BUCK-BOOST Converter Control Circuit, Control Method and Airbag Chip

Abstract

The present application relates to a BUCK-BOOST converter control circuit, a control method and an airbag chip, which detect the peak value of the inductor current through a current sampling compensation module to achieve stable control of the output voltage, have a fast dynamic response speed, good loop stability, and a simple circuit structure at the same time. The mode control module is used to achieve smooth switching of the working mode of the BUCK-BOOST converter, ensuring that the BUCK-BOOST converter can still work normally at high voltage levels. And because a ramp compensation unit is introduced into the circuit, it can effectively prevent subharmonic oscillations from occurring when the duty cycle of the PWM signal is greater than 50%, ensuring the stability of the system.

Description

Technical Field

[0001] The present application relates to the technical field of converter control, and particularly to a BUCK-BOOST converter control circuit, a control method, and an airbag chip. Background Art

[0002] Buck-Boost is a DC-DC converter that combines the functions of Buck (step-down) and Boost (step-up) converters. It can increase or decrease the voltage in the same circuit and is widely used in the airbag system of vehicles.

[0003] With the continuous improvement of the electrification level of automobiles, the traditional 12V automotive electrical system has been difficult to meet the requirements of modern automobiles for higher power, higher efficiency, and more complex electrical loads. The 48V automotive electrical system has emerged. By increasing the voltage level, this system can achieve greater power output, higher system efficiency, and lower production costs. With the increase in the voltage level, the Buck-Boost module in the airbag applied to this system also faces new challenges. It not only needs to have a larger input voltage range but also needs to be able to quickly respond to load changes to ensure the stability of the output voltage. Summary of the Invention

[0004] Based on this, in view of the above technical problems, it is necessary to provide a BUCK-BOOST converter control circuit, a control method, and an airbag chip that can smoothly switch the working mode.

[0005] In a first aspect, the present application provides a BUCK-BOOST converter control circuit, including:

[0006] A voltage division module for dividing the output voltage of the BUCK-BOOST converter to obtain a divided voltage;

[0007] An error amplifier for comparing and amplifying the divided voltage with a reference voltage to obtain a voltage error signal;

[0008] A current sampling compensation module for obtaining an inductor current sampling signal of the BUCK-BOOST converter and performing ramp compensation on the inductor current sampling signal to obtain a compensation signal;

[0009] A first comparator for comparing the compensation signal with the voltage error signal and generating a control signal when it is determined that the compensation signal matches the voltage error signal;

[0010] A mode control module is used to control the on / off of a first switch and a second switch in the BUCK-BOOST converter through the control signal, so as to control the working mode of the BUCK-BOOST converter.

[0011] In one embodiment, the mode control module includes:

[0012] A first flip-flop is used to output a first driving signal according to the logical processing result of the control signal and the current-limiting output signal and a first clock signal;

[0013] A logic unit is used to perform logical processing on the first driving signal and output a second driving signal;

[0014] A first driving unit is used to generate a first control signal for the first switch according to the second driving signal to control the on / off of the first switch;

[0015] A mode switching unit is used to determine the corresponding output state by judging whether the high level of the first driving signal overlaps with the high level of the second clock signal, and generate a second control signal for the second switch according to the output state to control the on / off of the second switch.

[0016] In one embodiment, the mode switching unit includes:

[0017] A comparator unit is used to compare the input voltage of the BUCK-BOOST converter with the reference voltage to obtain a comparison result;

[0018] [[ID=H4]]A second flip-flop is used to determine the output state according to the comparison result, the first driving signal and the second clock signal;

[0019] A second driving unit is used to generate a second control signal for the second switch according to the first driving signal and the output state.

[0020] In one embodiment, the comparator unit includes:

[0021] A voltage dividing sub-circuit is used to perform voltage division processing on the input voltage of the BUCK-BOOST converter to obtain a first voltage-divided input voltage and a second voltage-divided input voltage;

[0022] A second comparator is used to compare the first voltage-divided input voltage with the reference voltage to obtain a first comparison result;

[0023] A third comparator is used to compare the second voltage-divided input voltage with the reference voltage to obtain a second comparison result.

