Power supply circuit with low energy consumption and high stability

Abstract

The invention relates to the technical field of power supply, in particular to a power supply circuit with low energy consumption and high stability. According to the low-energy-consumption and high-stability power supply circuit provided by the invention, the starting circuit is controlled by a voltage signal provided when the external power circuit works normally to output a high-level starting signal, so that the current detection circuit and the internal control circuit are started to work; when the current detection circuit works, voltage signals provided by the parameter adjustment circuit and the power switch tube control the current detection signal generation circuit to output a current detection signal, and the internal control circuit controls the working state of the power switch tube based on the current detection signal in the working state to realize power supply; parameters of circuit elements of the parameter adjusting circuit are adjusted, so that energy consumption of the current detection circuit is reduced while the parameter adjusting circuit provides a large voltage signal, the battery power supply circuit is prevented from being mistakenly triggered to be turned off, and stability and reliability of the battery power supply circuit are ensured.

Description

Technical Field

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

[0002] The battery power supply circuit in the prior art is as Figure 1 shown, which 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 transistor MP, an internal control circuit, a current detection resistor RS and a comparator A1.

[0003] The current detection resistor RS is used to detect the current flowing through the power switch transistor MP. When the voltage on the current detection resistor RS is less than the reference voltage VREF, the comparator A1 outputs a high level to the internal control circuit, and the internal control circuit controls the conduction and cutoff of the power switch transistor MP according to the control logic when the circuit is working normally; when the voltage on the current detection resistor RS is greater than the reference voltage VREF, the comparator A1 outputs a low level to the internal control circuit, and the internal control circuit controls the power switch transistor MP to cutoff.

[0004] Obviously, when the battery power supply circuit is working normally, there is always current flowing through the current detection resistor RS, thereby increasing the energy consumption of the battery power supply circuit. At this time, if the resistance value of the current detection resistor RS is reduced to reduce the additional energy consumption, the reference voltage VREF also needs to be reduced accordingly. The smaller the reference voltage VREF is, the higher the accuracy requirements for the reference voltage VREF and the current detection resistor RS are. Therefore, at this time, if there is a slight fluctuation in the reference voltage VREF or the terminal voltage of the current detection resistor RS, it will cause the power switch transistor MP to be mis-cutoff, making the battery power supply circuit in an unstable working 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 in the power supply circuit in the prior art.

[0006] The technical solution provided by the present invention is as follows: The first aspect of the present invention provides a power supply circuit with low energy consumption and high stability, including: 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 startup signal of high level or low level according to the voltage signal output by the external power circuit; the current detection circuit and the internal control circuit are in a working state or a non-working state according to the startup signal of high level or low level; 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 a working 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 current detection signal of low level, and the internal control circuit outputs a first control signal according to the current detection signal of low level to control the normal operation of the power switch tube. On the contrary, the internal control circuit outputs a second control signal according to the current detection signal of high level to control the power switch tube to turn off; the parameters of the circuit elements in the parameter adjustment circuit can be adjusted so that the parameter adjustment circuit can provide a larger voltage signal while reducing the energy consumption of the current detection circuit.

[0007] In an alternative embodiment, when the external power circuit outputs a voltage signal greater than the first threshold voltage, the startup circuit outputs a startup signal of high level; when the external power circuit outputs a voltage signal less than the second threshold voltage, the startup circuit outputs a startup signal of low level; 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.

[0008] In an alternative embodiment, the first end of the startup 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 generation circuit. The second end of the startup circuit is connected to the second end of the parameter adjustment circuit, the second end of the current detection signal generation circuit, the first end of the power switch tube, and grounded. The third end of the startup 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 startup 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 generation circuit; the fourth end of the current detection signal generation 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 generation 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.

[0009] In an alternative 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 switching transistor, and a second switching transistor; one end of the first resistor is connected to the positive control terminal and the input terminal of the first controllable current source, the positive control terminal and the input terminal 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 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 grounded, the output terminal of the first controllable current source is connected to the first end of the first switching transistor, the first end of the second switching transistor, and the input terminal of the inverter, the second end of the first switching transistor is connected to the first end of an external power circuit, the third end of the first switching transistor is connected to the other end of the third resistor and the second end of the second switching transistor, the output terminal of the second controllable current source is connected to the third end of the second switching transistor, and the output terminal of the inverter is connected to the third end of a parameter adjustment circuit and the first end of an internal control circuit.

