Clamping circuit, chip and control method

Abstract

The present application discloses a clamping circuit, a chip and a control method, wherein the clamping circuit comprises: a startup module, a circuit voltage dividing module, a circuit protection module, a voltage selection module and an operational amplifier clamping module; the startup module is used to provide a startup voltage to a power supply terminal; the circuit voltage dividing module is used to divide the startup voltage to obtain a first voltage output to the operational amplifier clamping module; the circuit protection module is used to determine the trigger protection type of the chip according to the voltage on the pin, generate a trigger signal and send it to the voltage selection module; the voltage selection module is used to select a second voltage to output to the operational amplifier clamping module in response to the trigger signal; the operational amplifier clamping module is used to reduce the voltage value of the startup voltage to the clamping voltage value based on the magnitude relationship between the first voltage and the second voltage. The clamping circuit can reduce the input power of the chip while avoiding damage to the MOS tube in the chip, limit the maximum working current when the chip is restarted, and further reduce the short-circuit power consumption of the chip.

Description

Technical Field

[0001] The present invention generally relates to the technical field of switching converters, and in particular to a clamping circuit, a chip and a control method. Background Art

[0002] With the rapid development of electronic information technology, electronic devices have been increasingly used in people's daily lives, bringing great convenience to people, with their advantages of improving productivity and expanding information sources. Among them, chips, as the core components of electronic devices, are the basis for the intelligence, efficiency and integration of electronic products, and can provide electronic devices with data processing, storage, conversion, transmission and other functions.

[0003] In some cases, the chip will trigger overvoltage protection. Usually, the chip will enter the following three states after the protection is triggered: (1) the chip restarts directly after the protection is triggered; (2) the chip restarts after a delay in triggering the protection; (3) the chip is locked (Latch) after triggering the protection. Among them, in the above (2) state, the chip generally chooses to remember the clear signal timing restart, but if the chip enters the second state, it may restart repeatedly in a short period of time, which will increase the effective time of the chip output short circuit and the peak current of the switch tube. Since the excessive switch tube current will store a large amount of energy in the leakage inductance, the input power of the chip will be large, which greatly increases the short-circuit power consumption of the chip. Summary of the invention

[0004] In view of the above defects or deficiencies in the prior art, it is desirable to provide a clamping circuit, a chip and a control method.

[0005] In a first aspect, the present application provides a clamping circuit, which includes: a startup module, a circuit voltage division module, a circuit protection module, a voltage selection module and an operational amplifier clamping module;

[0006] The output end of the startup module is used to connect to the power supply end of the chip, the power supply end is also connected to the input end of the circuit voltage divider module, the output end of the circuit voltage divider module is connected to the first input end of the operational amplifier clamping module, the input end of the circuit protection module is connected to the detection pin of the chip, the output end of the circuit protection module is connected to the input end of the voltage selection module, the output end of the voltage selection module is connected to the second input end of the operational amplifier clamping module, and the output end of the operational amplifier clamping module is connected to the power supply end; wherein:

[0007] The startup module is used to provide a startup voltage to the power supply end;

[0008] The circuit voltage division module is used to divide the startup voltage to obtain a first voltage and output it to the operational amplifier clamping module;

[0009] The circuit protection module is used to determine the trigger protection type of the chip according to the voltage on the detection pin, generate a trigger signal and send it to the voltage selection module;

[0010] The voltage selection module is used for selecting a second voltage to be output to the operational amplifier clamping module in response to the trigger signal;

[0011] The operational amplifier clamping module is used to clamp the startup voltage based on the magnitude relationship between the voltage values ​​of the first voltage and the second voltage, so as to reduce the voltage value of the startup voltage to a clamping voltage value; wherein the clamping voltage value is determined by the voltage value of the second voltage.

[0012] In one of the embodiments, the trigger signal includes a first trigger signal, a second trigger signal and a third trigger signal;

[0013] The circuit protection module is specifically used for:

[0014] When the voltage on the detection pin meets a first preset condition, determining that the trigger protection type is a first type and generating the first trigger signal based on the first type;

[0015] When the voltage on the detection pin meets a second preset condition, determining that the trigger protection type is a second type and generating the second trigger signal based on the second type;

[0016] When the timing starts after the second trigger signal is generated and reaches the preset time, a third trigger signal is generated; wherein the first trigger signal and the second trigger signal are used to trigger the voltage selection module to output a second voltage with a different voltage value to the operational amplifier clamping module.

[0017] In one embodiment, the circuit protection module is further used for:

[0018] When the voltage on the detection pin does not satisfy the first preset condition and does not satisfy the second preset condition, it is determined that the chip is in a normal working state.

[0019] In one embodiment, the detection pin includes: a first pin and a second pin, and the input end of the circuit protection module is connected to the first pin and the second pin respectively;

[0020] The circuit protection module is also used for:

[0021] When it is detected that the voltage of the first pin is greater than a first preset threshold, determining that the voltage on the detection pin meets a first preset condition;

[0022] When it is detected that the voltage on the second pin is less than the second preset threshold or greater than the third preset threshold, it is determined that the voltage on the detection pin meets the second preset condition; wherein the second preset threshold is less than the third preset threshold.

[0023] In one embodiment, the voltage selection module is specifically used for:

[0024] In response to the first trigger signal, providing a second voltage having a first voltage value to the operational amplifier clamp module;

[0025] In response to the second trigger signal, providing a second voltage having a second voltage value to the operational amplifier clamp module;

[0026] In response to the third trigger signal, providing a second voltage having a first voltage value to the operational amplifier clamp module;

[0027] Wherein, the first voltage value is less than the second voltage value;

[0028] The first voltage value and the second voltage value correspond to different clamping voltage values, and the clamping voltage value corresponding to the first voltage value is smaller than the clamping voltage value corresponding to the second voltage value.

[0029] In one embodiment, the voltage selection module is further used for:

[0030] When the chip is in a normal working state and a spike voltage is detected, a second voltage having a third voltage value is provided to the operational amplifier clamping module;

[0031] Among them, the third voltage value is greater than the second voltage value; and the clamping voltage value corresponding to the third voltage value is greater than the clamping voltage value corresponding to the second voltage value.

[0032] In one of the embodiments, the operational amplifier clamping module is specifically used to: when the voltage value of the first voltage is greater than or equal to the voltage value of the second voltage, discharge current to reduce the voltage value of the start-up voltage to the clamping voltage value.

[0033] In one of the embodiments, the operational amplifier clamping module is further used to determine the clamping voltage value according to voltage values ​​of the first voltage, the second voltage and the start-up voltage.

[0034] In one of the embodiments, the circuit protection module includes an identification unit, and the identification unit is used to determine the trigger protection type of the chip according to the voltage on the detection pin.

[0035] In one embodiment, the circuit voltage divider module includes: a second resistor, a third resistor, a fourth resistor and a second capacitor; one end of the second resistor is connected to the power supply end, the other end of the second resistor is connected to one end of the third resistor, the other end of the third resistor is respectively connected to one end of the fourth resistor and one end of the second capacitor, the other end of the fourth resistor is connected to the other end of the second capacitor, and the other end of the fourth resistor and the other end of the second capacitor are both grounded.

[0036] In a second aspect, the present application provides a chip, comprising the clamping circuit as described in the first aspect above.

[0037] In a third aspect, the present application provides a control method, the method comprising:

[0038] A control method, characterized in that it is applied to the clamping circuit, the clamping circuit includes: a startup module, a circuit voltage division module, a circuit protection module, a voltage selection module and an operational amplifier clamping module; the control method includes:

[0039] The startup module provides a startup voltage to the power supply end;

[0040] The circuit voltage division module performs voltage division processing on the startup voltage to obtain a first voltage and outputs it to the operational amplifier clamping module;

[0041] The circuit protection module determines the trigger protection type of the chip according to the voltage on the detection pin, generates a trigger signal and sends it to the voltage selection module;

[0042] The voltage selection module selects a second voltage to output to the operational amplifier clamping module in response to the trigger signal;

[0043] The operational amplifier clamping module clamps the startup voltage based on the magnitude relationship between the voltage values ​​of the first voltage and the second voltage to reduce the voltage value of the startup voltage to a clamping voltage value; wherein the clamping voltage value is determined by the voltage value of the second voltage.

