CN116865556A - Charge pump precharge circuit and electronic equipment - Google Patents

Abstract

The invention provides a charge pump precharge circuit and electronic equipment. The power tube unit includes first, second, third and fourth switch tubes that are electrically connected. The first switch tube is connected to a supply voltage and passes through a diode. Coupled with a bootstrap capacitor, the bootstrap capacitor is coupled to the second switch tube and the flying capacitor respectively, the flying capacitor is coupled to the fourth switch tube and the precharge circuit respectively, the fourth switch tube is grounded, and one end of the second switch tube is coupled to Connect the output terminal of the charge pump and the output capacitor; in the precharge circuit, the fifth switch tube is coupled to the flying capacitor through the current limiting resistor, and its other end is grounded, and the protection module and the insertion detection module are coupled to the output terminal of the charge pump; thus When the device is connected to the charge pump, the fifth switch tube is controlled to be turned on within a set time period, and the battery is used to charge the flying capacitor, which simplifies the precharge circuit, so that the present invention can confirm whether the precharge is precharged without the need for external devices. When charging is completed, the charge pump is quickly precharged.

Description

Charge pump precharge circuit and electronic equipment

Technical field

The invention relates to the field of power electronics, and in particular to a charge pump precharge circuit and electronic equipment.

Background technique

In recent years, charge pumps, as a non-inductive DC-DC converter, use capacitors as energy storage components for voltage conversion. Due to their high conversion efficiency, they have been widely used in the power supply field, especially in the field of fast charging.

In power conversion circuits using charge pumps, flying capacitors and bootstrap capacitors are often used (as shown in Figure 1). The flying capacitor is used to complete the transfer of the accessed charge from the input to the output. This allows the voltage at the output end of the power conversion circuit to float to different voltage levels, and the bootstrap capacitor is used to complete the bootstrap boost of the drive circuit of the high-side power tube. In practical applications, before the power conversion circuit starts to work, the flying capacitor needs to be precharged, and the voltage value at both ends needs to be charged to close to the pre-output voltage of the power conversion circuit. If precharge is not performed, the power will When the switch is turned on, there will be a huge current in the circuit, which will burn out all the power devices in the circuit.

In the current circuit soft-start architecture, please refer to Figure 1. A current source is generally used to charge the flying capacitor. However, this charging speed is slow. In actual use, it is necessary to wait until the external overvoltage protection circuit is turned on and the current source Only after the mirror current is established can the flying capacitor be charged; and this charging method also requires an additional comparator to compare the voltage across the flying capacitor with the pre-output voltage to determine the end of pre-charging time.

Therefore, how to quickly precharge the charge pump and simplify the precharging circuit without requiring external devices to confirm whether precharging is completed has become an urgent technical problem that needs to be solved in the industry.

Contents of the invention

The present invention provides a charge pump precharging circuit and electronic equipment to solve the problem of how to quickly precharge a charge pump and simplify the precharging circuit without requiring external devices to confirm whether precharging is completed.

According to a first aspect of the present invention, a charge pump precharge circuit is provided. The charge pump is used to charge the battery of the connected device. The charge pump includes N power modules, and each group of power modules includes a power tube unit. , bootstrap capacitance and flying capacitance, where N is a positive integer; where:

The power tube unit includes a first switch tube, a second switch tube, a third switch tube and a fourth switch tube that are electrically connected in sequence. The first end of the first switch tube is coupled to a supply voltage. The first end of the first switch tube is also coupled to the first end of the bootstrap capacitor through a diode, and the second end of the bootstrap capacitor is coupled to the first end of the second switch tube and the first end of the bootstrap capacitor respectively. The first end of the flying capacitor and the second end of the flying capacitor are respectively coupled to the first end of the fourth switch tube and the first end of the precharge circuit. The second end of the fourth switch tube terminal is connected to ground, and the second terminal of the second switch tube serves as the output terminal of the power module, which is coupled to the output terminal of the charge pump and the first terminal of the output capacitor respectively, the negative electrode of the battery and the The second terminals of the output capacitors are both connected to ground;