[0010] In an alternative 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 switching transistor, a fourth switching transistor, a fifth switching transistor, and a sixth switching transistor; One end of the fourth resistor is connected to the positive control terminal and the input terminal of the third controllable current source, one end of the sixth resistor, the positive control terminal and the input terminal of the fourth controllable current source, the positive control terminal and the input terminal of the fifth controllable current source, the first end of the fifth switching transistor, 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 switching transistor, one end of the seventh resistor, the first end of the fourth switching transistor, the first end of the sixth switching transistor, one end of the ninth resistor and grounded, the output terminal of the third controllable current source is connected to the second end of the third switching transistor and the second end of the fourth switching transistor, and the third end of the third switching transistor is connected to the third end of the startup circuit; 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 terminal of the fourth controllable current source is connected to the third end of the fourth switching transistor, the output terminal of the fifth controllable current source is connected to the second end of the fifth switching transistor and the second end of the sixth switching transistor, the third end of the sixth switching transistor 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 switching transistor and the third end of a current detection signal generation circuit.

[0011] In an alternative embodiment, the current detection signal generation 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 transistor, an eighth switching transistor, a ninth switching transistor, and a tenth switching transistor; 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 transistor, the first end of the tenth switching transistor, and an 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 transistor. 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 is grounded. The other end of the twelfth resistor is connected to the first end of the seventh switching transistor and the second end of the ninth switching transistor. The second end of the seventh switching transistor is connected to the fourth terminal of the parameter adjustment circuit. The third end of the seventh switching transistor is connected to the first end of the eighth switching transistor 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 switching transistor and the second end of the tenth switching transistor. The third end of the eighth switching transistor is connected to the second end of the power switching transistor 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 terminal of the seventh controllable current source, and the positive control terminal of the eighth controllable current source. The third end of the ninth switching transistor is connected to the input terminal of the seventh controllable current source. The third end of the tenth switching transistor is connected to the input terminal of the eighth controllable current source and the second terminal of the internal control circuit.

[0012] In an alternative embodiment, the third switching transistor includes a plurality of third sub-switching transistors.

[0013] In an alternative embodiment, the first threshold voltage is expressed as:

[0014] The second threshold voltage is expressed as:

[0015] Wherein, VTH represents the turn-on voltage threshold of the first switching transistor, 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.

[0016] In an alternative embodiment, the voltage signal provided by the parameter adjustment circuit is expressed as:

[0017] Wherein, n represents the number of the third sub-switching tubes, RG represents the on-resistance of the third sub-switching tubes, IG represents the current of the third controllable current source, R8 represents the resistance value of the eighth resistor, and R9 represents the resistance value of the ninth resistor.

[0018] In an alternative embodiment, 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.

[0019] In an alternative embodiment, the magnitude of the voltage signal provided by the power switching tube is related to the magnitude of the current flowing through the power switching tube. When the current flowing through the power switching 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 switching tube is less than the threshold current, the current detection circuit outputs a low-level current detection signal, and the threshold current is determined by the following formula:

[0020] Wherein, represents the on-resistance of the power switching tube.

[0021] The technical solution of the present invention has the following advantages: The power supply circuit with low energy consumption and high stability provided by the present invention is controlled by the voltage signal provided by the external power circuit during normal operation to make the start-up circuit output a high-level start-up signal, so that the current detection circuit and the internal control circuit start to work; when the current detection circuit is working, the current detection signal generating circuit is controlled by the voltage signals provided by the parameter adjustment circuit and the power switching tube to output a current detection signal. When the internal control circuit is in the working state, it controls the working state of the power switching tube based on the current detection signal to realize power supply; wherein, by adjusting the parameters of the circuit elements of the parameter adjustment circuit, while the parameter adjustment circuit provides a larger voltage signal, the energy consumption of the current detection circuit is reduced, so that the battery power supply circuit will not be mis-triggered to turn off, ensuring the stable reliability of the battery power supply circuit.

[0022] In the present invention, by setting the difference between the first threshold voltage and the second threshold voltage to be greater than the preset threshold, when the voltage signal output by the external power circuit is disturbed, such as slightly lower than the first threshold voltage, the start-up circuit can still output a high-level start-up signal, thereby improving the stable reliability of the external power circuit, so that the battery power supply circuit will not be mis-triggered to turn off, ensuring the stable reliability of the battery power supply circuit. In addition, through the setting of the start-up 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, that is, the disturbance threshold of the battery power supply circuit can be adjusted.

[0023] In the present invention, by adjusting the parameters of the eighth resistor R8 and the ninth resistor R9, so that As large as possible, so as to reduce the size of , that is, the additional energy consumption caused by current detection can be reduced.

[0024] In the present invention, since the voltage signal provided by the parameter adjustment circuit is related to the proportional size of , at this time, on the basis that the resistance values of the eighth resistor R8 and the ninth resistor R9 are designed to meet the above proportional size, they are set as large as possible, so as to reduce the additional energy consumption caused by current detection.

