Protection circuit of power tube, chip and electronic equipment

Abstract

The utility model discloses a protection circuit of a power tube, a chip and electronic equipment, and belongs to the technical field of electronics. The protection circuit comprises: an input voltage detection module comprising an energy storage unit and a first clamping unit; the first end of the energy storage unit is used for coupling input voltage; the second end of the energy storage unit is connected with the output end of the input voltage detection module; the first end of the first clamping unit is connected with the output end of the input voltage detection module; the second end of the first clamping unit is connected with a ground wire; the pull-down module comprises a first switch tube and / or a second switch tube; the first switch tube is used for short-circuiting the grid electrode of the high-side power tube and the ground under the condition that the pull-down module is in a working state; and the second switch tube is used for short-circuiting the grid electrode of the low-side power tube and the ground under the condition that the pull-down module is in the working state. According to the protection circuit of the power tube, the chip and the electronic equipment provided by the invention, the power tube can be protected.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of electronics, and particularly relates to a protection circuit of a power tube, a chip and an electronic device. BACKGROUND

[0002] In a DC-DC (Direct Current-Direct Current) converter or other power supply chip, a wireless charger or a Class D amplifier, a structure of a high side (HS) power tube (HS tube) and a low side (LS) power tube (LS tube) in series is often used. For this structure, in the case of a very fast rising speed of an input voltage (Voltage Input, VIN), the power tube is easily damaged (including HS tube and / or LS tube damage). CONTENT OF THE UTILITY MODEL

[0003] The present application aims to at least solve one of the technical problems existing in the prior art. To this end, the present application provides a protection circuit of a power tube, a chip and an electronic device, which can protect the power tube in the HS tube and LS tube series structure.

[0004] In a first aspect, the present application provides a protection circuit of a power tube, which comprises: an input voltage detection module and a pull-down module; the output end of the input voltage detection module is connected with the pull-down module; in the case that the voltage at the output end of the input voltage detection module is greater than a target threshold value, the pull-down module is in a working state;

[0005] The input voltage detection module comprises an energy storage unit and a first clamping unit; the first end of the energy storage unit is used to connect an input voltage to couple the input voltage; the second end of the energy storage unit is connected with the output end of the input voltage detection module; the first end of the first clamping unit is connected with the output end of the input voltage detection module; the second end of the first clamping unit is connected with a ground;

[0006] The pull-down module comprises a first switch tube and / or a second switch tube;

[0007] The first switch tube is used to short the gate of a high side power tube with the ground in the case that the pull-down module is in a working state;

[0008] The second switch tube is used to short the gate of a low side power tube with the ground in the case that the pull-down module is in a working state.

[0009] The protection circuit of the power tube according to the application can conduct the input voltage to the output end of the input voltage detection module through the energy storage unit, so that the voltage of the output end of the input voltage detection module is raised, and the voltage of the output end of the input voltage detection module is clamped by the first clamping unit. In the case of rapid rise of the input voltage, the voltage of the gate of the target power tube can be pulled down by the pull-down module, the voltage of the gate of the target power tube can be reduced, the path of the power tube punch-through can be closed, the power tube punch-through can be eliminated, the larger current on the path can be avoided to cause damage to the power tube in the case of the power tube punch-through, the power tube can be protected, and the pull-down module can also be protected. In the case that the input voltage does not rise rapidly, the pull-down module is not started to pull down the voltage of the gate of the target power tube, and the pull-down module is closed to pull down the voltage of the gate of the target power tube after a long enough time, so that the normal work of the target circuit is ensured.

[0010] According to an embodiment of the application, the first switch tube is connected with the output end of the input voltage detection module, the gate of the high-side power tube and the ground wire respectively.

[0011] The second switch tube is connected with the output end of the input voltage detection module, the gate of the low-side power tube and the ground wire respectively.

[0012] According to an embodiment of the application, the first clamping unit comprises a Zener diode or at least one switch tube in series.

[0013] According to an embodiment of the application, the first switch tube is a high-voltage switch tube.

[0014] According to an embodiment of the application, the pull-down module further comprises a second clamping unit; the first end of the second clamping unit is connected with the gate of the high-side power tube; the second end of the second clamping unit is connected with a switch node; and the switch node is the connection point of the high-side power tube and the low-side power tube.

[0015] The protection circuit of the power tube according to the application can clamp the voltage of the gate of the HS tube by the second clamping unit, so as to prevent the HS tube from being damaged due to the voltage of the gate of the HS tube being pulled down too low.

[0016] According to an embodiment of the application, the second clamping unit comprises a diode; the first end of the second clamping unit is the cathode of the diode; and the second end of the second clamping unit is the anode of the diode.

[0017] According to an embodiment of the application, the protection circuit of the power tube further comprises a switch module; the switch module is connected with the output end of the input voltage detection module; and the switch module is used to control the output end of the input voltage detection module.

[0018] According to the protection circuit of the power tube, by arranging the switch module, the pull-down module can be prevented from performing pull-down on the voltage of the gate of the target power tube, and normal work of the target circuit can be ensured.

