Boost circuit with overcurrent protection, overcurrent protection method, and voltage booster

Abstract

The application relates to a BOOST circuit with overcurrent protection, an overcurrent protection method and a booster. The BOOST circuit comprises a switching circuit, a differential amplification circuit, a same-phase input end of the differential amplification circuit used for acquiring a reference voltage signal, an opposite-phase input end of the differential amplification circuit used for acquiring a feedback signal, the feedback signal being obtained based on an output voltage signal of the BOOST circuit, a first output end of the differential amplification circuit used for outputting a working mode signal, the working mode signal representing a current load state of the BOOST circuit, and an overcurrent protection circuit used for outputting a first enabling signal according to an inductance voltage signal flowing into the switching circuit and the working mode signal in the case that the switching circuit is in action; and the first enabling signal is used for enabling the differential amplification circuit. The application can reduce the overall power consumption of the BOOST circuit and effectively improve the working efficiency of the BOOST circuit.

Description

Technical Field

[0001] The present application relates to the field of electronic technology, and in particular to a BOOST circuit with overcurrent protection, an overcurrent protection method, and a booster. Background Art

[0002] Boost circuits are used in scenarios such as electric vehicle charging systems, uninterruptible power supplies, and solar power generation systems. Their primary function is to convert an input voltage signal into a higher output voltage signal, essentially boosting the input signal. When a boost circuit is operating, high currents can flow, potentially damaging the circuit. Therefore, overcurrent protection is often required.

[0003] However, the traditional overcurrent protection circuit needs to always monitor the working status of the BOOST circuit. This protection method will increase the overall power consumption of the circuit system and also affect the working efficiency of the BOOST circuit. Summary of the Invention

[0004] Based on this, it is necessary to provide a BOOST circuit, an overcurrent protection method and a booster with overcurrent protection that can achieve overcurrent protection with low power consumption in order to address the above technical problems.

[0005] In a first aspect, in one embodiment, the present application provides a BOOST circuit with overcurrent protection, comprising:

[0006] Switching circuit;

[0007] A differential amplifier circuit, wherein the non-inverting input terminal of the differential amplifier circuit is used to obtain a reference voltage signal, and the inverting input terminal of the differential amplifier circuit is used to obtain a feedback signal, the feedback signal being obtained based on the output voltage signal of the BOOST circuit; the first output terminal of the differential amplifier circuit is used to output an operating mode signal, the operating mode signal representing the current load state of the BOOST circuit; and

[0008] The overcurrent protection circuit is used to output a first enable signal based on the detected inductor voltage signal flowing into the switching circuit and the working mode signal when the switching circuit is in operation; the first enable signal is used to enable the differential amplifier circuit.

[0009] In one embodiment, the BOOST circuit further includes:

[0010] a first comparator, wherein a non-inverting input terminal of the first comparator is connected to one end of the switch circuit, and an inverting input terminal of the first comparator is connected to the second output terminal of the differential amplifier circuit;

[0011] a control logic circuit, wherein a first input terminal of the control logic circuit is connected to the output terminal of the first comparator, a second input terminal of the control logic circuit is used to be connected to the oscillator, and an output terminal of the control logic circuit is connected to the control terminal of the switch circuit;

[0012] The output end of the control logic circuit is used to output a first switching signal to determine the action of the switching circuit; the first enable signal is also used to enable the first comparator and the control logic circuit.

[0013] In one embodiment, the oscillator is used to output a periodic oscillation signal to the control logic circuit; the output terminal of the first comparator is used to output a mode selection signal; the first enable signal is also used to enable the oscillator;

[0014] If the oscillation signal input to the control logic circuit is a rising edge signal, the first switch signal output by the control logic circuit controls the switch circuit to be turned on;

[0015] If the mode selection signal input to the control logic circuit is a rising edge signal, the first switch signal output by the control logic circuit controls the switch circuit to be turned off.

[0016] In one embodiment, the BOOST circuit further includes:

[0017] An inductor unit, one end of which is used to obtain the input voltage signal of the BOOST circuit, and the other end of which is connected to the other end of the switch circuit;

[0018] a diode unit, wherein the anode of the diode unit is connected between the other end of the inductor unit and the other end of the switch circuit;

[0019] The capacitor unit has one end connected to the cathode of the diode unit and the other end connected to the ground.

[0020] In one embodiment, the switching circuit includes:

[0021] a first switching tube, one end of the first switching tube being connected between the other end of the inductor unit and the anode of the diode unit, and a control end of the first switching tube being connected to the output end of the control logic circuit to obtain a first switching signal;

[0022] a second switch tube, one end of the second switch tube being connected between one end of the first switch tube and the anode of the diode unit, and a control end of the second switch tube being connected to an output end of the control logic circuit to obtain a first switching signal;

[0023] A second comparator, wherein the non-inverting input terminal of the second comparator is connected to the other end of the first switch tube, the inverting input terminal of the second comparator is connected to the other end of the second switch, and the output terminal of the second comparator is connected to the non-inverting input terminal of the first comparator;

[0024] a first resistor, one end of the first resistor being connected between the non-inverting input terminal of the second comparator and the other end of the first switch tube, the other end of the first resistor being connected between the inverting input terminal of the second comparator and the other end of the second switch tube, and the other end of the first resistor being grounded;

[0025] a second resistor, one end of the second resistor being connected between the non-inverting input terminal of the first comparator and the output terminal of the second comparator, and the other end of the second resistor being grounded;

[0026] The first enable signal is also used to enable the second comparator.

[0027] In one embodiment, the size of the first switching tube and the size of the second switching tube are in a preset proportional relationship.

[0028] In one embodiment, the BOOST circuit further includes:

[0029] a first voltage-dividing resistor, one end of the first voltage-dividing resistor being used to obtain an output voltage signal, and the other end of the first voltage-dividing resistor being connected to an inverting input end of the differential amplifier circuit;

[0030] a second voltage-dividing resistor, one end of the second voltage-dividing resistor being connected between the other end of the first voltage-dividing resistor and the inverting input end of the differential amplifier circuit, and the other end of the second voltage-dividing resistor being grounded;

[0031] The feedback signal is a voltage signal obtained by dividing the output voltage signal by the first voltage-dividing resistor and the second voltage-dividing resistor.

