearly indicates otherwise, the singular form of the words used herein and in the appended claims includes the plural form and vice versa. Thus, when referring to the singular, the plural form of the corresponding term is generally included. Similarly, the words "comprise" and "include" are to be interpreted as inclusive rather than exclusive. Likewise, the terms "include" and "or" should be interpreted as inclusive, unless such interpretation is expressly prohibited herein. Where the term "example" is used herein, the "example" is merely illustrative and should not be considered exclusive or comprehensive.

[0085] Several embodiments of the present disclosure are described in detail above, but it is obvious that those skilled in the art can make various modifications and variations to the embodiments of the present disclosure without departing from the spirit and scope of the present disclosure. The protection scope of the present disclosure is defined by the attached claims.

Claims

1. A linear voltage stabilizing circuit, characterized in that: include: Pre-start module, voltage regulation module and reference module; The input end of the pre-start module and the power supply end of the voltage stabilizing module are connected to a power supply, the output end of the pre-start module is connected to the input end of the voltage stabilizing module, the output end of the voltage stabilizing module is connected to the power supply end of the reference module, and the reference output end of the reference module is connected to the control end of the voltage stabilizing module; The pre-start module is configured to start the voltage stabilizing module when the pre-start module is enabled and the power supply voltage is less than a first preset voltage during the power-on process of the power supply, and stop working when the power supply voltage is greater than or equal to the first preset voltage; the first preset voltage is related to the minimum operating voltage of the reference module; The voltage stabilizing module is configured to determine an analog power supply voltage according to the power supply voltage during the startup of the voltage stabilizing module, and provide the analog power supply voltage to the reference module to start the reference module; The voltage stabilizing module is provided with an output capacitor, and the voltage stabilizing module is further configured to stabilize the analog power supply voltage through the output capacitor during the startup process of the voltage stabilizing module, so that the analog power supply voltage is nearly equal to the power supply voltage.

2. The linear voltage stabilizing circuit according to claim 1, characterized in that: The pre-start module includes a control unit and a start unit; The input end of the control unit is connected to the power supply, the output end of the control unit is connected to the first input end of the start unit, the second input end of the start unit is connected to the enable signal, and the output end of the start unit is connected to the input end of the voltage stabilizing module; The control unit is configured to generate a start control signal when the power supply voltage is less than the first preset voltage during the power-on process, and stop working when the power supply voltage is greater than or equal to the first preset voltage; The startup unit is configured to generate a startup signal according to the startup control signal to start the voltage stabilizing module when the voltage of the enable signal is greater than a second preset voltage.

3. The linear voltage stabilizing circuit according to claim 2, characterized in that: The control unit includes a first pull-up resistor, a second pull-up resistor, a first transistor, a second transistor and a pull-down component; The first end of the first pull-up resistor is connected to the power supply, the second end of the first pull-up resistor is connected to the first end of the second pull-up resistor and the second end of the second transistor, the second end of the second pull-up resistor is connected to the control end of the first transistor, the second end of the first transistor, the control end of the second transistor and the output end of the pull-down component, the first end of the first transistor and the input end of the pull-down component are grounded, the first end of the second transistor is connected to the first input end of the startup unit, and the control end of the pull-down component is connected to the output end of the reference module; The reference module is configured to generate a shutdown indication signal when the power supply voltage is greater than or equal to the first preset voltage, wherein the shutdown indication signal includes at least one of a reference signal, a working state signal and a detection signal; The pull-down component is configured to turn off the second transistor according to the turn-off indication signal, so as to stop the control unit from working.

4. The linear voltage stabilizing circuit according to claim 3, characterized in that: The pull-down component includes a third transistor, a fourth transistor, and a fifth transistor; The second end of the third transistor is connected to the control end of the second transistor, the first end of the third transistor is grounded through the fourth transistor and the fifth transistor in sequence, the control end of the third transistor is connected to the reference output end of the reference module, the control end of the fourth transistor is connected to the working status output end of the reference module, and the control end of the fifth transistor is connected to the detection output end of the reference module.

5. The linear voltage stabilizing circuit according to claim 3, characterized in that: The reference module includes a bandgap reference source and a detection unit; The power supply end of the bandgap reference source and the power supply end of the detection unit are connected to the output end of the voltage stabilizing module, the reference output end of the bandgap reference source is connected to the first control end of the pull-down component and the first input end of the detection unit, the working state output end of the bandgap reference source is connected to the second control end of the pull-down component, the second input end of the detection unit is connected to the enable signal, and the detection output end of the detection unit is connected to the third control end of the pull-down component; The bandgap reference source is configured to pull up the reference signal when the power supply voltage is greater than or equal to the first preset voltage; and pull up the working state signal when the reference signal is stably output; The detection unit is configured to pull up the detection signal when the voltage of the enable signal is greater than the voltage of the reference signal.

6. The linear voltage stabilizing circuit according to claim 2, characterized in that: The startup unit includes a sixth transistor and a seventh transistor; The control end of the sixth transistor is connected to the output end of the control unit, the second end of the sixth transistor is connected to the control end of the voltage stabilizing module, the first end of the sixth transistor is connected to the ground through the seventh transistor, and the control end of the seventh transistor is connected to the enable signal.

7. The linear voltage stabilizing circuit according to claim 6, characterized in that: The startup unit further includes an eleventh transistor; The first end of the eleventh transistor is grounded, the second end of the eleventh transistor is connected to the first input end of the start-up unit, and the control end of the eleventh transistor is connected to the feedback end of the voltage stabilizing module; The eleventh transistor is configured to stabilize the feedback voltage of the voltage stabilizing module at a third preset voltage, so as to stabilize the analog power supply voltage at a fourth preset voltage during the power-on process, and the fourth preset voltage is linearly related to the third preset voltage.

8. The linear voltage stabilizing circuit according to claim 3, characterized in that: The pre-start module also includes a clamping unit; The input end of the clamp unit is connected to the first end of the first transistor, and the output end of the clamp unit is grounded; The clamping unit is configured to limit the control voltage of the second transistor to a clamping voltage when the power supply voltage is greater than a fifth preset voltage.

9. The linear voltage stabilizing circuit according to any one of claims 1 to 8, characterized in that: The voltage stabilizing module includes an eighth transistor, a ninth transistor, a tenth transistor, a third pull-up resistor, a first feedback resistor, a second feedback resistor and an operational amplifier; The control end of the eighth transistor is connected to the control end of the ninth transistor, the second end of the ninth transistor, the second end of the tenth transistor and the output end of the pre-start module, the first end of the eighth transistor is connected to the power supply, the first end of the ninth transistor is connected to the power supply through the third pull-up resistor, and the second end of the eighth transistor is connected to the first end of the first feedback resistor, the power supply end of the reference module and the first plate of the output capacitor; The second end of the first feedback resistor is connected to the first end of the second feedback resistor and the inverting input end of the operational amplifier, the second end of the second feedback resistor, the first end of the tenth transistor and the second plate of the output capacitor are grounded, the output end of the operational amplifier is connected to the control end of the tenth transistor, and the non-inverting input end of the operational amplifier is connected to the reference output end of the reference module.

10. A power chip, characterized in that: The invention comprises the linear voltage stabilizing circuit as described in any one of claims 1 to 9.

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