阅读说明：本技术 充电桩及其功率开关管的负压驱动电路 (Charging pile and negative pressure driving circuit of power switch tube thereof ) 是由 王彦 于 2020-11-24 设计创作，主要内容包括：本发明提供了一种充电桩及其功率开关管的负压驱动电路,所述电路包括三电平生成电路、关断开关管和负压截断管,三电平生成电路分别与关断开关管和功率开关管相连,负压截断管分别与关断开关管和功率开关管相连,其中,三电平生成电路用于生成三段电平,并且三段电平中的第一段电平发送至功率开关管,三段电平中的第二段电平发送至关断开关管,负压截断管用于接收功率开关管的控制信号,并在控制信号为负向控制信号时,截断负向控制信号,以使负向控制信号发送至关断开关管来控制关断开关管导通,从而实现功率开关管的关断。本发明能够保证负压的稳定性,并能够简化关断回路的设计,从而能够提高关断速度,并能够减少关断过程中产生的寄生电感。(The invention provides a charging pile and a negative pressure driving circuit of a power switch tube of the charging pile, wherein the circuit comprises a three-level generating circuit, a turn-off switch tube and a negative pressure cutoff tube, the three-level generating circuit is respectively connected with the turn-off switch tube and the power switch tube, the negative pressure cutoff tube is respectively connected with the turn-off switch tube and the power switch tube, the three-level generating circuit is used for generating three levels, a first level in the three levels is sent to the power switch tube, a second level in the three levels is sent to the turn-off switch tube, the negative pressure cutoff tube is used for receiving a control signal of the power switch tube, and when the control signal is a negative control signal, the negative control signal is cut off, so that the negative control signal is sent to the turn-off switch tube to control the turn-off switch tube to be conducted, and the turn-off of the. The invention can ensure the stability of negative pressure and simplify the design of a turn-off loop, thereby improving the turn-off speed and reducing the parasitic inductance generated in the turn-off process.)

1. A negative pressure driving circuit of a power switch tube is characterized by comprising a three-level generating circuit, a turn-off switch tube and a negative pressure cutoff tube, wherein the three-level generating circuit is respectively connected with the turn-off switch tube and the power switch tube, the negative pressure cutoff tube is respectively connected with the turn-off switch tube and the power switch tube, the three-level generating circuit is used for generating three levels, a first level in the three levels is sent to the power switch tube, a second level in the three levels is sent to the turn-off switch tube, the negative pressure cutoff tube is used for receiving a control signal of the power switch tube and cutting off the negative control signal when the control signal is a negative control signal, so that the negative control signal is sent to the turn-off switch tube to control the turn-off switch tube to be conducted, thereby realizing the turn-off of the power switch tube.

2. The negative voltage driving circuit of a power switch tube according to claim 1, wherein the three-level generating circuit comprises:

a drive power supply;

the cathode of the voltage stabilizing diode is connected with the anode of the driving power supply;

one end of the first resistor is connected with the anode of the voltage stabilizing diode;

one end of the second resistor is connected with the other end of the first resistor, and the other end of the second resistor is connected with the negative electrode of the driving power supply and is grounded;

one end of the first capacitor is connected with the anode of the driving power supply, and the other end of the first capacitor is connected with the anode of the voltage stabilizing diode;

one end of the second capacitor is connected with the anode of the voltage stabilizing diode, and the other end of the second capacitor is connected with the other end of the first resistor;

and one end of the third capacitor is connected with one end of the second resistor, and the other end of the third capacitor is connected with the negative electrode of the driving power supply and is grounded.

3. The negative voltage driving circuit of claim 2, wherein an anode of the zener diode, one end of the first resistor, the other end of the first capacitor, and one end of the second capacitor are connected to each other and generate the first segment level.

4. The negative voltage driving circuit of claim 3, wherein the other end of the first resistor, the one end of the second resistor, the other end of the second capacitor and the one end of the third capacitor are connected to each other and generate the second segment level.

5. The negative voltage driving circuit of claim 1, wherein the turn-off switch is a P-MOSFET, and the P-MOSFET is connected to the level generating circuit via a drain to receive the second segment of the level, and the P-MOSFET is connected to the power switch via a source.