[0019] According to an embodiment of the present application, the switch module comprises a third switch tube.

[0020] The first pole, the second pole and the third pole of the third switch tube are connected with an enable signal, the output end of the input voltage detection module and a ground wire respectively.

[0021] In a second aspect, the present application provides a chip, comprising the protection circuit of the power tube according to the first aspect.

[0022] In a third aspect, the present application provides an electronic device, comprising the chip according to the second aspect.

[0023] Additional aspects and advantages of the present application will be in part apparent and in part pointed out hereinafter. BRIEF DESCRIPTION OF DRAWINGS

[0024] The above and / or additional aspects and advantages of the present application will become apparent and be readily appreciated from the following description, including the appended drawings, wherein:

[0025] Figure 1 is one of the structural schematic diagrams of the protection circuit of the power tube provided by the embodiments of the present application;

[0026] Figure 2 is one of the structural schematic diagrams of the target circuit provided by the embodiments of the present application;

[0027] Figure 3 is another structural schematic diagram of the target circuit provided by the embodiments of the present application;

[0028] Figure 4 is a principle schematic diagram of the punch-through phenomenon of the power tube of the target circuit provided by the embodiments of the present application;

[0029] Figure 5 is a second structural schematic diagram of the protection circuit of the power tube provided by the embodiments of the present application;

[0030] Figure 6 is a working flow schematic diagram of the protection circuit of the power tube provided by the embodiments of the present application;

[0031] Figure 7 is a third structural schematic diagram of the protection circuit of the power tube provided by the embodiments of the present application;

[0032] Figure 8is a structural schematic diagram of a first clamping unit provided by an embodiment of the present application.

[0033] Figure 9 is a structural schematic diagram of a chip provided by an embodiment of the present application.

[0034] Figure 10 is a structural schematic diagram of an electronic device provided by an embodiment of the present application.

[0035] The figure mark: 100, the protection circuit of the power tube; 110, the target circuit; 101, the input voltage detection module; 102, the pull-down module; 710, the energy storage unit; 720, the first clamping unit; 750, the second clamping unit; 760, the switch module; 20, the chip; 30, the electronic device. DETAILED DESCRIPTION

[0036] The technical solutions in the embodiments of the present application will be clearly described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art belong to the scope of protection of the present application.

[0037] The terms "first", "second" and the like in the specification and claims of the present application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than that illustrated or described herein, and the objects distinguished by "first", "second" and the like are generally of a kind and do not limit the number of objects, for example, the first object can be one or more. In addition, "and / or" in the specification and claims means at least one of the connected objects, and the character " / ", generally represents a "or" relationship between the front and rear associated objects.

[0038] The power tube protection circuit, chip and electronic device provided by the embodiments of the present application will be described in detail below with reference to the drawings, through specific embodiments and their application scenarios.

[0039] As shown in the figure, Figure 1 The power tube protection circuit 100 includes: an input voltage detection module 101 and a pull-down module 102; the output end of the input voltage detection module 101 is connected with the pull-down module 102; in the case that the voltage at the output end of the input voltage detection module 101 is greater than a target threshold, the pull-down module 102 is in a working state.

[0040] In actual implementation, the protection circuit 100 of the power tube can be used to protect the target circuit 110. The target circuit 110 can include a circuit structure in series connection of a high-side power tube (which can be referred to as HS tube for short) and a low-side power tube (which can be referred to as LS tube for short). For other circuit structures of the target circuit 110 in addition to the circuit structure, embodiments of the present application do not make any limitation.

[0041] The HS tube and the LS tube are both power tubes. The HS tube is located at the high side, and the LS tube is located at the low side. For the type of the power tube, embodiments of the present application do not make any limitation. The power tube can be an electronic tube, a diode, a triode, a thyristor, or a field effect tube, etc. The field effect tube can be a Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET or MOS tube), an Insulate-Gate Bipolar Transistor (IGBT), or a Junction Field-Effect Transistor (JFET), etc. In the case where the HS tube and the LS tube are both MOS tubes, the HS tube and the LS tube can be referred to as a high-side MOS tube (MHS) and a low-side MOS tube (LHS), respectively.

[0042] For example, Figure 2 A target circuit 110 in a DC-DC converter is shown. Wherein, VDRV represents a driving voltage; VIN represents an input voltage of the target circuit 110, which is generally also an input voltage of the above-mentioned HS tube and LS tube in series connection; SW (Switch) represents a switching node, which is a connection point of the HS tube and the LS tube; BST (Bootstrap) represents a power supply pin; CBST represents a capacitor connected between the power supply pin and the SW; VOUT represents an output voltage of the target circuit 110; and L represents an inductor. Figure 2 The HS tube and the LS tube in the above-mentioned are MHS and LHS, respectively. Correspondingly, GT_HS represents a gate voltage of the HS tube, and GT_LS represents a gate voltage of the LS tube.