[0025] In the present invention, by selecting the eighth resistor R8 and the ninth resistor R9 with appropriate parameters, the voltage signal provided by the parameter adjustment circuit can be made as large as possible, and the situation that the battery power supply circuit is accidentally turned off due to too small parameter values during parameter fluctuations will not occur, thereby improving the stability of the battery power supply circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0027] Figure 1 FIG. is a schematic structural diagram of a battery power supply circuit in the related art; Figure 2 FIG. is a structural block diagram of a power supply circuit with low energy consumption and high stability in an embodiment of the present invention; Figure 3 FIG. is a schematic structural diagram of a power supply circuit with low energy consumption and high stability in an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0028] The following will clearly and completely describe the technical solutions of the present invention with reference to the drawings. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the protection scope of the present invention.

[0029] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0030] In the description of the present invention, it should be noted that unless otherwise clearly specified and limited, the terms "mounted", "connected", "coupled" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, and can also be the internal communication of two components. It can be a wireless connection or a wired connection. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0031] In addition, the technical features involved in different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0032] An embodiment of the present invention provides a power supply circuit with low energy consumption and high stability, as Figure 2 shown. The circuit includes: an external power circuit 10, a startup circuit 20, a current detection circuit, a power switch tube 50, and an internal control circuit 60; the startup circuit 20 outputs a startup signal of high level or low level according to the voltage signal output by the external power circuit 10; the current detection circuit and the internal control circuit 60 are in a working state or a non-working state according to the startup signal of high level or low level; the current detection circuit includes a parameter adjustment circuit 30 and a detection current signal generation circuit 40. When the current detection circuit and the internal control circuit 60 are in a working state, if the voltage signal provided by the parameter adjustment circuit 30 is greater than the voltage signal provided by the power switch tube 50, the detection current signal generation circuit 40 outputs a detection current signal of low level, and the internal control circuit 60 outputs a first control signal according to the detection current signal of low level to control the normal operation of the power switch tube 50. On the contrary, the internal control circuit 60 outputs a second control signal according to the detection current signal of high level to control the power switch tube 50 to turn off; the parameters of the circuit elements in the parameter adjustment circuit 30 can be adjusted so that while the parameter adjustment circuit 30 provides a larger voltage signal, the energy consumption of the current detection circuit is reduced.

[0033] Among them, the first end of the startup 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 generation circuit 40. The second end of the startup circuit 20 is connected to the second end of the parameter adjustment circuit 30, the second end of the current detection signal generation circuit 40, the first end of the power switch tube 50 and grounded. The third end of the startup 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 startup 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 generation circuit 40. The fourth end of the current detection signal generation 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 generation 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.

[0034] Specifically, the voltage signal output by the external power circuit indicates the voltage of the key node of the external power circuit. Among them, the external power circuit receives the electric energy provided when the power switch tube is turned on, and further processes the electric energy such as voltage conversion and power distribution to meet the load requirements. For the external power circuit, a circuit capable of implementing the corresponding functions in related technologies can be used. For example, the external power circuit is a switching power supply circuit, etc. It should be noted that this is only an example of the external power circuit, and the actual external power circuit is not limited to this. When the structure of the external power circuit is different, the position of the specific key node is also different. However, the voltage of this key node can indicate whether the external power circuit is working properly. When the startup circuit receives that the voltage of the key node of the external power circuit rises above the first threshold voltage, the external power circuit works normally and outputs a high-level startup signal. When the startup circuit receives that the voltage of the key node of the external power circuit drops below the second threshold voltage, the external power circuit does not work properly (such as a fault occurs, etc.) and outputs a low-level startup signal.

[0035] When the start-up circuit outputs a high-level start signal, the high-level start signal controls the current detection circuit and the internal control circuit to be in the working state; when the start-up circuit outputs a low-level start signal, the low-level start signal controls the current detection circuit and the internal control circuit to be in the non-working state. When the current detection circuit is in the working state, the parameter adjustment circuit inside it provides a voltage signal for the current detection signal generation circuit. At the same time, when current flows through the power switch tube, the power switch tube can also provide a voltage signal for the current detection signal generation circuit; and the current detection signal generation circuit generates different current detection signals based on the magnitudes of the voltage signals provided by the parameter adjustment circuit and the power switch tube. That is, 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.

[0036] Among them, 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. Therefore, this current detection circuit actually realizes the detection of the magnitude of the current flowing through the power switch tube (the power current to be measured). That is, when the power current to be measured is large, the current detection circuit outputs a high-level current detection signal; when the power current to be measured is small, the current detection circuit outputs a low-level current detection signal.

[0037] For the internal control circuit, when it receives the high-level start signal output by the start-up circuit, it is in the working state; at this time, if the internal control circuit then receives the low-level current detection signal output by the current detection circuit, according to the normal working control logic, it outputs a first control signal with high and low level switching to control the conduction and cut-off of the power switch tube; if the internal control circuit then receives the high-level current detection signal output by the current detection circuit, it outputs a low-level second control signal to control the power switch tube to cut off. And when the start-up circuit outputs a low-level start signal, the internal control circuit is in the non-working state and no control signal is output.