6. The negative voltage driving circuit of claim 5, wherein the negative voltage cutoff transistor is a diode, and the diode receives the control signal of the power switching transistor through a positive electrode and is connected to the gate of the P-MOSFET transistor, and further connected to the drain of the P-MOSFET transistor and the power switching transistor through a negative electrode.

7. The negative voltage driving circuit of the power switch tube as claimed in claim 6, wherein the control signal is a PWM signal.

8. A charging pile, characterized by comprising a negative voltage driving circuit of the power switching tube according to any one of claims 1 to 7.

Technical Field

The invention relates to the technical field of switch control, in particular to a negative-pressure driving circuit of a power switch tube and a charging pile.

Background

GaN, as a latest wide bandgap switching device, is suitable for a high frequency power circuit by virtue of its excellent turn-on characteristics, and is increasingly applied in the field of power electronics. However, the threshold of the driving voltage of GaN is very low, about 1V, and therefore, it is necessary to provide a negative voltage in the driving circuit to ensure the safe and stable operation of GaN.

However, in the conventional GaN driving circuit, a capacitor C is often connected in series to generate a negative voltage for driving, and specifically, as shown in fig. 1, when a driving signal for driving GaN, i.e., a PWM signal, is positive, a positive voltage is generated on the capacitor C, and when the driving signal for driving GaN, i.e., the PWM signal, is negative, the positive voltage of the capacitor C is applied to a gate terminal of GaN for driving. However, the negative pressure driving scheme has the following disadvantages: firstly, the negative voltage is often unstable because the negative voltage changes along with the duty ratio and the switching period of the PWM; secondly, the length of the whole driving circuit is too long, so that the driving circuit is not suitable for high-frequency application. The waveform of the driving signal for driving GaN is shown in fig. 2.

Disclosure of Invention

The present invention is directed to solving, at least to some extent, one of the technical problems in the art described above. Therefore, an object of the present invention is to provide a negative voltage driving circuit for a power switching tube, which can ensure the stability of negative voltage and simplify the design of a turn-off circuit, thereby increasing the turn-off speed and reducing the parasitic inductance generated during the turn-off process.

The second purpose of the invention is to provide a charging pile.

In order to achieve the above object, a first embodiment of the present invention provides a negative voltage driving circuit for a power switching tube, including a three-level generating circuit, a turn-off switching tube and a negative voltage cutoff tube, where the three-level generating circuit is respectively connected to the turn-off switching tube and the power switching tube, and the negative voltage cutoff tube is respectively connected to the turn-off switching tube and the power switching tube, where the three-level generating circuit is configured to generate three levels, a first level of the three levels is sent to the power switching tube, a second level of the three levels is sent to the turn-off switching tube, the negative voltage cutoff tube is configured to receive a control signal of the power switching tube, and when the control signal is a negative control signal, the negative control signal is cut off so that the negative control signal is sent to the turn-off switching tube to control the turn-off switching tube to be turned on, thereby realizing the turn-off of the power switch tube.

According to the negative-pressure driving circuit of the power switch tube, provided by the embodiment of the invention, the three-level generating circuit is used for generating three levels, a first level of the three levels is sent to the power switch tube, a second level of the three levels is sent to the turn-off switch tube, the negative-pressure cutoff tube is used for receiving a control signal of the power switch tube, and when the control signal is a negative control signal, the negative control signal is cut off, so that the negative control signal is sent to the turn-off switch tube to control the turn-off switch tube to be conducted, and the turn-off of the power switch tube is realized, therefore, the stability of negative pressure can be ensured, the design of a turn-off loop can be simplified, the turn-off speed can be improved, and parasitic inductance generated in the turn-off process can be.

