Circuit for reducing drive leakage current

Abstract

The embodiment of the utility model discloses a circuit for reducing driving leakage current, relates to the technical field of power electronics, can be used for solving the problem that leakage current flows into a post-stage circuit when a switching tube is driven, and comprises a first switching circuit and a second switching circuit. In other words, the first end of the first switching circuit inputs high level, the first switching circuit is conducted, the second end of the second switching circuit is connected with the power end, the second switching circuit is conducted, and the output end supplies power normally; when the driving chip is in a forbidden state, the signal input end inputs low level, the first switching circuit is cut off, the second switching circuit is also cut off, and the output end cuts off power supply. Therefore, when the driving chip does not work or does not work, power supply of the driving chip is cut off, so that the bootstrap capacitor in the driving chip cannot be charged, the problem of current leakage is solved from the source, and the circuit is simple in implementation logic and low in cost.

Description

Technical Field

[0001] The present application relates to the field of chemical power electronics technology, and in particular to a circuit for reducing driving leakage current. Background Art

[0002] With the continuous development of communication technology, data center power supply systems and integrated circuit chip technology, in the use of driver chip circuits, it is necessary to control the on and off of the switch tube through the driver chip. In the process of driver chip control, when the driver chip is not waving, the driver chip will charge the internal bootstrap capacitor due to the power supply, which will generate leakage current. The leakage current will follow the control signal output to the switch tube through the subsequent circuit, and affect the life of the components in the subsequent circuit, and seriously cause direct damage to the components.

[0003] The existing technology can basically realize the sampling detection of low-voltage line leakage current or the use of diode reverse leakage current suppression circuit. First, the low-voltage line leakage current detection device actually converts the leakage current detected by the leakage current detection module into a leakage current with DC bias by the DC bias module to improve the anti-interference ability of the signal, and the signal processing module performs signal superposition and amplification to further improve the signal anti-interference ability; second, the use of the diode reverse leakage current suppression circuit is actually to set up a detection circuit, a logic circuit, and a switching circuit to enable it to detect whether the diode is at a preset potential, and cooperate with the logic circuit to cut off the diode reverse current path, thereby achieving the purpose of suppressing the diode reverse leakage current.

[0004] However, the above scheme will have one or more of the following problems: 1. The low-voltage line leakage current sampling detection does not solve the leakage current problem, but uses signal processing to improve the signal anti-interference ability, and the sampling accuracy has a large deviation; 2. The diode reverse leakage current suppression circuit is expensive, and the circuit is complex or the circuit control logic is complex. Therefore, how to use a low-cost circuit to solve the leakage current flowing into the subsequent circuit when driving the switch tube is an urgent problem to be solved. Utility Model Content

[0005] In an embodiment of the present application, a circuit for reducing driving leakage current is provided. The influence of driving leakage current on subsequent circuits can be reduced by using a circuit composed of only one N+P type transistor, and a protective effect can also be achieved.

[0006] A circuit for reducing driving leakage current, suitable for coupling to an enable terminal of a driving chip, comprising a first switch circuit and a second switch circuit, wherein the first switch circuit and the second switch circuit both comprise a first terminal, a second terminal and a third terminal;

[0007] The first end of the first switch circuit is coupled to the enable end, the second end of the first switch circuit is connected to the first end of the second switch circuit, and the third end of the first switch circuit is connected to the ground end;

[0008] The second end of the second switch circuit is connected to the power supply end, and the third end of the second switch circuit is connected to the output end;

[0009] The enable terminal of the driving chip is used to control the enable / disable state of the chip.

[0010] It should be further explained that the second switching circuit includes a second transistor, the second end of the first switching circuit is connected to the base of the second transistor, the emitter of the second transistor is connected to the power supply end, and the collector of the second transistor is connected to the output end.

[0011] It should be further explained that the second switch circuit further includes a third resistor, a first end of the third resistor is connected to the second end of the first switch circuit, and a second end of the third resistor is connected to the first end of the second switch circuit.

