A power supply circuit with low energy consumption and high stability

Abstract

The present invention relates to the field of power supply technology, and in particular to a low-energy-consumption, high-stability power supply circuit. The low-energy-consumption, high-stability power supply circuit provided by the present invention is configured such that a voltage signal provided by an external power circuit during normal operation controls a startup circuit to output a high-level startup signal, thereby starting a current detection circuit and an internal control circuit. When the current detection circuit is operating, a voltage signal provided by a parameter adjustment circuit and a power switch tube controls a current detection signal generation circuit to output a current detection signal. When the internal control circuit is in operation, the power switch tube is controlled based on the current detection signal to achieve power supply by controlling the operating state of the power switch tube in the operating state. The parameters of the circuit elements of the parameter adjustment circuit are adjusted so that the parameter adjustment circuit reduces the energy consumption of the current detection circuit while providing a larger voltage signal, thereby preventing a battery power supply circuit from being mistakenly triggered to shut down, thereby ensuring the stability and reliability of the battery power supply circuit.

Description

Technical Field

[0001] The present invention relates to the technical field of power supply, and in particular to a power supply circuit with low energy consumption and high stability. Background Art

[0002] The battery powered circuit in the prior art is as follows Figure 1 As shown, it includes a semiconductor integrated circuit control chip, an external power circuit and a load (battery). The semiconductor integrated circuit control chip includes a power switch tube MP, an internal control circuit, a current sensing resistor RS and a comparator A1.

[0003] The current-sense resistor RS is used to detect the current flowing through the power switch tube MP. When the voltage across the current-sense resistor RS is less than the reference voltage VREF, the comparator A1 outputs a high level to the internal control circuit. The internal control circuit controls the on and off of the power switch tube MP according to the control logic when the circuit is normally operating. When the voltage across the current-sense resistor RS is greater than the reference voltage VREF, the comparator A1 outputs a low level to the internal control circuit. The internal control circuit controls the power switch tube MP to turn off.

[0004] Obviously, when the battery-powered circuit is operating normally, current always flows through the current-sense resistor RS, thereby increasing the energy consumption of the battery-powered circuit. At this time, if the resistance value of the current-sense resistor RS is reduced to reduce the additional energy consumption, the reference voltage VREF must also be reduced accordingly. The smaller the reference voltage VREF is, the higher the accuracy requirements for the reference voltage VREF and the current-sense resistor RS are. Therefore, at this time, if the reference voltage VREF or the terminal voltage of the current-sense resistor RS fluctuates slightly, it will cause the power switch MP to be erroneously turned off, causing the battery-powered circuit to be in an unstable operating state. Summary of the Invention

[0005] In view of this, the present invention provides a power supply circuit with low energy consumption and high stability to solve the technical problems of high energy consumption or poor stability of the power supply circuit in the prior art.

[0006] The technical solutions provided by the present invention are as follows:

[0007] A first aspect of the present invention provides a low-energy-consumption, high-stability power supply circuit, comprising: an external power circuit, a startup circuit, a current detection circuit, a power switch tube, and an internal control circuit; the startup circuit outputs a high-level or low-level startup signal according to a voltage signal output by the external power circuit; the current detection circuit and the internal control circuit are in an operating state or a non-operating state according to the high-level or low-level startup signal; the current detection circuit comprises a parameter adjustment circuit and a current detection signal generation circuit; when the current detection circuit and the internal control circuit are in an operating state, if the voltage signal provided by the parameter adjustment circuit is greater than the voltage signal provided by the power switch tube, the current detection signal generation circuit outputs a low-level current detection signal, and the internal control circuit outputs a first control signal according to the low-level current detection signal to control the normal operation of the power switch tube; conversely, the internal control circuit outputs a second control signal according to the high-level current detection signal to control the power switch tube to shut down; the parameters of the circuit elements in the parameter adjustment circuit are adjustable so that the parameter adjustment circuit reduces the energy consumption of the current detection circuit while providing a larger voltage signal.

[0008] In an optional embodiment, when the external power circuit outputs a voltage signal greater than a first threshold voltage, the start-up circuit outputs a high-level start-up signal; when the external power circuit outputs a voltage signal less than a second threshold voltage, the start-up circuit outputs a low-level start-up signal; the first threshold voltage is greater than the second threshold voltage, and the difference between the first threshold voltage and the second threshold voltage is greater than a preset threshold.

[0009] In an optional embodiment, the first end of the starting circuit is connected to the external power supply, the first end of the parameter adjustment circuit and the first end of the current detection signal generating circuit, the second end of the starting circuit is connected to the second end of the parameter adjustment circuit, the second end of the current detection signal generating circuit, the first end of the power switch tube and grounded, the third end of the starting circuit is connected to the third end of the parameter adjustment circuit and the first end of the internal control circuit, the fourth end of the starting circuit is connected to the first end of the external power circuit; the fourth end of the parameter adjustment circuit is connected to the third end of the current detection signal generating circuit; the fourth end of the current detection signal generating circuit is connected to the second end of the power switch tube and the second end of the external power circuit, the fifth end of the current detection signal generating circuit is connected to the second end of the internal control circuit; the third end of the internal control circuit is connected to the third end of the power switch tube.

[0010] In an optional embodiment, the startup circuit includes a first resistor, a second resistor, a third resistor, a first controllable current source, a second controllable current source, an inverter, a first switch tube and a second switch tube; one end of the first resistor is connected to the positive control end and input end of the first controllable current source, the positive control end and input end of the second controllable current source and an external power supply, the other end of the first resistor is connected to one end of the second resistor, the negative control end of the first controllable current source and the negative control end of the second controllable current source, the other end of the second resistor is connected to one end of the third resistor and is grounded, the output end of the first controllable current source is connected to the first end of the first switch tube, the first end of the second switch tube and the input end of the inverter, the second end of the first switch tube is connected to the first end of the external power circuit, the third end of the first switch tube is connected to the other end of the third resistor and the second end of the second switch tube, the output end of the second controllable current source is connected to the third end of the second switch tube, and the output end of the inverter is connected to the third end of the parameter adjustment circuit and the first end of the internal control circuit.