[0038] In the current detection circuit, in order to reduce its power consumption and improve the working stability, the parameters of the circuit elements in the parameter adjustment circuit are adjusted. For example, when the circuit elements include resistors, the resistance value of the corresponding resistor can be increased while increasing the voltage signal output by the parameter adjustment circuit. This can not only reduce the energy consumption of the parameter adjustment circuit, but also, because the voltage signal provided by the parameter adjustment circuit is large, the current detection signal will not fluctuate when the parameters fluctuate, that is, it will not cause problems such as mis-cut-off of the power switch tube, improving the stability of the power supply circuit.

[0039] In an alternative embodiment, when the external power circuit outputs a voltage signal greater than the first threshold voltage, the startup circuit outputs a high-level startup signal; when the external power circuit outputs a voltage signal less than the 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 perturbation, the voltage signal output by the startup circuit will not fluctuate. That is, through this setting, the stability and reliability of the circuit are improved, and the circuit will not have a false trigger shutdown situation.

[0040] In an alternative embodiment, as Figure 3 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 switching transistor M1, and a second switching transistor M2; one end of the first resistor R1 is connected to the positive control terminal and the input terminal of the first controllable current source G1, the positive control terminal and the 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, the other end of the second resistor R2 is connected to one end of the third resistor R3 and grounded, the output terminal of the first controllable current source G1 is connected to the first end of the first switching transistor M1, the first end of the second switching transistor M2, and the input terminal of the inverter U1, the second end of the first switching transistor M1 is connected to the first end of the external power circuit, the third end of the first switching transistor M1 is connected to the other end of the third resistor R3 and the second end of the second switching transistor M2, the output terminal of the second controllable current source G2 is connected to the third end of the second switching transistor M2, and the output terminal of the inverter U1 is connected to the third end of the parameter adjustment circuit and the first end of the internal control circuit.

[0041] Specifically, based on this startup circuit, when the circuit is powered on, a first current I1 (the first current flows through the first resistor R1, a voltage drop is generated across the first resistor R1, 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 switching transistor M2, and the source of the second switching transistor M2 is grounded through the third resistor R3. Therefore, the second switching transistor M2 is turned on, and a second controllable current is generated in the second controllable current source G2. At this time, since the current coefficients of the first controllable current source G1 and the second controllable current source G2 are designed as K:1, if the second controllable current is I1, and when the first controllable current is generated in the first controllable current source G1, the first controllable current is , so if the first switching transistor M1 is turned on, the terminal voltage of the third resistor R3, that is, the source voltage of the first switching transistor M1 is , 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 be greater than , the first switching transistor M1 is turned on. is the turn-on voltage threshold of the first switching transistor M1; after the first switching transistor M1 is turned on, it pulls down the gate voltage of the second switching transistor M2, and the second switching transistor M2 is turned off. At this time, the input terminal of the inverter U1 is at a low level, and the inverter U1 outputs a high-level start signal VG. And at this time, the terminal voltage of the third resistor R3, that is, the source voltage of the first switching transistor M1, decreases to , so when the voltage of the key node of the external power circuit drops to be less than , the first switching transistor M1 is turned off, the input voltage of the inverter U1 is pulled up, and the inverter U1 outputs a low-level start signal VG.

[0042] According to the above analysis, when the voltage of the key node of the external power circuit rises to be greater than the first threshold voltage, that is, , the external power circuit works normally. Therefore, at this time, the start circuit outputs a high-level start signal VG, so that the current detection circuit and the internal control circuit start to work; after that, if the external power circuit fails, causing the voltage of the key node of the external power circuit to drop to be less than the second threshold voltage, that is, , the external power circuit cannot work normally. Therefore, at this time, the start circuit outputs a low-level start signal VG, 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 (for example, due to reasons such as unbalanced charging of battery loads, it may cause the battery load to feedback voltage and current to the external power circuit, thereby causing the voltage of the key node of the external power circuit to be disturbed), slightly lower than the first threshold voltage, the start circuit still outputs a high-level start signal VG, thereby improving the stability and reliability of the detection of the key node voltage of the external power circuit, so that the battery power supply circuit will not be mis-triggered to turn off, ensuring the stability and reliability of the battery power supply circuit; at this time, 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 can be adjusted, 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.

[0043] In an alternative 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 switching transistor M3, a fourth switching transistor M4, a fifth switching transistor M5, and a sixth switching transistor M6; wherein, the third switching transistor M3 includes a plurality of third sub-switching transistors.