[0024] In one embodiment, the mode control module is further configured to:

[0025] When the input voltage of the BUCK - BOOST converter is greater than the output voltage multiplied by a first set multiple, control the first switch to turn on, charge the inductor of the BUCK - BOOST converter, and increase the compensation signal; when the compensation signal is equal to the voltage error signal, the control signal generates a high - level pulse, control the first switch to turn off until it is turned on again in the next clock cycle; and control the second switch to turn off so that the BUCK - BOOST converter operates in the buck mode;

[0026] When the input voltage of the BUCK - BOOST converter is less than the output voltage multiplied by a second set multiple, control the second switch to turn off based on the first drive signal so that the BUCK - BOOST converter operates in the boost mode.

[0027] In one embodiment, the mode control module is further configured to:

[0028] When the input voltage of the BUCK - BOOST converter is less than or equal to the output voltage multiplied by the first set multiple and greater than or equal to the output voltage multiplied by the second set multiple, at the initial moment, control the first switch to turn on and the second switch to turn off so that the BUCK - BOOST converter operates in the buck mode;

[0029] At the coincidence moment of the high level of the first drive signal and the high level of the second clock signal, control the second switch to turn on so that the BUCK - BOOST converter operates in the boost mode;

[0030] When the control signal generates a high - level pulse, control the first switch to turn off and control the second switch to turn off until they are turned on again in the next clock cycle; implement the bidirectional buck - boost mode of the BUCK - BOOST converter.

[0031] In one embodiment, the second clock signal has the same period as the first clock signal, and the high level of the second clock signal is delayed with respect to the high level of the first clock signal.

[0032] In a second aspect, the present application further provides a method for controlling a BUCK - BOOST converter, the method including:

[0033] Perform voltage division processing on the output voltage of the BUCK - BOOST converter to obtain a divided voltage;

[0034] Compare the divided voltage with a reference voltage and then amplify it to obtain a voltage error signal;

[0035] Obtain the inductor current sampling signal of the BUCK - BOOST converter, perform ramp compensation on the inductor current sampling signal to obtain a compensation signal;

[0036] Compare the compensation signal with the voltage error signal, and generate a control signal when it is determined that the compensation signal matches the voltage error signal;

[0037] Control the on - off of the first switch and the second switch in the BUCK - BOOST converter through the control signal to control the working mode of the BUCK - BOOST converter.

[0038] In one embodiment, the controlling the on - off of the first switch and the second switch in the BUCK - BOOST converter through the control signal to control the working mode of the BUCK - BOOST converter includes:

[0039] Obtain a first driving signal according to the logical processing result of the control signal and the current - limiting output signal and a first clock signal;

[0040] Perform logical processing on the first driving signal to obtain a second driving signal, and generate a first control signal for the first switch according to the second driving signal;

[0041] Determine the corresponding output state by judging whether the high level of the first driving signal overlaps with the high level of the second clock signal, and generate a second control signal for the second switch according to the output state to control the working mode of the BUCK - BOOST converter.

[0042] In a third aspect, the present application also provides an airbag chip, and the chip includes the BUCK - BOOST converter control circuit described in the first aspect above.

[0043] The above - mentioned BUCK - BOOST converter control circuit, control method and airbag chip detect the peak value of the inductor current through the current sampling compensation module, realize the stable control of the output voltage, have a fast dynamic response speed, good loop stability, and a simple circuit structure at the same time. The mode control module realizes the smooth switching of the working mode of the BUCK - BOOST converter, ensuring that the BUCK - BOOST converter can still work normally at a high voltage level. And because a ramp compensation unit is introduced into the circuit, it can effectively prevent sub - harmonic oscillation when the duty cycle of the PWM signal is greater than 50%, ensuring the stability of the system. Description of the Drawings

[0044] To more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the following will briefly introduce the accompanying drawings required for the description of the embodiments of the present application or related technologies. Obviously, the accompanying drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings.

[0045] Figure 1 It is a schematic diagram of the circuit structure of an asynchronous four-switch BUCK-BOOST in an embodiment;

[0046] Figure 2 It is a schematic diagram of the control circuit of a BUCK-BOOST converter in an embodiment;

[0047] Figure 3 It is a schematic diagram of the internal structure of a mode control module in an embodiment;

[0048] Figure 4 It is a schematic diagram of waveforms under different working modes in an embodiment;

[0049] Figure 5 It is a schematic flowchart of the control method of a BUCK-BOOST converter in an embodiment. Detailed implementation manners

[0050] In order to make the purpose, technical solutions and advantages of the present application clearer, the following further details the present application in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0051] Since the battery voltage of the 48V automotive electrical system is higher than that of the 12V one, the Buck-Boost module needs to have a larger input voltage range. At the same time, the load of the 48V automotive electrical system changes relatively fast, requiring the Buck-Boost circuit to be able to respond quickly to load changes to ensure the stability of the output voltage.