[0011] In an optional embodiment, the parameter adjustment circuit includes a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, a third controllable current source, a fourth controllable current source, a fifth controllable current source, a third switch tube, a fourth switch tube, a fifth switch tube, and a sixth switch tube;

[0012] One end of the fourth resistor is connected to the positive control terminal and input terminal of the third controllable current source, one end of the sixth resistor, the positive control terminal and input terminal of the fourth controllable current source, the positive control terminal and input terminal of the fifth controllable current source, the first end of the fifth switch tube, and an external power supply; the other end of the fourth resistor is connected to the negative control terminal of the third controllable current source and one end of the fifth resistor; the other end of the fifth resistor is connected to the first end of the third switch tube, one end of the seventh resistor, the first end of the fourth switch tube, the first end of the sixth switch tube, one end of the ninth resistor, and grounded; the output end of the third controllable current source is connected to the second end of the third switch tube and the second end of the fourth switch tube; and the third end of the third switch tube is connected to the third end of the startup circuit;

[0013] The other end of the sixth resistor is connected to the negative control end of the fourth controllable current source, the negative control end of the fifth controllable current source and the other end of the seventh resistor, the output end of the fourth controllable current source is connected to the third end of the fourth switch tube, the output end of the fifth controllable current source is connected to the second end of the fifth switch tube and the second end of the sixth switch tube, the third end of the sixth switch tube is connected to one end of the eighth resistor and the other end of the ninth resistor, and the other end of the eighth resistor is connected to the third end of the fifth switch tube and the third end of the current detection signal generating circuit.

[0014] In an optional embodiment, the current detection signal generating circuit includes a tenth resistor, an eleventh resistor, a twelfth resistor, a thirteenth resistor, a fourteenth resistor, a fifteenth resistor, a sixth controllable current source, a seventh controllable current source, an eighth controllable current source, a seventh switch tube, an eighth switch tube, a ninth switch tube, and a tenth switch tube;

[0015] One end of the tenth resistor is connected to one end of the twelfth resistor, one end of the thirteenth resistor, one end of the fourteenth resistor, the first end of the ninth switching tube, the first end of the tenth switching tube, and the external power supply; the other end of the tenth resistor is connected to one end of the eleventh resistor and the positive control terminal of the sixth switching tube; the other end of the eleventh resistor is connected to the negative control terminal and the output terminal of the sixth controllable current source, one end of the fifteenth resistor, the negative control terminal and the output terminal of the seventh controllable current source, the negative control terminal and the output terminal of the eighth controllable current source, and grounded; the other end of the twelfth resistor is connected to the first end of the seventh switching tube and the second end of the ninth switching tube; the second end of the seventh switching tube is connected to the fourth end of the parameter adjustment circuit; and the third end of the seventh switching tube is connected to the first end of the eighth switching tube and the input end of the sixth controllable current source;

[0016] The other end of the thirteenth resistor is connected to the second end of the eighth switch tube and the second end of the tenth switch tube, the third end of the eighth switch tube is connected to the second end of the power switch tube and the second end of the external power circuit, the other end of the fourteenth resistor is connected to the other end of the fifteenth resistor, the positive control end of the seventh controllable current source and the positive control end of the eighth controllable current source, the third end of the ninth switch tube is connected to the input end of the seventh controllable current source, and the third end of the tenth switch tube is connected to the input end of the eighth controllable current source and the second end of the internal control circuit.

[0017] In an optional implementation, the third switch tube includes a plurality of third sub-switch tubes.

[0018] In an optional implementation, the first threshold voltage is expressed as:

[0019]

[0020] The second threshold voltage is expressed as:

[0021]

[0022] Wherein, VTH represents the turn-on voltage threshold of the first switch tube, K represents the ratio of the current coefficients of the first controllable current source and the second controllable current source, R3 represents the resistance value of the third resistor, , VCC represents the external power supply voltage, R1 represents the resistance value of the first resistor, and R2 represents the resistance value of the second resistor.

[0023] In an optional implementation, the voltage signal provided by the parameter adjustment circuit is expressed as:

[0024]

[0025] Wherein, n represents the number of the third sub-switches, RG represents the on-resistance of the third sub-switches, IG represents the current of the third controllable current source, R8 represents the resistance of the eighth resistor, and R9 represents the resistance of the ninth resistor.

[0026] In an optional implementation, the current of the third controllable current source is determined according to the external power supply voltage, the resistance value of the fourth resistor, the resistance value of the fifth resistor, and the current coefficient of the third controllable current source.

[0027] In an optional embodiment, the magnitude of the voltage signal provided by the power switch tube is related to the magnitude of the current flowing through the power switch tube. When the current flowing through the power switch tube is greater than a threshold current, the current detection circuit outputs a high-level current detection signal; when the current flowing through the power switch tube is less than the threshold current, the current detection circuit outputs a low-level current detection signal. The threshold current is determined using the following formula:

[0028]

[0029] Where, Indicates the on-resistance of the power switch tube.

[0030] The technical solution of the present invention has the following advantages:

[0031] The low-energy-consumption and high-stability power supply circuit provided by the present invention uses a voltage signal provided by an external power circuit when operating normally to control a startup circuit to output a high-level startup signal, so that a current detection circuit and an internal control circuit start operating; when the current detection circuit is operating, a voltage signal provided by a parameter adjustment circuit and a power switch tube controls a current detection signal generation circuit to output a current detection signal; and when the internal control circuit is in an operating state, the operating state of the power switch tube is controlled based on the current detection signal to realize power supply; wherein, by adjusting the parameters of the circuit elements of the parameter adjustment circuit, the parameter adjustment circuit reduces the energy consumption of the current detection circuit while providing a large voltage signal, so that the battery power supply circuit will not be mistakenly triggered to shut down, thereby ensuring the stability and reliability of the battery power supply circuit.

