BUCK-BOOST converter control circuit, control method and safety airbag chip

Abstract

The invention relates to a BUCK-BOOST converter control circuit, a control method and a safety air bag chip, the peak value of inductive current is detected through a current sampling compensation module, stable control of output voltage is achieved, the dynamic response speed is high, the loop stability is good, and meanwhile the circuit structure is simple. According to the BUCK-BOOST converter, stable switching of the working modes of the BUCK-BOOST converter is achieved through the mode control module, and it is ensured that the BUCK-BOOST converter can still work normally under the high voltage level. And the slope compensation unit is introduced into the circuit, so that subharmonic oscillation can be effectively prevented when the duty ratio of the PWM signal is greater than 50%, and the stability of the system is ensured.

Description

Technical Field

[0001] The present application relates to the technical field of converter control, and in particular 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 vehicle airbag systems.

[0003] With the increasing degree of automobile electrification, the traditional 12V automotive electrical system has been unable to meet the needs of modern automobiles for higher power, higher efficiency and more complex electrical loads. The 48V automotive electrical system came into being. By increasing the voltage level, the system can achieve greater power output, higher system efficiency and lower production costs. As the voltage level increases, the Buck-Boost module used in the airbag of this system also faces new challenges. Not only does it need to have a larger input voltage range, but it also needs to be able to respond quickly to load changes and ensure the stability of the output voltage. Summary of the invention

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

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

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

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

[0008] A current sampling compensation module, used for acquiring an inductor current sampling signal of the BUCK-BOOST converter, performing slope compensation on the inductor current sampling signal, and obtaining a compensation signal;

[0009] A first comparator, configured to 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;

[0010] The mode control module is used to 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.

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

[0012] A first trigger, configured to output a first driving signal according to a logic processing result of the control signal and the current limiting output signal and a first clock signal;

[0013] a logic unit, configured to perform logic processing on the first drive signal and output a second drive signal;

[0014] a first driving unit, configured to generate a first control signal for the first switch according to the second driving signal, so as to control the on and off of the first switch;

[0015] The mode switching unit is used to determine the 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 generate a second control signal for the second switch according to the output state to control the on and off of the second switch.

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

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

[0018] a second trigger, configured to determine an output state according to the comparison result, the first drive signal and the second clock signal;

[0019] The 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 comprises:

[0021] A voltage dividing sub-circuit, used for performing voltage dividing 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, used for comparing the first divided input voltage with the reference voltage to obtain a first comparison result;

[0023] The third comparator is used to compare the second 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 of the first set multiple, the first switch is controlled to be turned on, the inductor of the BUCK-BOOST converter is charged, and the compensation signal increases; when the compensation signal is equal to the voltage error signal, the control signal generates a high level pulse, and the first switch is controlled to be turned off until it is turned on again in the next clock cycle; and the second switch is controlled to be turned off, so that the BUCK-BOOST converter operates in a step-down mode;

[0026] When the input voltage of the BUCK-BOOST converter is less than the output voltage of the second set multiple, the second switch is controlled to be turned off based on the first drive signal, so that the BUCK-BOOST converter operates in a 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 of the first set multiple and greater than or equal to the output voltage of the second set multiple, at the initial moment, the first switch is controlled to be turned on and the second switch is turned off, so that the BUCK-BOOST converter operates in a step-down mode;

[0029] At the moment when the high level of the first drive signal coincides with the high level of the second clock signal, controlling the second switch to open so that the BUCK-BOOST converter operates in a boost mode;

[0030] When the control signal generates a high level pulse, the first switch is controlled to be turned off, and the second switch is controlled to be turned off until it is turned on again in the next clock cycle; thus realizing the bidirectional step-up and step-down mode of the BUCK-BOOST converter.

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

[0032] In a second aspect, the present application further provides a BUCK-BOOST converter control method, the method comprising:

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

[0034] The divided voltage is compared with a reference voltage and then amplified to obtain a voltage error signal;

[0035] Acquiring an inductor current sampling signal of the BUCK-BOOST converter, and performing slope compensation on the inductor current sampling signal to obtain a compensation signal;

[0036] comparing the compensation signal with the voltage error signal, and generating a control signal if it is determined that the compensation signal matches the voltage error signal;

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

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

[0039] Obtaining a first drive signal according to a logic processing result of the control signal and the current limiting output signal and a first clock signal;

[0040] Performing logic processing on the first drive signal to obtain a second drive signal, and generating a first control signal for the first switch according to the second drive signal;

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

[0042] In a third aspect, the present application further provides an airbag chip, wherein the chip comprises the BUCK-BOOST converter control circuit described in the first aspect.