[0032] In one embodiment, the overcurrent protection circuit includes:

[0033] a third comparator, wherein a non-inverting input terminal of the third comparator is used to connect to a constant current source, and an enable terminal of the third comparator is used to obtain a second enable signal;

[0034] a third switching tube, one end of the third switching tube being connected to the inverting input end of the third comparator, the other end of the third switching tube being grounded, and a control end of the third switching tube being used to obtain a second switching signal, where the second switching signal is an inverted signal of the first switching signal;

[0035] a fourth switching tube, wherein one end of the fourth switching tube is used to obtain the inductor voltage signal, the other end of the fourth switching tube is connected between one end of the third switching tube and the inverting input end of the third comparator, and the control end of the fourth switching tube is used to obtain a third switching signal, where the third switching signal is an inverted signal of the second switching signal;

[0036] a fifth switching tube, wherein one end of the fifth switching tube is connected between the constant current source and the non-inverting input end of the third comparator, the other end of the fifth switching tube is grounded, and the control end of the fifth switching tube is used to obtain the second enable signal;

[0037] The second enable signal is obtained based on the working mode signal and the third switch signal.

[0038] In one embodiment, the overcurrent protection circuit further includes:

[0039] A first NOT gate circuit, wherein an input end of the first NOT gate circuit is used to obtain an operating mode signal;

[0040] a first AND gate circuit, wherein a first input end of the first AND gate circuit is connected to an output end of the first NOT gate circuit, and a second input end of the first AND gate circuit is used to obtain a third switch signal;

[0041] The output terminal of the first AND gate circuit outputs a second enable signal.

[0042] In one embodiment, the third input terminal of the first AND gate circuit is used to obtain a system enable signal;

[0043] Among them, the system enable signal is used to enable the BOOST circuit.

[0044] In one embodiment, the overcurrent protection circuit further includes:

[0045] a second AND gate circuit, wherein a first input terminal of the second AND gate circuit is used to obtain a system enable signal, and a second input terminal of the second AND gate circuit is connected to an output terminal of the third comparator;

[0046] The output terminal of the second AND gate circuit is used to output the first enable signal.

[0047] In one embodiment, when the differential amplified signal of the differential amplifier circuit is greater than or equal to a preset voltage threshold, the operating mode signal output by the differential amplifier circuit is a low-level signal; the differential amplified signal is obtained based on the feedback signal and the reference voltage signal;

[0048] When the differential amplified signal is less than the preset voltage threshold, the working mode signal output by the differential amplification circuit is a periodic square wave signal.

[0049] In a second aspect, in one embodiment, the present application provides an overcurrent protection method, which is applied to the BOOST circuit for overcurrent protection as described in any one of the above embodiments; the method comprises:

[0050] If the BOOST circuit is determined to be in a heavy-load state based on the output voltage signal, the overcurrent protection circuit is turned on during the charging phase and turned off during the freewheeling phase;

[0051] If the BOOST circuit is determined to be in a light-load state based on the output voltage signal, the operating state of the overcurrent protection circuit changes with the periodic operating mode signal: when the periodic operating mode signal is low, the overcurrent protection circuit is turned on during the charging phase and turned off during the freewheeling phase; when the periodic operating mode signal is high, the overcurrent protection circuit is turned off.

[0052] In a third aspect, in one embodiment, the present application provides a booster, comprising a BOOST circuit with overcurrent protection as described in any one of the above embodiments.

[0053] The above-mentioned BOOST circuit, overcurrent protection method, and booster with overcurrent protection realize the charging and discharging of the inductor of the BOOST circuit by controlling the conduction and cutoff of the switching circuit. It also uses a differential amplifier circuit to determine the current load state of the BOOST circuit based on the output voltage signal, and then determines the operating state of the overcurrent protection circuit based on the load state and operating stage of the BOOST circuit. Through the above-mentioned method, the present application can realize that the overcurrent protection circuit enters different operating states according to the different load states and operating stages of the BOOST circuit, thereby eliminating the need to always maintain the overcurrent protection function enabled during the operation of the BOOST circuit, reducing the overall power consumption of the BOOST circuit and effectively improving the operating efficiency of the BOOST circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the following briefly introduces the drawings required for use in the embodiments of the present application or related technical descriptions. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying any creative work.

[0055] Figure 1 A schematic diagram of the basic circuit structure of a BOOST circuit in one embodiment;

[0056] Figure 2 FIG1 is a schematic diagram of a circuit structure of a BOOST circuit with overcurrent protection in one embodiment;

[0057] Figure 3 A schematic diagram of input and output signals of an overcurrent protection circuit in one embodiment;

[0058] Figure 4 is a signal schematic diagram of a differential amplifier circuit in one embodiment;

[0059] Figure 5 FIG1 is a schematic diagram of a circuit structure of a BOOST circuit with overcurrent protection in another embodiment;

[0060] Figure 6 1 is a voltage waveform diagram of a BOOST circuit according to an embodiment;

[0061] Figure 7 FIG1 is a circuit structure diagram of a BOOST circuit with overcurrent protection in another embodiment;

[0062] Figure 8 is a signal diagram of a differential amplifier circuit in another embodiment;

[0063] Figure 9 is a partial structural diagram of an overcurrent protection circuit in one embodiment;

[0064] Figure 10 Schematic diagram of the relationship between various switch signals in one embodiment;

[0065] Figure 11 is a partial structural diagram of an overcurrent protection circuit in another embodiment;

[0066] Figure 12 is a partial structural diagram of an overcurrent protection circuit in yet another embodiment;

[0067] Figure 13 A partial structural diagram of an overcurrent protection circuit in yet another embodiment;

[0068] Figure 14 1 is a voltage waveform diagram of a BOOST circuit under heavy load in one embodiment;

[0069] Figure 15 1 is a voltage waveform diagram of a BOOST circuit under light load in one embodiment;

[0070] Figure 16 FIG. 4 is a flow chart of an overcurrent protection method in an embodiment. DETAILED DESCRIPTION

[0071] In order to make the purpose, technical solutions and advantages of this application more clear, the following further describes this application in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0072] It will be understood that the terms "first," "second," etc., used herein may be used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish a first element from another element. For example, a first resistor may be referred to as a second resistor, and similarly, a second resistor may be referred to as a first resistor without departing from the scope of this application. The first resistor and the second resistor are both resistors, but they are not the same resistor.