[0012] It should be further explained that the first switch circuit includes a first transistor;

[0013] The base of the first transistor is connected to the enable terminal of the driving chip, the emitter of the first transistor is connected to the ground terminal, and the collector of the first transistor is connected to the first end of the third resistor.

[0014] It should be further explained that the first switch circuit further includes a first resistor, a first end of the first resistor is connected to the base of the first transistor, and a second end of the first resistor is connected to the ground end.

[0015] It should be further explained that the first switching circuit also includes a first capacitor, a first end of the first capacitor is connected to the emitter of the first transistor, and a second end of the first capacitor is connected to the base of the first transistor.

[0016] It should be further explained that the circuit also includes a second resistor, a first end of the second resistor is connected to the enable end of the driving chip, and a second end of the second resistor is connected to the base of the first transistor.

[0017] It should be further explained that the first transistor is an NPN transistor.

[0018] It should be further explained that the second transistor is a PNP transistor.

[0019] It should be further explained that the circuit further includes a first diode, an anode of the first diode is connected to the enable terminal of the driving chip, and an anode of the first diode is connected to the first end of the first resistor.

[0020] In the embodiment of the present application, a circuit for reducing the driving leakage current is provided, the circuit includes a first switch circuit and a second switch circuit. When the driver chip is in an enabled state, that is, when working normally, the signal input terminal, that is, the first end of the first switch circuit, inputs a high level, the third end of the first switch circuit is connected to the ground terminal, the first switch circuit is turned on, and since the second end of the second switch circuit is connected to the power supply terminal, the second switch circuit is turned on, and the output terminal is powered normally; when the driver chip is in a disabled state, that is, when it is not working or damaged, the signal input terminal inputs a low level, the third end of the first switch circuit is connected to the ground terminal, the first switch circuit is turned off, and since the first switch circuit is turned off, the first end of the second switch circuit is disconnected, so that a loop cannot be formed, so the second switch circuit is also turned off, and the output terminal is disconnected from the power supply. Thus, the present application realizes that when the driver chip is not working or there is no wave action, the power supply of the driver chip is cut off, so that the internal bootstrap capacitor of the driver chip will not be charged, the leakage current problem is solved at the source, and the circuit implementation logic is simple and low-cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0022] Figure 1 is a circuit structure diagram for reducing driving leakage current provided by an embodiment of the present application;

[0023] Figure 2 is a circuit structure diagram for reducing driving leakage current in a specific embodiment of the present application;

[0024] Figure 3 It is a circuit structure diagram for reducing driving leakage current in another embodiment. Specific embodiments

[0025] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of this application.

[0026] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first" and "second" are used only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more features. In the description of the present application, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0027] In this application, the word "exemplary" is used to mean "used as an example, illustration, or description." Any embodiment described in this application as "exemplary" is not necessarily to be construed as being preferred or advantageous over other embodiments. The following description is given to enable any technician in the field to implement and use the present application. In the following description, details are listed for the purpose of explanation. It should be understood that a person of ordinary skill in the art can recognize that the present application can be implemented without using these specific details. In other instances, well-known structures and processes will not be elaborated in detail to avoid obscuring the description of the present application with unnecessary details. Therefore, the present application is not intended to be limited to the embodiments shown, but is consistent with the widest scope consistent with the principles and features disclosed in the present application.