[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 to achieve stable control of the output voltage. It has fast dynamic response speed, good loop stability and simple circuit structure. The mode control module is used to achieve smooth switching of the working mode of the BUCK-BOOST converter to ensure that the BUCK-BOOST converter can still work normally at high voltage levels. And because the slope compensation unit is introduced into the circuit, it can effectively prevent subharmonic oscillation when the duty cycle of the PWM signal is greater than 50%, ensuring the stability of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the related technologies, the drawings required for use in the embodiments of the present application or the related technical descriptions will be briefly introduced below. 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 creative work.

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

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

[0047] Figure 3 A schematic diagram of the internal structure of a mode control module in one embodiment;

[0048] Figure 4 Schematic diagram of waveforms in different working modes in one embodiment;

[0049] Figure 5 FIG. 4 is a flow chart of a BUCK-BOOST converter control method in one embodiment. DETAILED DESCRIPTION

[0050] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below 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 a 48V automotive electrical system is higher than that of a 12V system, the Buck-Boost module needs to have a larger input voltage range. At the same time, the load of a 48V automotive electrical system changes rapidly, requiring the Buck-Boost circuit to be able to respond quickly to load changes and ensure the stability of the output voltage.

[0052] Figure 1 The circuit structure of the asynchronous four-switch BUCK-BOOST is shown. The circuit includes two switch tubes ( and ), two diodes ( and ), an inductor ( ) and the input and output capacitance ( and ). By controlling the switch and The on-off of the voltage regulator is used to convert the modes of BUCK (step-down), BOOST (step-up) and BUCK-BOOST (bidirectional step-up and step-down) to achieve the step-up and step-down functions.

[0053] Depending on the loop architecture, the control mode of the asynchronous four-switch BUCK-BOOST can usually be divided into two types: voltage mode and current mode. Among them, the voltage mode control detects the output voltage It is compared with the reference voltage to generate an error signal for adjusting the duty cycle of the switch tube to ensure the stability of the output voltage. The common current mode control generally adopts the average current mode, which adjusts the average value of the inductor current to achieve the output voltage. It can achieve stable control, but its circuit structure is complex and requires high accuracy of current detection. It is usually suitable for high-precision power supply, battery charger, LED driver and other fields.

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

[0055] The voltage divider module is used to divide the output voltage of the BUCK-BOOST converter to obtain a divided voltage. Specifically, the voltage divider module consists of a resistor and The output voltage of the BUCK-BOOST converter is realized by a resistor divider network. After the voltage division module performs voltage division processing, the divided voltage is obtained .

[0056] The error amplifier is used to convert the divided voltage With reference voltage After comparison and amplification, the voltage error signal is obtained .

[0057] The current sampling compensation module is used to obtain the inductor current sampling signal of the BUCK-BOOST converter and perform slope 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 slope compensation unit. The inductor current of the BUCK-BOOST converter is sampled by the current sampling unit, and the sampling value is added to the slope compensation value of the slope compensation unit to obtain a compensation signal. .

[0058] The first comparator is used to convert the compensation signal The voltage error signal to compare and determine the compensation signal The voltage error signal In case of a match, a control signal is generated . Matching can be the case where the two signals are equal. For example, when determining the compensation signal The voltage error signal When they are equal, the first comparator outputs a high-level control signal .

[0059] Mode control module, used to control the signal Controlling the First Switch in a Buck-Boost Converter and the second switch The on-off of the control signal controls the working mode of the BUCK-BOOST converter. The input is sent to the mode control module, which processes the PWM signal to generate a PWM signal. The duty cycle of the PWM signal is adjusted to control the first switch. and the second switch The on-off of the BUCK-BOOST converter can be realized by smoothly switching the working mode of the BUCK-BOOST converter and stabilizing the output voltage.

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

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

[0062] The first trigger is used to output a first drive signal according to the logic processing result of the control signal and the current limiting output signal and the first clock signal; wherein the current limiting output signal is a signal used to determine whether the current of the BUCK-BOOST converter exceeds a threshold value, and for a normal working state, the signal is 0, that is, the current of the BUCK-BOOST converter does not exceed the threshold value. The logic processing result can be the result of a logic operation on the control signal and the current limiting output signal.

[0063] The logic unit is used to perform logic processing on the first driving signal and output a second driving signal.

[0064] The first driving unit is used to generate a first control signal for the first switch according to the second driving signal, so as to control the on and off of the first switch.