[0032] In the present invention, by setting the difference between the first threshold voltage and the second threshold voltage to be greater than a preset threshold, when the voltage signal output by the external power circuit is disturbed, such as slightly below the first threshold voltage, the startup circuit can still output a high-level startup signal, thereby improving the stability and reliability of the external power circuit, preventing the battery power supply circuit from being erroneously triggered to shut down, and ensuring the stability and reliability of the battery power supply circuit. In addition, by configuring the startup circuit structure, the difference between the first threshold voltage and the second threshold voltage can be adjusted by adjusting the resistance values ​​of the first resistor, the second resistor, and the third resistor, thereby adjusting the disturbance threshold of the battery power supply circuit.

[0033] In the present invention, by adjusting the parameters of the eighth resistor R8 and the ninth resistor R9, As large as possible, so as to reduce The size of the current detection can reduce the additional energy consumption.

[0034] In the present invention, since the voltage signal provided by the parameter adjustment circuit is At this time, the resistance values ​​of the eighth resistor R8 and the ninth resistor R9 are designed to meet the above ratio and are set as large as possible, thereby reducing the additional energy consumption caused by current detection.

[0035] In the present invention, the voltage signal provided by the parameter adjustment circuit can be adjusted by selecting the eighth resistor R8 and the ninth resistor R9 with appropriate parameters. The value of is as large as possible to avoid the battery power supply circuit being shut down by mistake when the parameter fluctuates due to the parameter value being too small, thereby improving the stability of the battery power supply circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0037] Figure 1 It is a structural diagram of a battery power supply circuit in the related art;

[0038] Figure 2 This is a structural block diagram of a low-energy-consumption and high-stability power supply circuit according to an embodiment of the present invention;

[0039] Figure 3 Schematic diagram of the structure of a low-energy-consumption and high-stability power supply circuit in an embodiment of the present invention. DETAILED DESCRIPTION

[0040] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0041] In the description of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation, and therefore should not be construed as limitations on the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0042] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; internal connections between two components; wireless connections or wired connections. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0043] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0044] The embodiment of the present invention provides a power supply circuit with low energy consumption and high stability, such as Figure 2As shown, the circuit includes: an external power circuit 10, a startup circuit 20, a current detection circuit, a power switch 50, and an internal control circuit 60. The startup circuit 20 outputs a high-level or low-level startup signal based on the voltage signal output by the external power circuit 10. The current detection circuit and the internal control circuit 60 are in an operating state or a non-operating state based on the high-level or low-level startup signal. The current detection circuit includes a parameter adjustment circuit 30 and a current detection signal generation circuit 40. When the current detection circuit and the internal control circuit 60 are in the operating state, if the voltage signal provided by the parameter adjustment circuit 30 is greater than the voltage signal provided by the power switch 50, the current detection signal generation circuit 40 outputs a low-level current detection signal. The internal control circuit 60 outputs a first control signal based on the low-level current detection signal to control the normal operation of the power switch 50. Conversely, the internal control circuit 60 outputs a second control signal based on the high-level current detection signal to control the power switch 50 to turn off. The parameters of the circuit elements in the parameter adjustment circuit 30 are adjustable so that the parameter adjustment circuit 30 can provide a larger voltage signal while reducing the energy consumption of the current detection circuit.

[0045] Among them, the first end of the starting circuit 20 is connected to the external power supply, the first end of the parameter adjustment circuit 30 and the first end of the current detection signal generating circuit 40, the second end of the starting circuit 20 is connected to the second end of the parameter adjustment circuit 30, the second end of the current detection signal generating circuit 40, the first end of the power switch tube 50 and grounded, the third end of the starting circuit 20 is connected to the third end of the parameter adjustment circuit 30 and the first end of the internal control circuit 60, the fourth end of the starting circuit 20 is connected to the first end of the external power circuit 10; the fourth end of the parameter adjustment circuit 30 is connected to the third end of the current detection signal generating circuit 40; the fourth end of the current detection signal generating circuit 40 is connected to the second end of the power switch tube 50 and the second end of the external power circuit 10, the fifth end of the current detection signal generating circuit 40 is connected to the second end of the internal control circuit 60; the third end of the internal control circuit 60 is connected to the third end of the power switch tube 50.

[0046] Specifically, the voltage signal output by the external power circuit indicates the voltage at a key node in the external power circuit. The external power circuit receives electrical energy provided by the power switch when it is turned on and performs further processing, such as voltage conversion and power distribution, on the electrical energy to meet load requirements. The external power circuit can employ circuits known in the relevant art that can implement corresponding functions. For example, the external power circuit can be a switching power supply circuit. It should be noted that this is merely an example of an external power circuit and is not limited to this embodiment. The location of the specific key node varies depending on the structure of the external power circuit. However, the voltage at the key node can indicate whether the external power circuit is functioning properly. When the startup circuit detects that the voltage at the key node of the external power circuit has increased to a value greater than a first threshold voltage, the external power circuit is functioning properly and outputs a high-level startup signal. When the startup circuit detects that the voltage at the key node of the external power circuit has decreased to a value less than a second threshold voltage, the external power circuit is not functioning properly (e.g., a fault has occurred) and outputs a low-level startup signal.

[0047] When the startup circuit outputs a high-level startup signal, the high-level startup signal controls the current detection circuit and the internal control circuit to be in an active state. When the startup circuit outputs a low-level startup signal, the low-level startup signal controls the current detection circuit and the internal control circuit to be in an inactive state. When the current detection circuit is in an active state, its internal parameter adjustment circuit provides a voltage signal to the current detection signal generation circuit. Simultaneously, when current flows through the power switch tube, the power switch tube can also provide a voltage signal to the current detection signal generation circuit. The current detection signal generation circuit generates different current detection signals based on the magnitude of the voltage signals provided by the parameter adjustment circuit and the power switch tube. Specifically, when the voltage signal provided by the parameter adjustment circuit is greater than the voltage signal provided by the power switch tube, the current detection signal generation circuit outputs a low-level current detection signal. When the voltage signal provided by the parameter adjustment circuit is less than the voltage signal provided by the power switch tube, the current detection signal generation circuit outputs a high-level current detection signal.