[0028] Example 1

[0029] like Figure 1As shown, the embodiment of the present application provides a circuit for reducing the driving leakage current, the circuit is suitable for coupling to the enable end (DRIVER-EN) of the driver chip, including a first switch circuit and a second switch circuit, the first switch circuit and the second switch circuit both include a first end, a second end and a third end; the first end of the first switch circuit is coupled to the enable end (DRIVER-EN), the second end of the first switch circuit is connected to the first end of the second switch circuit, and the third end of the first switch circuit is connected to the ground end; the second end of the second switch circuit is connected to the power supply end, and the third end of the second switch circuit is connected to the output end out; the enable end (DRIVER-EN) of the driver chip is used to control the enable / disable state of the chip. Wherein, the enable end (DRIVER-EN) of the driver chip is coupled to the first end of the first switch circuit, that is, the enable end (DRIVER-EN) of the driver chip is connected to the input end in, and the input end in is connected to the first end of the first switch circuit, and the enable / disable state control signal, that is, the high / low level signal is transmitted to the first switch circuit.

[0030] Specifically, when the driver chip is in an enabled state, that is, when it is working normally, the signal input terminal in, that is, the first end of the first switch circuit, inputs a high level, the third end of the first switch circuit is connected to the ground end, and the first switch circuit is turned on. Since the second end of the second switch circuit is connected to the power supply end, the second switch circuit is turned on, and the output terminal out is powered normally; when the driver chip is in a disabled state, that is, when it is not working or damaged, the signal input terminal in inputs a low level, the third end of the first switch circuit is connected to the ground end, and the first switch circuit is turned off. Since the first switch circuit is turned off, the first end of the second switch circuit is disconnected, so a loop cannot be formed, so the second switch circuit is also turned off, and the output terminal out is disconnected from the power supply.

[0031] The above circuit for reducing the driving leakage current prevents the subsequent circuit components from being damaged by the driving leakage current, and plays a role in reducing the driving leakage current and protecting the subsequent circuit components.

[0032] In a specific embodiment, Figure 2As shown, where +12V is the power supply, +12VD_VCC is the power supply for the driver chip, and the enable terminal (DRIVER-EN) represents the EN (enable) pin of the driver chip. The first switch circuit includes a first transistor Q1, which is an NPN transistor, the base of the first transistor Q1 is connected to the enable terminal (DRIVER-EN) of the driver chip, the emitter of the first transistor Q1 is connected to the ground terminal, and the collector of the first transistor Q1 is connected to the first end of the third resistor R3. Exemplarily, in order to protect the circuit, the first switch circuit is also provided with a pull-down resistor, denoted as the first resistor R1, the first end of the first resistor R1 is connected to the base of the first transistor Q1, and the second end of the first resistor R1 is connected to the ground terminal.

[0033] Exemplarily, the first switch circuit further includes a first capacitor C1, a first end of the first capacitor C1 is connected to the emitter of the first transistor Q1, and a second end of the first capacitor C1 is connected to the base of the first transistor Q1. The capacitor is connected between the signal line and the ground to form a bypass. When an interference signal enters the circuit, the interference will pass through the capacitor instead of the signal line, and the interference signal will be filtered out to the ground without affecting the normal signal on the signal line. Therefore, the capacitor can effectively reduce the interference noise level in the circuit and improve the quality and reliability of the signal.

[0034] The second switch circuit includes a second transistor Q2, which is a PNP transistor, the second end of the first switch circuit is connected to the base of the second transistor Q2, the emitter of the second transistor Q2 is connected to the power supply end, and the collector of the second transistor Q2 is connected to the output end out. Exemplarily, the second switch circuit can also be provided with a pull-down resistor, which is recorded as a third resistor R3, the first end of the third resistor R3 is connected to the second end of the first switch circuit, and the second end of the third resistor R3 is connected to the first end of the second switch circuit.

[0035] Exemplarily, in order to prevent the interference signal from misleading the first transistor Q1, a diode D1 may be provided to raise the conduction threshold, which is recorded as the first diode D1. The anode of the first diode D1 is connected to the enable terminal (DRIVER-EN) of the driver chip, and the anode of the first diode D1 is connected to the first end of the first resistor R1. The first diode D1 may be a common diode D1 with a threshold of about 0.7V. The size of the specific diode D1 may be selected by those skilled in the art according to actual conditions, and this embodiment will not be further limited thereto.