In addition, the negative voltage driving circuit of the power switch tube according to the above embodiment of the present invention may further have the following additional technical features:

according to an embodiment of the present invention, the three-level generating circuit includes: a drive power supply; the cathode of the voltage stabilizing diode is connected with the anode of the driving power supply; one end of the first resistor is connected with the anode of the voltage stabilizing diode; one end of the second resistor is connected with the other end of the first resistor, and the other end of the second resistor is connected with the negative electrode of the driving power supply and is grounded; one end of the first capacitor is connected with the anode of the driving power supply, and the other end of the first capacitor is connected with the anode of the voltage stabilizing diode; one end of the second capacitor is connected with the anode of the voltage stabilizing diode, and the other end of the second capacitor is connected with the other end of the first resistor; and one end of the third capacitor is connected with one end of the second resistor, and the other end of the third capacitor is connected with the negative electrode of the driving power supply and is grounded.

According to an embodiment of the present invention, the anode of the zener diode, one end of the first resistor, the other end of the first capacitor, and one end of the second capacitor are connected to each other, and the first segment level is generated.

According to an embodiment of the present invention, the other end of the first resistor, the one end of the second resistor, the other end of the second capacitor, and the one end of the third capacitor are connected to each other, and the second segment level is generated.

According to one embodiment of the invention, the turn-off switch tube is a P-MOSFET tube, the P-MOSFET tube is connected with the level generating circuit through a drain electrode to receive the second segment of level, and the P-MOSFET tube is connected with the power switch tube through a source electrode.

According to an embodiment of the invention, the negative voltage cutoff tube is a diode, and the diode receives a control signal of the power switch tube through a positive electrode and is connected with a gate electrode of the P-MOSFET tube, and in addition, the diode is respectively connected with a drain electrode of the P-MOSFET tube and the power switch tube through a negative electrode.

According to one embodiment of the invention, the control signal is a PWM signal.

In order to achieve the above object, a charging pile according to a first aspect of the present invention includes a negative voltage driving circuit of a power switch tube according to the first aspect of the present invention.

According to the charging pile provided by the embodiment of the invention, the negative voltage driving circuit of the power switch tube provided by the embodiment can ensure the stability of negative voltage, so that the quality of a product can be improved, the design of a turn-off loop can be simplified, the turn-off speed can be increased, and parasitic inductance generated in the turn-off process can be reduced.

Drawings

FIG. 1 is a prior art drive circuit topology;

FIG. 2 is a waveform diagram of a prior art driving signal;

FIG. 3 is a block diagram of a negative voltage driving circuit of a power switch tube according to an embodiment of the present invention;

FIG. 4 is a topology diagram of a negative voltage driving circuit of a power switch tube according to an embodiment of the invention;

fig. 5 is a waveform diagram of a driving signal generated by a negative voltage driving circuit of a power switch tube according to an embodiment of the invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Fig. 3 is a block diagram of a negative voltage driving circuit of a power switch tube according to an embodiment of the invention.

As shown in fig. 3, the negative voltage driving circuit of the power switch tube according to the embodiment of the present invention includes a three-level generating circuit 10, a turn-off switch tube 20, and a negative voltage cutoff tube 30, where the three-level generating circuit 10 is connected to the turn-off switch tube 20 and the power switch tube 100, respectively, and the negative voltage cutoff tube 30 is connected to the turn-off switch tube 20 and the power switch tube 100, respectively. The three-level generating circuit 10 is configured to generate three levels, a first level of the three levels is sent to the power switching tube 100, a second level of the three levels is sent to the turn-off switching tube 20, the negative voltage cutoff tube 30 is configured to receive a control signal of the power switching tube 100, and cut off the negative control signal when the control signal is a negative control signal, so that the negative control signal is sent to the turn-off switching tube 20 to control the turn-off switching tube 20 to be turned on, thereby turning off the power switching tube 100.

Specifically, as shown in fig. 4, the three-level generating circuit 10 may be respectively connected to the drain of the turn-off switch 20, i.e., Q2, and the source of the power switch 100, i.e., Q1, and may correspondingly transmit the generated first-stage level and second-stage level to the source of the power switch 100, i.e., Q1, and the drain of the turn-off switch 20, i.e., Q2; the negative pressure cutoff tube 30, that is, the positive electrode of D1, may be connected to the gate of the turn-off switch tube 20, that is, Q2, the negative electrode of the negative pressure cutoff tube 30, that is, D1, may be connected to the source of the turn-off switch tube 20, that is, Q2, and the gate of the power switch tube 100, that is, Q1, respectively, and the negative pressure cutoff tube 30, that is, Q2, may receive the control signal of the power switch tube 100, that is, Q1, through the positive electrode, and, when the control signal is a negative control signal, cut off the control signal, so that the negative control signal is sent to the gate of the turn-off switch tube 20, that is, Q2, to control the turn-off switch tube 20, that is, Q12 to be turned on, thereby achieving the turn-off of the power switch tube 100, that is, Q1, thereby, the stability of the negative pressure may.