[0044] The clamping circuit, chip and control method provided in the embodiment of the present application, the clamping circuit includes: a startup module, a circuit voltage divider module, a circuit protection module, a voltage selection module and an operational amplifier clamping module, the output end of the startup module is used to connect to the power supply end of the chip, the power supply end is also connected to the input end of the circuit voltage divider module, the output end of the circuit voltage divider module is connected to the first input end of the operational amplifier clamping module, the input end of the circuit protection module is connected to the detection pin of the chip, the output end of the circuit protection module is connected to the input end of the voltage selection module, the output end of the voltage selection module is connected to the second input end of the operational amplifier clamping module, and the output end of the operational amplifier clamping module is connected to the detection pin of the chip. Connected to the power supply end, wherein the startup module is used to provide a startup voltage to the power supply end, the circuit voltage divider module is used to divide the startup voltage to obtain a first voltage output to the operational amplifier clamping module, the circuit protection module is used to determine the trigger protection type of the chip according to the voltage on the detection pin, generate a trigger signal and send it to the voltage selection module, the voltage selection module is used to respond to the trigger signal, select the second voltage to output to the operational amplifier clamping module, and the operational amplifier clamping module is used to clamp the startup voltage based on the size relationship between the voltage value of the first voltage and the voltage value of the second voltage to reduce the voltage value of the startup voltage to the clamping voltage value. Compared with the prior art, the clamping circuit can determine the trigger protection type of the chip according to the voltage on the detection pin through the circuit protection module, so that the voltage selection module comprehensively considers the factors of the trigger protection type information, thereby selecting the corresponding second voltage, and through the operational amplifier clamping module according to the first voltage output by the circuit voltage divider module and the second voltage output by the voltage selection module, the start voltage is clamped to a lower clamping voltage value more accurately, thereby avoiding damage to the MOS tube in the chip while also reducing the input power of the chip, limiting the maximum operating current when the chip is restarted, and further reducing the short-circuit power consumption of the chip. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Other features, objects and advantages of the present application will become more apparent by reading the detailed description of non-limiting embodiments made with reference to the following drawings:

[0046] Figure 1 A schematic diagram of the structure of a clamping circuit provided in an embodiment of the present application;

[0047] Figure 2 A schematic diagram of the structure of a clamping circuit provided in another embodiment of the present application;

[0048] Figure 3 A schematic diagram of the structure of a circuit protection module provided in an embodiment of the present application;

[0049] Figure 4 A schematic diagram of the structure of a chip provided in an embodiment of the present application;

[0050] Figure 5A schematic flow chart of a control method for a clamping circuit provided in an embodiment of the present application;

[0051] Figure 6 A schematic flow chart of a control method of a clamping circuit provided in another embodiment of the present application;

[0052] Figure 7 A schematic flow chart of a control method for a clamping circuit provided in yet another embodiment of the present application;

[0053] Figure 8 The waveform diagrams corresponding to the trigger protection direct restart signal Rst, the trigger protection start timing signal fault_en, the trigger protection timing signal en_1s when the full 1s is reached, the voltage selection module output signal Vclamp, the circuit voltage divider module output signal vdd_clp, the VDD signal, the current IVDD signal on the VDD pin and the DRV signal provided in the embodiment of the present application.

[0054] Description of reference numerals:

[0055] Start-up module-10; circuit voltage division module-20; voltage selection module-30; circuit protection module-40; operational amplifier clamping module-50; logic controller-60; clamping circuit-100; peripheral circuit-200. DETAILED DESCRIPTION

[0056] The present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the relevant invention, rather than to limit the invention. It is also necessary to explain that, for ease of description, only the parts related to the invention are shown in the accompanying drawings.

[0057] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0058] It is understandable that the chip may restart repeatedly in a short period of time after triggering the protection, which increases the effective time of the chip output short circuit and the peak current of the switching tube. Since the excessive switching tube current will store a large amount of energy in the leakage inductance, the input power of the chip will be large, which greatly increases the short-circuit power consumption of the chip.

[0059] Based on the above defects, the present application provides a clamping circuit. Compared with the prior art, the clamping circuit can determine the trigger protection type of the chip according to the voltage on the detection pin through the circuit protection module, so that the voltage selection module comprehensively considers the trigger protection type information to select the corresponding second voltage, and through the operational amplifier clamping module according to the first voltage output by the circuit voltage divider module and the second voltage output by the voltage selection module, the start voltage is clamped to a lower clamping voltage value more accurately, thereby avoiding damage to the MOS tube in the chip while reducing the input power of the chip, limiting the maximum operating current when the chip is restarted, and further reducing the short-circuit power consumption of the chip.

[0060] See also Figure 1 As shown, Figure 1 A schematic diagram of the structure of the clamping circuit provided in the embodiment of the present application. The clamping circuit includes: a startup module 10, a circuit voltage divider module 20, a voltage selection module 30, a circuit protection module 40 and an operational amplifier clamping module 50. The output end of the startup module 10 is used to connect to the power supply end of the chip, and the power supply end is also connected to the input end of the circuit voltage divider module 20, the output end of the circuit voltage divider module 20 is connected to the first input end of the operational amplifier clamping module 50, the circuit protection module 40 is connected to the detection pin, the output end of the circuit protection module 40 is connected to the input end of the voltage selection module 30, the output end of the voltage selection module 30 is connected to the second input end of the operational amplifier clamping module 50, and the output end of the operational amplifier clamping module 50 is connected to the power supply end. Among them, the above-mentioned detection pin is connected to the detection pin at the detection pin. Figure 1 Not shown.

[0061] The startup module 10 is used to provide a startup voltage to the power supply end; the circuit voltage divider module 20 is used to divide the startup voltage to obtain a first voltage and output it to the operational amplifier clamping module 50; the circuit protection module 40 is used to determine the trigger protection type of the chip according to the voltage on the detection pin, generate a trigger signal and send it to the voltage selection module 30; the voltage selection module 30 is used to respond to the trigger signal and select the second voltage to output to the operational amplifier clamping module 50; the operational amplifier clamping module 50 is used to clamp the startup voltage based on the size relationship between the voltage value of the first voltage and the voltage value of the second voltage, so as to reduce the voltage value of the startup voltage to the clamping voltage value; wherein the clamping voltage value is determined by the voltage value of the second voltage.

[0062] Specifically, the clamping circuit provided in the embodiment of the present application can be applied to a switching power supply device, for example, it can be applied to a flyback converter (Flyback Converter) or a forward converter. The flyback converter is widely used in alternating current to direct current (AC / DC) and direct current to direct current (DC / DC) conversion, and provides insulation isolation between the input stage and the output stage.

[0063] Among them, the above-mentioned chip can be a processor chip, a sensor chip, a memory chip, a communication chip or a control chip. The chip can also include a peripheral circuit, which is used to realize functions such as calculation, storage, communication, sensing and control. The peripheral circuit can include a detection pin, and the input end of the circuit protection module can be connected to the detection pin of the chip.

[0064] The startup module 10 is used to provide a startup voltage to the power supply terminal of the chip, and the startup voltage can be a VDD voltage. The input end of the startup module 10 can be connected to the peripheral circuit of the chip, and is used to receive the VBULK signal sent by the peripheral circuit, and the output end is used to connect to the power supply terminal (VDD terminal) of the chip, and the power supply terminal of the chip can be understood as the pin VDD of the chip, that is, the output end of the startup module 10 is connected to the pin VDD of the chip, and the startup module 10 is used to provide a startup voltage to the power supply terminal of the chip according to the received VBULK signal.