[0048] The magnitude of the voltage signal provided by the power switch is related to the current flowing through it. Therefore, the current detection circuit effectively detects the magnitude of the current flowing through the power switch (the power current to be measured). Specifically, when the power current to be measured is high, the current detection circuit outputs a high-level current detection signal; when the power current to be measured is low, the current detection circuit outputs a low-level current detection signal.

[0049] The internal control circuit is in an operating state when it receives a high-level startup signal from the startup circuit. At this point, if the internal control circuit receives a low-level current detection signal from the current detection circuit, it outputs a high-low switching first control signal to control the on and off of the power switch according to the normal operating control logic. If the internal control circuit receives a high-level current detection signal from the current detection circuit, it outputs a low-level second control signal to control the off of the power switch. When the startup circuit outputs a low-level startup signal, the internal control circuit is in an inoperative state, and no control signal is output.

[0050] In a current detection circuit, to reduce power consumption and improve operational stability, the parameters of the circuit elements in the parameter adjustment circuit are adjusted. For example, if the circuit elements include resistors, the resistance of the corresponding resistor can be increased, thereby simultaneously increasing the voltage signal output by the parameter adjustment circuit. This not only reduces the energy consumption of the parameter adjustment circuit, but also, because the voltage signal provided by the parameter adjustment circuit is larger, fluctuations in the current detection signal are prevented when the parameters fluctuate. This prevents problems such as the power switch accidentally shutting down, thereby improving the stability of the power supply circuit.

[0051] In an optional embodiment, when the external power circuit outputs a voltage signal greater than a first threshold voltage, the startup circuit outputs a high-level startup signal; when the external power circuit outputs a voltage signal less than a second threshold voltage, the startup circuit outputs a low-level startup signal; the first threshold voltage is greater than the second threshold voltage, and the difference between the first threshold voltage and the second threshold voltage is greater than a preset threshold. By setting the difference between the first threshold voltage and the second threshold voltage to be relatively large, when the voltage signal output by the external power circuit fluctuates due to a disturbance, the voltage signal output by the startup circuit will not also fluctuate. This configuration improves the stability and reliability of the circuit, preventing the circuit from being falsely triggered or shutting down.

[0052] In an optional embodiment, as Figure 3As shown, the startup circuit includes a first resistor R1, a second resistor R2, a third resistor R3, a first controllable current source G1, a second controllable current source G2, an inverter U1, a first switch tube M1 and a second switch tube M2; one end of the first resistor R1 is connected to the positive control terminal and input terminal of the first controllable current source G1, the positive control terminal and input terminal of the second controllable current source G2 and an external power supply, the other end of the first resistor R1 is connected to one end of the second resistor R2, the negative control terminal of the first controllable current source G1 and the negative control terminal of the second controllable current source G2, and the other end of the second resistor R2 is connected to the positive control terminal of the first controllable current source G1 and the negative control terminal of the second controllable current source G2. One end is connected to one end of the third resistor R3 and is grounded, the output end of the first controllable current source G1 is connected to the first end of the first switching tube M1, the first end of the second switching tube M2, and the input end of the inverter U1, the second end of the first switching tube M1 is connected to the first end of the external power circuit, the third end of the first switching tube M1 is connected to the other end of the third resistor R3 and the second end of the second switching tube M2, the output end of the second controllable current source G2 is connected to the third end of the second switching tube M2, and the output end of the inverter U1 is connected to the third end of the parameter adjustment circuit and the first end of the internal control circuit.

[0053] Specifically, based on the startup circuit, when the circuit is powered on, a first current I1 (first current ), a voltage drop is generated across the first resistor R1, and the first controllable current source G1 and the second controllable current source G2 are turned on. At this time, the first controllable current source G1 pulls up the gate voltage of the second switch tube M2, and the source of the second switch tube M2 is grounded through the third resistor R3. Therefore, the second switch tube M2 is turned on, and a second controllable current is generated in the second controllable current source G2. At this time, since the current coefficient of the first controllable current source G1 and the second controllable current source G2 is designed to be K:1, if the second controllable current is I1, and after the first controllable current is generated in the first controllable current source G1, the first controllable current is Therefore, if the first switch tube M1 is turned on, the terminal voltage of the third resistor R3, that is, the source voltage of the first switch tube M1 is , so it can be obtained that after the circuit is powered on, when the voltage of the key node of the external power circuit rises to greater than When the first switch tube M1 is turned on, is the turn-on voltage threshold of the first switch tube M1; after the first switch tube M1 is turned on, it pulls down the gate voltage of the second switch tube M2, and the second switch tube M2 is turned off. At this time, the input end of the inverter U1 is at a low level, and the inverter U1 outputs a high-level start signal VG. At this time, the terminal voltage of the third resistor R3, that is, the source voltage of the first switch tube M1, is reduced to , so when the voltage of the key node of the external power circuit is reduced to less than When , the first switch tube M1 is turned off, the voltage at the input terminal of the inverter U1 is pulled high, and the inverter U1 outputs a low-level start signal VG.

[0054] According to the above analysis, when the voltage of the key node of the external power circuit rises to a value greater than the first threshold voltage, that is, When the external power circuit works normally, the startup circuit outputs a high-level startup signal VG, so that the current detection circuit and the internal control circuit start working; afterwards, if the external power circuit fails, the voltage of the key node of the external power circuit drops below the second threshold voltage, that is, When the external power circuit cannot work normally, the start-up circuit outputs a low-level start-up signal VG at this time, so that the current detection circuit and the internal control circuit are in a non-working state; at the same time, if the voltage of the key node of the external power circuit is disturbed (such as uneven charging of the battery load, which may cause the battery load to feed back voltage and current to the external power circuit, thereby causing the voltage of the key node of the external power circuit to be disturbed), when it is slightly lower than the first threshold voltage, the start-up circuit still outputs a high-level start-up signal VG, thereby improving the stability and reliability of the voltage detection of the key node of the external power circuit, so that the battery power supply circuit will not be mistakenly triggered to shut down, thereby ensuring the stability and reliability of the battery power supply circuit; at this time, the difference between the first threshold voltage and the second threshold voltage can be adjusted by adjusting the resistance values ​​of the first resistor R1, the second resistor R2 and the third resistor R3, so that the difference between the two is greater than the preset threshold, that is, the disturbance threshold of the battery power supply circuit is adjusted.