In one embodiment of the present invention, as shown in fig. 4, the three-level generating circuit 10 includes: a drive power supply, i.e., power supply V1, i.e., power supply V1; the cathode of the voltage stabilizing diode D3, D3, can be connected with the anode of the driving power supply V1; a first resistor, namely R1, one end of which is R1, can be connected with the anode of a voltage stabilizing diode, namely D3; a second resistor, i.e., R2, one end of the second resistor, i.e., R2, may be connected to the other end of the first resistor, i.e., R1, and the other end of the second resistor, i.e., R2, may be connected to the negative electrode of the driving power source, i.e., power source V1, and to ground; one end of a first capacitor, namely, C1, a first capacitor, namely, C1, may be connected to the positive electrode of the driving power supply, namely, the power supply V1, and the other end of the first capacitor, namely, C1, may be connected to the positive electrode of a zener diode, namely, D3; one end of a second capacitor, namely C2, namely C2, can be connected with the anode of a zener diode, namely D3, and the other end of the second capacitor, namely C2, can be connected with the other end of a first resistor, namely R1; one terminal of a third capacitor, i.e., C3, C3 may be connected to one terminal of a second resistor, i.e., R2, and the other terminal of the third capacitor, i.e., C3, may be connected to the negative terminal of the driving power supply, i.e., power supply V1, and to ground. The zener diode, D3, can also be selected according to the practical application, for example, the LDO linear regulator can be selected.

Further, as shown in fig. 4, the zener diode, i.e., the anode of D3, the first resistor, i.e., one end of R1, the first capacitor, i.e., the other end of C1, and the second capacitor, i.e., one end of C2 are connected to each other and generate a first segment level; the other end of the first resistor, i.e., R1, the one end of the second resistor, i.e., R2, the other end of the second capacitor, i.e., C2, and the one end of the third capacitor, i.e., C3, are connected to each other and generate a second segment level. It should be noted that the voltage levels of the first segment level and the second segment level can be obtained by correspondingly adjusting the resistance values of the first resistor, i.e., R1, i.e., R1, and the second resistor, i.e., R2, i.e., R2.

In one embodiment of the present invention, as shown in fig. 4, the off switch 20, i.e., Q2, may be a P-MOSFET, and the P-MOSFET may be connected to the level generating circuit, i.e., the second capacitor, i.e., the other end of C2, and one end of the third capacitor, i.e., C3, through the drain to receive the second level, and may be further connected to the gate of the power switch 100, e.g., the power switch 100, through the source. The P-MOSFET is used for executing turn-off action, so that the minimum turn-off loop design can be realized, and the fast action and the small parasitic inductance can be realized in high-frequency application as much as possible.

In one embodiment of the present invention, as shown in fig. 4, the negative voltage cutoff transistor 30, i.e., D1, may be a diode, and the diode may receive the control signal of the power switch transistor 100 through the positive electrode and may be connected to the gate of the P-MOSFET transistor, and may be further connected to the drain of the P-MOSFET transistor and the gate of the power switch transistor 100, e.g., the power switch transistor 100, through the negative electrode.

In an embodiment of the present invention, the control signal of the power switch tube 100 may be a PWM signal, wherein when the control signal, i.e. the PWM signal, is positive, the control signal, i.e. the PWM signal, may directly act on the gate of the power switch tube 100, i.e. the GaN power switch tube through the negative voltage cutoff tube 30, i.e. the diode D1, and when the control signal, i.e. the PWM signal, is negative, the control signal, i.e. the PWM signal, will be cut off by the negative voltage cutoff tube 30, i.e. the diode D1, to act on the gate of the turn-off switch tube 20, i.e. the P-MOSFET tube.