The precharge circuit includes a protection module, an insertion detection module, a control module, a fifth switching tube and a current limiting resistor; the first end of the fifth switching tube is coupled to the flying capacitor through the current limiting resistor. The second end of the fifth switch tube is grounded. The first end of the protection module and the first end of the insertion detection module are both coupled to the output end of the charge pump. The protection module The second end of the insertion detection module is connected to ground, the second end of the insertion detection module is coupled to the first end of the control module, and the second end of the control module is coupled to the control end of the fifth switching tube; wherein:

The insertion detection module is used to monitor the voltage of its first end in real time, and output a first signal to the control module according to the detected voltage, wherein the first signal is used to indicate whether the device is connected to the charge pump. ;

The control module is configured to: set a set time period, and when the first signal indicates that the device is connected to the charge pump, control the fifth switch to be turned on within the set time period. , and is disconnected after exceeding the set time period; when the first signal indicates that the device is not connected to the charge pump, the fifth switch tube is controlled to be disconnected.

Optionally, the first switch tube, the second switch tube, the third switch tube and the fourth switch tube are NMOS tubes or NPN type BJT transistors.

Optionally, the control module is specifically configured as:

When the first signal indicates that the device is connected to the charge pump, a high level is output to the control end of the fifth switch through its second end within the set time period to control the third switch. The fifth switch tube is turned on, and after exceeding the set time period, a low level is output through its second terminal to the control terminal of the fifth switch tube to control the disconnection of the fifth switch tube;

When the first signal indicates that the device is not connected to the charge pump, a low level is output to the control end of the fifth switch tube through its second terminal to control the fifth switch tube to be turned off.

Optionally, the control module is also used to set an anti-peak pulse duration; the control module includes a first timing unit and a logic control unit; wherein:

The first end of the first timing unit is coupled to the first end of the insertion detection module, its second end is coupled to a clock signal, and its third end is coupled to the first end of the logic control unit, to output a first time signal; the second terminal of the logic control unit receives the clock signal, and its third terminal is coupled to the control terminal of the fifth switch; wherein the first time signal includes a first sub-signal and second sub-signal;

Wherein, the first timing unit is configured to: start timing the access time of the device only when the first signal indicates that the device is connected to the charge pump, and output the said anti-spike pulse duration after The first sub-signal is sent to the first terminal of the logic control unit; otherwise, the second sub-signal is output to the first terminal of the logic control unit;

The logic control unit is configured to: start timing when its first terminal receives the first sub-signal, and output a high level to the fifth switching tube through its second terminal within the set time period. The control terminal is used to control the conduction of the fifth switch tube, and after the set time period is exceeded, it outputs a low level to the control terminal of the fifth switch tube through its second terminal to control the fifth switch tube. disconnect;

When the first terminal receives the second sub-signal, the second terminal outputs a low level to the control terminal of the fifth switching tube to control the fifth switching tube to turn off.

Optionally, the fourth terminal of the logic control unit receives an enable clock signal to set the set duration, and the fifth terminal thereof receives a power-on reset signal.

Optionally, the insertion detection module includes a comparator;

The non-inverting input terminal of the comparator is coupled to the output terminal of the charge pump, the inverting input terminal of the comparator receives a reference voltage, and the output terminal is coupled to the first terminal of the control module.

Optionally, the protection module includes a first capacitor and a first resistor;

The first terminal of the first capacitor and the first terminal of the first resistor are both coupled to the output terminal of the charge pump, and the second terminal of the first capacitor and the second terminal of the first resistor are coupled to the output terminal of the charge pump. All are grounded.

Optionally, the protection module includes a second capacitor and a sixth switch;

The first end of the second capacitor and the first end of the sixth switch are both coupled to the output end of the charge pump, and the second end of the second capacitor and the third end of the sixth switch are Both ends are grounded, and the control end of the sixth switch tube is coupled to the second end of the control module.

Optionally, the control module is also configured to:

When the first signal indicates that the device is connected to the charge pump, the sixth switch is controlled to be turned on within the set time period, and to be turned off after exceeding the set time period; in the third A signal indicates that when the device is not connected to the charge pump, the sixth switch tube is controlled to be turned off.

Optionally, the charge pump is a half-voltage power conversion circuit.