[0043] For another example, Figure 3 A target circuit 110 commonly found in another power chip, wireless charger, or Class D amplifier is shown. Wherein, VIN represents an input voltage of the target circuit 110; and SW represents a switching node, which is a connection point of the HS tube and the LS tube. Figure 3 The HS tube and the LS tube in the above-mentioned are MHS and LHS, respectively. Correspondingly, GT_HS represents a gate voltage of the HS tube, and GT_LS represents a gate voltage of the LS tube.

[0044] It should be noted that,Figure 2 and Figure 3 Although both HS and LS are MOS transistors, one skilled in the art can understand that HS and LS are other types of power transistors based on Figure 2 and Figure 3 .

[0045] For the circuit structure in which HS and LS are connected in series, there is a risk that the power transistors will be turned on when the input voltage VIN rises too fast. During the power-on process of the target circuit, the input voltage VIN will gradually rise to a preset value. The rising speed of the input voltage VIN can be used to represent the power-on speed of the target circuit. The faster the rising speed of the input voltage VIN, the faster the power-on speed of the target circuit; otherwise, the slower the rising speed of the input voltage VIN, the slower the power-on speed of the target circuit.

[0046] The principle of the phenomenon of the power transistors being turned on can be shown in Figure 4 . Taking the target circuit shown in Figure 3 as an example, because the MOS transistors have parasitic capacitances, a circuit structure as shown in the left half of Figure 4 is formed. Here, cgd_hs and cgd_ls represent the parasitic capacitances of MHS and LHS respectively. If the rising speed of the input voltage VIN is too fast, the gate voltages of MHS and LHS will be pulled up (as shown in the right half of Figure 4 ). After the gate voltages of MHS and LHS are pulled up, MHS and LHS will be weakly turned on, and there will be a current path from VIN-SW-GND. Here, SW represents the connection point of the HS and LS transistors, and GND represents the ground. In the case where the gate voltages of MHS and LHS are pulled up to a high level, the current in the current path is very large, which can easily cause MHS and / or LHS to be damaged. The above risk of damage during power-on generally occurs within tens of microseconds of the power-on of VIN. The faster the power-on rate, the higher the voltage, and the greater the risk.

[0047] For both HS and LS, although the way of adding a resistor between the gate (G) and the source (S) can be used to pull down the gate voltage so that it is not easily pulled up. However, if the resistance value of the resistor is too large, the pull-down capability is not obvious; if the resistance value of the resistor is too small, the drain current of the power transistor will cause its power consumption to be too large during normal operation.

[0048] The protection circuit 100 of the power transistor can include an input voltage detection module 101 and a pull-down module 102, etc. The output end of the input voltage detection module 101 is connected with the pull-down module 102, so that the pull-down module 102 works according to the output of the input voltage detection module 101.

[0049] The output end of the input voltage detection module 101 is connected with the pull-down module 102, and according to the voltage of the output end of the input voltage detection module 101, the pull-down module 102 can be in different states.

[0050] In some embodiments, when the voltage of the output end of the input voltage detection module 101 is greater than a target threshold, the pull-down module 102 can be in an operating state. When the voltage of the output end of the input voltage detection module 101 is less than or equal to the target threshold, the pull-down module 102 can be in an off state or a non-operating state. The specific value of the target threshold is not limited in the embodiments of the present application.

[0051] It should be noted that the input voltage detection module 101 can couple the input voltage VIN to the output end of itself, so that the output end of the input voltage detection module 101 can output different voltages. The voltage of the output end of the input voltage detection module 101 can be used to indicate the rising speed of the input voltage VIN of the target circuit 110. When the rising speed of the input voltage VIN of the target circuit 110 is fast, the voltage of the output end of the input voltage detection module 101 is greater than the target threshold, and when the rising speed of the input voltage VIN of the target circuit 110 is slow, the voltage of the output end of the input voltage detection module 101 is less than the target threshold.

[0052] In some embodiments, when the rising speed of the input voltage VIN of the target circuit 110 is greater than a preset value, the output end of the input voltage detection module 101 outputs a target driving signal; the target driving signal is used to drive the pull-down module 102. The target driving signal can be a voltage greater than the target threshold. When the rising speed of the input voltage VIN is greater than the preset value, the output end of the input voltage detection module 101 can output a voltage greater than the target threshold; when the rising speed of the input voltage VIN is less than or equal to the preset value, the output end of the input voltage detection module 101 can output a voltage less than the target threshold.

[0053] In some embodiments, the input end of the input voltage detection module 101 can be connected with the input voltage VIN. The input voltage detection module 101 can detect the rising speed of the input voltage VIN, that is, whether the target circuit 110 is powered on quickly. When the rising speed of the input voltage VIN is greater than a preset value, the output end of the input voltage detection module 101 can output a target driving signal. When the rising speed of the input voltage VIN is less than or equal to the preset value, the output end of the input voltage detection module 101 does not output the target driving signal. The specific value of the preset value is not limited in the embodiments of the present application.