[0065] The mode switching unit is used to determine the 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 generate a second control signal for the second switch according to the output state to control the on and off of the second switch. The second clock signal has the same period as the first clock signal, and the high level of the second clock signal is delayed after the high level of the first clock signal. For example, if the period is , then there is a difference between the high level of the second clock signal and the high level of the first clock signal delay.

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

[0067] The comparator unit is used to compare the input voltage of the BUCK-BOOST converter with the reference voltage to obtain a comparison result. The comparator unit may specifically include: a voltage divider subcircuit, used to divide the input voltage of the BUCK-BOOST converter to obtain a first divided input voltage and a second divided input voltage; a second comparator, used to compare the first divided input voltage with the reference voltage to obtain a first comparison result; and a third comparator, used to compare the second divided input voltage with the reference voltage to obtain a second comparison result.

[0068] The second trigger is used to determine the output state according to the comparison result, the first driving signal and the second clock signal.

[0069] The 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.

[0070] In an exemplary embodiment, the structure of the mode control module may be as follows: Figure 3 The form shown below combines Figure 3 The mode control principle is further explained. Among them, the first trigger is Figure 3 The RS flip-flop in the second flip-flop is Figure 3 The D flip-flop in the second comparator is Figure 3 The third comparator in comp1 is Figure 3 comp2 in.

[0071] Specifically, the control signal output by the first comparator is and current limiting output signal 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 The output signal of the NOR gate 31 is then connected to the S terminal of the RS trigger through an inverter 32, and the R terminal of the RS trigger is connected to the first clock signal vclk. The voltage error signal When equal, The signal generates a pulse, and the output state of the RS trigger changes from low to high until it is reset to low again in the next clock cycle. The output of the RS trigger and the vclk signal are connected to the input of the second NOR gate 33. When both signals are low, the output is high level. When one of the signals becomes high, the output is low level. The output signal of the NOR gate 33 is the first drive signal. After the signal is processed by the logic unit, the second drive signal is output. . The signal passes through the first driving unit and generates a first switch The first control signal TG1.

[0072] The signal is connected to the input of the D flip-flop. is the clock signal of the D flip-flop, i.e., the second clock signal, which has the same period as the first clock signal vclk, but its high level exists The delay of is the period of the clock signal. Then, by determining the first drive signal Is the high level of the second clock signal The high level coincides with the D flip-flop to change the output state of the D flip-flop, thereby controlling the second switch The output voltage of the BUCK-BOOST converter is After being processed by the voltage divider circuit and combined with the reference voltage The second comparison result output by the third comparator comp2 and the first clock signal inverted by the inverter 34 are processed by logic gates (including the NAND gate 35 and the inverter 36 connected in sequence) and connected to the Reset end 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 end of the third NOR gate 37, and are inverted by the inverter 38 and connected to the first drive signal. They are connected to a NAND gate 39 , and an output signal of the NAND gate 39 is processed by a second driving unit to generate a second control signal TG2 for the second switch.

[0073] In the above embodiment, the D flip-flop and the comparator unit in the mode control module are used to judge Is the high level of the signal consistent with The high level of the signal coincides with the Signal and The signal is compared to control the switch and The on-off of the circuit changes the working mode of the circuit and ensures the stability of the output voltage of the BUCK-BOOST circuit. At the same time, it realizes the seamless switching of the BUCK-BOOST working mode conversion. 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 follows Figure 4 As shown, the corresponding working process may include:

[0075] when When (that is, the input voltage of the BUCK-BOOST converter Output voltage greater than the first setting multiple , wherein the first setting multiple can be greater than 1.1, preferably 1.17), the circuit works in BUCK mode, the switch tube Open, the inductor in the BUCK-BOOST converter To charge, The signal increases. Signal and When the signals are equal, The signal generates a pulse. At this time, and The signal changes from high to low, and TG1 changes from low to high on the falling edge of the pulse signal, controlling the first switch It is turned off and on again in the next clock cycle. The signal is processed by the voltage divider circuit and The signals are compared, comp1 outputs a low level, and comp2 outputs a high level. The output signal of comp2 and the inverted vclk signal are processed by the logic gate and connected to the Reset terminal of the D flip-flop. At this time, The duration of the high level of the signal is The high level duration of the signal does not overlap, and the output state of the D flip-flop remains unchanged and remains low. The output signal of the D flip-flop is connected to the input end of the third NOR gate 37 together with the output signal of comp1. The NOR gate outputs a high level, which is inverted and connected to the input end of the third NOR gate 37. The signals are connected to the input terminal of the NAND gate 39. Since one input signal of the NAND gate 39 is at a low level, the output signal of the NAND gate 39 is at a high level. This signal is input to the second driving unit to generate a switch transistor. The control signal TG2 is at a low level, thus turning off the switch. .