[0073] It can be understood that the “connection” in the following embodiments should be understood as “electrical connection”, “communication connection”, etc. if there is transmission of electrical signals or data between the connected circuits, modules, units, etc.

[0074] It is understood that “at least one” refers to one or more, “a plurality” refers to two or more, and “at least a portion of an element” refers to a portion or all of an element.

[0075] As used herein, the singular forms "a," "an," and "the" may also include the plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "include," "comprising," "having," and the like specify the presence of stated features, integers, steps, operations, components, parts, or combinations thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, components, parts, or combinations thereof. Furthermore, the term "and / or" as used in this specification includes any and all combinations of the relevant listed items.

[0076] BOOST circuits are often used in electric vehicle charging systems, uninterruptible power supply systems, solar power generation systems, and other occasions. Figure 1 As shown, the basic circuit structure of a BOOST circuit can include an inductor unit L, a switch unit S, a diode unit D, and a capacitor unit CL. It is primarily used to boost the circuit's input voltage VIN to an output voltage VOUT that is higher than the input voltage. That is, the BOOST circuit can achieve the function of boosting the input voltage VIN through the operation of the inductor unit L and the switch unit S. It is understood that the aforementioned switch unit can be either a single switching element or a switching circuit composed of multiple switching elements (such as a switching transistor) combined with other circuit elements (such as a current comparator, etc.).

[0077] Boost circuits offer advantages such as high conversion efficiency, a wide voltage regulation range, and high output current. However, Boost circuits often have complex peripheral circuitry and large output ripple, which can lead to abnormally high currents and damage the circuit. Therefore, overcurrent protection mechanisms must be implemented within the Boost circuit to protect the circuit.

[0078] Traditional overcurrent protection circuits used in BOOST circuits often need to keep their overcurrent protection function enabled at all times to protect the circuit. However, this approach actually affects the operating efficiency of the BOOST and increases the overall power consumption of the circuit.

[0079] In order to solve the above problem, in one embodiment, Figures 2 to 4 As shown, the present application provides a BOOST circuit 200 with overcurrent protection, the BOOST circuit comprising:

[0080] Switch circuit 202;

[0081] A differential amplifier circuit EA, wherein a non-inverting input terminal of the differential amplifier circuit EA is used to obtain a reference voltage signal VREF, and an inverting input terminal of the differential amplifier circuit EA is used to obtain a feedback signal VFB, where the feedback signal VFB is obtained based on the output voltage signal of the BOOST circuit 200; a first output terminal of the differential amplifier circuit EA is used to output an operating mode signal BURST_EN, where the operating mode signal BURST_EN indicates the current load state of the BOOST circuit 200; and

[0082] The overcurrent protection circuit OCP is used to output a first enable signal EN based on the detected inductor voltage signal VSW flowing into the switch circuit 202 and the operating mode signal BURST_EN when the switch circuit 202 is in operation; the first enable signal EN is used to enable the differential amplifier circuit EA.

[0083] The switch circuit 202 can be configured to charge the inductor unit L of the BOOST circuit 200 when it is turned on, and discharge the inductor unit L of the BOOST circuit 200 when it is turned off. In some examples, when the inductor unit L is charging, the BOOST circuit 200 is considered to enter a charging phase; when the inductor unit L is discharging, the BOOST circuit 200 enters a freewheeling phase. Figure 2 PGND and VSS shown both represent circuit grounds.

[0084] It is understood that the switch circuit 202 can be composed of one or more switching transistors, current comparators, and other circuit elements. The specific structure of the switch circuit 202 can be determined based on actual application requirements, as long as it can achieve the functions of circuit conduction and cutoff. The embodiment of the present application does not specifically limit the specific structure of the switch circuit 202. It should be noted that when the specific structure of the switch circuit 202 includes components such as a current comparator, the overcurrent protection circuit OCP can also enable the current comparator and other components in the switch circuit 202 via the first enable signal EN.

[0085] For example, as shown in the following formula 1, when the differential amplifier circuit EA is in operation, a corresponding differential amplified signal may be output at the second output terminal of the differential amplifier circuit EA according to the reference voltage signal VREF at the non-inverting input terminal and the feedback signal VFB at the inverting input terminal:

[0086] VD = A * (VREF - VFB) (Equation 1)

[0087] Wherein, VD is the differential amplified signal output by the differential amplifier circuit EA, A is the gain of the differential amplifier circuit EA, VREF is the reference voltage signal VREF, and VFB is the feedback signal VFB. Optionally, the feedback signal VFB can be obtained by voltage-dividing the output voltage signal of the BOOST circuit 200.

[0088] In some examples, when the differential amplified signal VD exceeds a preset voltage threshold, the differential amplification circuit EA determines that the current load state of the BOOST circuit 200 is in a heavy load state; when the differential amplified signal VD does not exceed the preset voltage threshold, the differential amplification circuit EA determines that the current load state of the BOOST circuit 200 is in a light load state.