[0065] The input end of the above-mentioned circuit voltage divider module 20 is connected to the power supply end, that is, connected to the pin VDD of the chip, and the output end is connected to the first input end of the operational amplifier clamp module 50. The circuit voltage divider module 20 is used to divide the startup voltage to obtain the first voltage, and perform signal packaging processing on the first voltage into a vdd_clp signal, and then send the vdd_clp signal to the operational amplifier clamp module 50.

[0066] The input end of the circuit protection module 40 is connected to the detection pin, that is, it can be connected to the peripheral circuit of the chip through the detection pin. The detection pin can be at least two pins. Different detection pins have different functions and correspond to different detection voltages. A detection unit can be provided inside the circuit protection module 40 to obtain the corresponding voltage through the detection pin. The output end of the circuit protection module 40 is connected to the input end of the voltage selection module 30.

[0067] The above-mentioned power supply end can power the circuit protection module 40 to make it work. The circuit protection module 40 can obtain the voltage on the detection pin, and determine the trigger protection type of the chip according to the voltage on the detection pin, and then generate a trigger signal according to the trigger protection type. The trigger protection type information can be signal packaged into a corresponding trigger signal, and the trigger signal is sent to the voltage selection module 30.

[0068] Among them, the triggered protection type may include a direct restart method and may also include other restart methods. The direct restart method can be understood as restarting immediately after the chip triggers the protection operation. Other restart methods can be understood as restarting after the chip triggers the protection operation and meets the preset conditions. The preset conditions can, for example, be that a timer starts counting after the chip triggers the protection, and restarts when the counting meets the preset time.

[0069] When the trigger protection type is a direct restart mode, the corresponding generated trigger signal is an Rst signal; when the trigger protection type is other restart modes, for example, when the timing starts after the protection is triggered, the corresponding generated trigger signal is a fault_en signal; when the trigger protection timing reaches the preset time ns, the corresponding generated trigger signal is an en_ns signal, wherein n is a custom setting according to actual needs, n>0, for example, n can be 1, and when n is 1, the corresponding generated trigger signal is an en_1s signal.

[0070] The input end of the voltage selection module 30 is connected to the output end of the circuit protection module 40, and is used to receive and respond to the trigger signal, and select the corresponding second voltage according to the trigger signal, wherein different trigger signals correspond to different second voltages, and the second voltage can be determined according to the trigger protection type of the trigger signal. The output end of the voltage selection module 30 is connected to the second input end of the operational amplifier clamping module 50, and is used to send the second voltage to the operational amplifier clamping module 50.

[0071] Optionally, the voltage selection module 30 may generate a corresponding Vclamp signal according to the second voltage, for example, by performing signal packaging processing on the second voltage to obtain a corresponding Vclamp signal, and sending the Vclamp signal to the operational amplifier clamping module 50 .

[0072] The first input terminal of the operational amplifier clamp module 50 is connected to the circuit voltage divider module 20, the second input terminal is connected to the voltage selection module 30, and the output terminal is connected to the power supply terminal, that is, connected to the pin VDD of the chip. The operational amplifier clamp module 50 is used to receive and respond to the Vclamp signal and the vdd_clp signal, and perform analysis processing on the Vclamp signal and the vdd_clp signal, that is, obtain the first voltage from the vdd_clp signal, obtain the second voltage from the Vclamp signal, and then determine whether it is necessary to discharge the current to reduce the startup voltage based on the first voltage and the second voltage. When the current needs to be discharged, the startup voltage is clamped to reduce the voltage value of the startup voltage to the clamping voltage value, and the clamping voltage value is determined by the voltage value of the second voltage.

[0073] The clamping circuit provided in the embodiment of the present application includes: a startup module, a circuit voltage dividing module, a circuit protection module, a voltage selection module and an operational amplifier clamping module, wherein the output end of the startup module is used to be connected to the power supply end of the chip, and the power supply end is also connected to the input end of the circuit voltage dividing module, the output end of the circuit voltage dividing module is connected to the first input end of the operational amplifier clamping module, the input end of the circuit protection module is connected to the detection pin of the chip, the output end of the circuit protection module is connected to the input end of the voltage selection module, the output end of the voltage selection module is connected to the second input end of the operational amplifier clamping module, and the output end of the operational amplifier clamping module is connected to the power supply end. The startup module is used to provide a startup voltage to the power supply end, the circuit voltage division module is used to divide the startup voltage to obtain a first voltage output to the op amp clamping module, the circuit protection module is used to determine the trigger protection type of the chip according to the voltage on the detection pin, generate a trigger signal and send it to the voltage selection module, the voltage selection module is used to select the second voltage in response to the trigger signal and output it to the op amp clamping module, and the op amp clamping module is used to clamp the startup voltage based on the magnitude relationship between the voltage value of the first voltage and the voltage value of the second voltage, so as to reduce the voltage value of the startup voltage to the clamping voltage value. Compared with the prior art, the clamping circuit can determine the trigger protection type of the chip according to the voltage on the detection pin through the circuit protection module, so that the voltage selection module comprehensively considers the factors of the trigger protection type information, thereby selecting the corresponding second voltage, and through the op amp clamping module according to the first voltage output by the circuit voltage division module and the second voltage output by the voltage selection module, the startup voltage is clamped to a lower clamping voltage value more accurately, thereby avoiding damage to the MOS tube in the chip while reducing the input power of the chip, limiting the maximum working current when the chip is restarted, and further reducing the short-circuit power consumption of the chip.

[0074] In one embodiment, see Figure 2 As shown, the startup module includes: a VBULK unit, a first resistor R1 and a first capacitor C1; one end of the first resistor R1 is connected to one end of the VBULK unit, the other end of the first resistor R1 is respectively connected to one end of the first capacitor C1 and a power supply end, the other end of the first capacitor C1 is connected to the other end of the VBULK unit, and the other end of the VBULK unit and the other end of the first capacitor C1 are both grounded.

[0075] It should be noted that the above-mentioned VBULK unit may include a positive electrode and a negative electrode, and the VBULK unit is used to provide an input voltage to provide a startup voltage for the chip according to the input voltage. The positive electrode of the VBULK unit is connected to one end of the first resistor R1, and the above-mentioned first resistor R1 can be used to limit the current in the circuit. The other end of the first resistor R1 is connected to the upper plate of the first capacitor C1, and the first capacitor C1 is charged to achieve the purpose of voltage stabilization. The lower plate of the first capacitor C1 is connected to the negative electrode of the VBULK unit, and the lower plate of the first capacitor C1 and the negative electrode of the VBULK unit are both grounded. Among them, the first capacitor C1 is a kind of energy storage element, which is used to store charge and has an impedance effect on alternating current.

[0076] In this embodiment, the startup module includes a VBULK unit, a first resistor and a first capacitor, and can limit the current through the first resistor and charge the first capacitor to achieve voltage stabilization, so that the startup voltage provided to the chip is more stable, which facilitates subsequent modules to perform corresponding operations based on a more stable voltage.

[0077] In one embodiment, the circuit voltage divider module includes: a second resistor R2, a third resistor R3, a fourth resistor R4 and a second capacitor C2; one end of the second resistor R2 is connected to the power supply end, the other end of the second resistor R2 is connected to one end of the third resistor R3, the other end of the third resistor R3 is respectively connected to one end of the fourth resistor R4 and one end of the second capacitor C2, the other end of the fourth resistor R4 is connected to the other end of the second capacitor, and the other end of the fourth resistor R4 and the other end of the second capacitor C2 are both grounded.