[0044] One end of the fourth resistor R4 is connected to the positive control terminal and the input terminal of the third controllable current source G3, one end of the sixth resistor R6, the positive control terminal and the input terminal of the fourth controllable current source G4, the positive control terminal and the input terminal of the fifth controllable current source G5, the first terminal of the fifth switching transistor 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 switching transistor M3, one end of the seventh resistor R7, the first terminal of the fourth switching transistor M4, the first terminal of the sixth switching transistor M6, one end of the ninth resistor R9, and grounded. The output terminal of the third controllable current source G3 is connected to the second terminal of the third switching transistor M3 and the second terminal of the fourth switching transistor M4. The third terminal of the third switching transistor M3 is connected to the third terminal of the startup circuit; The other end of the sixth resistor R6 is connected to the negative control terminals of the fourth controllable current source G4 and the fifth controllable current source G5 and the other end of the seventh resistor R7. The output terminal of the fourth controllable current source G4 is connected to the third terminal of the fourth switching transistor M4. The output terminal of the fifth controllable current source G5 is connected to the second terminal of the fifth switching transistor M5 and the second terminal of the sixth switching transistor M6. The third terminal of the sixth switching transistor 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 terminal of the fifth switching transistor M5 and the third terminal of the current detection signal generation circuit.

[0045] In an alternative embodiment, the current detection signal generation 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 switching transistor M7, an eighth switching transistor M8, a ninth switching transistor M9, and a tenth switching transistor M10; 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, the first terminal of the ninth switching transistor M9, the first terminal of the tenth switching transistor 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 terminal of the sixth switching transistor M6. The other end of the eleventh resistor R11 is connected to the negative control terminal and the output terminal of the sixth controllable current source G6, one end of the fifteenth resistor R15, the negative control terminal and the output terminal of the seventh controllable current source G7, the negative control terminal and the output terminal of the eighth controllable current source G8, and grounded. The other end of the twelfth resistor R12 is connected to the first terminal of the seventh switching transistor M7 and the second terminal of the ninth switching transistor M9. The second terminal of the seventh switching transistor M7 is connected to the fourth terminal of the parameter adjustment circuit. The third terminal of the seventh switching transistor M7 is connected to the first terminal of the eighth switching transistor M8 and the input terminal of the sixth controllable current source G6; The other end of the thirteenth resistor R13 is connected to the second end of the eighth switching transistor M8 and the second end of the tenth switching transistor M10. The third end of the eighth switching transistor M8 is connected to the second end of the power switching transistor 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 terminal of the seventh controllable current source G7, and the positive control terminal of the eighth controllable current source G8. The third end of the ninth switching transistor M9 is connected to the input terminal of the seventh controllable current source G7. The third end of the tenth switching transistor M10 is connected to the input terminal of the eighth controllable current source G8 and the second end of the internal control circuit.

[0046] Specifically, based on the structure of the above current detection circuit, when the start circuit outputs start signals of different levels, the current detection circuit is in a working state or a non-working state.