According to a third aspect of the present invention, an electronic device is provided, including the charge pump precharge circuit provided in any one of the first aspects of the present invention.

In the charge pump precharge circuit and electronic equipment provided by the present invention, the power tube unit includes a first switch tube, a second switch tube, a third switch tube and a fourth switch tube that are electrically connected. The first switch tube is coupled to A supply voltage, which is also coupled to a bootstrap capacitor through a diode. The bootstrap capacitor is coupled to the second switch tube and the flying capacitor respectively. The flying capacitor is coupled to the fourth switch tube and the precharge circuit respectively. The fourth switch The tube is also grounded, and one end of the second switch tube serves as the output terminal of the power module, which is also coupled to the output terminal of the charge pump and the output capacitor respectively. The negative electrode of the battery and the output capacitor are both grounded; in the precharge circuit, the fifth switch The tube is coupled to the flying capacitor through the current limiting resistor, the protection module and the insertion detection module are coupled to the output end of the charge pump; the protection module and the fifth switch tube are grounded; when the device is connected to the charge pump, the fifth switch tube is controlled The switch tube is turned on within the set time period, and the battery is used to charge the flying capacitor, which simplifies the precharging circuit. Therefore, the present invention can quickly precharge the charge pump without requiring external devices to confirm whether precharging is completed. Charge.

Description of the drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the following will briefly introduce the drawings needed to describe the embodiments or the prior art. Obviously, the drawings in the following description are only These are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without exerting creative efforts.

Figure 1 is a schematic structural diagram of a charge pump precharge circuit in the prior art;

Figure 2 is a schematic structural diagram of a charge pump precharge circuit in an embodiment of the present invention;

Figure 3 is a schematic diagram 2 of the structure of the charge pump precharge circuit in the embodiment of the present invention;

Figure 4 is a schematic diagram 3 of the structure of the charge pump precharge circuit in the embodiment of the present invention;

Explanation of reference symbols:

11-Power module;

21-Protection module;

22-Insert the detection module;

23-Control module;

231-First timing unit;

232-Logic control unit;

Cboot-bootstrap capacitor;

Cfly-flying capacitor;

Q1-the first switch tube;

Q2-the second switch tube;

Q3-The third switching tube;

Q4-the fourth switch tube;

Q9-the fifth switching tube;

Q10-the tenth switching tube;

Q11-the sixth switching tube;

PMID-supply voltage;

Cout-output capacitor;

RL-current limiting resistor;

CLK - clock signal;

EN_CLK-enable clock signal;

POR-power-on reset signal;

C1-first capacitor;

C2-the second capacitor;

R1 - the first resistor.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention.

The terms "first", "second", "third", "fourth", etc. (if present) in the description and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects without necessarily using Used to describe a specific order or sequence. It is to be understood that the data so used are interchangeable under appropriate circumstances so that the embodiments of the invention described herein are capable of being practiced in sequences other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, e.g., a process, method, system, product, or apparatus that encompasses a series of steps or units and need not be limited to those explicitly listed. Those steps or elements may instead include other steps or elements not expressly listed or inherent to the process, method, product or apparatus.

The technical solution of the present invention will be described in detail below with specific examples. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments.

In view of the existing technology, it is difficult to quickly precharge the charge pump without requiring external devices to confirm whether precharging is completed, and to simplify the precharging circuit. The invention provides a charge pump precharge circuit and electronic equipment. The power tube unit includes a first switch tube, a second switch tube, a third switch tube and a fourth switch tube that are electrically connected. The first switch tube is coupled to is connected to a supply voltage, and is also coupled to a bootstrap capacitor through a diode. The bootstrap capacitor is coupled to the second switch tube and the flying capacitor respectively. The flying capacitor is coupled to the fourth switch tube and the precharge circuit respectively. The four switch tubes are also grounded, and one end of the second switch tube serves as the output terminal of the power module, which is also coupled to the output terminal of the charge pump and the output capacitor respectively. The negative electrode of the battery and the output capacitor are both grounded; in the precharge circuit, the third The five switch tubes are coupled to the flying capacitor through the current limiting resistor, the protection module and the insertion detection module are coupled to the output end of the charge pump; the protection module and the fifth switch tube are grounded; when the device is connected to the charge pump, the control The fifth switch tube is turned on within the set time period, and the battery is used to charge the flying capacitor, which simplifies the precharging circuit. Therefore, the present invention can quickly charge the charge pump without requiring external devices to confirm whether precharging is completed. Perform precharge.