[0055] In an optional embodiment, the parameter adjustment circuit includes a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, a third controllable current source G3, a fourth controllable current source G4, a fifth controllable current source G5, a third switch tube M3, a fourth switch tube M4, a fifth switch tube M5 and a sixth switch tube M6; wherein the third switch tube M3 includes multiple third sub-switch tubes.

[0056] One end of the fourth resistor R4 is connected to the positive control terminal and input terminal of the third controllable current source G3, one end of the sixth resistor R6, the positive control terminal and input terminal of the fourth controllable current source G4, the positive control terminal and input terminal of the fifth controllable current source G5, the first terminal of the fifth switch M5, and an external power supply. The other end of the fourth resistor R4 is connected to the negative control terminal of the third controllable current source G3 and one end of the fifth resistor R5. The other end of the fifth resistor R5 is connected to the first terminal of the third switch M3, one end of the seventh resistor R7, the first end of the fourth switch M4, the first end of the sixth switch M6, one end of the ninth resistor R9, and grounded. The output end of the third controllable current source G3 is connected to the second end of the third switch M3 and the second end of the fourth switch M4. The third end of the third switch M3 is connected to the third end of the startup circuit.

[0057] The other end of the sixth resistor R6 is connected to the negative control terminal of the fourth controllable current source G4, the negative control terminal of the fifth controllable current source G5, and the other end of the seventh resistor R7. The output end of the fourth controllable current source G4 is connected to the third end of the fourth switch tube M4. The output end of the fifth controllable current source G5 is connected to the second end of the fifth switch tube M5 and the second end of the sixth switch tube M6. The third end of the sixth switch tube M6 is connected to one end of the eighth resistor R8 and the other end of the ninth resistor R9. The other end of the eighth resistor R8 is connected to the third end of the fifth switch tube M5 and the third end of the current detection signal generating circuit.

[0058] In an optional embodiment, the current detection signal generating circuit includes a tenth resistor R10, an eleventh resistor R11, a twelfth resistor R12, a thirteenth resistor R13, a fourteenth resistor R14, a fifteenth resistor R15, a sixth controllable current source G6, a seventh controllable current source G7, an eighth controllable current source G8, a seventh switch tube M7, an eighth switch tube M8, a ninth switch tube M9, and a tenth switch tube M10;

[0059] One end of the tenth resistor R10 is connected to one end of the twelfth resistor R12, one end of the thirteenth resistor R13, one end of the fourteenth resistor R14, a first end of the ninth switch M9, a first end of the tenth switch M10, and an external power supply. The other end of the tenth resistor R10 is connected to one end of the eleventh resistor R11 and the positive control end of the sixth switch M6. The other end of the eleventh resistor R11 is connected to the negative control end and the output end of the sixth controllable current source G6, one end of the fifteenth resistor R15, the negative control end and the output end of the seventh controllable current source G7, the negative control end and the output end of the eighth controllable current source G8, and ground. The other end of the twelfth resistor R12 is connected to the first end of the seventh switch M7 and the second end of the ninth switch M9. The second end of the seventh switch M7 is connected to the fourth end of the parameter adjustment circuit. The third end of the seventh switch M7 is connected to the first end of the eighth switch M8 and the input end of the sixth controllable current source G6.

[0060] The other end of the thirteenth resistor R13 is connected to the second end of the eighth switch tube M8 and the second end of the tenth switch tube M10. The third end of the eighth switch tube M8 is connected to the second end of the power switch tube and the second end of the external power circuit. The other end of the fourteenth resistor R14 is connected to the other end of the fifteenth resistor R15, the positive control end of the seventh controllable current source G7, and the positive control end of the eighth controllable current source G8. The third end of the ninth switch tube M9 is connected to the input end of the seventh controllable current source G7. The third end of the tenth switch tube M10 is connected to the input end of the eighth controllable current source G8 and the second end of the internal control circuit.

[0061] Specifically, based on the structure of the above-mentioned current detection circuit, when the startup circuit outputs startup signals of different levels, the current detection circuit is in an operating state or a non-operating state.

[0062] (1) When the start signal VG is at a high level and the high-level start signal VG is input into each sub-switch tube of the third switch tube M3 and the internal control circuit, each sub-switch tube of the third switch tube M3 is turned on, and the internal control circuit starts to work and outputs a high-level control signal VS, and the power switch tube MP is turned on;

[0063] At this time, current flows through the fourth resistor R4 and the fifth resistor R5, and a voltage drop is generated across the fourth resistor R4, causing a third controllable current to flow through the third controllable current source G3. In addition, by designing the current coefficients of the fourth resistor R4, the fifth resistor R5, and the third controllable current source G3, a third controllable current of any magnitude can be obtained, hereinafter represented by IG. At the same time, the on-resistances of the sub-switches and the power switch MP of the third switch M3 can be obtained based on the chip manufacturing process, and are represented by RG and RP, respectively. Therefore, at this time, the on-resistance of the third switch M3 is , where n is the number of sub-switches of the third switch tube M3;

[0064] From the above analysis, we can know that the gate voltage of the fourth switch tube M4 is , that is, the gate voltage of the fourth switch tube M4 is pulled high, and the fourth switch tube M4 is turned on; at the same time, current flows through the sixth resistor R6 and the seventh resistor R7, and a voltage drop is generated across the sixth resistor R6, so that the fourth controllable current source G4 and the fifth controllable current source G5 are both turned on. At this time, since the fourth switch tube M4 is turned on, the fourth controllable current flows through the fourth controllable current source G4. At the same time, since the fourth controllable current source G4 and the fourth switch tube M4 are connected in series, the current flowing through the fourth switch tube M4 is equal to the fourth controllable current source G4. The fifth controllable current source G5 increases the gate voltage of the fifth switch tube M5, and the fifth switch tube M5 is turned on. At this time, the current flowing through the eighth resistor R8 and the ninth resistor R9 gradually increases, and the gate voltage of the sixth switch tube M6 also increases accordingly, and the sixth switch tube M6 is turned on. At this time, the fifth controllable current flows through the fifth controllable current source G5. At the same time, the current coefficient of the fourth controllable current source G4 and the fifth controllable current source G5 is designed to be 1:1, so it can be obtained that the fourth controllable current = the fifth controllable current;