[0047] (1) When the start signal VG is at a high level, and after this high-level start signal VG is input to each sub-switching transistor of the third switching transistor M3 and the internal control circuit, each sub-switching transistor of the third switching transistor M3 is turned on, and the internal control circuit starts to work, outputting a high-level control signal VS, and the power switching transistor MP is turned on; At this time, current flows through the fourth resistor R4 and the fifth resistor R5, a voltage drop is generated across the fourth resistor R4, so that a third controllable current flows through the third controllable current source G3. And 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, denoted as IG in the following text; at the same time, according to the chip manufacturing process, the on-resistances of each sub-switching transistor of the third switching transistor M3 and the power switching transistor MP can be obtained, denoted as RG and RP respectively. Therefore, at this time, the on-resistance of the third switching transistor M3 is , where n is the number of sub-switching transistors of the third switching transistor M3; From the above analysis, the gate voltage of the fourth switching transistor M4 is , that is, the gate voltage of the fourth switching transistor M4 is pulled high, and the fourth switching transistor M4 conducts; 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, causing both the fourth controllable current source G4 and the fifth controllable current source G5 to conduct. At this time, since the fourth switching transistor M4 conducts, a 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 switching transistor M4 are connected in series, the current flowing through the fourth switching transistor M4 is equal to the fourth controllable current. And after the fifth controllable current source G5 conducts, it pulls up the gate voltage of the fifth switching transistor M5, and the fifth switching transistor M5 conducts. 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 switching transistor M6 also increases, and the sixth switching transistor M6 conducts. At this time, a fifth controllable current flows through the fifth controllable current source G5. At the same time, the current coefficients of the fourth controllable current source G4 and the fifth controllable current source G5 are designed to be 1:1, so it can be obtained that the fourth controllable current = the fifth controllable current; As the current flowing through the ninth resistor R9 gradually increases, the gate voltage of the sixth switching transistor M6 gradually increases, the gate-source voltage difference of the sixth switching transistor M6 gradually increases, and the current flowing through the sixth switching transistor M6 gradually increases. When the current flowing through the sixth switching transistor M6 is greater than the fifth controllable current, the gate voltage of the fifth switching transistor M5 is pulled low, the fifth switching transistor M5 is turned off, the gate voltage of the sixth switching transistor M6 is pulled low through the ninth resistor R9, the sixth switching transistor M6 is turned off, and the gate voltage of the fifth switching transistor M5 is pulled high again through the fifth controllable current source G5, the fifth switching transistor M5 conducts, and the circuit enters the next cycle; Therefore, when the circuit enters a steady state, the current flowing through the sixth switching transistor M6 = the fifth controllable current = the fourth controllable current = the current flowing through the fourth switching transistor M4. At this time, the gate-source voltage difference of the fourth switching transistor M4 is equal to the gate-source voltage difference of the sixth switching transistor M6. Since the source of the fourth switching transistor M4 is connected to the source of the sixth switching transistor M6, the gate voltage of the sixth switching transistor M6 = the gate voltage of the fourth switching transistor M4 = , so at this time, the current flowing through the eighth resistor R8 and the ninth resistor R9 = , from which the gate voltage of the seventh switching transistor M7 can be obtained = ; After that, current flows through the tenth resistor R10 and the eleventh resistor R11, and a voltage drop is generated across the eleventh resistor R11, causing the sixth controllable current source G6 to conduct, thereby pulling down the source voltages of the seventh switching transistor M7 and the eighth switching transistor M8; at the same time, since the internal control circuit starts to work and outputs a high-level control signal VS, the power switching transistor MP conducts. Therefore, the measured power current IP flows through the power switching transistor MP. And since the on-resistance of the power switching transistor MP is RP, the gate voltage of the eighth switching transistor M8 can be obtained = , so at this time, both the seventh switch tube M7 and the eighth switch tube M8 are turned on. The gate voltage of the ninth switch tube M9 is pulled down through the seventh switch tube M7 and the sixth controllable current source G6, and the gate voltage of the tenth switch tube M10 is pulled down through 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, currents flow through the fourteenth resistor R14 and the fifteenth resistor R15, and a voltage drop is generated across the two ends of the fifteenth resistor R15, causing a seventh controllable current and an eighth controllable current to be generated in the seventh controllable current source G7 and the eighth controllable current source G8 respectively. At the same time, the current coefficients of the seventh controllable current source G7 and the eighth controllable current source G8 are designed to be 1:1. At this time, combined with Figure 3 the circuit structure, it can be known that the current flowing through the ninth switch tube M9 = the seventh controllable current = the eighth controllable current.

[0048] When the power current IP to be measured is small, the gate voltage of the eighth switch tube M8 is less than the gate voltage of the seventh switch tube M7. Therefore, the gate-source voltage difference of the eighth switch tube M8 is less than the gate-source voltage difference of the seventh switch tube M7, and the current flowing through the eighth switch tube M8 is less 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 two ends of the thirteenth resistor R13 is less than the voltage difference across the two ends of the twelfth resistor R12. Therefore, it can be obtained that the gate voltage of the ninth switch tube M9 is less than the gate voltage of the tenth switch tube M10, and 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 detection current signal VO is pulled down. Therefore, after the high-level start signal VG and the low-level detection current signal VO are input into the internal control circuit, the internal control circuit outputs a control signal VS with a high-low level switching according to the control logic during normal circuit operation to control the conduction and cutoff of the power switch tube MP; When the power current IP to be measured is relatively large, the gate voltage of the eighth switching transistor M8 is greater than the gate voltage of the seventh switching transistor M7. Therefore, the gate-source voltage difference of the eighth switching transistor M8 is greater than the gate-source voltage difference of the seventh switching transistor M7, and the current flowing through the eighth switching transistor M8 is greater than the current flowing through the seventh switching transistor 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. Thus, it can be obtained that the gate voltage of the ninth switching transistor M9 is greater than the gate voltage of the tenth switching transistor M10, and the gate-source voltage difference of the ninth switching transistor M9 is less than the gate-source voltage difference of the tenth switching transistor M10. Therefore, the current flowing through the ninth switching transistor M9 is less than the current flowing through the tenth switching transistor M10, that is, at this time, the eighth controllable current is less than the current flowing through the tenth switching transistor 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 switching transistor MP.

[0049] (2) When the start signal VG is at a low level, the gate voltages of all the sub-switching transistors in the third switching transistor are at a low level, and the third switching transistor is in an 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 an off state. Therefore, at this time, the power switching transistor MP is also in an off state.