Please refer to Figure 2. An embodiment of the present invention provides a charge pump precharge circuit. The charge pump is used to charge the battery of the connected device. It is characterized in that the charge pump includes N power modules 11. Each group of power modules Modules 11 each include a power tube unit, a bootstrap capacitor Cboot and a flying capacitor Cfly, where N is a positive integer; where:

Taking the power tube unit on the left in Figure 2 as an example, the power tube unit includes a first switch tube Q1, a second switch tube Q2, a third switch tube Q3 and a fourth switch tube Q4 that are electrically connected in sequence. A first terminal of a switching tube Q1 is coupled to a supply voltage PMID. The first terminal of the first switching tube Q1 is also coupled to a first terminal of the bootstrap capacitor Cboot1 through a diode D9. The bootstrap capacitor Cboot1 The second terminal of the capacitor Cboot1 is coupled to the first terminal of the second switch Q2 and the first terminal of the flying capacitor Cfly1 respectively. The second terminal of the flying capacitor Cfly1 is coupled to the first terminal of the second switch Q2 and the first terminal of the flying capacitor Cfly1 respectively. The first end of the four-switch transistor Q4 and the first end of the precharge circuit, the second end of the fourth switch transistor Q4 is grounded, and the second end of the second switch transistor Q2 serves as the output end of the power module 11 , which are respectively coupled to the output terminal of the charge pump and the first terminal of the output capacitor Cout, and the negative electrode of the battery and the second terminal of the output capacitor Cout are both grounded;

The precharge circuit includes a protection module 21, an insertion detection module 22, a control module 23, a fifth switching tube Q9 and a current limiting resistor RL1; the first end of the fifth switching tube Q9 is coupled through the current limiting resistor RL1 to the second end of the flying capacitor Cfly, the second end of the fifth switch Q9 is grounded, and the first end of the protection module 21 and the first end of the insertion detection module 22 are coupled to the The output end of the charge pump, the second end of the protection module 21 is grounded, the second end of the insertion detection module 22 is coupled to the first end of the control module 23, the second end of the control module 23 Coupled to the control end of the fifth switching tube Q9; where:

The insertion detection module 22 is used to monitor the voltage VBAT of its first end in real time, and output a first signal to the control module 23 according to the detected voltage, wherein the first signal is used to indicate whether the device is connected to the The charge pump;

The control module 23 is configured to: set a set time period, and when the first signal indicates that the device is connected to the charge pump, control the fifth switch Q9 within the set time period. is turned on and turned off after exceeding the set time period; when the first signal indicates that the device is not connected to the charge pump, the fifth switch tube Q9 is controlled to be turned off.

Wherein, the first switching tube Q1, the second switching tube Q2, the third switching tube Q3 and the fourth switching tube Q4 are NMOS tubes or NPN type BJT transistors.

Regarding the power module on the right in Figure 2, its connection method is the same as the power tube module on the left. In one example, the control module 23 is also coupled to the control end of the tenth switching tube Q10 (not shown in Figure 2 ), used to control the on-off state of the tenth switching tube Q10, wherein when the first signal indicates that the device is connected to the charge pump, the tenth switching tube Q10 is controlled to turn on and off during the set time period. When the first signal indicates that the device is not connected to the charge pump, the tenth switch Q10 is controlled to be turned off.

In the case of multiple power modules, in a preferred implementation, the control module 23 is also configured to:

The flying capacitor Cfly corresponding to each power module is charged sequentially according to a predetermined sequence.

In the example shown in Figure 2, the charge pump is a half-voltage power conversion circuit, which includes two power modules 11. This is an example for further explanation:

In this 2:1 half-voltage power conversion circuit, the output end of the charge pump is coupled to the battery of the device, and the voltage value of the supply voltage PMID is set to twice the voltage value of the battery. Due to its circuit Components will cause voltage loss, so in actual settings, the voltage value of the supply voltage PMID is set to be slightly greater than twice the voltage value of the battery.