[0078] Specifically, the second capacitor C2 can be used for filtering, and the starting voltage signal of the power supply end can be converted into a current signal suitable for filtering by filtering, so as to achieve the removal or amplification of the signal. One end of the second resistor R2 can be connected to the other end of the first resistor R1 through the power supply end, the other end of the second resistor R2 is connected to one end of the third resistor R3, and the other end of the third resistor R3 is connected to one end of the fourth resistor R4. The second capacitor C2 is connected in parallel with the fourth resistor R4, which can be understood as the upper plate of the second capacitor C2 is respectively connected to the other end of the third resistor R3 and one end of the fourth resistor R4, the other end of the fourth resistor R4 is connected to the lower plate of the second capacitor C2, and the other end of the fourth resistor R4 and the lower plate of the second capacitor C2 are both grounded.

[0079] The second resistor R2, the third resistor R3, and the fourth resistor R4 jointly realize the voltage division function, and the third resistor R3 and the fourth resistor R4 jointly act to divide the startup voltage (VDD voltage) to obtain the first voltage. Optionally, this embodiment can perform signal encapsulation processing on the first voltage to obtain a voltage division signal vdd_clp, which can be expressed by the following formula:

[0080]

[0081] Wherein, R2 is the resistance value of the second resistor, R3 is the resistance value of the third resistor, R4 is the resistance value of the fourth resistor, and VDD is the starting voltage of the power supply end.

[0082] Since the circuit voltage divider module in this embodiment includes the second resistor, the third resistor, the fourth resistor and the second capacitor, it can divide the starting voltage and accurately determine the first voltage, thereby providing accurate data guidance information for subsequent operations, making it easier for the subsequent operational amplifier clamping module to determine whether the current needs to be discharged based on more accurate information, thereby improving the accuracy of the clamping process.

[0083] In one embodiment, the trigger signal includes a first trigger signal, a second trigger signal and a third trigger signal.

[0084] The circuit protection module is specifically used for: when the voltage on the detection pin meets the first preset condition, determining that the trigger protection type is the first type and generating a first trigger signal based on the first type; when the voltage on the detection pin meets the second preset condition, determining that the trigger protection type is the second type and generating a second trigger signal based on the second type; when the timing starts after the second trigger signal is generated and reaches the preset time, generating a third trigger signal; wherein the first trigger signal and the second trigger signal are used to trigger the voltage selection module to output a second voltage with a different voltage value to the op amp clamp module.

[0085] It is understandable that the first preset condition and the second preset condition can be customized according to actual needs. The first type can be a direct restart mode, and the corresponding trigger signal generated is the Rst signal; the second type can be other restart modes, such as starting the timing after the protection is triggered, and the corresponding trigger signal generated is the fault_en signal. The first type is used to indicate that the chip directly restarts after the protection is triggered, and the second type is used to indicate that the timer starts timing after the chip triggers the protection.

[0086] It should be noted that the input end of the circuit protection module 40 is connected to the first pin and the second pin respectively. A comparator may be provided inside the circuit protection module 40, and the comparator is used to detect the voltage on the first pin of the chip and / or the voltage on the second pin, and determine the trigger protection type according to the voltage on the first pin and / or the voltage on the second pin, and encapsulate the trigger protection type to generate a first trigger signal, and then send the first trigger signal to the voltage selection module 30. Different trigger protection types generate different trigger signals.

[0087] As an implementable manner, the circuit protection module 40 can determine whether the first preset condition is met according to the voltage on the first pin, and when the first preset condition is met, determine that the trigger protection type is the first type and encapsulate the first type to generate a first trigger signal, and then send the first trigger signal to the voltage selection module 30. When the first preset condition is not met, the chip can work normally.

[0088] As another possible implementation, the circuit protection module 40 can determine whether the second preset condition is met according to the voltage on the second pin, and when the second preset condition is met, determine that the trigger protection type is the second type, perform packaging processing on the second type to generate a second trigger signal, and then send the second trigger signal to the voltage selection module 30. When the second preset condition is not met, the chip can work normally.

[0089] As another possible implementation, the circuit protection module 40 generates a third trigger signal after generating the second trigger signal and starts timing, and when the preset time is reached, the circuit protection module 40 generates the third trigger signal, and then sends the third trigger signal to the voltage selection module 30 .

[0090] The circuit protection module 40 is further used to determine that the chip is in a normal working state when the voltage on the detection pin does not meet the first preset condition and does not meet the second preset condition.

[0091] See also Figure 3 As shown, the detection pins include: a first pin and a second pin, and the input end of the circuit protection module 40 is connected to the first pin and the second pin respectively.

[0092] The circuit protection module 40 is specifically used to: when it is detected that the voltage of the first pin is greater than the first preset threshold, determine that the voltage on the detection pin meets the first preset condition;

[0093] When it is detected that the voltage on the second pin is less than the second preset threshold or greater than the third preset threshold, it is determined that the voltage on the detection pin meets the second preset condition; wherein the second preset threshold is less than the third preset threshold.

[0094] It should be noted that the above-mentioned first preset threshold, second preset threshold and third preset threshold can be customized according to actual needs. The first preset threshold and the second preset threshold and the third preset threshold are set independently. The first preset threshold and the second preset threshold can be the same or different. The first preset threshold and the third preset threshold can be the same or different. The second preset threshold is smaller than the third preset threshold.

[0095] Specifically, the chip may crash or operate normally during operation. When the chip is in the crash state, the circuit protection module 40 may detect the voltage on the first pin, and compare the voltage on the first pin with the first preset threshold, and determine whether the first preset condition is met based on the comparison result. When the first preset condition is not met, the chip is in a normal working state, and may detect the voltage on the second pin, and compare the voltage on the second pin with the second preset threshold and the third preset threshold, and determine whether the second preset condition is met based on the comparison result.

[0096] Among them, the voltage on the first pin can be used to determine whether it is a direct trigger restart mode. The first pin can be, for example, a CS pin, which can be understood as a current detection or sampling terminal; the voltage on the second pin can be used to determine whether it is other trigger restart modes. The second pin can be, for example, a ZCD pin, which can be understood as an inductor current zero-crossing detection terminal.

[0097] Specifically, after obtaining the voltage on the first pin, the circuit protection module 40 can compare the voltage on the first pin with the first preset threshold. When the voltage on the first pin is greater than the first preset threshold, it is determined that the voltage on the detection pin meets the first preset condition, and the trigger protection type is determined to be the first type, that is, the chip directly restarts after triggering the protection. After obtaining the voltage on the second pin, the circuit protection module 40 can compare the voltage on the second pin with the second preset threshold and the third preset threshold respectively. When the voltage on the second pin is less than the second preset threshold, it is determined that the voltage on the detection pin meets the second preset condition, and the trigger protection type is determined to be the second type, or, when the voltage on the second pin is greater than the third preset threshold, it is determined that the voltage on the detection pin meets the second preset condition, and the trigger protection type is determined to be the second type, that is, the timer starts timing after the chip triggers the protection. When the voltage on the first pin is not greater than the first preset threshold, and the voltage on the second pin is between the second preset threshold and the third preset threshold, it is determined that the chip is in a normal working state.

[0098] It can be understood that, taking the second pin as the ZCD pin as an example, when the voltage on the ZCD pin is greater than the third preset threshold value, it is characterized that the ZCD pin on the chip is in an overvoltage state, and the voltage on the detection pin meets the second preset condition and determines that the trigger protection type is the second type; when the voltage on the ZCD pin is less than the second preset threshold value, it is characterized that the ZCD pin on the chip is in an undervoltage state, and the voltage on the detection pin meets the second preset condition and determines that the trigger protection type is the second type.

[0099] Furthermore, when the trigger protection type is the first type, the first type is signal encapsulated and processed to generate a first trigger signal, and the first trigger signal is the Rst signal; when the trigger protection type is the second type, the second type is signal encapsulated and processed to generate a second trigger signal, and the second trigger signal is the fault_en signal. When the internal timer of the chip starts timing and reaches the preset time, it restarts. The corresponding third trigger signal can be en_ns, where n is greater than 0. The n can be customized according to actual needs, for example, it can be 1. The corresponding third trigger signal is en_1s, and the en_1s indicates that when the internal timer of the chip starts timing, it will restart when it reaches 1s.

