Switch locking circuit and high-side switch circuit

Abstract

The embodiment of the invention provides a switch locking circuit which is connected with the control end of a switch transistor, the first end of the switch transistor is connected with a first power supply, and the second end of the switch transistor is used for being connected with a controlled component. Wherein the switch locking circuit is used for being opened when the switch transistor is closed and limiting the control end of the switch transistor at a closing voltage so as to maintain the closing state of the switch transistor, and the switch locking circuit is also used for being closed when the switch transistor is opened. Therefore, the problem that the switching transistor is not closed firmly due to the fact that the voltage of the power supply is coupled to the control end of the switching transistor through the parasitic capacitor is avoided, and the reliability of the switching transistor during closing is improved.

Description

Technical Field

[0001] The present disclosure relates to the technical field of switching power supplies, and in particular to a switch locking circuit and a high-side switch circuit. Background Art

[0002] Metal Oxide Semiconductor (MOS) high-side switches are currently widely used in many fields such as automobiles, industry, and mobile devices due to their low loss, easy driving, high reliability, and near-ideal switching characteristics.

[0003] In the related art, when the switch transistor is turned off, the voltage of the power supply is coupled to the control terminal of the switch transistor through the parasitic capacitance, resulting in a higher voltage at the control terminal of the switch transistor, so that the switch transistor cannot be effectively turned off. Summary of the invention

[0004] Embodiments of the present disclosure provide a switch locking circuit and a high-side switch circuit.

[0005] In a first aspect, an embodiment of the present disclosure provides a switch locking circuit, wherein the switch locking circuit is connected to a control end of a switch transistor, a first end of the switch transistor is connected to a first power supply, and a second end of the switch transistor is used to connect to a controlled component; wherein:

[0006] The switch locking circuit is used to turn on when the switch transistor is turned off, and limit the control end of the switch transistor to a turn-off voltage to maintain the turn-off state of the switch transistor. The switch locking circuit is also used to turn off when the switch transistor is turned on.

[0007] In some embodiments, the switch locking circuit includes a first locking circuit; a first end of the first locking circuit is connected to the control end of the switch transistor, and a second end of the first locking circuit is connected to a first shutdown power supply; wherein:

[0008] The first locking circuit is used to turn on when the switch transistor is turned off, and limit the control terminal of the switch transistor to a turn-off voltage to maintain the turn-off state of the switch transistor, and the first locking circuit is also used to turn off when the switch transistor is turned on;

[0009] The first shutdown power supply is used to provide the shutdown voltage.

[0010] In some embodiments, the first lock circuit includes a first lock switch and an attenuation module;

[0011] One end of the attenuation module serves as the first end of the first locking circuit and is connected to the control end of the switch transistor; the other end of the attenuation module is connected to the first end of the first locking switch; the attenuation module is a resistor or an inductor;

[0012] The second end of the first locking switch is connected to the first shutdown power supply as the second end of the first locking circuit.

[0013] In some embodiments, the switch locking circuit further includes a second locking circuit; a first end of the second locking circuit is connected to the control end of the switch transistor, and a second end of the second locking circuit is connected to a second shutdown power supply; wherein:

[0014] The second locking circuit is used to turn on after a preset time when the switch transistor is turned off, and limit the control terminal of the switch transistor to the turn-off voltage to maintain the switch transistor in the off state, and the second locking circuit is also used to turn off when the switch transistor is turned on;

[0015] The second shutdown power supply is used to provide the shutdown voltage.

[0016] In some embodiments, the second lock circuit includes a second lock switch;

[0017] The first end of the second locking switch serves as the first end of the second locking circuit and is connected to the control end of the switching transistor. The second end of the second locking switch serves as the second end of the second locking circuit and is connected to the second shutdown power supply.

[0018] In some embodiments, the switch transistor is an NMOS transistor, and the shutdown voltages provided by the first shutdown power supply and the second shutdown power supply are both less than 300 millivolts.