[0076] when When (i.e. Output voltage less than or equal to the first set multiple , and the output voltage is greater than or equal to the second set multiple , wherein the second setting multiple can be a number around 0.85 close to 1 and less than the second setting multiple, preferably 0.83), the circuit works in BUCK-BOOST mode. Initially, the circuit works in BUCK mode, and the switch tube Open, When The duration of the high level of the signal is When the high level duration of the signal partially overlaps, at the moment of high level overlap, the output state of the D flip-flop changes from low to high. The low level of the output is processed by the logic gate and output signal. This signal is in phase with The two signals are connected to the input terminal of the NAND gate 39. When the two signals are high at the same time, the NAND gate 39 outputs a low level, and the TG2 generated by the second driving unit is high, which controls the switch tube. When turned on, the circuit starts to work in BOOST mode. When the signal generates a pulse, and The signal changes from high to low, TG1 changes from low to high, and the switch Turn off; TG2 changes from high to low, the switch tube It is turned off until it is turned on again in the next clock cycle.

[0077] when When (i.e. Output voltage that is less than the second setting multiple ), the circuit works in BOOST mode. At this time, The signal is processed by the voltage divider circuit and The signals are compared, and both comp1 and comp2 output high level. The duration of the high level of the signal is The high level duration of the signal does not overlap, and the output state of the D flip-flop remains unchanged and remains low. The output signal is processed by the logic gate to generate a high level and The signals are connected to the input terminal of the NAND gate 39, and then the switch tube is generated by the second driving unit. The control signal TG2, at this time, TG2 follows When When the signal generates a pulse, TG1 changes from low to high, and the switch Turn off; TG2 changes from high to low, the switch tube The BUCK-BOOST converter is turned off and turned on again in the next clock cycle, thus achieving seamless switching when the BUCK-BOOST converter switches between operating modes.

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

[0079] Based on the same inventive concept, the embodiment of the present application also provides a control method for implementing the BUCK-BOOST converter control circuit involved above. The implementation scheme for solving the problem provided by the method is similar to the implementation scheme recorded in the above control circuit, so the specific limitations of one or more BUCK-BOOST converter control method embodiments provided below can refer to the limitations of the BUCK-BOOST converter control circuit above, and will not be repeated here.

[0080] In one embodiment, Figure 5 As shown, the present application also provides a BUCK-BOOST converter control method, which is applied to Figure 2 or Figure 3 The control circuit of FIG. 1 is taken as an example to illustrate, and specifically may include the following steps:

[0081] Step 502, dividing the output voltage of the BUCK-BOOST converter to obtain a divided voltage;

[0082] Step 504, comparing the divided voltage with a reference voltage and amplifying the resultant voltage to obtain a voltage error signal;

[0083] Step 506, obtaining an inductor current sampling signal of the BUCK-BOOST converter, and performing slope compensation on the inductor current sampling signal to obtain a compensation signal;

[0084] Step 508, 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;

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

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

[0088] In an exemplary embodiment, the 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 input voltage and a second divided input voltage; comparing the first divided input voltage with the reference voltage to obtain a first comparison result; and comparing the second divided input voltage with the reference voltage to obtain a second comparison result.

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

[0090] It should be understood that, although the various steps in the flowcharts involved in the above-mentioned embodiments are displayed in sequence according to the indication of the arrows, these steps are not necessarily executed in sequence according to the order indicated by the arrows. Unless there is a clear explanation in this article, the execution of these steps does not have a strict order restriction, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above-mentioned embodiments can 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 part of the steps or stages in other steps.

[0091] A person of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment method can be completed by instructing the relevant hardware through a computer program, and 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-mentioned methods. Among them, any reference to the memory, database or other medium used in the embodiments provided in the present 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), magnetic 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. As an illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The database involved in each embodiment provided in this application may include at least one of a relational database and a non-relational database. Non-relational databases may include distributed databases based on blockchains, etc., but are not limited to this. The processor involved in each embodiment provided in this application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, an artificial intelligence (AI) processor, etc., but are not limited to this.

[0092] The technical features of the above embodiments may be combined arbitrarily. 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.