[0089] Furthermore, the operating mode signal BURST_EN includes a heavy-load mode signal and a light-load mode signal; the heavy-load mode signal indicates that the BOOST circuit 200 is currently in a heavy-load state, and the light-load mode signal indicates that the BOOST circuit 200 is currently in a light-load state. It will be understood that if the BOOST circuit 200 is currently in a heavy-load state as determined by the differential amplification signal, the differential amplification circuit EA outputs the heavy-load mode signal from the first output terminal; if the BOOST circuit 200 is currently in a light-load state as determined by the differential amplification signal, the differential amplification circuit EA outputs the light-load mode signal from the first output terminal. Optionally, the heavy-load mode signal can be a low-level signal, and the light-load mode signal can be a periodically changing logic level signal.

[0090] For example, the overcurrent protection circuit OCP can stop the BOOST circuit 200 from operating if the inductor current IL and / or the inductor voltage signal VSW of the BOOST circuit 200 exceed a preset threshold value. The inductor current IL is the current value of the inductor unit L of the BOOST circuit 200. For example, when the inductor current IL of the BOOST circuit 200 exceeds a preset current threshold value, it can be determined that an overcurrent condition has occurred in the BOOST circuit 200. In this case, the overcurrent protection circuit OCP disables circuit modules such as the differential amplifier circuit EA, stopping the BOOST circuit 200 from operating, thereby preventing various components of the BOOST circuit 200 from being damaged by the abnormal current.

[0091] In some examples, the specific structure of the switch circuit 202 includes circuit elements such as a current comparator. When an overcurrent occurs in the BOOST circuit 200, the overcurrent protection circuit OCP can also disable these circuit elements to achieve circuit protection, which is not repeated here.

[0092] Furthermore, the overcurrent protection circuit OCP can determine the current operation of the switch circuit 202 based on the first switch signal NDR that controls whether the switch circuit 202 is turned on or off. When the switch circuit 202 is in operation, the overcurrent protection circuit OCP can determine the current operating stage and load state of the boost circuit 200 based on the detected inductor voltage signal VSW flowing into the switch circuit 202 and the operating mode signal BURST_EN. Furthermore, the current operating state of the overcurrent protection circuit OCP is determined based on the boost circuit's operating stage and load state.

[0093] In some possible implementations, if the BOOST circuit 200 is currently in a heavy-load state as determined by the operating mode signal BURST_EN, the overcurrent protection circuit OCP may be turned on during the charging phase of the BOOST circuit 200 and turned off during the freewheeling phase of the BOOST circuit 200; if the BOOST circuit 200 is currently in a light-load state as determined by the operating mode signal BURST_EN, the operating state of the overcurrent protection circuit OCP will undergo a state transition as the level of the operating mode signal BURST_EN periodically changes. For example, when the periodic operating mode signal BURST_EN is currently at a low level, the overcurrent protection circuit OCP is turned on during the charging phase and turned off during the freewheeling phase (the same as in the heavy-load case); when the periodic operating mode signal BURST_EN is currently at a high level, the overcurrent protection circuit OCP is turned off.

[0094] It can be understood that an overcurrent fault of the BOOST circuit 200 usually occurs during the charging stage under a heavy load state. The embodiment of the present application uses the above method to enable the BOOST circuit 200 to adaptively enable the overcurrent protection circuit OCP according to the current operating stage and load status, thereby avoiding the energy waste caused by always turning on the overcurrent protection function, thereby reducing the overall power consumption of the BOOST circuit 200 and improving the working efficiency of the BOOST circuit 200.

[0095] The BOOST circuit with overcurrent protection described above realizes the charging and discharging of the BOOST circuit inductor by controlling the conduction and cutoff of the switch circuit, and determines the current load state of the BOOST circuit based on the output voltage signal through the differential amplifier circuit. Then, the working state of the overcurrent protection circuit is adjusted according to the load state and operation stage of the BOOST circuit, so that the BOOST circuit can adaptively enable the overcurrent protection function, thereby reducing the overall power consumption of the BOOST circuit and effectively improving the working efficiency of the BOOST circuit.

[0096] In one embodiment, Figure 5 As shown, the BOOST circuit 200 further includes:

[0097] a first comparator COMP1, wherein a non-inverting input terminal of the first comparator COMP1 is connected to one end of the switch circuit 202, and an inverting input terminal of the first comparator COMP1 is connected to the second output terminal of the differential amplifier circuit EA;

[0098] a control logic circuit 204 , wherein a first input terminal of the control logic circuit 204 is connected to the output terminal of the first comparator COMP1 , a second input terminal of the control logic circuit 204 is connected to the oscillator OSC, and an output terminal of the control logic circuit 204 is connected to the control terminal of the switch circuit 202 ;

[0099] The output terminal of the control logic circuit 204 is used to output the first switch signal NDR to determine the action of the switch circuit 202 ; the first enable signal EN is also used to enable the first comparator COMP1 and the control logic circuit 204 .

[0100] For example, the first comparator COMP1 can output a mode selection signal MODE to the control logic circuit 204 based on the inductor current detection signal from the switch circuit 202 and the differential amplification signal from the differential amplifier circuit EA. The control logic circuit 204 can control the operating state of the switch circuit 202 based on the received mode selection signal MODE.

[0101] Specifically, when the inductor current detection signal from the switch circuit 202 is greater than the differential amplified signal VD output from the differential amplifier circuit EA, the first comparator COMP1 sends a corresponding mode selection signal MODE to the first input terminal of the control logic circuit 204. The control logic circuit 204 adjusts the operating state of the switch circuit 202 according to the received mode selection signal MODE.

[0102] In one embodiment, the oscillator OSC is used to output a periodic oscillation signal CLK to the control logic circuit 204; the output terminal of the first comparator COMP1 is used to output a mode selection signal; the first enable signal EN is also used to enable the oscillator OSC;

[0103] If the oscillation signal CLK input to the control logic circuit 204 is a rising edge signal, the first switch signal NDR output by the control logic circuit 204 controls the switch circuit 202 to be turned on;

[0104] If the mode selection signal input to the control logic circuit 204 is a rising edge signal, the first switch signal NDR output by the control logic circuit 204 controls the switch circuit 202 to be turned off.