[0019] In some embodiments, the switch transistor is a PMOS tube, and the shutdown voltage provided by the first shutdown power supply and the second shutdown power supply is greater than the difference between the voltage of the first power supply and 300 millivolts.

[0020] In some embodiments, the switch transistor is a triode, and the shutdown voltage provided by the first shutdown power supply and the second shutdown power supply is greater than the voltage of the first power supply, or the shutdown voltage is less than the voltage of the controlled component.

[0021] In some embodiments, the preset time is greater than or equal to 20 nanoseconds and less than or equal to 2 microseconds.

[0022] In some embodiments, the first locking switch and / or the second locking switch are transistors.

[0023] In a second aspect, an embodiment of the present disclosure provides a high-side switch circuit, comprising a switch transistor and a switch locking circuit according to any one of the above embodiments, wherein the switch locking circuit is connected to a control end of the switch transistor, a first end of the switch transistor is connected to a first power supply, and a second end of the switch transistor is connected to a controlled component; wherein,

[0024] The first power supply is used to provide a first voltage to the switching transistor;

[0025] The switching transistor is used to transmit the first voltage to the controlled component when the switching transistor is turned on;

[0026] The switch locking circuit is used to turn on when the switch transistor is turned off, and limit the control end of the switch transistor to a turn-off voltage to maintain the turn-off state of the switch transistor. The switch locking circuit is also used to turn off when the switch transistor is turned on.

[0027] The embodiment of the present disclosure provides a switch locking circuit, which is connected to the control end of the switch transistor, the first end of the switch transistor is connected to the first power supply, and the second end of the switch transistor is used to connect the controlled component; wherein: the switch locking circuit is used to turn on when the switch transistor is turned off, and limit the control end of the switch transistor to the off voltage to maintain the off state of the switch transistor, and the switch locking circuit is also used to turn off when the switch transistor is turned on. In this way, by adding a switch protection circuit, the voltage of the control end of the switch transistor can be maintained at the off voltage when the switch transistor is turned off; the problem of the switch transistor being unreliable to turn off caused by the voltage of the power supply being coupled to the control end of the switch transistor through parasitic capacitance is avoided, and the reliability of the switch transistor when it is turned off is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 A schematic diagram of the structure of the switch locking circuit provided in the embodiment of the present disclosure Figure 1 ;

[0029] Figure 2 A schematic diagram of the voltage waveform of the VCC port under the ET mode and APT provided in the embodiment of the present disclosure;

[0030] Figure 3 A schematic diagram of the structure of a controlled component provided in an embodiment of the present disclosure;

[0031] Figure 4 A schematic diagram of the structure of the switch locking circuit provided in the embodiment of the present disclosure Figure 2 ;

[0032] Figure 5A schematic diagram of the structure of the switch locking circuit provided in the embodiment of the present disclosure Figure 3 ;

[0033] Figure 6 A schematic diagram of the structure of the switch locking circuit provided in the embodiment of the present disclosure Figure 4 ;

[0034] Figure 7 A schematic diagram of the structure of the high-side switch circuit provided in the embodiment of the present disclosure Figure 1 ;

[0035] Figure 8 A schematic diagram of the structure of the high-side switch circuit provided in the embodiment of the present disclosure Figure 2 . DETAILED DESCRIPTION

[0036] The following will be combined with the drawings in the embodiments of the present disclosure to clearly and completely describe the technical solutions in the embodiments of the present disclosure. It is understood that the specific embodiments described herein are only used to explain the relevant disclosure, rather than to limit the disclosure. It should also be noted that, for the convenience of description, only the parts related to the relevant disclosure are shown in the drawings.

[0037] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which the present disclosure belongs. The terms used herein are only for the purpose of describing the embodiments of the present disclosure and are not intended to limit the present disclosure.

[0038] In the following description, reference is made to “some embodiments”, which describe a subset of all possible embodiments, but it will be understood that “some embodiments” may be the same subset or different subsets of all possible embodiments and may be combined with each other without conflict.