[0093] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A BUCK-BOOST converter control circuit, characterized in that: include: A voltage dividing module, used for dividing the output voltage of the BUCK-BOOST converter to obtain a divided voltage; An error amplifier, used for comparing the divided voltage with a reference voltage and amplifying the voltage to obtain a voltage error signal; A current sampling compensation module, used for acquiring an inductor current sampling signal of the BUCK-BOOST converter, performing slope compensation on the inductor current sampling signal, and obtaining a compensation signal; A first comparator, configured to 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; The mode control module is used to 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.

2. The control circuit according to claim 1, characterized in that: The mode control module comprises: A first trigger, configured to output a first driving signal according to a logic processing result of the control signal and the current limiting output signal and a first clock signal; a logic unit, configured to perform logic processing on the first drive signal and output a second drive signal; a first driving unit, configured to generate a first control signal for the first switch according to the second driving signal, so as to control the on and off of the first switch; The mode switching unit is used to determine the 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 generate a second control signal for the second switch according to the output state to control the on and off of the second switch.

3. The control circuit according to claim 2, characterized in that: The mode switching unit comprises: A comparator unit, used for comparing the input voltage of the BUCK-BOOST converter with the reference voltage to obtain a comparison result; a second trigger, configured to determine an output state according to the comparison result, the first drive signal and the second clock signal; The 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.

4. The control circuit according to claim 3, characterized in that: The comparator unit comprises: A voltage dividing sub-circuit, used for performing voltage dividing 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; A second comparator, used for comparing the first divided input voltage with the reference voltage to obtain a first comparison result; The third comparator is used to compare the second divided input voltage with the reference voltage to obtain a second comparison result.

5. The control circuit according to any one of claims 2 to 4, characterized in that: The mode control module is also used for: When the input voltage of the BUCK-BOOST converter is greater than the output voltage of the first set multiple, the first switch is controlled to be turned on, the inductor of the BUCK-BOOST converter is charged, and the compensation signal increases; when the compensation signal is equal to the voltage error signal, the control signal generates a high level pulse, and the first switch is controlled to be turned off until it is turned on again in the next clock cycle; and the second switch is controlled to be turned off, so that the BUCK-BOOST converter operates in a step-down mode; When the input voltage of the BUCK-BOOST converter is less than the output voltage of the second set multiple, the second switch is controlled to be turned off based on the first drive signal, so that the BUCK-BOOST converter operates in a boost mode.

6. The control circuit according to any one of claims 2 to 4, characterized in that: The mode control module is also used for: When the input voltage of the BUCK-BOOST converter 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, at the initial moment, the first switch is controlled to be turned on and the second switch is turned off, so that the BUCK-BOOST converter operates in a step-down mode; At the moment when the high level of the first drive signal coincides with the high level of the second clock signal, controlling the second switch to open so that the BUCK-BOOST converter operates in a boost mode; When the control signal generates a high level pulse, the first switch is controlled to be turned off, and the second switch is controlled to be turned off until it is turned on again in the next clock cycle; A bidirectional step-up / step-down mode of the BUCK-BOOST converter is realized.

7. The control circuit according to any one of claims 2 to 4, characterized in that: The second clock signal has the same period as the first clock signal, and a high level of the second clock signal is delayed compared to a high level of the first clock signal.

8. A BUCK-BOOST converter control method, characterized in that: The method comprises: Performing voltage division processing on the output voltage of the BUCK-BOOST converter to obtain a divided voltage; The divided voltage is compared with a reference voltage and then amplified to obtain a voltage error signal; Acquiring an inductor current sampling signal of the BUCK-BOOST converter, and performing slope compensation on the inductor current sampling signal to obtain a compensation signal; comparing the compensation signal with the voltage error signal, and generating a control signal if it is determined that the compensation signal matches the voltage error signal; The control signal is used to control the on and off of the first switch and the second switch in the BUCK-BOOST converter to control the working mode of the BUCK-BOOST converter.

9. The method according to claim 8, characterized in that The step of controlling the on / off of the first switch and the second switch in the BUCK-BOOST converter by the control signal to control the working mode of the BUCK-BOOST converter includes: Obtaining a first drive signal according to a logic processing result of the control signal and the current limiting output signal and a first clock signal; Performing logic processing on the first drive signal to obtain a second drive signal, and generating a first control signal for the first switch according to the second drive signal; By judging whether the high level of the first driving signal overlaps with the high level of the second clock signal, the corresponding output state is determined, and a second control signal for the second switch is generated according to the output state to control the working mode of the BUCK-BOOST converter.

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

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