When the half-voltage power conversion circuit operates normally, taking the power module 11 on the left as an example, the first switching tube Q1, the second switching tube Q2, the third switching tube Q3 and the third switching tube Q3 are The control terminals of the four switch tubes Q4 respectively receive the first control signal CHG1, the second control signal DHG1, the third control signal CLG1 and the fourth control signal DLG1; they set the switching values of each switch tube according to the number of power modules 11 in the charge pump. On or off time;

Wherein, if the clock signal CLK received by the charge pump is in the first phase, the first switch Q1 and the third switch Q3 are controlled to be closed, and the second switch Q2 and the fourth switch are controlled to be closed. When tube Q4 is disconnected, the flying capacitor Cfly and the output capacitor Cout are connected in series to divide the voltage. In this case:

Vcfly+Vcout=VIN;

If the clock signal CLK received by the charge pump is in the second phase, the second switch Q2 and the fourth switch Q4 are controlled to be closed, and the first switch Q1 and the third switch Q3 are controlled. disconnected, the flying capacitor Cfly and the output capacitor Cout are connected in parallel, in this case:

Vcfly=Vcout;

Wherein, Vcfly is the voltage value of the flying capacitor Cfly, Vcout is the voltage value of the output capacitor Cout, and VIN is the voltage value of the second terminal of the bootstrap capacitor Cboot.

In summary, the voltage value of the output capacitor Cout is Vcout=VIN/2; according to the power conservation principle, the current flowing into the battery Iout=2*Ivin; where Ivin is the current flowing through the second switch Q2 or the third The current value of the current of switch Q3.

According to the working principle of the power conversion circuit, before the power conversion circuit starts to work, the flying capacitor Cfly needs to be precharged, and the voltage value at both ends needs to be charged to close to the pre-output voltage of the power conversion circuit. If it is not precharged, Then there will be a huge current in the circuit at the moment the power switch is turned on, which will burn out all the power devices in the circuit.

Please refer to Figure 2. When the first signal received by the control module 23 indicates that the device is connected to the charge pump, the fifth switch Q9 is controlled to be turned on within the set time period. During this period Since the second end of the flying capacitor Cfly is connected to the ground through the current limiting resistor RL1 and the fifth switching tube Q9, the battery connects to the flying capacitor through the body diode of the second switching tube Q2. The capacitor Cfly is charged so that the voltage value at the first terminal of the flying capacitor Cfly is the voltage value of the battery minus the voltage value of the body diode voltage drop, and the voltage value at the second terminal is close to ground, so that the voltage value at the device can be Within a certain period of time, the voltage value across the flying capacitor Cfly is charged to a value close to the pre-output voltage of the power conversion circuit (that is, the voltage of the battery minus the voltage of the body diode voltage drop).

In an example, when the first signal received by the control module 23 indicates that the device is connected to the charge pump, the turn-on signal PRE_CHG is output to the control end of the fifth switch Q9 to control the fifth switch. Switch Q9 is turned on within the set time period.

In a specific implementation, the control module 23 is specifically configured as:

When the first signal indicates that the device is connected to the charge pump, a high level is output to the control end of the fifth switch Q9 through its second end within the set time period to control the The fifth switching tube Q9 is turned on, and after the set time period is exceeded, a low level is output through its second terminal to the control terminal of the fifth switching tube Q9 to control the fifth switching tube Q9 to be turned off;

When the first signal indicates that the device is not connected to the charge pump, the second terminal outputs a low level to the control terminal of the fifth switch Q9 to control the fifth switch Q9 to turn off. open.

In this case, in one example, the fifth switch transistor Q9 is an NMOS transistor or an NPN BJT transistor. Of course, the present invention is not limited to this, and PMOS tubes, etc. can also be used. Accordingly, the control module 23 can be configured to: output a low level to the fifth switch through its second end within the set time period. The control end of the transistor Q9 is used to control the conduction of the fifth switching transistor Q9; after the set time period is exceeded, a high level is output to the control end of the fifth switching transistor Q9 through its second end to control the conduction of the fifth switching transistor Q9. The fifth switching tube Q9 is turned off; when the first signal indicates that the device is not connected to the charge pump, a high level is output to the control terminal of the fifth switching tube Q9 through its second terminal, so as to The fifth switching tube Q9 is controlled to be turned off. Those skilled in the art can select other switching elements and the type of signal output by the control module 23 to control the fifth switching tube Q9 as needed.