[0039] It should be pointed out that the terms "first\second\third" involved in the embodiments of the present disclosure are merely used to distinguish similar objects and do not represent a specific ordering of the objects. It can be understood that "first\second\third" can be interchanged in a specific order or sequence where permitted, so that the embodiments of the present disclosure described here can be implemented in an order other than that illustrated or described here.

[0040] At present, MOS high-side switches are widely used in many fields such as automobiles, industry, and mobile devices due to their low loss, easy drive, high reliability, and near-ideal switching characteristics, and cover the control and protection of currents within tens of amperes. However, for high-frequency application environments (GHz level), due to parasitic resistance and capacitance and coupling crosstalk, the control and protection of high-side switches are complex, and the industry generally uses PMOS tubes (i.e. MPS) as high-side switch devices.

[0041] Furthermore, when a PMOS tube is used as a high-side switch device, it is relatively easy to control the terminal voltage to turn on or off the PMOS tube. However, there are two disadvantages of using a PMOS tube as a high-side switch device: first, the carrier mobility of the PMOS tube is low, and more area is required to achieve the same on-resistance requirement; second, the gate-source voltage of the PMOS tube used as a high-side switch device is greatly affected by power supply fluctuations, so the on-resistance of the switch is unstable. In the related art, when an N-type MOS tube (NMOS tube) is used as a high-side switch device, when the switch transistor is turned off, the voltage of the power supply will be coupled to the control terminal of the switch transistor through parasitic capacitance, resulting in a higher voltage at the control terminal of the switch transistor, making it impossible to effectively turn off the switch transistor.

[0042] Based on this, the embodiment of the present disclosure provides a switch locking circuit, which is connected to the control end of the switch transistor, the first end of the switch transistor is connected to the first power supply, and the second end of the switch transistor is used to connect the controlled component; wherein: the switch locking circuit is used to turn on when the switch transistor is turned off, and limit the control end of the switch transistor to the off voltage to maintain the off state of the switch transistor, and the switch locking circuit is also used to turn off when the switch transistor is turned on. In this way, by adding a switch protection circuit, the voltage of the control end of the switch transistor can be maintained at the off voltage when the switch transistor is turned off; the problem of the switch transistor being unreliable to turn off caused by the voltage of the power supply being coupled to the control end of the switch transistor through parasitic capacitance is avoided, and the reliability of the switch transistor when it is turned off is improved.

[0043] The switch locking circuit in the embodiment of the present disclosure is described in detail below with reference to the accompanying drawings.

[0044] Figure 1 A switch locking circuit 300 is provided in an embodiment of the present disclosure, such as Figure 1 As shown, the switch locking circuit 300 is connected to the control end of the switch transistor 120, the first end of the switch transistor 120 is connected to the first power supply 110, and the second end of the switch transistor 120 is used to connect the controlled component 140; wherein: the switch locking circuit 300 is used to turn on when the switch transistor 120 is turned off, and limit the control end of the switch transistor 120 to the off voltage to maintain the off state of the switch transistor 120, and the switch locking circuit 300 is also used to turn off when the switch transistor 120 is turned on.

[0045] Here, the first power supply 110 is used to output a first voltage, and the first voltage may be a voltage for supplying power to the controlled component 140. The first voltage may be VCC_PS1 ( Figure 1The second voltage may be the output voltage of the voltage stabilizing circuit, and the second voltage may be represented by V2. In other embodiments, the first voltage and the second voltage may also be other voltages, or may be provided by other power supply circuits.

[0046] It should be noted that the first voltage can be a fixed voltage or a variable voltage. The first power supply 110 supplies power and operates in either of two modes: envelope tracking mode (ET mode) and average power tracking mode (Average Power Tracking mode, APT mode); the voltage waveform diagram of the first voltage in the ET mode and the APT mode is shown in FIG. Figure 2 shown.