[0100] Among them, after the circuit protection module generates the corresponding trigger signal, the trigger signal can be sent to the voltage selection module 30. When the trigger signal is triggered, the corresponding output is a high level, that is, the output is 1; when it is not triggered, the output is a low level, that is, the output is 0.

[0101] The circuit protection module in this embodiment can determine the trigger protection type more comprehensively and accurately based on the voltage on the first pin and the voltage on the second pin by detecting the voltage on the first pin and the voltage on the second pin, so as to generate a corresponding trigger signal based on the trigger protection type and send it to the voltage selection module, thereby improving the accuracy of determining the trigger protection type.

[0102] In one embodiment, the voltage selection module is specifically used to: provide a second voltage having a first voltage value to the op amp clamp module in response to a first trigger signal; provide a second voltage having a second voltage value to the op amp clamp module in response to a second trigger signal; and provide a second voltage having a first voltage value to the op amp clamp module in response to a third trigger signal.

[0103] The first voltage value is smaller than the second voltage value; the first voltage value and the second voltage value correspond to different clamping voltage values, and the clamping voltage value corresponding to the first voltage value is smaller than the clamping voltage value corresponding to the second voltage value.

[0104] Specifically, the second voltage may be pre-stored in the voltage selection module, and there is a mapping relationship between different trigger protection types and different second voltage values, and the mapping relationship is also stored in the voltage selection module 30. When the voltage selection module 30 receives the first trigger signal, it responds to the first trigger signal and selects the first voltage value V1; when the voltage selection module 30 receives the second trigger signal, it responds to the second trigger signal and selects the second voltage value V2; when the third trigger signal is received, it responds to the third trigger signal and selects the first voltage value V1. The first voltage value V1 < the second voltage value V2. The clamping voltage value corresponding to the first voltage value V1 is less than the clamping voltage value corresponding to the second voltage value.

[0105] After selecting the corresponding second voltage according to the received trigger signal, the voltage selection module 30 may perform signal packaging processing on the second voltage to obtain a Vclamp signal, and send the Vclamp signal to the operational amplifier clamping module 50 .

[0106] Optionally, the voltage selection module 30 is also used to provide a second voltage having a third voltage value to the operational amplifier clamping module 50 when the chip is in a normal working state and a spike voltage is detected; wherein the third voltage value V3 is greater than the second voltage value V2, and the clamping voltage value corresponding to the third voltage value V3 is greater than the clamping voltage value corresponding to the second voltage value V2.

[0107] It can be understood that when the chip is in normal working state, it can detect in real time whether there is a spike voltage. When there is a spike voltage, in order to avoid damaging the chip MOS tube, the startup voltage needs to be clamped. The voltage selection module 30 can perform signal packaging processing on the third voltage value V3 according to the selection of the third voltage value, and obtain the Vclamp signal, and send the Vclamp signal to the operational amplifier clamping module 50.

[0108] The voltage selection module in this embodiment can select the corresponding second voltage according to the received trigger signal to output the second voltage to the operational amplifier clamping module, so that the operational amplifier clamping module can determine whether current discharge processing is required based on the second voltage to reduce input power.

[0109] In one embodiment, the operational amplifier clamping module 50 is specifically configured to discharge current to reduce the voltage value of the startup voltage to the clamping voltage value when the first voltage is greater than or equal to the second voltage.

[0110] Specifically, the first input terminal of the operational amplifier clamp module 50 is connected to the output terminal of the circuit voltage divider module 20, the second input terminal is connected to the output terminal of the voltage selection module 30, and the output terminal of the operational amplifier clamp module 50 is connected to the power supply terminal. The operational amplifier clamp module 50 receives the voltage division signal vdd_clp signal from the circuit voltage divider module 20, and receives the Vclamp signal from the voltage selection module 30, analyzes the vdd_clp signal and the Vclamp signal to obtain the first voltage and the second voltage, and performs a clamping process on the startup voltage to the clamping voltage value based on the first voltage and the second voltage, so as to reduce the voltage value of the startup voltage to the clamping voltage value.

[0111] In the process of clamping the startup voltage to the clamping voltage value based on the magnitude relationship between the voltage value of the first voltage and the voltage value of the second voltage, it can be determined whether to clamp the startup voltage based on the magnitude relationship between the voltage value of the first voltage and the voltage value of the second voltage. When the voltage value of the second voltage is less than the voltage value of the first voltage, the operational amplifier clamping module needs to perform current discharge processing; when the voltage value of the second voltage is not less than the voltage value of the first voltage, the operational amplifier clamping module does not need to perform current discharge processing, determines the clamping voltage value and reduces the voltage value of the startup voltage to the clamping voltage value. In the process of the operational amplifier clamping module 50 performing current discharge processing, the discharge current channel inside the operational amplifier clamping module 50 can be opened to start discharging the first capacitor C1 in the startup module to clamp the startup voltage to the clamping voltage value.

[0112] As an implementable method, when the circuit protection module 40 outputs the Rst signal to the voltage selection module 30, the voltage selection module 30 selects the first voltage value V1, and generates a corresponding Vclamp signal to output to the operational amplifier clamping module 50. The operational amplifier clamping module 50 determines the magnitude relationship between the first voltage and the first voltage value V1. When the first voltage is greater than or equal to the first voltage value V1, the first clamping voltage value VDD1 is determined according to the first voltage value V1, and then the startup voltage is clamped to the first clamping voltage value VDD1. The chip stops switching and is disconnected after dropping to the lowest voltage VDD_OFF, and then the chip is restarted.

[0113] As another implementable method, when the circuit protection module 40 outputs the fault_en signal to the voltage selection module 30, the chip stops the switching action, the voltage selection module 30 selects the second voltage value V2, and generates a corresponding Vclamp signal to output to the operational amplifier clamping module 50, the operational amplifier clamping module 50 determines the magnitude relationship between the first voltage and the second voltage value V2, when the first voltage is greater than or equal to the second voltage value V2, determines the second clamping voltage value VDD2 according to the second voltage value V2, and then performs clamping processing on the startup voltage to the second clamping voltage value VDD2. And the timer inside the chip starts timing. When the timing reaches a preset time, for example, the preset time is 1s, the circuit protection module 40 outputs the en_1s signal to the voltage selection module 30. The voltage selection module 30 selects the first voltage value V1 and generates a corresponding Vclamp signal to output to the operational amplifier clamping module 50. The operational amplifier clamping module 50 determines the magnitude relationship between the first voltage and the first voltage value V1. When the first voltage is greater than or equal to the first voltage value V1, the first clamping voltage value VDD1 is determined according to the first voltage value V1, and then the startup voltage is clamped to the first clamping voltage value VDD1, and is disconnected after dropping to the minimum voltage VDD_OFF, and then the chip is restarted.

[0114] As another implementable method, when the chip is in a normal working state, whether a spike voltage occurs is detected in real time. If a spike voltage is detected, the voltage selection module 30 selects the third voltage value V3, and generates a corresponding Vclamp signal to output to the operational amplifier clamping module 50. The operational amplifier clamping module 50 determines the magnitude relationship between the first voltage and the third voltage value V3. When the first voltage is greater than or equal to the third voltage value V3, the third clamping voltage value VDD3 is determined according to the second voltage value V3, and then the startup voltage is clamped to the third clamping voltage value VDD3.

[0115] Optionally, the operational amplifier clamping module 50 is further used to determine a clamping voltage value according to voltage values ​​of the first voltage, the second voltage and the start-up voltage.

[0116] It should be noted that the above clamping voltage value is the voltage value corresponding to the clamping process of the startup voltage VDD, and the clamping voltage value can be pre-defined according to actual needs. When it is pre-defined, the second voltage can be determined according to the clamping voltage value, and the second voltage value is determined based on the clamping voltage value, the resistance value of the second resistor, the resistance value of the third resistor, and the resistance value of the fourth resistor by the following formula:

[0117]

[0118] Wherein, 1≤n≤3, R2 is the resistance value of the second resistor, R3 is the resistance value of the third resistor, R4 is the resistance value of the fourth resistor, V n is the voltage value of the second voltage, VDD n is the clamping voltage value.