[0054] In some embodiments, with reference to Figure 7The input voltage detection module 101 includes an energy storage unit 710 and a first clamping unit 720. The first end of the energy storage unit 710 is used to connect the input voltage VIN of the target circuit 110. The second end of the energy storage unit 710 is connected with the output end of the input voltage detection module 101. The first end of the first clamping unit 720 is connected with the output end of the input voltage detection module 101. The second end of the first clamping unit 720 is connected with the ground.

[0055] In actual implementation, the input voltage detection module 101 can include the energy storage unit 710 and the first clamping unit 720.

[0056] The energy storage unit 710 and the first clamping unit 720 can be connected in series. The connection point of the energy storage unit 710 and the first clamping unit 720 can be the output end of the input voltage detection module 101. The voltage of the output end can be denoted as GT_PLDN.

[0057] The energy storage unit 710 can be connected with the input voltage VIN, and under the action of the input voltage VIN, the energy storage unit 710 couples the electric charge to the output end of the input voltage detection module 101.

[0058] The first clamping unit 720 can be connected with the ground, i.e., grounded. The first clamping unit 720 is used to limit the voltage GT_PLDN of the output end of the input voltage detection module 101. In some embodiments, the first clamping unit 720 can adopt any circuit with clamping function.

[0059] The energy storage unit 710 can transmit the change of the input voltage VIN to GT_PLDN. In the case of rapid rise of the input voltage VIN, GT_PLDN can be high (i.e., greater than the target threshold), so that the target drive signal is a high voltage. The amplitude of GT_PLDN is limited by the first clamping unit 720, preventing GT_PLDN from being too high to damage the pull-down module 102. It can be understood that in the case of GT_PLDN being high, the pull-down module 102 can pull down GT_HS and / or GT_LS, thereby closing MHS and MLS.

[0060] It should be noted that due to the self-consumption characteristics of the first clamping unit 720, the electric charge coupled to GT_PLDN through the energy storage unit 710 will be gradually discharged by the first clamping unit 720. After a time td, the voltage of GT_PLDN is already very low and is insufficient to drive the pull-down module 102 to reduce the voltage of the gate of the target power tube, so that the pull-down is closed and the voltage of the gate of the target power tube is no longer reduced through the pull-down module 102.

[0061] It should be noted that, due to the self-consumption characteristic of the first clamping unit 720, in the case that the rising speed of the input voltage VIN is slow (less than a preset value), the charge coupled to the GT PLDN will be quickly discharged (the discharging speed of the first clamping unit 720 is greater than the charging speed of the energy storage unit 710, and the GT PLDN will not increase to the target threshold value), and the target driving signal will not be output. It can be understood that the target threshold value can be a voltage sufficient to drive the pull-down module 102. For example, in the case that the pull-down module 102 includes a switching tube such as a transistor, the target threshold value can be greater than or equal to the off voltage of the switching tube.

[0062] In some embodiments, the pull-down module 102 includes the first switching tube M PL HS and / or the second switching tube M PL LS.

[0063] In actual implementation, the input voltage detection module 101 can control whether the pull-down module 102 performs pull-down on the voltage of the gate of the power tube protected thereby according to the rising speed of the VIN. In the case that the pull-down module 102 is in a working state, the pull-down module 102 can perform pull-down on the voltage of the gate of the target power tube, thereby protecting the target power tube; in the case that the pull-down module 102 is not in a working state (for example, a closed state or a non-working state), the pull-down module 102 does not perform pull-down on the voltage of the gate of the target power tube.

[0064] In some embodiments, the target power tube can be an HS tube in the target circuit 110, or the target power tube can be an LS tube, or the target power tube can be both an HS tube and an LS tube in the target circuit 110.

[0065] In actual implementation, the pull-down module 102 can include the first switching tube M PL HS for lowering the voltage of the gate of the HS tube, or include the second switching tube M PL LS for lowering the voltage of the gate of the LS tube, or include both the first switching tube M PL HS for lowering the voltage of the gate of the HS tube and the second switching tube M PL LS for lowering the voltage of the gate of the LS tube. The first switching tube M PL HS and / or the second switching tube M PL LS both function to pull down the switching tube.

[0066] The first switching tube M PL HS is used to turn on the connection between the gate of the high-side power tube and the ground in the case that the pull-down module 102 is in a working state.

[0067] In actual implementation, when the voltage at the output end of the input voltage detection module 101 is greater than the target threshold, the pull-down module 102 is in the working state, and the first switch tube M_PL_HS is also in the working state. When the first switch tube M_PL_HS is in the working state, the second pole and the third pole of the first switch tube M_PL_HS are turned on, thereby turning on the connection between the gate of the HS tube and the ground wire, achieving the short circuit between the gate of the HS tube and the ground, and thus the voltage at the gate of the HS tube can be reduced, and GT_HS can be pulled low.

[0068] The specific type of the first switch tube M_PL_HS is not limited in the embodiments of the present application, for example, the first switch tube M_PL_HS can be a MOS tube, an IGBT or a triode, etc. When the first switch tube M_PL_HS is a MOS tube, the first pole can be a gate, the second pole can be a drain, and the third pole can be a source.