[0065] As the current flowing through the ninth resistor R9 gradually increases, the gate voltage of the sixth switch tube M6 gradually increases, the gate-source voltage difference of the sixth switch tube M6 gradually increases, and the current flowing through the sixth switch tube M6 gradually increases. When the current flowing through the sixth switch tube M6 is greater than the fifth controllable current, the gate voltage of the fifth switch tube M5 is pulled down, the fifth switch tube M5 is turned off, the gate voltage of the sixth switch tube M6 is pulled down through the ninth resistor R9, the sixth switch tube M6 is turned off, and the gate voltage of the fifth switch tube M5 is pulled up again through the fifth controllable current source G5, the fifth switch tube M5 is turned on, and the circuit enters the next cycle;

[0066] Therefore, when the circuit enters a steady state, the current flowing through the sixth switch tube M6 = the fifth controllable current = the fourth controllable current = the current flowing through the fourth switch tube M4. Therefore, at this time, the gate-source voltage difference of the fourth switch tube M4 is equal to the gate-source voltage difference of the sixth switch tube M6. Since the source of the fourth switch tube M4 is connected to the source of the sixth switch tube M6, the gate voltage of the sixth switch tube M6 = the gate voltage of the fourth switch tube M4 = , so at this time, the current flowing through the eighth resistor R8 and the ninth resistor R9 = , so the gate voltage of the seventh switch tube M7 = ;

[0067] Afterwards, current flows through the tenth resistor R10 and the eleventh resistor R11, generating a voltage drop across the eleventh resistor R11, turning on the sixth controllable current source G6, thereby lowering the source voltages of the seventh switch tube M7 and the eighth switch tube M8. Simultaneously, the internal control circuit starts operating and outputs a high-level control signal VS, turning on the power switch tube MP. Therefore, the power current to be measured IP flows through the power switch tube MP. Since the on-resistance of the power switch tube MP is RP, the gate voltage of the eighth switch tube M8 can be obtained as = Therefore, at this time, the seventh switch tube M7 and the eighth switch tube M8 are both turned on, the gate voltage of the ninth switch tube M9 is pulled down by the seventh switch tube M7 and the sixth controllable current source G6, the gate voltage of the tenth switch tube M10 is pulled down by the eighth switch tube M8 and the sixth controllable current source G6, the ninth switch tube M9 and the tenth switch tube M10 are turned on, at this time, current flows through the fourteenth resistor R14 and the fifteenth resistor R15, and a voltage drop is generated across the fifteenth resistor R15, so that the seventh controllable current source G7 and the eighth controllable current source G8 generate a seventh controllable current and an eighth controllable current, respectively. At the same time, the current coefficient of the seventh controllable current source G7 and the eighth controllable current source G8 is designed to be 1:1. At this time, combined with Figure 3 From the circuit structure, it can be seen that the current flowing through the ninth switch tube M9 = the seventh controllable current = the eighth controllable current.

[0068] When the power current IP to be measured is small, the gate voltage of the eighth switch tube M8 is smaller than the gate voltage of the seventh switch tube M7. Therefore, the gate-source voltage difference of the eighth switch tube M8 is smaller than the gate-source voltage difference of the seventh switch tube M7. The current flowing through the eighth switch tube M8 is smaller than the current flowing through the seventh switch tube M7. Since the resistance value of the twelfth resistor R12 is equal to the resistance value of the thirteenth resistor R13, the voltage difference across the thirteenth resistor R13 is smaller than the voltage difference across the twelfth resistor R12. Therefore, it can be obtained that the gate voltage of the ninth switch tube M9 is smaller than the gate voltage of the tenth switch tube M10. voltage, the gate-source voltage difference of the ninth switch tube M9 is greater than the gate-source voltage difference of the tenth switch tube M10. Therefore, the current flowing through the ninth switch tube M9 is greater than the current flowing through the tenth switch tube M10. That is, at this time, the eighth controllable current is greater than the current flowing through the tenth switch tube M10, and the current detection signal VO is pulled low. Therefore, after the high-level start signal VG and the low-level current detection signal VO are input into the internal control circuit, the internal control circuit outputs a high-low level switching control signal VS to control the conduction and shutdown of the power switch tube MP according to the control logic during normal operation of the circuit;

[0069] When the power current IP to be measured is large, the gate voltage of the eighth switch tube M8 is greater than the gate voltage of the seventh switch tube M7. Therefore, the gate-source voltage difference of the eighth switch tube M8 is greater than the gate-source voltage difference of the seventh switch tube M7. The current flowing through the eighth switch tube M8 is greater than the current flowing through the seventh switch tube M7. Since the resistance value of the twelfth resistor R12 is equal to the resistance value of the thirteenth resistor R13, the voltage difference across the thirteenth resistor R13 is greater than the voltage difference across the twelfth resistor R12. Therefore, it can be obtained that the gate voltage of the ninth switch tube M9 is greater than The gate voltage of the tenth switch tube M10 and the gate-source voltage difference of the ninth switch tube M9 are smaller than the gate-source voltage difference of the tenth switch tube M10. Therefore, the current flowing through the ninth switch tube M9 is smaller than the current flowing through the tenth switch tube M10. That is, at this time, the eighth controllable current is smaller than the current flowing through the tenth switch tube M10, and the current detection signal VO is pulled high. Therefore, after the high-level start signal VG and the high-level current detection signal VO are input into the internal control circuit, the internal control circuit outputs a low-level control signal VS, thereby turning off the power switch tube MP.

[0070] (2) When the start signal VG is at a low level, the gate voltages of the sub-switch tubes in the third switch tube are all at a low level, and the third switch tube is in the off state. At the same time, after the low-level start signal VG is input into the internal control circuit, the internal control circuit is in the off state. Therefore, at this time, the power switch tube MP is also in the off state.