[0047] In addition, the structural diagram of the controlled component 140 is as follows Figure 3 As shown, the controlled component 140 may include a power amplifier 141 (Power Amplifier, PA). The first end of the power amplifier 141 is connected to the second end of the switch transistor 120 through the port 142; the second end of the power amplifier 141 is grounded; the input end of the power amplifier 141 is used to receive the RF input signal RF_in; the output end of the power amplifier 141 is used to output the RF output signal RF_out. It should be noted that Figure 3 The controlled component 140 in FIG. 1 is a simplified structural diagram. In fact, the controlled component 140 can be any achievable circuit structure.

[0048] In the disclosed embodiment, the switch transistor 120 may be a PMOS transistor, an NMOS transistor or a triode, etc. By adding a switch protection circuit, when the switch transistor is turned off, the voltage at the control terminal of the switch transistor can be kept at a turn-off voltage; the problem of the switch transistor being unreliable to turn off due to the voltage of the power supply being coupled to the gate of the switch transistor through parasitic capacitance is avoided, and the reliability of the switch transistor when it is turned off is improved.

[0049] Next, please refer to Figure 4 , the switch locking circuit 300 provided in the embodiment of the present disclosure is further described.

[0050] In some embodiments, please refer to Figure 4The switch locking circuit 300 includes a first locking circuit 310; a first end of the first locking circuit 310 is connected to the control end of the switch transistor 120, and a second end of the first locking circuit 310 is connected to the first shutdown power supply 330; wherein: the first locking circuit 310 is used to turn on when the switch transistor 120 is turned off, and limit the control end of the switch transistor 120 to the shutdown voltage to maintain the shutdown state of the switch transistor 120, and the first locking circuit 310 is also used to turn off when the switch transistor 120 is turned on; the first shutdown power supply 330 is used to provide the shutdown voltage.

[0051] In some embodiments, please refer to Figure 4 The first locking circuit 310 includes a first locking switch 311 and an attenuation module 312; one end of the attenuation module 312 serves as the first end of the first locking circuit 310 and is connected to the control end of the switching transistor 120; the other end of the attenuation module 312 is connected to the first end of the first locking switch 311; the attenuation module 312 is a resistor or an inductor; the second end of the first locking switch 311 serves as the second end of the first locking circuit 310 and is connected to the first shutdown power supply.

[0052] The attenuation module 312 is provided in the first locking circuit 310 to prevent excessive discharge current through the first locking switch 311 at the moment when the switch transistor 120 is turned off, thereby ensuring reliable turn-off of the switch transistor 120 .

[0053] Since the voltage of the attenuation module 312 in the first locking circuit 310 may fluctuate, causing the shutdown voltage to be unstable, in order to further ensure that the switch transistor is stably turned off, some embodiments further include a second locking circuit 320 to stabilize the shutdown voltage; please refer to Figure 5 , a first end of the second locking circuit 320 is connected to the control end of the switching transistor 120, and a second end of the second locking circuit 320 is connected to the second shutdown power supply 340; wherein: the second locking circuit 320 is used to turn on after a preset time when the switching transistor 120 is turned off, and limit the control end of the switching transistor 120 to a shutdown voltage to maintain the switching transistor 120 in a closed state, and the second locking circuit 320 is also used to turn off when the switching transistor 120 is turned on; the second shutdown power supply 340 is used to provide a shutdown voltage.

[0054] In some embodiments, please refer to Figure 5 The second locking circuit 320 includes a second locking switch 321; the first end of the second locking switch 321 serves as the first end of the second locking circuit 320 and is connected to the control end of the switching transistor 120, and the second end of the second locking switch 321 serves as the second end of the second locking circuit 320 and is connected to the second shutdown power supply 340.

[0055] In some embodiments, the first locking switch 311 and / or the second locking switch 321 may be a transistor, for example, a field effect transistor, or a bipolar transistor. In the embodiment of the present disclosure, the first locking switch 311 and the second locking switch 321 are both NMOS transistors.