[0069] The first pole, the second pole and the third pole of the second switch tube M_PL_LS are connected with the output end of the input voltage detection module 101, the gate of the low-side power tube and the ground wire respectively, so as to turn on the connection between the gate of the low-side power tube and the ground wire when the pull-down module 102 is in the working state.

[0070] In actual implementation, when the voltage at the output end of the input voltage detection module 101 is greater than the target threshold, the pull-down module 102 is in the working state, and the second switch tube M_PL_LS is also in the working state. When the second switch tube M_PL_LS is in the working state, the second pole and the third pole of the second switch tube M_PL_LS are turned on, thereby turning on the connection between the gate of the LS tube and the ground wire, achieving the short circuit between the gate of the LS tube and the ground, and thus the voltage at the gate of the LS tube can be reduced, and GT_LS can be pulled low.

[0071] It can be understood that the second switch tube M_PL_LS can pull GT_LS to GND (ground) and turn off the LS tube.

[0072] The specific type of the second switch tube M_PL_LS is not limited in the embodiments of the present application, for example, the second switch tube M_PL_LS can be a MOS tube, an IGBT or a triode, etc. When the second switch tube M_PL_LS is an IGBT, the first pole can be a gate, the second pole can be a collector, and the third pole can be an emitter.

[0073] It can be understood that when GT_PLDN is high, the first switch tube M_PL_HS can pull GT_HS low, thereby turning off the MHS, and the second switch tube can pull GT_LS low, thereby turning off the MLS.

[0074] It should be noted that the pass-through of the power tube is VIN-HS tube-SW-LS tube-GND, so closing only the HS tube (pulling down the gate voltage of the HS tube), or closing only the LS tube (pulling down the gate voltage of the LS tube), or closing both the HS tube and the LS tube (pulling down the gate voltages of the HS tube and the LS tube) can prevent the power tube from passing through, thereby protecting the two power tubes such as the HS tube and the LS tube.

[0075] It should be noted that the input voltage detection module 101 can also stop outputting the target drive signal when the rising speed of the input voltage VIN changes from greater than the preset value to less than the target value. The target value is less than the preset value. The target value can be very close to 0. It can be understood that the output end of the input voltage detection module 101 stops outputting the target drive signal, and the pull-down module 102 no longer lowers the voltage at the gate of the target power tube.

[0076] In some embodiments, referring to Figure 6 The working process of the protection circuit 100 of the power tube can include the following steps.

[0077] Step 610: detecting whether the rising speed of the input voltage VIN is greater than a preset value.

[0078] If yes, steps 620 and 630 can be performed.

[0079] Step 620: pulling down the voltage at the gate of the target power tube.

[0080] Step 630: outputting the target drive signal for a duration of td.

[0081] The duration of td of the target drive signal is to have enough time to pull down the voltage at the gate of the target power tube. The specific value of the duration of td is not limited in the embodiments of the present application.

[0082] Step 640: closing the pull-down.

[0083] After the duration of td of the target drive signal, the power tube passing through is not formed, and the pull-down of the voltage at the gate of the target power tube can be closed to avoid the voltage at the gate being too low and to ensure the normal working of the target circuit.

[0084] According to the protection circuit of the power tube provided in the embodiment of the present application, the input voltage is conducted to the output end of the input voltage detection module through the energy storage unit, so that the voltage of the output end of the input voltage detection module is raised, and the voltage of the output end of the input voltage detection module is clamped by the first clamping unit, so that the pull-down module is opened to pull down the voltage of the gate of the target power tube in the case of rapid rise of the input voltage, the voltage of the gate of the target power tube is reduced, the path of the power tube punch-through is closed, the power tube punch-through is eliminated, the power tube is protected, the pull-down module is also protected, the pull-down module is not opened to pull down the voltage of the gate of the target power tube in the case of no rapid rise of the input voltage, and the pull-down of the voltage of the gate of the target power tube by the pull-down module is closed after a long enough time, so as to ensure the normal work of the target circuit.

[0085] In some embodiments, the first pole, the second pole and the third pole of the first switch tube M_PL_HS are connected with the output end of the input voltage detection module 101, the gate of the high-side power tube and the ground wire respectively.

[0086] In actual implementation, the first pole of the first switch tube M_PL_HS can be connected with the output end of the input voltage detection module 101, the second pole of the first switch tube M_PL_HS can be connected with the gate of the HS tube, and the third pole of the first switch tube M_PL_HS can be grounded.

[0087] Based on the above connection relationship, in the case that the pull-down module 102 is in the working state, the second pole and the third pole of the first switch tube M_PL_HS are turned on, the gate of the HS tube is short-circuited with the ground, so that the voltage of the gate of the HS tube can be reduced, and GT_HS is pulled down.

[0088] The first pole, the second pole and the third pole of the second switch tube M_PL_LS are connected with the output end of the input voltage detection module 101, the gate of the low-side power tube and the ground wire respectively.