[0052] Figure 1 The circuit structure of the asynchronous four-switch BUCK-BOOST is shown. This circuit includes two switching transistors ( and ), two diodes ( and ), an inductor ( ), and input and output capacitors ( and ). By controlling the switching transistors and Perform mode conversion of BUCK (step-down), BOOST (step-up), and BUCK-BOOST (bidirectional step-up / step-down) for on / off, and achieve the function of step-up / step-down.

[0053] According to different loop architectures, the control modes of asynchronous four-switch BUCK-BOOST can generally be divided into two types: voltage mode and current mode. Among them, voltage mode control detects the output voltage and compares it with the reference voltage to generate an error signal for adjusting the duty cycle of the switching transistor, ensuring the stability of the output voltage. However, this mode is not sensitive to changes in the input voltage and has poor dynamic response. The common current mode control generally adopts the average current mode, which realizes the stable control of the output voltage by adjusting the average value of the inductor current . However, its circuit structure is complex and has high requirements for the accuracy of current detection, and is usually applicable to fields such as high-precision power supplies, battery chargers, and LED drivers.

[0054] Based on this, the embodiment of the present application provides a BUCK-BOOST converter control circuit for controlling the working mode of the BUCK-BOOST converter based on peak current mode, as Figure 2 shown. This control circuit includes:

[0055] A voltage division module for performing voltage division processing on the output voltage of the BUCK-BOOST converter to obtain a divided voltage. Specifically, the voltage division module is implemented by a resistor voltage division network composed of resistors and . The output voltage of the BUCK-BOOST converter undergoes voltage division processing through the voltage division module to obtain a divided voltage .

[0056] An error amplifier for comparing and amplifying the divided voltage with the reference voltage to obtain a voltage error signal .

[0057] A current sampling compensation module for obtaining the inductor current sampling signal of the BUCK-BOOST converter and performing ramp compensation on the inductor current sampling signal to obtain a compensation signal . Specifically, the current sampling compensation module can be implemented by a current sampling unit and a ramp compensation unit. The inductor current of the BUCK-BOOST converter is sampled through the current sampling unit, and the sampling value is added to the ramp compensation value of the ramp compensation unit to obtain a compensation signal .

[0058] A first comparator for comparing the compensation signal Compare with the voltage error signal to determine the compensation signal and the voltage error signal match, generate a control signal . Among them, the match can be the case where the two signals are equal. For example, when it is determined that the compensation signal and the voltage error signal are equal, the first comparator outputs a high-level control signal .

[0059] The mode control module is used to control the on and off of the first switch and the second switch in the BUCK - BOOST converter through the control signal to control the working mode of the BUCK - BOOST converter. Specifically, the control signal is input into the mode control module, which is processed by the mode control module to generate a PWM signal. By adjusting the duty cycle of the PWM signal, the on and off of the first switch and the second switch are controlled to achieve a smooth switching of the working mode of the BUCK - BOOST converter and stabilize the output voltage.

[0060] The above - mentioned BUCK - BOOST converter control circuit controls the working mode of the BUCK - BOOST converter based on peak - current mode. By detecting the peak value of the inductor current through the current sampling compensation module, it realizes the stable control of the output voltage. It has a fast dynamic response speed, good loop stability, and a simple circuit structure. The mode control module realizes a smooth switching of the working mode of the BUCK - BOOST converter, ensuring that the BUCK - BOOST converter can still work normally at high voltage levels. And because a ramp compensation unit is introduced into the circuit, it can effectively prevent sub - harmonic oscillations when the duty cycle of the PWM signal is greater than 50%, ensuring the stability of the system.

[0061] In an exemplary embodiment, the above - mentioned mode control module may specifically include:

[0062] The first flip - flop is used to output a first driving signal according to the logical processing result of the control signal and the current - limiting output signal and the first clock signal; among them, the current - limiting output signal is a signal used to judge whether the current of the BUCK - BOOST converter exceeds the threshold. For the normal working state, this signal is 0, that is, the current of the BUCK - BOOST converter does not exceed the threshold. The logical processing result can be the operation result after performing a logical operation on the control signal and the current - limiting output signal.