[0050] Specifically, based on the above current detection circuit, when the power current IP to be measured is relatively large, such that the voltage drop across the power switching transistor MP is greater than when the high-level current detection signal VO is input into the internal control circuit, and the internal control circuit outputs a low-level control signal VS to turn off the power switching transistor MP; when the power current IP to be measured is relatively small, such that the voltage drop across the power switching transistor MP is less than when the low-level current detection signal VO is input into the internal control circuit, and the internal control circuit outputs a control signal VS with a high-low level switching according to the control logic during normal circuit operation to control the conduction and off of the power switching transistor MP.

[0051] Therefore, the threshold current of the power current IP to be measured ; from this threshold current, it can be seen that by adjusting the parameters of the eighth resistor R8 and the ninth resistor R9, making as large as possible, thereby reducing that is, reducing the additional energy consumption brought by current detection; and the resistance values of the eighth resistor R8 and the ninth resistor R9 can be set as large as possible to reduce the additional energy consumption brought by current detection; at the same time, by selecting appropriate parameters for the eighth resistor R8 and the ninth resistor R9, the result of the threshold current that is, The value is as large as possible, so that there will be no situation where the battery power supply circuit is accidentally turned off due to too small parameter values when the parameters fluctuate, thereby improving the stability of the battery power supply circuit.

[0052] In the present invention, through the cooperation of the structures of each part of the starting circuit, the stability and reliability of the voltage detection at the key node of the external power circuit are improved, so that the battery power supply circuit will not be accidentally triggered to turn off, ensuring the stability and reliability of the battery power supply circuit.

[0053] In the present invention, by adjusting the resistance values of the first resistor R1, the second resistor R2, and the third resistor R3, the adjustment of the difference between the first threshold voltage and the second threshold voltage is realized, that is, the adjustment of the disturbance threshold of the battery power supply circuit is realized.

[0054] In the present invention, by adjusting the parameters of the eighth resistor R8 and the ninth resistor R9, it is made that as large as possible, so as to reduce the magnitude of, that is, the additional energy consumption caused by current detection can be reduced.

[0055] In the present invention, since the threshold current is related to the proportional magnitude of, at this time, on the basis that the resistance values of the eighth resistor R8 and the ninth resistor R9 are designed to meet the above proportional magnitude, they are set as large as possible, thereby reducing the additional energy consumption caused by current detection.

[0056] In the present invention, by selecting the eighth resistor R8 and the ninth resistor R9 with appropriate parameters, the threshold current is obtained, that is The value is as large as possible, so that there will be no situation where the battery power supply circuit is accidentally turned off due to too small parameter values when the parameters fluctuate, thereby improving the stability of the battery power supply circuit.

[0057] Although the exemplary embodiments and their advantages have been described in detail, those skilled in the art can make various changes, substitutions, and modifications to these embodiments without departing from the spirit of the present invention and the protection scope defined by the appended claims. Such modifications and variations all fall within the scope defined by the appended claims. For other examples, those of ordinary skill in the art should easily understand that the order of the process steps can be changed while maintaining the protection scope of the present invention.

[0058] In addition, the scope of application of the present invention is not limited to the processes, mechanisms, manufacturing, compositions of matter, means, methods and steps of the specific embodiments described in the specification. From the disclosure of the present invention, those of ordinary skill in the art will readily understand that for processes, mechanisms, manufacturing, compositions of matter, means, methods or steps that already exist or will be developed in the future, and which perform substantially the same functions or achieve substantially the same results as the corresponding embodiments described in the present invention, they can be applied in accordance with the present invention. Therefore, the appended claims of the present invention are intended to include such processes, mechanisms, manufacturing, compositions of matter, means, methods or steps within their scope of protection.

Claims

1. A power supply circuit with low energy consumption and high stability, characterized in that, Including: An external power circuit, a startup circuit, a current detection circuit, a power switch transistor, and an internal control circuit; The startup circuit outputs a startup signal of high level or low level according to the voltage signal output by the external power circuit; The current detection circuit and the internal control circuit are in a working state or a non-working state according to the startup signal of high level or low level; The current detection circuit includes a parameter adjustment circuit and a detection current signal generation circuit. When the current detection circuit and the internal control circuit are in a working state, if the voltage signal provided by the parameter adjustment circuit is greater than the voltage signal provided by the power switch transistor, the detection current signal generation circuit outputs a detection current signal of low level, and the internal control circuit outputs a first control signal according to the detection current signal of low level to control the normal operation of the power switch transistor. On the contrary, the internal control circuit outputs a second control signal according to the detection current signal of high level to control the power switch transistor to turn off; The parameters of the circuit elements in the parameter adjustment circuit can be adjusted so that while the parameter adjustment circuit provides a larger voltage signal, the power consumption of the current detection circuit is reduced.