[0089] In actual implementation, the first pole of the second switch tube M_PL_LS can be connected with the output end of the input voltage detection module 101, the second pole of the second switch tube M_PL_LS can be connected with the gate of the LS tube, and the third pole of the second switch tube M_PL_LS can be grounded.

[0090] Based on the above connection relationship, in the case that the pull-down module 102 is in the working state, the second pole and the third pole of the second switch tube M_PL_LS are turned on, the gate of the LS tube is short-circuited with the ground, so that the voltage of the gate of the LS tube can be reduced, and GT_LS is pulled down.

[0091] The protection circuit of the power tube provided in the embodiment of the present application can reduce the voltage of the gate of the HS tube through the first switch tube, and / or reduce the voltage of the gate of the LS tube through the second switch tube, can close the path of the power tube punch-through, can eliminate the power tube punch-through, avoid the larger current on the path to cause the power tube to be damaged in the presence of the power tube punch-through, and can protect the power tube.

[0092] In some embodiments, the first clamping unit 720 includes a Zener diode or at least one switch tube in series.

[0093] In actual implementation, referring to Figure 8 , the first clamping unit 720 includes a Zener diode or at least one switch tube in series. Figure 8 Three structures of the first clamping unit 720 are shown, from left to right, including three MOS tubes in series, a Zener diode, and three triodes in series. The triodes and MOS tubes are switch tubes. It can be understood that, in addition to triodes and MOS, the first clamping unit 720 can also use other types of switch tubes. The number of switch tubes included in the first clamping unit 720 can also not be 3. The number of switch tubes included in the first clamping unit 720 is not specifically limited in the present application, and can also be 1 or 2 or 4, etc.

[0094] In some embodiments, the cathode of the Zener diode can be used as the first end of the first clamping unit 720 and connected to the output end of the input voltage detection module 101; and the anode of the Zener diode can be used as the second end of the first clamping unit 720 and grounded.

[0095] The protection circuit of the power tube provided in the embodiment of the present application can include a Zener diode or at least one switch tube in series in the first clamping unit, can clamp the voltage of the output end of the input voltage detection module, can enable the voltage of the gate of the target power tube to be pulled down in the case of rapid rise of the input voltage, thereby protecting the power tube and protecting the pull-down module, can not enable the voltage of the gate of the target power tube to be pulled down in the case of no rapid rise of the input voltage, and can close the pull-down after a long enough time to ensure the normal operation of the target circuit.

[0096] In some embodiments, in the case where the first clamping unit includes a plurality of switch tubes, the first pole and the second pole of each of the plurality of switch tubes are connected; and the third pole of each of the plurality of switch tubes and the second pole of another switch tube are connected.

[0097] In actual implementation,

[0098] In some embodiments, the energy storage unit 710 includes one or more capacitors.

[0099] In actual implementation, the energy storage unit 710 can include a capacitor module C. The capacitor module C can include one capacitor or multiple capacitors. The multiple capacitors can be connected in series, in parallel, or in a mixed manner.

[0100] It can be understood that the first clamping unit 720 can prevent the input voltage VIN from being coupled through a voltage (i.e., GT_PLDN) of the capacitor module C that is too high to damage the pull-down switch tubes M_PL_HS and M_PL_LS.

[0101] According to the protection circuit of the power tube provided in the embodiments of the present application, the change of the input voltage is transmitted to the output end of the input voltage detection module through the capacitor module, and the voltage at the output end of the input voltage detection module is clamped through the first clamping unit, so that the pull-down module can be switched to the working state in time to reduce the voltage at the gate of the target power tube, to realize the closing of the pass-through path of the power tube, thereby protecting the power tube.

[0102] In some embodiments, the pull-down module 102 can include a first switch module and a first pull-down resistor R1 as shown in FIG. 2. Figure 5 The first pull-down resistor R1 can be connected to the gate of the HS tube and the switch node SW. The first switch module can be arranged between the first pull-down resistor R1 and the gate of the HS tube, or can also be arranged between the first pull-down resistor R1 and the switch node SW. In the case that the input voltage detection module 101 outputs the target drive signal, the first switch module is in a closed state to open the pull-down of the voltage GT_HS at the gate of the HS tube; in the case that the input voltage detection module 101 does not output the target drive signal, the first switch module is in an open state to close the pull-down of the voltage GT_HS at the gate of the HS tube.

[0103] In some embodiments, the pull-down module 102 can include a second switch module and a second pull-down resistor R2 as shown in FIG. 3. Figure 5 The second pull-down resistor R2 can be connected to the gate of the LS tube and the ground. The second switch module can be arranged between the second pull-down resistor R2 and the gate of the LS tube, or can also be arranged between the second pull-down resistor R2 and the ground. In the case that the input voltage detection module 101 outputs the target drive signal, the second switch module is in a closed state to open the pull-down of the voltage GT_LS at the gate of the LS tube; in the case that the input voltage detection module 101 does not output the target drive signal, the second switch module is in an open state to close the pull-down of the voltage GT_LS at the gate of the LS tube.