[0063] A logic unit for logically processing a first drive signal and outputting a second drive signal.

[0064] A first drive unit for generating a first control signal for a first switch according to the second drive signal to control the on / off of the first switch.

[0065] A mode switching unit for determining a corresponding output state by judging whether the high level of the first drive signal overlaps with the high level of the second clock signal, and then generating a second control signal for a second switch according to the output state to control the on / off of the second switch. Wherein, the second clock signal has the same period as the first clock signal, and the high level of the second clock signal is delayed from the high level of the first clock signal. For example, if the period is , there is a delay between the high level of the second clock signal and the high level of the first clock signal.

[0066] In an exemplary embodiment, the above mode switching unit may specifically include:

[0067] A comparator unit for comparing the input voltage of a BUCK-BOOST converter with a reference voltage to obtain a comparison result. Specifically, the comparator unit may include: a voltage dividing sub-circuit for dividing the input voltage of the BUCK-BOOST converter to obtain a first divided input voltage and a second divided input voltage; a second comparator for comparing the first divided input voltage with the reference voltage to obtain a first comparison result; a third comparator for comparing the second divided input voltage with the reference voltage to obtain a second comparison result.

[0068] A second flip-flop for determining an output state according to the comparison result, the first drive signal and the second clock signal.

[0069] A second drive unit for generating a second control signal for the second switch according to the first drive signal and the output state.

[0070] In an exemplary embodiment, the structure of the above mode control module may be in the form as Figure 3 shown. The following further illustrates its mode control principle in conjunction with Figure 3 . Wherein, the above first flip-flop is the RS flip-flop in Figure 3 , the second flip-flop is the D flip-flop in Figure 3 , the second comparator is comp1 in Figure 3 , and the third comparator is comp2 in Figure 3 .

[0071] Specifically, the control signal output by the first comparator and the current limiting output signal is connected to the two input terminals of the first NOR gate 31. When the signal is low, the output signal of the NOR gate 31 is inverted with respect to the compensation signal. The output signal of the NOR gate 31 is then connected to the S terminal of the RS flip-flop through an inverter 32, and the R terminal of the RS flip-flop is connected to the first clock signal vclk. When the compensation signal is equal to the voltage error signal a pulse is generated by the signal, and the output state of the RS flip-flop changes from low to high until it is reset to low again in the next clock cycle. The output terminal of the RS flip-flop and the vclk signal are connected to the input terminals of the second NOR gate 33. When both signals are low, a high level is output, and when one of the signals becomes high, a low level is output. The output signal of the NOR gate 33 is the first drive signal . After being processed by the logic unit, the second drive signal is output. The

[0072] signal is connected to the input terminal of the D flip-flop, is the clock signal of the D flip-flop, that is, the second clock signal. The period of this second clock signal is the same as that of the first clock signal vclk, but there is a delay in its high level, where is the period of the clock signal. Then, by judging whether the high level of the first drive signal coincides with the high level of the second clock signal , the output state of the D flip-flop is changed, thereby controlling the on / off of the second switch to change the working mode of the circuit. At the same time, the output voltage of the BUCK-BOOST converter is processed by the voltage dividing sub-circuit and compared with the reference voltage . The second comparison result output by the third comparator comp2 and the first clock signal after being inverted by the inverter 34 are processed by a logic gate (including the NAND gate 35 and the inverter 36 connected in sequence) and then connected to the Reset terminal of the D flip-flop. The first comparison result output by the second comparator comp1 and the output signal of the D flip-flop are connected to the input terminals of the third NOR gate 37 together. After being inverted by the inverter 38, they are connected to the NAND gate 39 together with the first drive signal . The output signal of the NAND gate 39 is processed by the second drive unit to generate the second control signal TG2 for the second switch.

[0073] In the above embodiment, through the D flip-flop and the comparator unit in the mode control module, by judging Whether the high level of the signal coincides with the high level of the signal and compare the signal and the signal, so as to control the switching transistor and to turn on and off, change the working mode of the circuit, ensure the stability of the output voltage of the BUCK-BOOST circuit, and achieve seamless switching during the BUCK-BOOST working mode conversion. And the circuit structure is simple, the control logic is concise, the production cost is low, and the system reliability is high.