[0056] When the switch transistor 120 is turned off, the first locking circuit 310 is turned on, and then the second locking circuit 320 is turned on after a preset time. In this way, not only can the problem of burning the switch locking circuit 300 due to excessive discharge current generated at the moment when the switch transistor 120 is turned off be avoided, but also the voltage of the switch transistor 120 can be quickly maintained at the off voltage through the second locking switch 321, thereby improving the working efficiency of the switch locking circuit 300.

[0057] In some embodiments, the preset time is greater than or equal to 20 nanoseconds and less than or equal to 2 microseconds. For example, the preset time may be 40 or 100 nanoseconds.

[0058] In some embodiments, the switch transistor 120 is an NMOS transistor, and the first shutdown power supply 330 and the second shutdown power supply 340 are both ground. In other embodiments, the first shutdown power supply and the second shutdown power supply may also provide other voltages; for example, a voltage less than 300 millivolts. That is, when the switch transistor 120 is an NMOS transistor, by setting the control terminal of the switch transistor 120 to a low level voltage (i.e., the control terminal voltage of the switch transistor is less than the voltage of its second terminal), the switch transistor 120 can be stably turned off.

[0059] Please refer to Figure 6 , the first shutdown power supply 330 and the second shutdown power supply 340 are both grounded, the first locking switch 311 and the second locking switch 321 are both NMOS tubes, the attenuation module 312 is a resistor, and the first locking switch 311 and the second locking switch 321 can be controlled to be turned on or off respectively through the clock signals CTRL1 and CTRL2. In this way, leakage through two parasitic capacitors when the switch transistor 120 is turned off is avoided, namely, the first capacitor 281 between the first end and the gate end of the switch transistor 120, and the second capacitor 282 between the second end and the gate end of the switch transistor 120; through the switch locking circuit 300, namely, the first locking circuit 310 and the second locking circuit 320, the control terminal voltage of the switch transistor can be kept at the shutdown voltage, thereby ensuring that the switch transistor 120 is closed more reliably.

[0060] It should be noted that when the first capacitor 281 and the second capacitor 282 are metal plate capacitors, the switch locking circuit 300 can still ensure that the switch transistor 120 is closed more reliably.

[0061] In some embodiments, the switch transistor 120 is a PMOS transistor, and the first shutdown power source 330 and the second shutdown power source 340 are both greater than the difference between the voltage of the first power source 110 and 300 millivolts. In other words, when the switch transistor 120 is a PMOS transistor, the switch transistor 120 can be stably turned off by setting the control terminal of the switch transistor to a high level voltage (that is, the control terminal voltage of the switch transistor is greater than the voltage of its second terminal).

[0062] In some embodiments, the switch transistor 120 is a triode, and the first shutdown power supply 330 and the second shutdown power supply 340 are both greater than the voltage of the first power supply 110, or the shutdown voltage is less than the voltage of the controlled component 140. For example, when the triode is a PNP triode, when the voltage at the first end of the switch transistor (i.e., the voltage of the first power supply) is greater than the voltage at its control end, the PNP triode is turned on, so the voltage at the first end of the switch transistor can be set to be less than the voltage at its control end, so that the PNP triode can be turned off. For another example, when the triode is an NPN triode, when the voltage at the control end of the switch transistor 120 is greater than the voltage at its second end, the NPN triode is turned on, so the voltage at the control end of the switch transistor can be set to be less than the voltage at its second end, so that the NPN triode can be turned off.

[0063] In summary, in order to avoid leakage through two parasitic capacitors (i.e., the parasitic capacitor between the first end and the control end of the switch transistor 120, and the parasitic capacitor between the second end and the control end of the switch transistor 120) when the switch transistor 120 is turned off, by adding the switch locking circuit 300, i.e., the first locking circuit 310 and the second locking circuit 320, the control end voltage of the switch transistor can be kept at the turn-off voltage, thereby ensuring that the switch transistor 120 is closed more reliably. In addition, since the instantaneous current is too large when the switch transistor 120 is turned off, directly closing the second locking circuit 320 may burn the second locking circuit 320. Therefore, after a preset time has passed after the switch transistor 120 is closed, the second locking circuit 320 is opened again, thereby reducing the damage to the second locking circuit 320 caused by the instantaneous current, thereby increasing the service life of the switch locking circuit. In addition, the attenuation module 312 in the first locking circuit 310 consumes the instantaneous current when the switching transistor 120 is turned off. Furthermore, since the voltage of the attenuation module 312 swings with the voltage of the first power supply 110, after a preset time, the voltage of the control end of the switching transistor needs to be maintained stable at a turn-off voltage through the second locking circuit 320.