[0119] In this embodiment, the voltage value of the second voltage can be accurately determined by the clamping voltage value, the resistance value of the second resistor, the resistance value of the third resistor and the resistance value of the fourth resistor. After the voltage selection module selects the voltage value of the second voltage, the starting voltage is powered down to the clamping voltage value to reduce the input power, thereby limiting the maximum operating current during restart.

[0120] On the other hand, an embodiment of the present application provides a chip, which includes the clamping circuit 100 provided in the above embodiment.

[0121] Specifically, the chip may be a processor chip, a sensor chip, a memory chip, a communication chip or a control chip. The chip may also include a peripheral circuit 200, which is used to realize functions such as computing, storage, communication, sensing and control.

[0122] Exemplarily, when the chip is a central processing unit chip, the logical operation can perform calculation and control tasks; when the chip is a graphics processing unit chip, the logical operation can process graphics data; it may also include a storage circuit for storing data required for computer operation, for example, when the chip is a random access memory chip, the storage circuit is used to temporarily store data required for computer operation; when the chip is a read-only memory chip, the storage circuit is used to store fixed programs and data; it may also include an analog conversion circuit for converting physical quantities into electrical signals or digital signals, for example, when the chip is a sound sensor chip, the analog conversion circuit is used to convert sound signals into electrical signals, and when the chip is a photoelectric sensor chip, the analog conversion circuit is used to convert optical signals into electrical signals; it may also include a communication circuit for realizing communication and connection between devices, for example, when the chip is a wireless communication chip, the communication circuit is used to realize wireless network connection.

[0123] See also Figure 4 As shown, the above-mentioned peripheral circuit 200 may include a VAC unit, an EMI filer, an RCD absorption circuit, a DRV unit, etc. The VAC unit is connected in parallel with the EMI filer, the RCD absorption circuit is connected to one end of the startup module, and one end of the peripheral circuit 200 is connected to the startup module of the clamping circuit 100. The above-mentioned clamping circuit 100 may also include a logic controller 60, one end of which is connected to the circuit protection module 40, and the other end is connected to the DRV unit, that is, connected to the pin VDD of the chip. The logic controller 60 can generate a control signal and send it to the circuit protection module 40, so that the circuit protection module 40 receives and responds to the control signal, detects the voltage on the CS pin and the ZCD pin, determines the trigger protection type of the chip according to the voltage on the CS pin and the ZCD pin, and then generates a corresponding trigger signal according to the trigger protection type and sends it to the voltage selection module 30, and then the voltage selection module 30 selects the corresponding voltage to generate a Vclamp signal and sends it to the operational amplifier clamping module, so that the operational amplifier clamping module receives and responds to the Vclamp signal, and based on the Vclamp signal and the voltage division signal vdd_clp signal received from the circuit voltage division module, clamps the startup voltage to reduce the voltage value of the startup voltage to the clamping voltage value.

[0124] The chip provided in this embodiment includes the above-mentioned clamping circuit, which can determine the trigger protection type of the chip according to the voltage on the detection pin through the circuit protection module, so that the voltage selection module comprehensively considers the factors of the trigger protection type information, thereby selecting the corresponding second voltage, and through the operational amplifier clamping module according to the first voltage output by the circuit voltage divider module and the second voltage output by the voltage selection module, the startup voltage is clamped to a lower clamping voltage value more accurately, thereby avoiding damage to the MOS tube in the chip while also reducing the input power of the chip, limiting the maximum operating current when the chip is restarted, and further reducing the short-circuit power consumption of the chip.

[0125] On the other hand, the embodiment of the present application further provides a control method. Applied to the clamping circuit provided in the above embodiment, Figure 5 FIG. 1 is a flow chart of a control method according to an embodiment of the present application. Figure 5 As shown, the method includes:

[0126] S101, the starting module provides a starting voltage to the power supply end.

[0127] S102: The circuit voltage-dividing module divides the startup voltage to obtain a first voltage and outputs it to the operational amplifier clamping module.

[0128] S103: The circuit protection module determines the trigger protection type of the chip according to the voltage on the detection pin, generates a trigger signal and sends it to the voltage selection module.

[0129] S104 , the voltage selection module selects a second voltage to output to the operational amplifier clamping module in response to the trigger signal.

[0130] S105. The operational amplifier clamping module clamps the startup voltage based on the magnitude relationship between the voltage value of the first voltage and the voltage value of the second voltage to reduce the voltage value of the startup voltage to a clamping voltage value; wherein the clamping voltage value is determined by the voltage value of the second voltage.

[0131] It can be understood that the above clamping circuit may include a startup module, a circuit voltage division module, a circuit protection module, a voltage selection module and an operational amplifier clamping module.

[0132] The trigger signal may include a first trigger signal, a second trigger signal and a third trigger signal; the circuit protection module determines the trigger protection type of the chip according to the voltage on the detection pin and generates a trigger signal, including:

[0133] When the voltage on the detection pin meets the first preset condition, the trigger protection type is determined to be the first type and a first trigger signal is generated based on the first type; when the voltage on the detection pin meets the second preset condition, the trigger protection type is determined to be the second type and a second trigger signal is generated based on the second type; when the timing starts after the second trigger signal is generated and reaches the preset time, a third trigger signal is generated; wherein the first trigger signal and the second trigger signal are used to trigger the voltage selection module to output a second voltage with a different voltage value to the op amp clamp module.

[0134] See also Figure 6 As shown, Figure 6 FIG. 1 is a flow chart of a control method provided in an embodiment of the present application, which can be executed by a circuit protection module and an op amp clamp module. Figure 6 As shown, the method includes:

[0135] S201. The circuit protection module obtains chip VBULK information.

[0136] S202: Determine whether the chip triggers the first type.

[0137] S203: When the first type is triggered, a second voltage corresponding to the first type is selected through a voltage selection module, and a Vclamp signal is generated, and the Vclamp signal is sent to an operational amplifier clamping module.

[0138] S204: When the first type is not triggered, determine whether the chip triggers the second type.

[0139] S205 . When the second type is triggered, a second voltage corresponding to the second type is selected through a voltage selection module, and a Vclamp signal is generated, and the Vclamp signal is sent to an operational amplifier clamping module.

[0140] S206 , the operational amplifier clamping module determines a clamping voltage value according to the second voltage, performs clamping processing on the startup voltage, and reduces the voltage value of the startup voltage to the clamping voltage value.

[0141] See also Figure 7 As shown, the circuit protection module can obtain the VBULK information of the chip from the startup module in real time. The VBULK information is used to provide a startup voltage to the circuit voltage division module and the circuit protection module, and the startup voltage is divided by the circuit voltage division module to obtain a first voltage. The first voltage can be expressed by the following formula:

[0142]

[0143] Among them, R2 is the resistance value corresponding to the second resistor, R3 is the resistance value corresponding to the third resistor, R4 is the resistance value corresponding to the fourth resistor, VDD is the voltage value of the startup voltage, and vdd_clp is the voltage value of the first voltage.

[0144] After the circuit voltage divider module outputs the first voltage, the identification unit inside the circuit protection module can be used to determine whether the chip triggers the corresponding trigger protection type, which includes the Rst protection type and other protection types.

[0145] As an implementable method, when the chip is in a downtime state, the identification unit inside the circuit protection module first determines whether the chip triggers the Rst protection type. When it is identified that the Rst protection type is triggered, the Rst signal is output to the voltage selection module. The voltage selection module selects the first voltage value V1 and generates a corresponding Vclamp signal. The Vclamp signal is sent to the operational amplifier clamping module. The operational amplifier clamping module determines the first clamping voltage value VDD1 according to the first voltage value V1, the voltage value of the first voltage and the voltage value of the start-up voltage, and clamps the start-up voltage to the first clamping voltage value VDD1. If it is identified that the Rst protection type is not triggered, the chip continues to work.