[0104] In some embodiments, the first switch tube M_PL_HS is a high-voltage switch tube.

[0105] In actual implementation, the first switch tube M PL HS can be a high-voltage switch tube. The second electrode of the first switch tube M PL HS needs to withstand high voltage, and the use of the high-voltage switch tube can prevent the first switch tube M PL HS from being damaged by a high voltage at the gate of the HS tube when the HS tube is normally working or powered on.

[0106] In some embodiments, the pull-down module 102 further includes a second clamping unit 750; a first end of the second clamping unit 750 is connected to the gate of the HS tube; a second end of the second clamping unit 750 is connected to a switch node SW in the target circuit 110; the switch node is a connection point of the HS tube and the LS tube.

[0107] In actual implementation, the pull-down module 102 can further include the second clamping unit 750. The second clamping unit 750 can be arranged between the gate of the HS tube and the switch node SW to clamp the voltage at the gate of the HS tube, mainly to prevent the voltage at the gate of the HS tube from being pulled down too low.

[0108] The second clamping unit 750 is configured to limit the voltage at the gate of the HS tube. In some embodiments, the second clamping unit 750 can be any circuit with clamping function.

[0109] According to the protection circuit of the power tube provided in the embodiments of the present application, the voltage at the gate of the HS tube is clamped by the second clamping unit, so as to prevent the HS tube from being damaged due to the voltage at the gate of the HS tube being pulled down too low.

[0110] In some embodiments, the second clamping unit 750 includes a diode D; a first end of the second clamping unit 750 is the cathode of the diode; and a second end of the second clamping unit 750 is the anode of the diode.

[0111] In actual implementation, the second clamping unit 750 can be a diode D. The anode of the diode D can be connected to the switch node SW, and the cathode of the diode D can be connected to the gate of the HS tube. Through the above arrangement, the first switch tube M PL HS can pull down GT HS, but the diode D can clamp GT HS to the voltage of SW minus the cut-off voltage of the diode D, so as to prevent the MHS from being damaged due to being pulled to a voltage between the gate and the switch node.

[0112] The cut-off voltage of the diode D is not specifically limited in the embodiments of the present application. For example, the cut-off voltage of the diode D can be 0.7V or 0.5V, etc.

[0113] According to the protection circuit of the power tube provided in the embodiments of the present application, the voltage at the gate of the HS tube is clamped by the diode, so as to prevent the HS tube from being damaged due to the voltage at the gate of the HS tube being pulled down too low.

[0114] In some embodiments, the protection circuit 100 of the power tube further comprises a switch module 760; the switch module 760 is connected to the output end of the input voltage detection module 101; and the switch module 760 is configured to control the output end of the input voltage detection module 101.

[0115] In actual implementation, the protection circuit 100 of the power tube can further be provided with the switch module 760. The switch module 760 is connected to the output end of the input voltage detection module 101 to control the output of the input voltage detection module 101.

[0116] In the case where the target circuit 110 works normally, the switch module 760 can be in a closed state; and in the case where the target circuit 110 does not work normally (for example, the power-up has not ended or an abnormality occurs, etc.), the switch module 760 can be in an open state.

[0117] In some embodiments, in the case where the switch module 760 is in the closed state, the output end of the input voltage detection module 101 does not output the target drive signal regardless of whether the rising speed of the input voltage VIN is greater than a preset value; and in the case where the switch module 760 is in the open state, the output end of the input voltage detection module 101 outputs the target drive signal in the case where the rising speed of the input voltage VIN is greater than the preset value.

[0118] In some embodiments, the input signal of the switch module 760 can be an enable signal EN_PWR. The EN_PWR is high when the target circuit 110 works normally, and can pull down the GT_PLDN to the GND, which can prevent the M_PL_HS and the M_PL_LS from being mistakenly opened, thereby affecting the normal logic.

[0119] In some embodiments, the switch module 760 can adopt any kind of switch tube or switch circuit. The specific structure of the switch module 760 is not limited in the embodiments of the present application.

[0120] According to the protection circuit 100 of the power tube provided in the embodiments of the present application, by setting the switch module, the pull-down of the voltage of the gate of the target power tube by the pull-down module can be prevented, and the normal work of the target circuit can be ensured.

[0121] In some embodiments, the switch module 760 comprises a third switch tube; the first pole, the second pole and the third pole of the third switch tube are respectively connected to the enable signal, the output end of the input voltage detection module and the ground wire.

[0122] In actual implementation, the switch module 760 can realize the switching function based on the third switch tube. The first pole of the third switch tube can be connected to the enable signal EN_PWR, the second pole of the third switch tube can be connected to the output end of the input voltage detection module 101, and the third pole of the third switch tube can be grounded.