[0064] In the embodiment of the present disclosure, a second locking circuit 320 is added, and when the switch transistor 120 is turned off, the gate terminal of the second locking circuit 320 is placed at a shutdown voltage. At the same time, in order to avoid excessive discharge current through the second locking circuit 320 at the moment of the switch transistor 120 being turned off, the second locking circuit 320 is delayed to open relative to the first locking circuit 310, and at the same time, an attenuation module 312 is provided in the first locking circuit 310 to limit the discharge current when the switch transistor 120 is turned off. In this way, when the switch transistor 120 is turned off, the charge at the control terminal of the switch transistor 120 flows into the first shutdown power supply 330 via the first locking circuit 310, ensuring that the switch transistor 120 is reliably turned off. At the same time, after the switch transistor 120 is turned off, the second locking circuit 320 stably maintains the control terminal of the switch transistor 120 at the shutdown voltage, so that when the first power supply 110 is in the ET mode, the switch transistor 120 has no leakage current, and the switch transistor 120 can be reliably turned off.

[0065] The present disclosure also provides a high-side switch circuit 100. Figure 1 As shown, the high-side switch circuit 100 includes a switching transistor 120 and a switch locking circuit 300 as in the above embodiment, the switch locking circuit 300 is connected to the control end of the switching transistor 120, the first end of the switching transistor 120 is connected to the first power supply 110, and the second end of the switching transistor 120 is connected to the controlled component 140; wherein the first power supply 110 is used to provide a first voltage to the switching transistor 120; the switching transistor 120 is used to transmit the first voltage to the controlled component 140 when the switching transistor 120 is turned on; the switch locking circuit 300 is used to turn on when the switching transistor 120 is turned off, and limit the control end of the switching transistor 120 to the off voltage to maintain the off state of the switching transistor 120, and the switch locking circuit 300 is also used to turn off when the switching transistor 120 is turned on.

[0066] Next, the high-side switch circuit 100 is described by taking the switch transistor 120 as NMOS as an example. It should be noted that the switch locking circuit 300 is omitted when describing the high-side switch circuit 100. The connection relationship of the switch locking circuit 300 is understood by referring to the above embodiment, and will not be repeated here. Below, the high-side switch circuit in the embodiment of the present disclosure is described in detail with reference to the accompanying drawings.

[0067] Figure 7 A schematic diagram of the structure of a high-side switch circuit 100 provided in an embodiment of the present disclosure is shown in FIG. Figure 7As shown, the high-side switch circuit 100 includes: a first power supply 110, a switching transistor 120 and a driving circuit 130, wherein the first end of the switching transistor 120 is connected to the first power supply 110, the second end of the switching transistor 120 is connected to the controlled component 140, and the gate end (i.e., the control end) of the switching transistor 120 is connected to the driving circuit 130; wherein: the first power supply 110 is used to provide a first voltage to the switching transistor 120; the driving circuit 130 is used to receive a second voltage, and to lift the second voltage to obtain a bias voltage, and to turn on the switching transistor 120 according to the bias voltage; wherein, the lifting process makes the difference between the voltage at the gate end of the switching transistor 120 and the voltage at the second end of the switching transistor 120 greater than a preset difference; when the switching transistor 120 is turned on, the switching transistor 120 transmits the first voltage to the controlled component 140.