[0146] Further, the circuit protection module can determine whether to trigger other protection types through an internal identification unit. When it is identified that other protection types are triggered, the other protection types can be, for example, fault_en protection types. When it is identified that the fault_en protection type is triggered, a fault_en signal is output to the voltage selection module. The voltage selection module selects the second voltage value V2 and generates a corresponding Vclamp signal. The Vclamp signal is sent to the operational amplifier clamping module. The operational amplifier clamping module determines the second clamping voltage value VDD2 according to the second voltage value V2, the voltage value of the first voltage and the voltage value of the start-up voltage, and clamps the start-up voltage to the second clamping voltage value VDD2. The timer starts timing. When it is determined that the chip triggers protection 1s later, an en_1s signal is output to the voltage selection module. The voltage selection module selects the first voltage value V1 and generates a corresponding Vclamp signal. The Vclamp signal is sent to the operational amplifier clamping module. The operational amplifier clamping module clamps the start-up voltage to the first clamping voltage value VDD1. When the chip does not trigger other protection types, the chip works normally and detects whether there is a spike voltage. If a spike voltage is detected, the voltage selection module selects the third voltage value V3, generates a corresponding Vclamp signal and sends it to the operational amplifier clamping module. The operational amplifier clamping module determines the second clamping voltage value VDD3 according to the third voltage value V3, the voltage value of the first voltage and the voltage value of the start-up voltage, and then clamps the start-up voltage to the third clamping voltage value VDD3.

[0147] In the process of judging whether the chip triggers the Rst protection type or other protection types, the circuit protection module may detect the voltage on the pin in real time, and the voltage on the pin includes the voltage on the first pin and the voltage on the second pin. When judging whether the Rst protection type is triggered, the circuit protection module may compare the voltage on the first pin with the first preset threshold to judge whether the chip triggers the Rst protection. When the voltage on the first pin is greater than the first preset threshold, it is determined that the Rst protection is triggered; when the voltage on the first pin is not greater than the first preset threshold, it is determined that the chip does not trigger the Rst protection, that is, the chip continues to work.

[0148] When judging whether to trigger other protection types, the circuit protection module may detect the voltage on the second pin in real time, and then compare the voltage on the second pin with the second preset threshold and the third preset threshold. When the voltage on the second pin is less than the second preset threshold, the chip is in an undervoltage state, and it is determined that the chip triggers other protection types; when the voltage on the second pin is greater than the third preset threshold, the chip is in an overvoltage state, and it is determined that the chip triggers other protection types. When the voltage on the second pin is between the second preset threshold and the third preset threshold, it indicates that the chip has not triggered other protection types, that is, the chip continues to work.

[0149] It should be noted that an identification unit is provided inside the circuit protection module, and the identification unit is used to determine the trigger protection type of the chip according to the voltage on the detection pin.

[0150] It is understandable that a detection circuit may be provided inside the above-mentioned identification unit, and the voltage on the above-mentioned detection pin may be obtained through the detection circuit, and the trigger protection type of the chip may be determined according to the voltage on the detection pin.

[0151] See also Figure 8 As shown, Figure 8 These are the waveform diagrams corresponding to the protection direct restart signal Rst, the protection start timing signal fault_en, the protection timing signal en_1s when the protection is triggered for 1s, the voltage selection module output signal Vclamp, the circuit voltage divider module output signal vdd_clp, the VDD signal, the current IVDD signal on the VDD pin, and the DRV signal, respectively. The DRV signal is used to characterize the switching action of the chip.

[0152] It should be noted that when the chip triggers protection and restarts directly, at time t1, the corresponding trigger protection direct restart signal Rst becomes a high level, and the voltage selector output signal Vclamp is generated after selecting the first voltage value V1, and the first voltage value V1 is compared with the first voltage in the circuit voltage divider module output signal vdd_clp. When the first voltage is less than, greater than or equal to the first voltage value V1, the first clamping voltage value VDD1 corresponding to the first voltage value V1 is determined, and the startup voltage is clamped to the first clamping voltage value VDD1. At this time, the IVDD current becomes IVDD_SINK, and the chip stops the switching action and triggers VDD_OFF to re-enter the power-on startup process.

[0153] When the chip is working normally, it can detect in real time whether there is a spike voltage in the VDD signal. When the VDD signal detects the presence of a spike voltage, the voltage selector output signal Vclamp also has a spike voltage signal at the same time, that is, at time t2, the voltage selector selects the third voltage value V3 and compares it with the circuit voltage divider module output signal vdd_clp, determines the third clamping voltage value VDD3 corresponding to the third voltage value V3, and starts the voltage clamping process to the third clamping voltage value VDD3. At this time, the IVDD current becomes IVDD_SINK, and the chip stops switching.

[0154] When the chip triggers the fault_en signal protection, the timing starts and the fault_en signal becomes a high level, that is, at time t3, the voltage selector output signal Vclamp is generated after selecting the second voltage value V2, and the second voltage value V2 is compared with the first voltage in the circuit voltage divider module output signal vdd_clp. When the first voltage is greater than or equal to the second voltage value V2, the second clamping voltage value VDD2 corresponding to the second voltage value V2 is determined, and the startup voltage is clamped to the second clamping voltage value VDD2. At this time, the IVDD current becomes IVDD_SINK, and the chip stops switching. When the protection trigger timing reaches 1s, the en_1s signal becomes high level, that is, at t4, the voltage selection module outputs a signal Vclamp, which selects the first voltage value V1 and compares it with the first voltage in the circuit voltage divider module output signal vdd_clp. When the first voltage is less than or equal to the first voltage value V1, the first clamping voltage value VDD1 corresponding to the first voltage value V1 is determined, the startup voltage is clamped to the first clamping voltage value VDD1, and VDD_OFF is triggered to re-enter the power-on startup process. At t5, when the chip is powered on again, it enters VDD_ON and the chip works normally.

[0155] The control method of the clamping circuit provided in the embodiment of the present application can determine the trigger protection type of the chip according to the voltage on the detection pin through the circuit protection module, so that the voltage selection module comprehensively considers the factors of the trigger protection type information, thereby selecting the corresponding second voltage, and more accurately clamps the startup voltage to a lower clamping voltage value through the operational amplifier clamping module according to the first voltage output by the circuit voltage divider module and the second voltage output by the voltage selection module, thereby avoiding damage to the MOS tube in the chip while reducing the input power of the chip, limiting the maximum operating current when the chip is restarted, and further reducing the short-circuit power consumption of the chip.

[0156] It should be noted that although the operations of the method of the present invention are described in a particular order in the accompanying drawings, this does not require or imply that the operations must be performed in this particular order, or that all the operations shown must be performed to achieve the desired results. On the contrary, the steps depicted in the flow chart can be performed in a different order. Additionally or alternatively, some steps can be omitted, multiple steps can be combined into one step, and / or one step can be decomposed into multiple steps.