[0123] In some embodiments, when the enable signal EN_PWR is high, the third switch tube can be in an amplification state or a saturation state, the switch module 760 is in a closed state, and GT_PLDN can be pulled low to GND, preventing the first switch tube M_PL_HS and the second switch tube M_PL_LS from being mistakenly opened to affect the normal working logic of the target circuit 110 when the target circuit 110 is normally working. When the enable signal EN_PWR is high, the third switch tube can be in an off state, and the switch module 760 is in an open state, which has no effect on GT_PLDN.

[0124] According to the power tube protection circuit provided in the embodiments of the present application, by setting the third switch tube, the pull-down module can be prevented from mistakenly performing pull-down on the voltage of the gate of the target power tube, and the normal working of the target circuit can be ensured.

[0125] The embodiments of the present application further provide a chip 20.

[0126] As shown in the figure, the chip 20 includes the power tube protection circuit 100 of the above embodiments, and the same effects can be achieved. To avoid repetition, no further description is given. Figure 9

[0127] In some embodiments, the chip 20 can further include the target circuit 101 of the above embodiments.

[0128] The embodiments of the present application further provide an electronic device.

[0129] As shown in the figure, the electronic device 30 includes the chip 20 described above, and the same effects can be achieved. To avoid repetition, no further description is given. Figure 10

[0130] ​​The electronic device 30 can be a terminal, or can be other than the terminal. For example, the electronic device can be a mobile phone, a tablet computer, a notebook computer, a palm computer, a vehicle-mounted electronic device, a Mobile Internet Device (MID), an augmented reality (AR) / virtual reality (VR) device, a robot, a wearable device, an ultra-mobile personal computer (UMPC), a netbook, or a personal digital assistant (PDA), etc., and can also be a server, a Network Attached Storage (NAS), a personal computer (PC), a television (TV), a cash register, or a self-service machine, etc. The embodiments of the present application are not limited thereto.

[0131] The embodiments of the present application are described above with reference to the drawings; however, the present application is not limited to the specific embodiments described above, which are merely illustrative, but rather the specific embodiments described above are illustrative rather than restrictive, and a person of ordinary skill in the art can make many forms without departing from the spirit of the present application and the scope of protection of the claims, which are all within the scope of protection of the present application.

[0132] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "exemplary embodiment", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the exemplary description of the above terms does not necessarily mean the same embodiment or example. Also, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0133] Although the embodiments of the present application have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, alternatives, and variations can be made thereto without departing from the principles and spirit of the present application, and the scope of the present application is defined by the claims and their equivalents.

Claims

1. A protection circuit for a power tube, characterized by The application relates to a protection circuit of a power tube. The protection circuit comprises an input voltage detection module and a pull-down module. The output end of the input voltage detection module is connected with the pull-down module; the pull-down module is in a working state when the voltage at the output end of the input voltage detection module is greater than a target threshold value. The input voltage detection module comprises an energy storage unit and a first clamping unit; the first end of the energy storage unit is used for connecting an input voltage to couple the input voltage; the second end of the energy storage unit is connected with the output end of the input voltage detection module; the first end of the first clamping unit is connected with the output end of the input voltage detection module; and the second end of the first clamping unit is connected with a ground wire. The pull-down module comprises a first switch tube and / or a second switch tube. The first switch tube is used for short-circuiting the gate of a high-side power tube and the ground wire when the pull-down module is in the working state. The second switch tube is used for short-circuiting the gate of a low-side power tube and the ground wire when the pull-down module is in the working state.

2. The protection circuit for a power tube according to claim 1, characterized in that, The first switch tube is connected with the output end of the input voltage detection module, the gate of the high-side power tube and the ground wire respectively. The second switch tube is connected with the output end of the input voltage detection module, the gate of the low-side power tube and the ground wire respectively.

3. The protection circuit for a power tube according to claim 1, wherein The first clamping unit comprises a Zener diode or at least one switch tube in series.

4. The protection circuit for a power tube according to claim 1, characterized in that, The first switch tube is a high-voltage switch tube.

5. The protection circuit for a power tube according to claim 1, wherein The pull-down module further comprises a second clamping unit; the first end of the second clamping unit is connected with the target electrode of the high-side power tube; the second end of the second clamping unit is connected with a switch node; and the switch node is the connection point of the high-side power tube and the low-side power tube.

6. The protection circuit for a power tube according to claim 5, wherein The second clamping unit comprises a diode; the first end of the second clamping unit is the cathode of the diode; and the second end of the second clamping unit is the anode of the diode.

7. The protection circuit for a power tube according to any one of claims 1 to 6, characterized in that, The application further relates to a protection circuit of a power tube. The protection circuit comprises a switch module. The switch module is connected with the output end of the input voltage detection module; and the switch module is used for controlling the output end of the input voltage detection module.

8. The protection circuit for a power tube according to claim 7, characterized in that, The switch module comprises a third switch tube. The first electrode, the second electrode and the third electrode of the third switch tube are connected with an enable signal, the output end of the input voltage detection module and a ground wire respectively.

9. A chip, characterized by The application further relates to a chip.

10. An electronic device, comprising: The chip comprises the protection circuit of the power tube.

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