[0071] Specifically, based on the above current detection circuit, when the power current IP to be measured is large, the voltage drop across the power switch MP is greater than When the high-level current detection signal VO is input into the internal control circuit, the internal control circuit outputs the low-level control signal VS, thereby turning off the power switch MP; when the power current to be measured IP is small, the voltage drop across the power switch MP is less than When the low-level current detection signal VO is input to the internal control circuit, the internal control circuit outputs a high-low level switching control signal VS to control the on and off of the power switch MP according to the control logic when the circuit is working normally.

[0072] Therefore, the threshold current of the power current IP to be measured is From the threshold current, it can be seen that by adjusting the parameters of the eighth resistor R8 and the ninth resistor R9, As large as possible, so as to reduce The size of the eighth resistor R8 and the ninth resistor R9 can be set as large as possible, thereby reducing the additional energy consumption caused by the current detection; at the same time, by selecting the appropriate parameters of the eighth resistor R8 and the ninth resistor R9, the threshold current The result is The value of is as large as possible to avoid the battery power supply circuit being shut down by mistake when the parameter fluctuates due to the parameter value being too small, thereby improving the stability of the battery power supply circuit.

[0073] In the present invention, by coordinating the structures of various parts of the starting circuit, the stability and reliability of the voltage detection of key nodes of the external power circuit are improved, so that the battery power supply circuit will not be mistakenly triggered to shut down, thereby ensuring the stability and reliability of the battery power supply circuit.

[0074] In the present invention, by adjusting the resistance values ​​of the first resistor R1, the second resistor R2 and the third resistor R3, the difference between the first threshold voltage and the second threshold voltage is adjusted, that is, the disturbance threshold of the battery power supply circuit is adjusted.

[0075] In the present invention, by adjusting the parameters of the eighth resistor R8 and the ninth resistor R9, As large as possible, so as to reduce The size of the current detection can reduce the additional energy consumption.

[0076] In the present invention, since the threshold current is related to At this time, the resistance values ​​of the eighth resistor R8 and the ninth resistor R9 are designed to meet the above ratio and are set as large as possible, thereby reducing the additional energy consumption caused by current detection.

[0077] In the present invention, the threshold current can be adjusted by selecting the eighth resistor R8 and the ninth resistor R9 with appropriate parameters. The result is The value of is as large as possible to avoid the battery power supply circuit being shut down by mistake when the parameter fluctuates due to the parameter value being too small, thereby improving the stability of the battery power supply circuit.

[0078] Although exemplary embodiments and their advantages have been described in detail, those skilled in the art may make various changes, substitutions, and modifications to these embodiments without departing from the spirit of the present invention and the scope of protection defined by the appended claims. Such modifications and variations fall within the scope defined by the appended claims. For other examples, those skilled in the art will readily appreciate that the order of the process steps may be varied while remaining within the scope of protection of the present invention.

[0079] Furthermore, the scope of application of the present invention is not limited to the processes, mechanisms, manufactures, compositions of matter, means, methods, and steps of the specific embodiments described in the specification. From the disclosure of the present invention, a person of ordinary skill in the art will readily understand that any currently existing or later developed processes, mechanisms, manufactures, compositions of matter, means, methods, or steps that perform substantially the same functions or achieve substantially the same results as the corresponding embodiments described herein may be applied in accordance with the present invention. Therefore, the claims appended hereto are intended to include within their scope such processes, mechanisms, manufactures, compositions of matter, means, methods, or steps.

Claims

1. A low energy consumption and high stability power supply circuit, characterized in that: include: External power circuit, startup circuit, current detection circuit, power switch tube and internal control circuit; The startup circuit outputs a high level or low level startup signal according to the voltage signal output by the external power circuit; The current detection circuit and the internal control circuit are in an operating state or a non-operating state according to the high level or low level start signal; The current detection circuit includes a parameter adjustment circuit and a current detection signal generation circuit. When the current detection circuit and the internal control circuit are in an operating state, if the voltage signal provided by the parameter adjustment circuit is greater than the voltage signal provided by the power switch tube, the current detection signal generation circuit outputs a low-level current detection signal. The internal control circuit outputs a first control signal based on the low-level current detection signal to control the normal operation of the power switch tube. Conversely, the internal control circuit outputs a second control signal based on the high-level current detection signal to control the power switch tube to shut down. The parameters of the circuit elements in the parameter adjustment circuit can be adjusted so that the parameter adjustment circuit can reduce the energy consumption of the current detection circuit while providing a larger voltage signal; The parameter adjustment circuit includes a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, a third controllable current source, a fourth controllable current source, a fifth controllable current source, a third switch tube, a fourth switch tube, a fifth switch tube, and a sixth switch tube; One end of the fourth resistor is connected to the positive control terminal and input terminal of the third controllable current source, one end of the sixth resistor, the positive control terminal and input terminal of the fourth controllable current source, the positive control terminal and input terminal of the fifth controllable current source, the first end of the fifth switch tube, and an external power supply. The other end of the fourth resistor is connected to the negative control terminal of the third controllable current source and one end of the fifth resistor. The other end of the fifth resistor is connected to the first end of the third switch tube, one end of the seventh resistor, the first end of the fourth switch tube, the first end of the sixth switch tube, one end of the ninth resistor, and grounded. The output end of the third controllable current source is connected to the second end of the third switch tube and the second end of the fourth switch tube. The third end of the third switch tube is connected to the third end of the startup circuit. The third end of the startup circuit is used to output a high-level or low-level startup signal. The other end of the sixth resistor is connected to the negative control terminal of the fourth controllable current source, the negative control terminal of the fifth controllable current source, and the other end of the seventh resistor. The output end of the fourth controllable current source is connected to the third end of the fourth switching tube. The output end of the fifth controllable current source is connected to the second end of the fifth switching tube and the second end of the sixth switching tube. The third end of the sixth switching tube is connected to one end of the eighth resistor and the other end of the ninth resistor. The other end of the eighth resistor is connected to the third end of the fifth switching tube and the third end of the current detection signal generating circuit. The third end of the current detection signal generating circuit is used to receive the voltage signal provided by the parameter adjustment circuit. The parameters of the circuit elements that can be adjusted in the parameter adjustment circuit are the resistance values ​​of the eighth resistor and the ninth resistor.