[0036] Exemplarily, the circuit also includes a second resistor R2, which can ensure that the switch is turned off at a critical input voltage, wherein the first end of the second resistor R2 is connected to the enable end (DRIVER-EN) of the driver chip, and the second end of the second resistor R2 is connected to the base of the first transistor Q1.

[0037] Thus, when the driver chip works normally, the enable terminal (DRIVER-EN) outputs a high level, Q1 is turned on, Q2 is turned on, and the +12VD_VCC driver chip is powered normally. When the driver chip does not work or is damaged, the enable terminal (DRIVER-EN) outputs a low level, Q1 is turned off, Q2 is turned off, and the +12VD_VCC driver chip is powered off. Therefore, the circuit of this implementation solves the leakage current problem at the source.

[0038] Example 2

[0039] In another specific embodiment, based on Embodiment 1, a circuit for reducing driving leakage current may be further simplified.

[0040] like Figure 3 As shown, where +12V is the power supply, +12VD_VCC is the power supply for the driver chip, and the enable terminal (DRIVER-EN) represents the EN (enable) pin of the driver chip. Exemplarily, the first switch circuit may include a first transistor Q1, a first resistor R1, and a first capacitor C1. Wherein, the base of the first transistor is connected to the enable terminal (DRIVER-EN) of the driver chip, the emitter of the first transistor is connected to the first end of the first resistor R1, and the second end of the first resistor R1 is connected to the ground terminal. In this embodiment, the first resistor R1 is used as a pull-down resistor protection circuit. It should be noted that the circuit also includes a second resistor R2, which can ensure that the switch is turned off at a critical input voltage, the first end of the second resistor R2 is connected to the enable terminal (DRIVER-EN) of the driver chip, and the second end of the first resistor R1 is connected to the base of the first transistor Q1.

[0041] Exemplarily, the first end of the first capacitor C1 is connected to the second end of the second resistor R2, and the second end of the first capacitor C1 is connected to the base of the first transistor Q1. The function of the capacitor in this embodiment is to reduce the interference noise level in the circuit and improve the quality and reliability of the signal.

[0042] Exemplarily, the second switch circuit includes a second transistor Q2, the second transistor Q2 is a PNP transistor, the second end of the first switch circuit is connected to the base of the second transistor Q2, the emitter of the second transistor Q2 is connected to the power supply end, and the collector of the second transistor Q2 is connected to the output end out. Exemplarily, the second switch circuit can also be provided with a pull-down resistor, which is recorded as a third resistor R3, the first end of the third resistor R3 is connected to the second end of the first switch circuit, and the second end of the third resistor R3 is connected to the first end of the second switch circuit.

[0043] Therefore, on the basis of Embodiment 1, the components of the first switch circuit are simplified, that is, the first diode D1 is no longer provided for raising the conduction threshold. The circuit of this embodiment can still achieve the technical effect of using a simple and low-cost circuit to prevent the subsequent circuit components from being damaged by the driving leakage current under normal circumstances.

[0044] Example 3

[0045] In another specific embodiment, Figure 2-Figure 3 As shown, the above two circuits can also realize level conversion. Exemplarily, the circuit can be coupled to the enable end of a microcontroller (MCU) or a microprocessor. When it is necessary to pass signals of different levels to the enable end of the MCU or the microprocessor, the level conversion circuit can be used to adapt the signal level. Exemplarily, the circuit can also be coupled to the input enable end of a logic gate chip. Since the logic gate chip usually has a specific input level requirement, the level conversion circuit can be used to convert signals of different levels into a level suitable for the input enable end of the logic gate chip. Exemplarily, the circuit can also drive the input enable end of a chip, such as a motor driver chip, an LED driver chip, etc. When it is necessary to control the enable or disable of the driver chip through the input enable end, the level conversion circuit can be used to adapt the signal level. Exemplarily, the circuit can also be the enable end of a trigger chip. Since the trigger chip usually requires a specific level to be triggered, the level conversion circuit can be used to convert signals of different levels into the enable level of the trigger chip.