[0074] Specifically, Figure 3 the waveforms of the circuit shown in different working modes are as Figure 4 shown, then the corresponding working process can include:

[0075] When (that is, the input voltage of the BUCK-BOOST converter is greater than the output voltage of the first set multiple , where the first set multiple can be above 1.1, preferably 1.17), the circuit works in the BUCK mode, and the switching transistor turns on, charges the inductor in the BUCK-BOOST converter, the signal increases. When the signal is equal to the signal, the signal generates a pulse. At this time, and the signal changes from high to low, and TG1 changes from low to high at the falling edge of the pulse signal, controlling the first switch to turn off until it is turned on again in the next clock cycle. At the same time, the signal is processed by the voltage dividing circuit and compared with the signal, comp1 outputs a low level, and comp2 outputs a high level. The output signal of comp2 and the inverted vclk signal are processed by a logic gate and connected to the Reset terminal of the D flip-flop. At this time, the high level duration of the signal does not coincide with the high level duration of the signal, and the output state of the D flip-flop remains unchanged and remains low. The output signal of the D flip-flop and the output signal of comp1 are connected to the input terminal of the third NOR gate 37 together. The NOR gate outputs a high level, and the inverted high level signal is connected to the input terminal of the NAND gate 39 together with the signal. Since one input signal of the NAND gate 39 is a low level, the output signal of the NAND gate 39 is a high level. This signal is input to the second driving unit to generate the switching transistor The control signal TG2 is at a low level, so the switching transistor is turned off .

[0076] When (that is, is less than or equal to the output voltage of the first set multiple , and greater than or equal to the output voltage of the second set multiple , where the second set multiple can be a number close to 1 and less than the second set multiple, preferably 0.83), the circuit operates in the BUCK - BOOST mode. Initially, the circuit operates in the BUCK mode, and the switching transistor is turned on, is turned off. When the high - level duration of the signal coincides with part of the high - level duration of the signal, at the moment of high - level coincidence, the output state of the D - flip - flop changes from low to high. This signal and the low - level output of are processed by a logic gate to output a signal in phase with the signal. This signal and the signal are connected to the input terminal of NAND gate 39. When both signals are at a high level, NAND gate 39 outputs a low level, and then the TG2 generated after being processed by the second driving unit is at a high level to control the switching transistor to turn on, and the circuit starts to operate in the BOOST mode. When the signal generates a pulse, and the signal changes from high to low, TG1 changes from low to high, and the switching transistor is turned off; TG2 changes from high to low, and the switching transistor is turned off until it is turned on again in the next clock cycle.

[0077] When (that is, is less than the output voltage of the second set multiple ), the circuit operates in the BOOST mode. At this time, the signal is processed by a voltage - dividing circuit and compared with the signal, and both comp1 and comp2 output high levels. Since the high - level duration of the signal does not coincide with the high - level duration of the signal, the output state of the D - flip - flop remains unchanged and remains low. This signal and the output signal of are processed by a logic gate to generate a high level and are connected to the input terminal of NAND gate 39 together with the signal, and then the control signal TG2 of the switching transistor is generated through the second driving unit. At this time, TG2 changes with the change of . When When the signal generates a pulse, TG1 changes from low to high, and the switching tube turns off; TG2 changes from high to low, and the switching tube turns off until it is turned on again in the next clock cycle. Thus, seamless switching during the working mode conversion of the BUCK - BOOST converter is achieved.

[0078] Each module in the above - mentioned BUCK - BOOST converter control can be implemented in whole or in part by software, hardware, and their combination. Each of the above - mentioned modules can be embedded in the processor of the computer device in hardware form or be independent of it, or be stored in the memory of the computer device in software form, so that the processor can call and execute the operations corresponding to each of the above - mentioned modules.

[0079] Based on the same inventive concept, the embodiment of the present application also provides a control method for implementing the above - mentioned BUCK - BOOST converter control circuit. The implementation solution provided by this method to solve the problem is similar to the implementation solution described in the above - mentioned control circuit. Therefore, the specific limitations in one or more embodiments of the following BUCK - BOOST converter control methods can refer to the limitations on the BUCK - BOOST converter control circuit in the above text, and will not be repeated here.