[0105] For example, the oscillator (OSC) can output a periodically varying square wave oscillation signal CLK. It is understood that the oscillator OSC can be either an external oscillation circuit connected to the BOOST circuit or a circuit component built into the BOOST circuit that outputs the oscillation signal CLK, and this embodiment of the present application does not impose any specific limitations. When the oscillator OSC is built into the BOOST circuit, the overcurrent protection circuit OCP can also enable the built-in oscillator OSC via the first enable signal EN.

[0106] Specifically, if Figure 6 As shown, when receiving a rising edge signal from the oscillator OSC, the control logic circuit 204 outputs a high-level first switching signal NDR to the switch circuit 202, so as to control the switch circuit 202 to be turned on through the first switching signal NDR, thereby charging the inductor unit L, gradually increasing the inductor current IL, and the BOOST circuit is in the charging stage; when receiving a rising edge signal from the first comparator COMP1, the control logic circuit 204 outputs a low-level first switching signal NDR to the switch circuit 202, so as to control the switch circuit 202 to be turned off through the first switching signal NDR, thereby discharging the inductor unit L, gradually reducing the inductor current IL, and the BOOST circuit is in the freewheeling stage.

[0107] In one embodiment, Figure 2 As shown, the BOOST circuit 200 further includes:

[0108] An inductor unit L, one end of the inductor unit L is used to obtain the input voltage signal VIN of the BOOST circuit, and the other end of the inductor unit L is connected to the other end of the switch circuit 202;

[0109] a diode unit D, wherein the anode of the diode unit D is connected between the other end of the inductor unit L and the other end of the switch circuit 202;

[0110] The capacitor unit CL has one end connected to the cathode of the diode unit D, and the other end of the capacitor unit CL is grounded.

[0111] In some examples, the inductor unit L may be one or more inductors. When the inductor unit L includes multiple inductors, the inductance value of the entire inductor unit L can be changed by changing the specifications, quantity, and connection relationship of each inductor.

[0112] In some possible implementations, the capacitor unit CL may be one or more capacitors. When the capacitor unit CL includes multiple capacitors, the capacitance value of the entire capacitor unit CL may be changed by changing the specifications, quantity, and connection relationship of each inductor.

[0113] In one embodiment, Figure 7 As shown, the switch circuit 202 includes:

[0114] A first switch tube MN1, one end of the first switch tube MN1 is connected between the other end of the inductor unit L and the anode of the diode unit D, and a control end of the first switch tube MN1 is connected to the output end of the control logic circuit 204 to obtain a first switching signal NDR;

[0115] a second switch tube MN2, one end of the second switch tube MN2 being connected between one end of the first switch tube MN1 and the anode of the diode unit D, and a control end of the second switch tube MN2 being connected to the output end of the control logic circuit 204 to obtain the first switch signal NDR;

[0116] a second comparator ICOMP, wherein a non-inverting input terminal of the second comparator ICOMP is connected to the other end of the first switch tube MN1, an inverting input terminal of the second comparator ICOMP is connected to the other end of the second switch, and an output terminal of the second comparator ICOMP is connected to the non-inverting input terminal of the first comparator COMP1;

[0117] a first resistor R1, one end of the first resistor R1 being connected between the non-inverting input terminal of the second comparator ICOMP and the other end of the first switch MN1, the other end of the first resistor R1 being connected between the inverting input terminal of the second comparator ICOMP and the other end of the second switch MN2, and the other end of the first resistor R1 being grounded;

[0118] a second resistor R2, one end of the second resistor R2 is connected between the non-inverting input end of the first comparator COMP1 and the output end of the second comparator ICOMP, and the other end of the second resistor R2 is grounded;

[0119] The first enable signal EN is also used to enable the second comparator ICOMP.

[0120] Specifically, the control logic circuit 204 outputs the first switching signal NDR to the control terminals of the first switch MN1 and the second switch MN2 simultaneously, so that the first switch MN1 and the second switch MN2 are turned on or off simultaneously, and both maintain the same switching state.

[0121] Furthermore, in the above-mentioned switch circuit 202 , the branch where the first switch transistor MN1 is located can be used to mirror the current of the branch where the second switch transistor MN2 is located.

[0122] In some examples, the first resistor R1 can be set to a resistor with a relatively small resistance. After the mirrored inductor current flowing out of the first switch tube MN1 passes through the first resistor R1 with a relatively small resistance, a relatively small inductor detection voltage VLsense is generated. Since the inductor detection voltage VLsense is relatively small, the second comparator ICOMP can output a corresponding inductor detection current ILsense based on the inductor detection voltage VLsense. The inductor detection current ILsense can further obtain an inductor current detection signal through the second resistor R2. It can be understood that there is a certain proportional relationship between the above-mentioned inductor detection current ILsense and the inductor current IL of the BOOST circuit, and the inductor current detection signal can be used to characterize the magnitude of the inductor current IL of the current BOOST circuit. Optionally, the second comparator ICOMP can be a current comparator.

[0123] In one embodiment, the size of the first switch transistor MN1 and the size of the second switch transistor MN2 are in a preset proportional relationship.

[0124] For example, the above-mentioned size may refer to the width-to-length ratio of the switch tube. Optionally, the second switch tube MN2 may be a power tube.

[0125] For example, if the sizes of the first switch MN1 and the second switch MN2 have a preset ratio of 1:N, since the current flowing through the second switch MN2 is equal to the inductor current during the charging phase, the current flowing through the first switch MN1 is IL / N.

[0126] In one embodiment, Figure 8 As shown, the BOOST circuit 200 further includes:

[0127] a first voltage-dividing resistor Rf1 , one end of the first voltage-dividing resistor Rf1 being used to obtain the output voltage signal VOUT, and the other end of the first voltage-dividing resistor Rf1 being connected to the inverting input end of the differential amplifier circuit EA;

[0128] a second voltage-dividing resistor Rf2, one end of the second voltage-dividing resistor Rf2 is connected between the other end of the first voltage-dividing resistor Rf1 and the inverting input end of the differential amplifier circuit EA, and the other end of the second voltage-dividing resistor Rf2 is grounded;

[0129] The feedback signal VREF is a voltage signal obtained by dividing the output voltage signal VOUT by the first voltage dividing resistor Rf1 and the second voltage dividing resistor Rf2 .