In actual use, if the battery of the device is connected to the charge pump, due to the inductance, capacitance and other components of the electronic components, an instantaneous high voltage that is much higher than the normal operating voltage will be generated in the system. In order to prevent the charge pump from being damaged by the instantaneous high voltage, the charge pump can be allowed to operate normally after the time of the possible instantaneous high voltage has passed. In one embodiment, the control module 23 is also used to set an anti-peak pulse duration. ; In this case, please refer to Figure 3, the control module 23 includes a first timing unit 231 and a logic control unit 232; wherein:

The first terminal of the first timing unit 231 is coupled to the first terminal of the insertion detection module 22 , the second terminal of the first timing unit 231 is coupled to a clock signal CLK, and the third terminal of the first timing unit 231 is coupled to the logic control unit 232 . The first terminal is to output the first time signal; the second terminal of the logic control unit 232 receives the clock signal CLK, and its third terminal is coupled to the control terminal of the fifth switch Q9; wherein, the The first time signal includes a first sub-signal and a second sub-signal;

Wherein, the first timing unit 231 is configured to: start timing the access time of the device only when the first signal indicates that the device is connected to the charge pump, and output the all-in-one time after the anti-glitch pulse duration. the first sub-signal to the first terminal of the logic control unit 232; otherwise, output the second sub-signal to the first terminal of the logic control unit 232;

The logic control unit 232 is configured to: start timing when its first terminal receives the first sub-signal, and output a high level to the fifth switch tube through its second terminal within the set time period. The control end of Q9 is used to control the conduction of the fifth switching transistor Q9, and after the set time period is exceeded, a low level is output to the control end of the fifth switching transistor Q9 through its second end to control the The fifth switching tube Q9 is disconnected;

When the first terminal receives the second sub-signal, the second terminal outputs a low level to the control terminal of the fifth switch Q9 to control the fifth switch Q9 to turn off.

In a preferred embodiment, please refer to FIG. 3 , the fourth terminal of the logic control unit 232 receives the enable clock signal EN_CLK to set the set time length, and the fifth terminal receives the power-on reset signal POR.

Regarding other modules of the precharge circuit, the details are as follows:

In one implementation, please refer to Figure 3, the insertion detection module 22 includes a comparator;

The non-inverting input terminal of the comparator is coupled to the output terminal of the charge pump, the inverting input terminal of the comparator receives a reference voltage Vref, and the output terminal is coupled to the first terminal of the control module 23 .

In this case, by comparing the voltage value of the voltage at the output terminal of the charge pump and the voltage value of the reference voltage Vref, it is possible to avoid having the battery of the device connected to the charge pump while monitoring whether the battery of the device is connected to the charge pump. Lower voltage batteries are connected to the charge pump, causing equipment damage.

It should be understood that the specific components of the insertion detection module 22 are only examples. In other examples, the voltage of the differential data line corresponding to its downstream port can also be monitored.

In one implementation, please refer to FIG. 4 , the protection module 21 includes a first capacitor C1 and a first resistor R1;

The first terminal of the first capacitor C1 and the first terminal of the first resistor R1 are both coupled to the output terminal of the charge pump, and the second terminal of the first capacitor C1 and the first resistor R1 The second terminals are all grounded.

Wherein, if the first capacitor C1 is a large capacitor, low-frequency interference signals can be filtered; if the first capacitor C1 is a small capacitor, high-frequency interference signals can be filtered; and the conduction of the first resistor R1 The impedance is higher.

In another implementation, please refer to FIG. 3 , the protection module 21 includes a second capacitor C2 and a sixth switch Q11;

The first terminal of the second capacitor C2 and the first terminal of the sixth switching tube are both coupled to the output terminal of the charge pump. The second terminal of the second capacitor C2 and the sixth switching tube The second terminals of Q11 are both grounded, and the control terminal of the sixth switch Q11 is coupled to the second terminal of the control module 23 .