The operation of the negative voltage driving circuit of the power switch tube of the present invention will be further described with reference to fig. 4 and 5 by taking GaN power switch tube as an example.

In an embodiment of the present invention, the driving power supply in the three-level generating circuit 10 may be determined according to the characteristics of the GaN power switch, that is, the voltage of the power supply V1 is 5V, and of course, in other embodiments of the present invention, different power supply voltages, for example, 6V or 8V, may be selected according to the characteristics of the GaN power switch.

Further, the voltage levels of the first segment level and the second segment level can be adjusted by adjusting the resistance values of the first resistor, i.e., R1, and the second resistor, i.e., R2, for example, the first segment level can be adjusted to 1V, and the second segment level can be adjusted to 3V, but in other embodiments of the present invention, the first segment level and the second segment level of other voltage levels can be obtained by adjusting the resistance values of the first resistor, i.e., R1, and the second resistor, i.e., R2, for example, the first segment level of 2V and the second segment level of 3V can be obtained.

Further, when the negative voltage cutoff tube 30, i.e., the diode D1, receives a control signal, i.e., a PWM signal, of the power switch tube 100, i.e., the GaN power switch tube through the positive electrode, and the control signal, i.e., the PWM signal, is in the positive direction, the control signal, i.e., the PWM signal, may directly act on the gate of the power switch tube 100, i.e., the GaN power switch tube through the negative voltage cutoff tube 30, i.e., the diode D1, so as to control the power switch tube 100, i.e., the GaN power switch tube to be turned on; when the negative voltage cutoff tube 30, i.e., the diode D1, receives a control signal, i.e., a PWM signal, of the power switching tube 100, i.e., the GaN power switching tube through the positive electrode, and the control signal, i.e., the PWM signal, is negative, the control signal, i.e., the PWM signal, is cut off by the negative voltage cutoff tube 30, i.e., the diode D1, so that the control signal, i.e., the PWM signal, acts on the gate of the turn-off switching tube 20, i.e., the P-MOSFET tube, to turn on and turn off the switching tube 20, i.e., the P-MOSFET tube, and finally turn-off the power switching tube 100, i. Fig. 5 shows a waveform diagram of a driving signal generated by the negative voltage driving circuit of the power switch tube.

It should be noted that the negative voltage driving circuit of the power switch tube of the present invention is not only applicable to GaN power switch tubes, but also applicable to other power switch tubes, for example, in other embodiments of the present invention, it may also be applicable to SiC MOSFET switch tubes.

According to the negative-pressure driving circuit of the power switch tube, provided by the embodiment of the invention, the three-level generating circuit is used for generating three levels, a first level of the three levels is sent to the power switch tube, a second level of the three levels is sent to the turn-off switch tube, the negative-pressure cutoff tube is used for receiving a control signal of the power switch tube, and when the control signal is a negative control signal, the negative control signal is cut off, so that the negative control signal is sent to the turn-off switch tube to control the turn-off switch tube to be conducted, and the turn-off of the power switch tube is realized, therefore, the stability of negative pressure can be ensured, the design of a turn-off loop can be simplified, the turn-off speed can be improved, and parasitic inductance generated in the turn-off process can be.

The invention further provides a charging pile corresponding to the negative-voltage driving circuit of the power switch tube provided by the embodiment.

The charging pile provided by the embodiment of the invention comprises the negative voltage driving circuit of the power switch tube provided by the embodiment, and the specific implementation mode of the charging pile refers to the embodiment.

According to the charging pile provided by the embodiment of the invention, the negative voltage driving circuit of the power switch tube provided by the embodiment can ensure the stability of negative voltage, so that the quality of a product can be improved, the design of a turn-off loop can be simplified, the turn-off speed can be increased, and parasitic inductance generated in the turn-off process can be reduced.

In the description of the present invention, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implying any number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. The meaning of "plurality" is two or more unless specifically limited otherwise.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the present invention, unless otherwise expressly stated or limited, the first feature "on" or "under" the second feature may be directly contacting the first and second features or indirectly contacting the first and second features through an intermediate. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.