[0157] In summary, the clamping circuit, chip and control method provided in the embodiments of the present application include: a startup module, a circuit voltage divider module, a circuit protection module, a voltage selection module and an operational amplifier clamping module. The output end of the startup module is used to connect to the power supply end of the chip, and the power supply end is also connected to the input end of the circuit voltage divider module. The output end of the circuit voltage divider module is connected to the first input end of the operational amplifier clamping module, the input end of the circuit protection module is connected to the detection pin of the chip, the output end of the circuit protection module is connected to the input end of the voltage selection module, the output end of the voltage selection module is connected to the second input end of the operational amplifier clamping module, and the output end of the operational amplifier clamping module is connected to the detection pin of the chip. The output end is connected to the power supply end, wherein the startup module is used to provide a startup voltage to the power supply end, the circuit voltage divider module is used to divide the startup voltage to obtain a first voltage and output it to the operational amplifier clamping module, the circuit protection module is used to determine the trigger protection type of the chip according to the voltage on the detection pin, generate a trigger signal and send it to the voltage selection module, the voltage selection module is used to respond to the trigger signal, select the second voltage to output to the operational amplifier clamping module, and the operational amplifier clamping module is used to clamp the startup voltage based on the size relationship between the voltage value of the first voltage and the voltage value of the second voltage to reduce the voltage value of the startup voltage to the clamping voltage value. Compared with the prior art, the clamping circuit can determine the trigger protection type of the chip according to the voltage on the detection pin through the circuit protection module, so that the voltage selection module comprehensively considers the factors of the trigger protection type information, thereby selecting the corresponding second voltage, and through the operational amplifier clamping module according to the first voltage output by the circuit voltage divider module and the second voltage output by the voltage selection module, the start voltage is clamped to a lower clamping voltage value more accurately, thereby avoiding damage to the MOS tube in the chip while also reducing the input power of the chip, limiting the maximum operating current when the chip is restarted, and further reducing the short-circuit power consumption of the chip.

[0158] The above description is only a preferred embodiment of the present application and an explanation of the technical principles used. Those skilled in the art should understand that the scope of the invention involved in the present application is not limited to the technical solution formed by a specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the inventive concept. For example, the above features are replaced with (but not limited to) technical features with similar functions disclosed in the present application.

Claims

1. A clamping circuit, characterized in that: include: Start-up module, circuit voltage division module, circuit protection module, voltage selection module and operational amplifier clamping module; The output end of the startup module is used to connect to the power supply end of the chip, the power supply end is also connected to the input end of the circuit voltage divider module, the output end of the circuit voltage divider module is connected to the first input end of the operational amplifier clamping module, the input end of the circuit protection module is connected to the detection pin of the chip, the output end of the circuit protection module is connected to the input end of the voltage selection module, the output end of the voltage selection module is connected to the second input end of the operational amplifier clamping module, and the output end of the operational amplifier clamping module is connected to the power supply end; wherein: The startup module is used to provide a startup voltage to the power supply end; The circuit voltage division module is used to divide the startup voltage to obtain a first voltage and output it to the operational amplifier clamping module; The circuit protection module is used to determine the trigger protection type of the chip according to the voltage on the detection pin, generate a trigger signal and send it to the voltage selection module; The voltage selection module is used for selecting a second voltage to be output to the operational amplifier clamping module in response to the trigger signal; The operational amplifier clamping module is used to clamp the startup voltage when the voltage value of the first voltage is greater than or equal to the voltage value of the second voltage, so as to reduce the voltage value of the startup voltage to a clamping voltage value; wherein the clamping voltage value is determined by the voltage value of the second voltage.

2. The clamping circuit according to claim 1, characterized in that: The trigger signal includes a first trigger signal, a second trigger signal and a third trigger signal; The circuit protection module is specifically used for: When the voltage on the detection pin meets a first preset condition, determining that the trigger protection type is a first type and generating the first trigger signal based on the first type; When the voltage on the detection pin meets a second preset condition, determining that the trigger protection type is a second type and generating the second trigger signal based on the second type; When the timing starts after the second trigger signal is generated and reaches the preset time, a third trigger signal is generated; wherein the first trigger signal and the second trigger signal are used to trigger the voltage selection module to output a second voltage with a different voltage value to the operational amplifier clamping module.

3. The clamping circuit according to claim 2, characterized in that: The circuit protection module is also used for: When the voltage on the detection pin does not satisfy the first preset condition and does not satisfy the second preset condition, it is determined that the chip is in a normal working state.

4. The clamping circuit according to claim 2, characterized in that: The detection pin includes: a first pin and a second pin, and the input end of the circuit protection module is connected to the first pin and the second pin respectively; The circuit protection module is also used for: When it is detected that the voltage of the first pin is greater than a first preset threshold, determining that the voltage on the detection pin meets a first preset condition; When it is detected that the voltage on the second pin is less than the second preset threshold or greater than the third preset threshold, it is determined that the voltage on the detection pin meets the second preset condition; wherein the second preset threshold is less than the third preset threshold.

5. The clamping circuit according to claim 2 or 3, characterized in that: The voltage selection module is specifically used for: In response to the first trigger signal, providing a second voltage having a first voltage value to the operational amplifier clamp module; In response to the second trigger signal, providing a second voltage having a second voltage value to the operational amplifier clamp module; In response to the third trigger signal, providing a second voltage having a first voltage value to the operational amplifier clamp module; Wherein, the first voltage value is less than the second voltage value; The first voltage value and the second voltage value correspond to different clamping voltage values, and the clamping voltage value corresponding to the first voltage value is smaller than the clamping voltage value corresponding to the second voltage value.

6. The clamping circuit according to claim 5, characterized in that: The voltage selection module is also used for: When the chip is in a normal working state and a spike voltage is detected, a second voltage having a third voltage value is provided to the operational amplifier clamping module; Among them, the third voltage value is greater than the second voltage value; and the clamping voltage value corresponding to the third voltage value is greater than the clamping voltage value corresponding to the second voltage value.

7. The clamping circuit according to claim 1, characterized in that: The operational amplifier clamping module is specifically used to discharge current to reduce the voltage value of the start-up voltage to the clamping voltage value when the voltage value of the first voltage is greater than or equal to the voltage value of the second voltage.

8. The clamping circuit according to claim 7, characterized in that: The operational amplifier clamping module is further used to determine the clamping voltage value according to voltage values ​​of the first voltage, the second voltage and the start-up voltage.

9. The clamping circuit according to claim 1, characterized in that: The circuit protection module comprises an identification unit, and the identification unit is used to determine the trigger protection type of the chip according to the voltage on the detection pin.

10. The clamping circuit according to claim 1, characterized in that: The above-mentioned circuit voltage divider module includes: a second resistor R2, a third resistor R3, a fourth resistor R4 and a second capacitor C2; one end of the second resistor R2 is connected to the power supply end, the other end of the second resistor R2 is connected to one end of the third resistor R3, the other end of the third resistor R3 is respectively connected to one end of the fourth resistor R4 and one end of the second capacitor C2, the other end of the fourth resistor R4 is connected to the other end of the second capacitor, and the other end of the fourth resistor R4 and the other end of the second capacitor C2 are both grounded.

11. A chip, characterized in that: The chip comprises the clamping circuit as described in any one of claims 1 to 10 above.

12. A control method, characterized in that: Applied to the clamping circuit according to any one of claims 1 to 10, the control method comprises: The startup module provides a startup voltage to the power supply end; The circuit voltage division module performs voltage division processing on the startup voltage to obtain a first voltage and outputs it to the operational amplifier clamping module; The circuit protection module determines the trigger protection type of the chip according to the voltage on the detection pin, generates a trigger signal and sends it to the voltage selection module; The voltage selection module selects a second voltage to output to the operational amplifier clamping module in response to the trigger signal; When the voltage value of the first voltage is greater than or equal to the voltage value of the second voltage, the operational amplifier clamping module clamps the startup voltage to reduce the voltage value of the startup voltage to a clamping voltage value; wherein the clamping voltage value is determined by the voltage value of the second voltage.

13. The method according to claim 12, characterized in that The trigger signal includes a first trigger signal, a second trigger signal and a third trigger signal; The circuit protection module determines the trigger protection type of the chip according to the voltage on the detection pin and generates a trigger signal, including: When the voltage on the detection pin meets a first preset condition, determining that the trigger protection type is a first type and generating the first trigger signal based on the first type; When the voltage on the detection pin meets a second preset condition, determining that the trigger protection type is a second type and generating the second trigger signal based on the second type; When the timing starts after the second trigger signal is generated and reaches the preset time, a third trigger signal is generated; wherein the first trigger signal and the second trigger signal are used to trigger the voltage selection module to output a second voltage with a different voltage value to the operational amplifier clamping module.

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