Wherein, if the second capacitor C2 is a large capacitor, low-frequency interference signals can be filtered; if the second capacitor C2 is a small capacitor, high-frequency interference signals can be filtered. When the sixth switch Q11 is turned on, it can be considered as a switch with a weak pull-down function, and its conduction resistance is high, so that the circuit can be protected.

In this case, in one implementation, the control module 23 is further configured to:

When the first signal indicates that the device is connected to the charge pump, the sixth switch Q11 is controlled to be turned on within the set time period, and to be turned off after exceeding the set time period; in the The first signal indicates that when the device is not connected to the charge pump, the sixth switch Q11 is controlled to be turned off.

Of course, the present invention does not limit the specific implementation of the protection circuit. Any conceivable circuit structure is within the protection scope of the present invention, such as introducing TVS diodes, etc. Those skilled in the art can set the protection as needed. Module 21.

In addition, embodiments of the present invention also provide an electronic device that includes the above-mentioned charge pump precharging circuit. As an example, the device can be a fast charging charging plug, a power bank, and of course other devices that require power supply.

To sum up, the present invention includes a first switch tube, a second switch tube, a third switch tube and a fourth switch tube that are electrically connected through a power tube unit. The first switch tube is coupled to a supply voltage and is also connected through a power tube unit. The diode is coupled to the bootstrap capacitor, the bootstrap capacitor is coupled to the second switch tube and the flying capacitor respectively, the flying capacitor is coupled to the fourth switch tube and the precharge circuit respectively, the fourth switch tube is also grounded, and the second switch One end of the tube serves as the output terminal of the power module, and is also coupled to the output terminal of the charge pump and the output capacitor respectively. The output capacitor is grounded. In the precharge circuit, the fifth switching tube is coupled to the flying capacitor through a current limiting resistor. The protection module and the insertion detection module are both coupled to the output end of the charge pump; the protection module and the fifth switch tube are grounded; when the device is connected to the charge pump, the fifth switch tube is controlled to be turned on within a set time period, and the battery is used Charging the flying capacitor simplifies the precharging circuit, so that the present invention can quickly precharge the charge pump without requiring external devices to confirm whether precharging is completed.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention, but not to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: The technical solutions described in the foregoing embodiments can still be modified, or some or all of the technical features can be equivalently replaced; and these modifications or substitutions do not deviate from the essence of the corresponding technical solutions from the technical solutions of the embodiments of the present invention. scope.

Claims (11)