[0080] In one embodiment, as Figure 5 shown, the present application also provides a BUCK - BOOST converter control method. Taking the application of this method to the Figure 2 or Figure 3 control circuit as an example for illustration, it may specifically include the following steps:

[0081] Step 502: Perform voltage division processing on the output voltage of the BUCK - BOOST converter to obtain a divided voltage;

[0082] Step 504: Compare the divided voltage with a reference voltage and then amplify it to obtain a voltage error signal;

[0083] Step 506: Obtain the inductor current sampling signal of the BUCK - BOOST converter, and perform ramp compensation on the inductor current sampling signal to obtain a compensation signal;

[0084] Step 508: Compare the compensation signal with the voltage error signal, and generate a control signal when it is determined that the compensation signal matches the voltage error signal;

[0085] Step 510: Control the on - off of the first switch and the second switch in the BUCK - BOOST converter through the control signal to control the working mode of the BUCK - BOOST converter.

[0086] In an exemplary embodiment, controlling the on / off states of the first switch and the second switch in the BUCK-BOOST converter through the control signal to control the working mode of the BUCK-BOOST converter includes: obtaining a first driving signal according to the logical processing result of the control signal and the current-limiting output signal and a first clock signal; performing logical processing on the first driving signal to obtain a second driving signal, and generating a first control signal for the first switch according to the second driving signal; determining a corresponding output state by judging whether the high level of the first driving signal overlaps with the high level of the second clock signal, and generating a second control signal for the second switch according to the output state to control the working mode of the BUCK-BOOST converter.

[0087] In an exemplary embodiment, determining a corresponding output state by judging whether the high level of the first driving signal overlaps with the high level of the second clock signal, and generating a second control signal for the second switch according to the output state includes: comparing the input voltage of the BUCK-BOOST converter with the reference voltage to obtain a comparison result; determining the output state according to the comparison result, the first driving signal and the second clock signal; and generating a second control signal for the second switch according to the first driving signal and the output state.

[0088] In an exemplary embodiment, comparing the input voltage of the BUCK-BOOST converter with the reference voltage to obtain a comparison result includes: performing voltage division processing on the input voltage of the BUCK-BOOST converter to obtain a first divided voltage input and a second divided voltage input; comparing the first divided voltage input with the reference voltage to obtain a first comparison result; and comparing the second divided voltage input with the reference voltage to obtain a second comparison result.

[0089] In an embodiment, the present application further provides an airbag chip, which may include a BUCK-BOOST converter control circuit as shown in Figure 2 or Figure 3 Specifically, the chip can be applied to a 48V automotive electrical system, so as to achieve a wide input voltage range, high conversion efficiency and excellent dynamic performance.

[0090] It should be understood that although the steps in the flowcharts involved in the embodiments described above are shown sequentially according to the indications of the arrows, these steps are not necessarily executed sequentially in the order indicated by the arrows. Unless there is a clear indication in this article, there is no strict order restriction for the execution of these steps, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the embodiments described above may include multiple steps or multiple stages. These steps or stages are not necessarily executed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be executed alternately or in turn with at least a part of the steps or stages in other steps or other steps.

[0091] Those of ordinary skill in the art can understand that all or part of the processes in the methods of the above embodiments can be completed by instructing relevant hardware through a computer program. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above methods. Among them, any reference to a memory, database, or other medium used in the embodiments provided in this application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetoresistive random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM), etc. The databases involved in the embodiments provided in this application can include at least one of relational databases and non-relational databases. Non-relational databases can include distributed databases based on blockchain, etc., without limitation. The processors involved in the embodiments provided in this application can be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, data processing logics based on quantum computing, artificial intelligence (AI) processors, etc., without limitation.

[0092] The technical features of the above embodiments can be combined arbitrarily. For the sake of concise description, 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, it should be considered to be within the scope recorded in this application.

[0093] The above-described embodiments merely represent several implementation manners of the present application. The description thereof is relatively specific and detailed, but it should not be construed as a limitation on the patent scope of the present application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all fall within the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the appended claims.