[0130] Specifically, the BOOST circuit can use the first voltage-dividing resistor Rf1 and the second voltage-dividing resistor Rf2 to divide the output voltage signal VOUT of the BOOST circuit to obtain the feedback signal VREF. After the feedback signal VREF is input into the differential amplifier circuit EA, a feedback loop can be formed.

[0131] In one embodiment, Figure 9 As shown, the overcurrent protection circuit OCP includes:

[0132] a third comparator COMP3, wherein a non-inverting input terminal of the third comparator COMP3 is used to connect to a constant current source Iref, and an enable terminal of the third comparator COMP3 is used to obtain a second enable signal ENOCP;

[0133] a third switch transistor MN3, one end of the third switch transistor MN3 being connected to the inverting input end of the third comparator COMP3, the other end of the third switch transistor MN3 being grounded, and a control end of the third switch transistor MN3 being used to obtain a second switch signal NDR_N, where the second switch signal NDR_N is an inverted signal of the first switch signal NDR;

[0134] a fourth switch MN4, one end of the fourth switch MN4 being used to obtain the inductor voltage signal VSW, the other end of the fourth switch MN4 being connected between one end of the third switch MN3 and the inverting input end of the third comparator COMP3, and a control end of the fourth switch MN4 being used to obtain a third switching signal NDR_NN, which is an inverted signal of the second switching signal NDR_N;

[0135] a fifth switch tube MN5, where one end of the fifth switch tube MN5 is connected between the constant current source Iref and the non-inverting input end of the third comparator COMP3, the other end of the fifth switch tube MN5 is grounded, and a control end of the fifth switch tube MN5 is used to obtain the second enable signal ENOCP;

[0136] The second enable signal ENOCP is obtained based on the operating mode signal BURST_EN and the third switch signal NDR_NN.

[0137] For example, the relationship among the first switching signal NDR, the second switching signal NDR_N and the third switching signal NDR_NN is as follows: Figure 10 As shown. It can be understood that the control logic circuit 204 outputs the first switching signal NDR, the second switching signal NDR_N is the inverted signal of the first switching signal NDR, and the third switching signal NDR_NN is the inverted signal of the second switching signal NDR_N. The above inverted signals can be Figure 10 The NOT gate circuit shown is obtained.

[0138] Specifically, the third comparator COMP3 of the over-current protection circuit OCP can determine whether the current BOOST circuit has an over-current fault according to the input signal. In some examples, in the case that the BOOST circuit has an over-current fault, the third comparator COMP3 can output a low-level over-current judgment signal OCP_OUT, and in the case that the over-current judgment signal OCP_OUT is low, the first enable signal EN disables various circuit modules of the BOOST circuit, thereby avoiding damage to circuit elements caused by abnormal current.

[0139] In one embodiment, as shown in Figure 11 the over-current protection circuit OCP further comprises:

[0140] a first NOT gate circuit 208, an input end of the first NOT gate circuit 208 being configured to obtain the working mode signal BURST_EN;

[0141] a first AND gate circuit 210, a first input end of the first AND gate circuit 210 being connected to an output end of the first NOT gate circuit 208, and a second input end of the first AND gate circuit 210 being configured to obtain the third switch signal NDR_NN;

[0142] wherein an output end of the first AND gate circuit 210 outputs the second enable signal ENOCP.

[0143] Specifically, the over-current protection circuit OCP can determine the signal type of the second enable signal ENOCP according to the third switch signal NDR_NN and the inverse signal of the working mode signal BURST_EN, thereby realizing control of the fifth switch tube MN5 and the third comparator COMP3.

[0144] In one embodiment, as shown in Figure 12 a third input end of the first AND gate circuit 210 is configured to obtain a system enable signal ENBOOST;

[0145] wherein the system enable signal ENBOOST is configured to enable the BOOST circuit.

[0146] Specifically, if the system enable signal ENBOOST is high, it indicates that the current BOOST circuit is working, and the first AND gate circuit 210 needs to determine the signal type of the output second enable signal ENOCP according to the third switch signal NDR_NN and the inverse signal of the working mode signal BURST_EN; if the system enable signal ENBOOST is low, it indicates that the entire BOOST circuit needs to be turned off, and the first AND gate circuit 210 outputs a low-level second enable signal ENOCP to control the fifth switch tube MN5 to be off and disable the third comparator COMP3.

[0147] In one embodiment, as Figure 13 As shown, the overcurrent protection circuit OCP also includes:

[0148] A second AND gate circuit 212, wherein a first input terminal of the second AND gate circuit 212 is used to obtain the system enable signal ENBOOST, and a second input terminal of the second AND gate circuit 212 is connected to an output terminal of the third comparator COMP3;

[0149] The output terminal of the second AND gate circuit 212 is used to output the first enable signal EN.

[0150] Specifically, if the system enable signal ENBOOST is high, indicating that the current BOOST circuit is working, the second AND gate circuit 212 determines the signal type of the first enable signal EN according to the overcurrent judgment signal OCP_OUT of the third comparator COMP3, thereby realizing overcurrent protection; if the system enable signal ENBOOST is high, indicating that the entire BOOST circuit needs to be shut down, the second AND gate circuit 212 outputs the low-level first enable signal EN, disabling all circuit modules controlled by the first enable signal EN.

[0151] In one embodiment, when the differential amplification signal VD of the differential amplification circuit EA is greater than or equal to a preset voltage threshold, the operating mode signal BURST_EN output by the differential amplification circuit EA is a low-level signal; the differential amplification signal VD is obtained based on the feedback signal VFB and the reference voltage signal VREF;

[0152] When the differential amplified signal VD is less than the preset voltage threshold, the operating mode signal BURST_EN output by the differential amplifying circuit EA is a periodic square wave signal.