1. A charge pump precharge circuit, which is used to charge the battery of the connected device. It is characterized in that the charge pump includes N power modules, and each group of power modules includes a power tube unit and a bootstrap capacitor. And flying capacitance, where N is a positive integer; where: The power tube unit includes a first switch tube, a second switch tube, a third switch tube and a fourth switch tube that are electrically connected in sequence. The first end of the first switch tube is coupled to a supply voltage. The first end of the first switch tube is also coupled to the first end of the bootstrap capacitor through a diode, and the second end of the bootstrap capacitor is coupled to the first end of the second switch tube and the first end of the bootstrap capacitor respectively. The first end of the flying capacitor and the second end of the flying capacitor are respectively coupled to the first end of the fourth switch tube and the first end of the precharge circuit. The second end of the fourth switch tube terminal is connected to ground, and the second terminal of the second switch tube serves as the output terminal of the power module, which is coupled to the output terminal of the charge pump and the first terminal of the output capacitor respectively, the negative electrode of the battery and the The second terminals of the output capacitors are both connected to ground; The precharge circuit includes a protection module, an insertion detection module, a control module, a fifth switching tube and a current limiting resistor; the first end of the fifth switching tube is coupled to the flying capacitor through the current limiting resistor. The second end of the fifth switch tube is grounded. The first end of the protection module and the first end of the insertion detection module are both coupled to the output end of the charge pump. The protection module The second end of the insertion detection module is connected to ground, the second end of the insertion detection module is coupled to the first end of the control module, and the second end of the control module is coupled to the control end of the fifth switching tube; wherein: The insertion detection module is used to monitor the voltage of its first end in real time, and output a first signal to the control module according to the detected voltage, wherein the first signal is used to indicate whether the device is connected to the charge pump. ; The control module is configured to: set a set time period, and when the first signal indicates that the device is connected to the charge pump, control the fifth switch to be turned on within the set time period. , and is disconnected after exceeding the set time period; when the first signal indicates that the device is not connected to the charge pump, the fifth switch tube is controlled to be disconnected. 2. The charge pump precharge circuit according to claim 1, characterized in that the first switch tube, the second switch tube, the third switch tube and the fourth switch tube are NMOS tubes or NPN type BJT transistor. 3. The charge pump precharge circuit according to claim 2, wherein the control module is specifically configured to: When the first signal indicates that the device is connected to the charge pump, a high level is output to the control end of the fifth switch through its second end within the set time period to control the third switch. The fifth switch tube is turned on, and after exceeding the set time period, a low level is output through its second terminal to the control terminal of the fifth switch tube to control the disconnection of the fifth switch tube; When the first signal indicates that the device is not connected to the charge pump, a low level is output to the control end of the fifth switch tube through its second terminal to control the fifth switch tube to be turned off. 4. The charge pump precharge circuit according to claim 3, wherein the control module is also used to set an anti-peak pulse duration; the control module includes a first timing unit and a logic control unit; wherein: The first end of the first timing unit is coupled to the first end of the insertion detection module, its second end is coupled to a clock signal, and its third end is coupled to the first end of the logic control unit, to output a first time signal; the second terminal of the logic control unit receives the clock signal, and its third terminal is coupled to the control terminal of the fifth switch; wherein the first time signal includes a first sub-signal and second sub-signal; Wherein, the first timing unit is configured to: start timing the access time of the device only when the first signal indicates that the device is connected to the charge pump, and output the said anti-spike pulse duration after The first sub-signal is sent to the first terminal of the logic control unit; otherwise, the second sub-signal is output to the first terminal of the logic control unit; The logic control unit is configured to: start timing when its first terminal receives the first sub-signal, and output a high level to the fifth switching tube through its second terminal within the set time period. The control terminal is used to control the conduction of the fifth switch tube, and after the set time period is exceeded, it outputs a low level to the control terminal of the fifth switch tube through its second terminal to control the fifth switch tube. disconnect; When the first terminal receives the second sub-signal, the second terminal outputs a low level to the control terminal of the fifth switching tube to control the fifth switching tube to turn off. 5. The charge pump precharge circuit according to claim 4, characterized in that the fourth terminal of the logic control unit receives an enable clock signal to set the set time length, and the fifth terminal thereof receives a power-on reset. Signal. 6. The charge pump precharge circuit according to claim 1, wherein the insertion detection module includes a comparator; The non-inverting input terminal of the comparator is coupled to the output terminal of the charge pump, the inverting input terminal of the comparator receives a reference voltage, and the output terminal is coupled to the first terminal of the control module. 7. The charge pump precharge circuit according to claim 1, wherein the protection module includes a first capacitor and a first resistor; The first terminal of the first capacitor and the first terminal of the first resistor are both coupled to the output terminal of the charge pump, and the second terminal of the first capacitor and the second terminal of the first resistor are coupled to the output terminal of the charge pump. All are grounded. 8. The charge pump precharge circuit according to claim 1, wherein the protection module includes a second capacitor and a sixth switch; The first end of the second capacitor and the first end of the sixth switch are both coupled to the output end of the charge pump, and the second end of the second capacitor and the third end of the sixth switch are Both ends are grounded, and the control end of the sixth switch tube is coupled to the second end of the control module. 9. The charge pump precharge circuit according to claim 8, wherein the control module is further configured to: When the first signal indicates that the device is connected to the charge pump, the sixth switch is controlled to be turned on within the set time period, and to be turned off after exceeding the set time period; in the third A signal indicates that when the device is not connected to the charge pump, the sixth switch tube is controlled to be turned off. 10. The charge pump precharge circuit according to any one of claims 1 to 9, characterized in that the charge pump is a half-voltage power conversion circuit. 11. An electronic device, characterized by comprising the charge pump precharge circuit according to any one of claims 1-10.