[0046] A specific level conversion embodiment is given below. Figure 3As shown, for example, the control signal is a signal sent by a digital signal processor (DSP), and its high level is 3.3V and its low level is 0V. When the control signal outputs a high level, the first transistor Q1 is turned on, and the collector of the first transistor Q1 is pulled down to a low level (0V). At the same time, the corresponding first transistor Q2 is turned on, and the collector of the first transistor Q2 outputs a high level (12V). In this case, when the enable signal is a high level, the first transistor Q1 and the first transistor Q2 are turned on at the same time, and the conduction of the first transistor Q1 causes the collector potential of the first transistor Q1 to be pulled down to 0V, so the first transistor Q2 is turned on, so that the collector of the first transistor Q2 outputs a high level (12V). Thus, this embodiment can achieve level conversion. The above is a detailed introduction to a circuit for reducing driving leakage current provided in an embodiment of the present application. Specific examples are used in this article to illustrate the principles and embodiments of the present application. The description of the above embodiments is only used to help understand the method of the present application and its core idea; at the same time, for technical personnel in this field, according to the idea of ​​the present application, there will be changes in the specific embodiments and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A circuit for reducing driver leakage current, suitable for coupling to an enable terminal of a driver chip, characterized in that: The device comprises a first switch circuit and a second switch circuit, wherein the first switch circuit and the second switch circuit each comprise a first end, a second end and a third end; The first end of the first switch circuit is coupled to the enable end, the second end of the first switch circuit is connected to the first end of the second switch circuit, and the third end of the first switch circuit is connected to the ground end; The second end of the second switch circuit is connected to the power supply end, and the third end of the second switch circuit is connected to the output end; The enable terminal of the driving chip is used to control the enable / disable state of the chip.

2. A circuit for reducing driving leakage current as claimed in claim 1, characterized in that: The second switch circuit includes a second transistor, the second end of the first switch circuit is connected to the base of the second transistor, the emitter of the second transistor is connected to the power supply end, and the collector of the second transistor is connected to the output end.

3. A circuit for reducing driving leakage current as claimed in claim 2, characterized in that: The second switch circuit further includes a third resistor, a first end of the third resistor is connected to the second end of the first switch circuit, and a second end of the third resistor is connected to the first end of the second switch circuit.

4. A circuit for reducing driving leakage current as claimed in claim 3, characterized in that: The first switch circuit includes a first transistor; The base of the first transistor is connected to the enable terminal of the driving chip, the emitter of the first transistor is connected to the ground terminal, and the collector of the first transistor is connected to the first end of the third resistor.

5. A circuit for reducing driving leakage current as claimed in claim 4, characterized in that: The first switch circuit further includes a first resistor, a first end of the first resistor is connected to the base of the first transistor, and a second end of the first resistor is connected to the ground end.

6. A circuit for reducing driving leakage current as claimed in claim 5, characterized in that: The circuit further includes a first diode, an anode of the first diode is connected to the enable terminal of the driving chip, and an anode of the first diode is connected to the first end of the first resistor.

7. A circuit for reducing driving leakage current as claimed in claim 4, characterized in that: The circuit further includes a second resistor, a first end of the second resistor is connected to an enable end of the driving chip, and a second end of the second resistor is connected to a base of the first transistor.

8. A circuit for reducing driving leakage current as claimed in claim 4, characterized in that: The first switch circuit further includes a first capacitor, a first end of the first capacitor is connected to the emitter of the first transistor, and a second end of the first capacitor is connected to the base of the first transistor.

9. A circuit for reducing driving leakage current as claimed in claim 4, characterized in that: The first transistor is an NPN transistor.

10. A circuit for reducing driving leakage current according to any one of claims 5 or 6, characterized in that: The second transistor is a PNP transistor.

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