[0153] Specifically, if Figure 14 As shown, Figure 14 Figure 2 shows the voltage waveform of the boost circuit in a heavily loaded state without experiencing an overcurrent fault. When the differential amplification signal VD of the differential amplifier circuit EA is greater than or equal to a preset voltage threshold, indicating that the boost circuit is currently in a heavily loaded state, the differential amplifier circuit EA outputs a low-level operating mode signal BURST_EN. At this time, the second enable signal ENOCP is affected by the first switch signal NDR output by the control logic circuit 204. The third comparator COMP3 of the overcurrent protection circuit OCP is normally enabled when the inductor unit L is charging (i.e., during the charging phase, when the inductor current IL increases), but is disabled when the inductor unit L is discharging (i.e., during the freewheeling phase, when the inductor current IL decreases). In other words, in a heavily loaded state, the overcurrent protection circuit OCP is enabled during the charging phase of the boost circuit and disabled during the freewheeling phase of the boost circuit.

[0154] Furthermore, if Figure 15 As shown, Figure 15 Fig. 4 is a voltage waveform diagram of the BOOST circuit in the light load state. When the differential amplification signal VD of the differential amplification circuit EA is less than the preset voltage threshold, it indicates that the current BOOST circuit is in the light load state, and the working mode signal BURST_EN output by the differential amplification circuit EA is a square wave signal with periodically changing levels. It can be understood that, in the case that the current BOOST circuit is in the light load state, when the working mode signal BURST_EN is a low-level signal, the second enable signal ENOCP is affected by the first switch signal NDR output by the control logic circuit 204, and the third comparator COMP3 of the overcurrent protection circuit OCP can be normally enabled when the inductor unit L is charging, and disabled when the inductor unit L is discharging; when the working mode signal BURST_EN is a high-level signal, the second enable signal ENOCP remains low to disable the third comparator COMP3 of the overcurrent protection circuit OCP. That is, in the light load state, the BOOST circuit makes the overcurrent protection circuit OCP in the closed state for most of the time, thereby realizing the ultra-low static power consumption of the overcurrent protection circuit OCP in the light load state.

[0155] In the above manner, the BOOST circuit can adaptively enable and stop the overcurrent protection circuit according to different load states and running stages, thereby effectively reducing the overall power consumption of the BOOST circuit and further improving the working efficiency of the BOOST circuit.

[0156] In one embodiment, as shown in Figure 16 Fig. 5, the present application provides an overcurrent protection method applied to the overcurrent protection BOOST circuit 200 as described in any of the above embodiments; the method comprises the following steps S162 to S164. Wherein:

[0157] Step S162, if it is determined according to the output voltage signal that the BOOST circuit is in the heavy load state, the overcurrent protection circuit is opened in the charging stage and closed in the freewheeling stage.

[0158] Step S164, if it is determined according to the output voltage signal that the BOOST circuit is in the light load state, the working state of the overcurrent protection circuit changes with the periodic working mode signal: when the periodic working mode signal is low, the overcurrent protection circuit is opened in the charging stage and closed in the freewheeling stage; when the periodic working mode signal is high, the overcurrent protection circuit is closed.

[0159] Wherein, the periodic working mode signal can be the working mode signal with periodically changing levels output by the differential amplification circuit as described in the above embodiments.

[0160] It can be understood that the specific implementation methods of the various steps of the method embodiments of the present application are already included in the above-mentioned BOOST circuit embodiments, and will not be described in detail here.

[0161] It should be understood that, although the various steps in the flowcharts involved in the method embodiments described above are displayed in sequence as indicated by the arrows, these steps are not necessarily executed in sequence in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order restriction on the execution of these steps, and these steps can be executed in other orders. Moreover, at least a portion of the steps in the flowcharts involved in the various embodiments described above may include multiple steps or multiple stages, and these steps or stages are not necessarily executed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily to be carried out in sequence, but can be executed in turn or alternately with other steps or at least a portion of steps or stages in other steps.

[0162] In one embodiment, the present application provides a booster, which includes a BOOST circuit with overcurrent protection as described in any one of the above embodiments.

[0163] The technical features of the above embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this application.

[0164] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present application. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, and these modifications and improvements fall within the scope of protection of the present application. Therefore, the scope of protection of the present application shall be determined by the appended claims.

Claims

1. A BOOST circuit with overcurrent protection, characterized in that: include: Switching circuit; A differential amplifier circuit, wherein a non-inverting input terminal of the differential amplifier circuit is used to obtain a reference voltage signal, and an inverting input terminal of the differential amplifier circuit is used to obtain a feedback signal, wherein the feedback signal is obtained based on the output voltage signal of the BOOST circuit; a first output terminal of the differential amplifier circuit is used to output an operating mode signal, wherein the operating mode signal represents a current load state of the BOOST circuit; as well as, an overcurrent protection circuit, configured to output a first enable signal based on a detected inductor voltage signal flowing into the switching circuit and the operating mode signal when the switching circuit is in operation; The first enable signal is used to enable the differential amplifier circuit; The BOOST circuit further includes: a first comparator, wherein a non-inverting input terminal of the first comparator is connected to one end of the switch circuit, and an inverting input terminal of the first comparator is connected to the second output terminal of the differential amplifier circuit; a control logic circuit, wherein a first input terminal of the control logic circuit is connected to the output terminal of the first comparator, a second input terminal of the control logic circuit is used to be connected to an oscillator, and an output terminal of the control logic circuit is connected to the control terminal of the switch circuit; The output terminal of the control logic circuit is used to output a first switching signal to determine the action of the switching circuit; the first enable signal is also used to enable the first comparator and the control logic circuit; The overcurrent protection circuit comprises: a third comparator, wherein a non-inverting input terminal of the third comparator is used to connect to a constant current source, and an enable terminal of the third comparator is used to obtain a second enable signal; a third switching tube, one end of the third switching tube being connected to the inverting input end of the third comparator, the other end of the third switching tube being grounded, and a control end of the third switching tube being used to obtain a second switching signal, where the second switching signal is an inverted signal of the first switching signal; a fourth switching tube, one end of the fourth switching tube being used to obtain the inductor voltage signal, the other end of the fourth switching tube being connected between one end of the third switching tube and the inverting input end of the third comparator, and a control end of the fourth switching tube being used to obtain a third switching signal, where the third switching signal is an inverted signal of the second switching signal; a fifth switching tube, wherein one end of the fifth switching tube is connected between the constant current source and the non-inverting input end of the third comparator, the other end of the fifth switching tube is grounded, and the control end of the fifth switching tube is used to obtain the second enable signal; The second enable signal is obtained based on the working mode signal and the third switch signal.