2. The power supply circuit with low energy consumption and high stability according to claim 1, characterized in that When the external power circuit outputs a voltage signal greater than the first threshold voltage, the startup circuit outputs a startup signal of high level; when the external power circuit outputs a voltage signal less than the second threshold voltage, the startup circuit outputs a startup signal of low level; 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-power high-stability power supply circuit according to claim 2, characterized in that: The first end of the startup circuit is connected to the external power supply, the first end of the parameter adjustment circuit, and the first end of the detection current signal generation circuit. The second end of the startup circuit is connected to the second end of the parameter adjustment circuit, the second end of the detection current signal generation circuit, the first end of the power switch transistor and grounded. The third end of the startup 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 startup 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 detection current signal generation circuit; The fourth end of the detection current signal generation circuit is connected to the second end of the power switch transistor and the second end of the external power circuit. The fifth end of the detection current signal generation 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 transistor.

4. The power supply circuit with low energy consumption and high stability 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 transistor, and a second switch transistor; One end of the first resistor is connected to the positive control terminal and the input terminal of the first controllable current source, the positive control terminal and the input terminal 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 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 grounded. The output terminal of the first controllable current source is connected to the first terminal of the first switching transistor, the first terminal of the second switching transistor, and the input terminal of the inverter. The second terminal of the first switching transistor is connected to the first terminal of the external power circuit. The third terminal of the first switching transistor is connected to the other end of the third resistor and the second terminal of the second switching transistor. The output terminal of the second controllable current source is connected to the third terminal of the second switching transistor. The output terminal of the inverter is connected to the third terminal of the parameter adjustment circuit and the first terminal of the internal control circuit.

5. The power supply circuit with low energy consumption and high stability according to claim 3, characterized in that, 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 switching transistor, a fourth switching transistor, a fifth switching transistor, and a sixth switching transistor; One end of the fourth resistor is connected to the positive control terminal and the input terminal of the third controllable current source, one end of the sixth resistor, the positive control terminal and the input terminal of the fourth controllable current source, the positive control terminal and the input terminal of the fifth controllable current source, the first terminal of the fifth switching transistor, 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 terminal of the third switching transistor, one end of the seventh resistor, the first terminal of the fourth switching transistor, the first terminal of the sixth switching transistor, one end of the ninth resistor and grounded. The output terminal of the third controllable current source is connected to the second terminal of the third switching transistor and the second terminal of the fourth switching transistor. The third terminal of the third switching transistor is connected to the third terminal of the startup circuit; 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 terminal of the fourth controllable current source is connected to the third terminal of the fourth switching transistor. The output terminal of the fifth controllable current source is connected to the second terminal of the fifth switching transistor and the second terminal of the sixth switching transistor. The third terminal of the sixth switching transistor 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 terminal of the fifth switching transistor and the third terminal of the current detection signal generation circuit.

6. The power supply circuit with low energy consumption and high stability according to claim 3, characterized in that, The current detection signal generation 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 transistor, an eighth switching transistor, a ninth switching transistor, and a tenth switching transistor; 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 transistor, the first end of the tenth switching transistor, and an 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 transistor. 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 is grounded. The other end of the twelfth resistor is connected to the first end of the seventh switching transistor and the second end of the ninth switching transistor. The second end of the seventh switching transistor is connected to the fourth terminal of the parameter adjustment circuit. The third end of the seventh switching transistor is connected to the first end of the eighth switching transistor 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 switching transistor and the second end of the tenth switching transistor. The third end of the eighth switching transistor is connected to the second end of the power switching transistor 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 terminal of the seventh controllable current source, and the positive control terminal of the eighth controllable current source. The third end of the ninth switching transistor is connected to the input terminal of the seventh controllable current source. The third end of the tenth switching transistor is connected to the input terminal of the eighth controllable current source and the second terminal of the internal control circuit.

7. The power supply circuit with low energy consumption and high stability according to claim 5, characterized in that, The third switching transistor includes a plurality of third sub-switching transistors.

8. The power supply circuit with low energy consumption and high stability 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 switching transistor, K represents the ratio of the current coefficients of the first controllable current source and the second controllable current source, and 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.

9. The power supply circuit with low energy consumption and high stability according to claim 7, characterized in that, The voltage signal provided by the parameter adjustment circuit is expressed as: Wherein, n represents the number of the third sub-switching transistors, RG represents the on-resistance of the third sub-switching transistors, IG represents the current of the third controllable current source, R8 represents the resistance value of the eighth resistor, and R9 represents the resistance value of the ninth resistor.

10. The power supply circuit with low energy consumption and high stability according to claim 9, 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.

11. The power supply circuit with low energy consumption and high stability according to claim 9, characterized in that The magnitude of the voltage signal provided by the power switching transistor is related to the magnitude of the current flowing through the power switching transistor. When the current flowing through the power switching transistor is greater than the threshold current, the current detection circuit outputs a high-level current detection signal; when the current flowing through the power switching transistor 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: In the formula, represents the on-resistance of the power switch transistor.

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