Claims

1. A BUCK - BOOST converter control circuit, characterized in that, Including: A voltage division module for performing voltage division processing on the output voltage of the BUCK - BOOST converter to obtain a divided voltage; An error amplifier for comparing and amplifying the divided voltage with a reference voltage to obtain a voltage error signal; A current sampling compensation module for acquiring an inductor current sampling signal of the BUCK - BOOST converter and performing ramp compensation on the inductor current sampling signal to obtain a compensation signal; A first comparator for comparing the compensation signal with the voltage error signal and generating a control signal when it is determined that the compensation signal matches the voltage error signal; A mode control module for controlling the on - off of a first switch and a second switch in the BUCK - BOOST converter through the control signal to control the working mode of the BUCK - BOOST converter; The mode control module includes: A first flip - flop for outputting a first driving signal according to the logical processing result of the control signal and a current - limiting output signal and a first clock signal; the current - limiting output signal is a signal used to determine whether the current of the BUCK - BOOST converter exceeds a threshold. When the current of the BUCK - BOOST converter does not exceed the threshold, the current - limiting output signal is at a low level; A logic unit for performing logical processing on the first driving signal and outputting a second driving signal; A first driving unit for generating a first control signal for the first switch according to the second driving signal to control the on - off of the first switch; A mode switching unit for determining a corresponding output state by judging whether the high level of the first driving signal overlaps with the high level of a second clock signal, and generating a second control signal for the second switch according to the output state to control the on - off of the second switch; The mode switching unit includes: A comparator unit for comparing the input voltage of the BUCK - BOOST converter with the reference voltage to obtain a comparison result; A second flip - flop for determining an output state according to the comparison result, the first driving signal and the second clock signal; A second driving unit for generating a second control signal for the second switch according to the first driving signal and the output state.

2. The control circuit according to claim 1, wherein The comparator unit includes: A voltage division sub - circuit for performing voltage division processing on the input voltage of the BUCK - BOOST converter to obtain a first divided input voltage and a second divided input voltage; A second comparator for comparing the first divided input voltage with the reference voltage to obtain a first comparison result; A third comparator for comparing the second divided input voltage with the reference voltage to obtain a second comparison result.

3. The control circuit according to claim 1 or 2, characterized in that, The mode control module is further configured to: When the input voltage of the BUCK - BOOST converter is greater than the output voltage multiplied by a first set multiple, control the first switch to turn on, charge the inductor of the BUCK - BOOST converter, and the compensation signal increases; when the compensation signal is equal to the voltage error signal, the control signal generates a high - level pulse, control the first switch to turn off until it is turned on again in the next clock cycle; and control the second switch to turn off so that the BUCK - BOOST converter operates in the buck mode; When the input voltage of the BUCK - BOOST converter is less than the output voltage multiplied by a second set multiple, based on the first drive signal, control the second switch to turn off so that the BUCK - BOOST converter operates in the boost mode.

4. The control circuit according to claim 1 or 2, characterized in that, The mode control module is further configured to: When the input voltage of the BUCK - BOOST converter is less than or equal to the output voltage multiplied by the first set multiple and greater than or equal to the output voltage multiplied by the second set multiple, at the initial moment, control the first switch to turn on and the second switch to turn off so that the BUCK - BOOST converter operates in the buck mode; At the coincidence moment of the high level of the first drive signal and the high level of the second clock signal, control the second switch to turn on so that the BUCK - BOOST converter operates in the boost mode; When the control signal generates a high - level pulse, control the first switch to turn off and control the second switch to turn off until they are turned on again in the next clock cycle; Implement the bidirectional buck - boost mode of the BUCK - BOOST converter.

5. The control circuit according to claim 1 or 2, characterized in that, The second clock signal has the same period as the first clock signal, and the high level of the second clock signal is delayed with respect to the high level of the first clock signal.

6. A control method for a BUCK - BOOST converter, characterized in that, The method is applied to the BUCK - BOOST converter control circuit according to any one of claims 1 to 5, and the method includes: Perform voltage division processing on the output voltage of the BUCK - BOOST converter to obtain a divided voltage; Compare the divided voltage with a reference voltage and amplify it to obtain a voltage error signal; Obtain a sampling signal of the inductor current of the BUCK - BOOST converter, perform ramp compensation on the inductor current sampling signal to obtain a compensation signal; Compare the compensation signal with the voltage error signal, and generate a control signal when it is determined that the compensation signal matches the voltage error signal; Control the on - off of the first switch and the second switch in the BUCK - BOOST converter through the control signal to control the operating mode of the BUCK - BOOST converter.

7. An airbag chip, characterized in that, The chip includes the BUCK - BOOST converter control circuit according to any one of claims 1 to 5.

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