2. The BOOST circuit according to claim 1, wherein: The oscillator is used to output a periodic oscillation signal to the control logic circuit; the output end of the first comparator is used to output a mode selection signal; the first enable signal is also used to enable the oscillator; If the oscillation signal input to the control logic circuit is a rising edge signal, the first switching signal output by the control logic circuit controls the switching circuit to be turned on; If the mode selection signal input to the control logic circuit is a rising edge signal, the first switch signal output by the control logic circuit controls the switch circuit to be turned off.

3. The BOOST circuit according to claim 1, wherein: Also includes: an inductor unit, one end of which is used to obtain an input voltage signal of the BOOST circuit, and the other end of which is connected to the other end of the switch circuit; a diode unit, wherein the anode of the diode unit is connected between the other end of the inductor unit and the other end of the switch circuit; A capacitor unit, one end of the capacitor unit is connected to the cathode of the diode unit, and the other end of the capacitor unit is grounded.

4. The BOOST circuit according to claim 3, characterized in that: The switching circuit comprises: a first switching tube, one end of the first switching tube being connected between the other end of the inductor unit and the anode of the diode unit, and a control end of the first switching tube being connected to the output end of the control logic circuit to obtain the first switching signal; a second switching tube, one end of the second switching tube being connected between one end of the first switching tube and the anode of the diode unit, and a control end of the second switching tube being connected to the output end of the control logic circuit to obtain the first switching signal; a second comparator, wherein a non-inverting input terminal of the second comparator is connected to the other end of the first switch tube, an inverting input terminal of the second comparator is connected to the other end of the second switch, and an output terminal of the second comparator is connected to the non-inverting input terminal of the first comparator; a first resistor, one end of the first resistor being connected between the non-inverting input terminal of the second comparator and the other end of the first switching transistor, the other end of the first resistor being connected between the inverting input terminal of the second comparator and the other end of the second switching transistor, and the other end of the first resistor being grounded; a second resistor, one end of the second resistor being connected between the non-inverting input terminal of the first comparator and the output terminal of the second comparator, and the other end of the second resistor being grounded; The first enable signal is also used to enable the second comparator.

5. The BOOST circuit according to claim 4, characterized in that: The size of the first switching tube and the size of the second switching tube are in a preset proportional relationship.

6. The BOOST circuit according to claim 1, wherein: Also includes: a first voltage-dividing resistor, one end of the first voltage-dividing resistor being used to obtain the output voltage signal, and the other end of the first voltage-dividing resistor being connected to the inverting input end of the differential amplifier circuit; a second voltage-dividing resistor, one end of the second voltage-dividing resistor being connected between the other end of the first voltage-dividing resistor and the inverting input end of the differential amplifier circuit, and the other end of the second voltage-dividing resistor being grounded; The feedback signal is a voltage signal obtained by dividing the output voltage signal by the first voltage-dividing resistor and the second voltage-dividing resistor.

7. The BOOST circuit according to claim 1, characterized in that: The overcurrent protection circuit further includes: a first NOT gate circuit, wherein an input end of the first NOT gate circuit is used to obtain the working mode signal; a first AND gate circuit, wherein a first input end of the first AND gate circuit is connected to an output end of the first NOT gate circuit, and a second input end of the first AND gate circuit is used to obtain a third switching signal; Wherein, the output end of the first AND gate circuit outputs the second enable signal.

8. The BOOST circuit according to claim 7, characterized in that: The third input terminal of the first AND gate circuit is used to obtain a system enable signal; The system enable signal is used to enable the BOOST circuit.

9. The BOOST circuit according to claim 1, wherein: The overcurrent protection circuit further includes: a second AND gate circuit, wherein a first input terminal of the second AND gate circuit is used to obtain a system enable signal, and a second input terminal of the second AND gate circuit is connected to an output terminal of the third comparator; Wherein, the output end of the second AND gate circuit is used to output the first enable signal.

10. The BOOST circuit according to any one of claims 1 to 9, characterized in that: When the differential amplification signal of the differential amplification circuit is greater than or equal to a preset voltage threshold, the working mode signal output by the differential amplification circuit is a low-level signal; the differential amplification signal is obtained based on the feedback signal and the reference voltage signal; When the differential amplified signal is less than the preset voltage threshold, the operating mode signal output by the differential amplification circuit is a periodic square wave signal.

11. An overcurrent protection method, characterized in that: A BOOST circuit for overcurrent protection according to any one of claims 1 to 10; the method comprising: If the BOOST circuit is determined to be in a heavy-load state according to the output voltage signal, the overcurrent protection circuit is turned on during the charging phase and turned off during the freewheeling phase; If it is determined based on the output voltage signal that the BOOST circuit is in a light-load state, the working state of the overcurrent protection circuit changes with the periodic working mode signal: when the periodic working mode signal is at a low level, the overcurrent protection circuit is turned on in the charging stage and turned off in the freewheeling stage; when the periodic working mode signal is at a high level, the overcurrent protection circuit is turned off.

12. A booster, characterized in that: The invention comprises a BOOST circuit with overcurrent protection according to any one of claims 1 to 10.

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