2. The low-energy-consumption and high-stability power supply circuit according to claim 1, characterized in that: When the external power circuit outputs a voltage signal greater than a first threshold voltage, the startup circuit outputs a high-level startup signal; when the external power circuit outputs a voltage signal less than a second threshold voltage, the startup circuit outputs a low-level startup signal; the first threshold voltage is greater than the second threshold voltage, and the difference between the first threshold voltage and the second threshold voltage is greater than a preset threshold.

3. The low-energy-consumption and high-stability power supply circuit according to claim 2, characterized in that: A first end of the startup circuit is connected to an external power supply, one end of the fourth resistor, and a first end of the current detection signal generating circuit; a second end of the startup circuit is connected to the other end of the fifth resistor, the second end of the current detection signal generating circuit, the first end of the power switch tube, and grounded; a third end of the startup circuit is also connected to the first end of the internal control circuit; and a fourth end of the startup circuit is connected to the first end of the external power circuit; The fourth end of the current detection signal generating circuit is connected to the second end of the power switch tube and the second end of the external power circuit, and the fifth end of the current detection signal generating circuit is connected to the second end of the internal control circuit; The third terminal of the internal control circuit is connected to the third terminal of the power switch tube.

4. The low-energy-consumption and high-stability power supply circuit according to claim 3, characterized in that: The startup circuit includes a first resistor, a second resistor, a third resistor, a first controllable current source, a second controllable current source, an inverter, a first switch tube, and a second switch tube; One end of the first resistor is connected to the positive control terminal and input terminal of the first controllable current source, the positive control terminal and input terminal of the second controllable current source, and the external power supply; the other end of the first resistor is connected to one end of the second resistor, the negative control terminal of the first controllable current source, and the negative control terminal of the second controllable current source; the other end of the second resistor is connected to one end of the third resistor and is grounded; the output end of the first controllable current source is connected to the first end of the first switching tube, the first end of the second switching tube, and the input end of the inverter; the second end of the first switching tube is connected to the first end of the external power circuit; the third end of the first switching tube is connected to the other end of the third resistor and the second end of the second switching tube; the output end of the second controllable current source is connected to the third end of the second switching tube; and the output end of the inverter is connected to the third end of the third switching tube and the first end of the internal control circuit.

5. The low-energy-consumption and high-stability power supply circuit according to claim 3, characterized in that: The current detection signal generating circuit includes a tenth resistor, an eleventh resistor, a twelfth resistor, a thirteenth resistor, a fourteenth resistor, a fifteenth resistor, a sixth controllable current source, a seventh controllable current source, an eighth controllable current source, a seventh switching tube, an eighth switching tube, a ninth switching tube, and a tenth switching tube; One end of the tenth resistor is connected to one end of the twelfth resistor, one end of the thirteenth resistor, one end of the fourteenth resistor, the first end of the ninth switching tube, the first end of the tenth switching tube, and the external power supply; the other end of the tenth resistor is connected to one end of the eleventh resistor and the positive control terminal of the sixth controllable current source; the other end of the eleventh resistor is connected to the negative control terminal and the output terminal of the sixth controllable current source, one end of the fifteenth resistor, the negative control terminal and the output terminal of the seventh controllable current source, the negative control terminal and the output terminal of the eighth controllable current source, and grounded; the other end of the twelfth resistor is connected to the first end of the seventh switching tube and the second end of the ninth switching tube; the second end of the seventh switching tube is connected to the other end of the eighth resistor; and the third end of the seventh switching tube is connected to the first end of the eighth switching tube and the input terminal of the sixth controllable current source; The other end of the thirteenth resistor is connected to the second end of the eighth switch tube and the second end of the tenth switch tube, the third end of the eighth switch tube is connected to the second end of the power switch tube and the second end of the external power circuit, the other end of the fourteenth resistor is connected to the other end of the fifteenth resistor, the positive control end of the seventh controllable current source and the positive control end of the eighth controllable current source, the third end of the ninth switch tube is connected to the input end of the seventh controllable current source, and the third end of the tenth switch tube is connected to the input end of the eighth controllable current source and the second end of the internal control circuit.

6. The low-energy-consumption and high-stability power supply circuit according to claim 1, characterized in that: The third switch tube includes a plurality of third sub-switch tubes.

7. The low-energy-consumption and high-stability power supply circuit according to claim 4, characterized in that: The first threshold voltage is expressed as: The second threshold voltage is expressed as: Wherein, VTH represents the turn-on voltage threshold of the first switch tube, K represents the ratio of the current coefficients of the first controllable current source and the second controllable current source, R3 represents the resistance value of the third resistor, , VCC represents the external power supply voltage, R1 represents the resistance value of the first resistor, and R2 represents the resistance value of the second resistor.

8. The low-energy-consumption and high-stability power supply circuit according to claim 6, characterized in that: The voltage signal provided by the parameter adjustment circuit is expressed as: Wherein, n represents the number of the third sub-switches, RG represents the on-resistance of the third sub-switches, IG represents the current of the third controllable current source, R8 represents the resistance of the eighth resistor, and R9 represents the resistance of the ninth resistor.

9. The low-energy-consumption and high-stability power supply circuit according to claim 8, characterized in that: The current of the third controllable current source is determined according to the external power supply voltage, the resistance value of the fourth resistor, the resistance value of the fifth resistor, and the current coefficient of the third controllable current source.

10. The low-energy-consumption and high-stability power supply circuit according to claim 8, characterized in that: The magnitude of the voltage signal provided by the power switch tube is related to the magnitude of the current flowing through the power switch tube. When the current flowing through the power switch tube is greater than the threshold current, the current detection circuit outputs a high-level current detection signal; when the current flowing through the power switch tube is less than the threshold current, the current detection circuit outputs a low-level current detection signal. The threshold current is determined by the following formula: Where, Indicates the on-resistance of the power switch tube.

Images