[0068] In some embodiments, the driving circuit 130 cannot stably drive the second voltage of the switch transistor to be raised. Here, the second voltage may be, for example, 2.5V, and the preset difference may be, for example, 5V. In actual implementation, the preset difference may also be other values ​​that can turn on the switch transistor 120, such as 6V, 6.5V, 7V, etc. Since the second voltage is raised by the driving circuit 130, the switch transistor 120 in the high-side switch circuit 100 may be an NMOS tube (i.e., MNS), so as to turn on the switch transistor 120 by setting the voltage of the gate terminal of the switch transistor 120 to be greater than the voltage of the second terminal thereof.

[0069] In the embodiment of the present disclosure, since the driving circuit raises the received second voltage, the gate voltage of the switching transistor is higher. In this way, the switching transistor can adopt an NMOS tube with a smaller size and stable switch resistance as a high-side switch, which not only reduces the area of ​​the high-side switch circuit but also stabilizes the switch resistance.

[0070] Next, please refer to Figure 8 , the high-side switch circuit 100 provided in the embodiment of the present disclosure is further described.

[0071] In some embodiments, please refer to Figure 8The high-side switch circuit 100 also includes a second power supply 151, and the drive circuit 130 includes: a first charge pump circuit 131 and a second charge pump circuit 132; the first end of the first charge pump circuit 131 is coupled to the second power supply 151, and the second end of the first charge pump circuit 131 is connected to the first end of the second charge pump circuit 132; the second end of the second charge pump circuit 132 is connected to the gate end of the switching transistor 120; wherein: the second power supply 151 is used to provide a second voltage; the first charge pump circuit 131 is used to raise the second voltage to obtain a preset voltage; the second charge pump circuit 132 is used to further raise the preset voltage to obtain a bias voltage.

[0072] It should be noted that the first end of the first charge pump circuit 131 is coupled to the second power supply 151: it means that the first end of the first charge pump circuit 131 and the second power supply 151 can be directly connected or indirectly connected, that is, "coupling" includes two ways of direct connection or indirect connection. The "coupling" that appears in the subsequent description can be understood with reference to the above explanation.

[0073] In the embodiment of the present disclosure, the value of the second voltage output by the second power supply 151 is within a certain range, here, the certain range may be within 2.5V-3V, and the second voltage may be, for example, 2.5V, 2.6V, etc. In some embodiments, the second power supply 151 may be a voltage stabilizing circuit, wherein the voltage stabilizing circuit is used to convert the battery voltage VBAT to output the second voltage. In other embodiments, the voltage stabilizing circuit may also convert the voltage of other power supplies.

[0074] Here, the first charge pump circuit 131 may be a VX2 CP (twice charge pump), which is used to increase the second voltage by two times to obtain a preset voltage; for example, the second voltage is 3V, and the first charge pump circuit 131 increases the 3V second voltage V2 by two times to output a preset voltage of 6V. The second charge pump circuit 132 may be a QPUMP (gate drive charge pump), which is used to further increase the preset voltage to obtain a bias voltage, for example, 8V. It should be noted that the first charge pump circuit 131 may also increase the second voltage V2 to other voltage values, for example, by 1.5 times.

[0075] It should also be noted that in Figure 8 In the embodiment, the first power supply supplies power to the switch transistor 120 through the port 111, the controlled component is connected to the switch transistor 120 through the port 142, and the second power supply 151 is connected to the battery voltage VBAT through the port 152. In addition, the high-side switch circuit 100 further includes a port GND connected to the ground terminal, and some components in the high-side switch circuit 100 are grounded through the port GND.

[0076] In the disclosed embodiment, since the driving circuit raises the received second voltage, the gate voltage of the switch transistor 120 is stably increased, so that when the switch transistor 120 is an NMOS transistor, the switch transistor 120 can be turned on or off; in addition, since the NMOS transistor has a higher carrier mobility characteristic, the high-side switch circuit can have a stronger driving current capability, thereby improving the current density and efficiency.

[0077] In some embodiments, the third terminal of the second charge pump circuit 132 is connected to the second terminal of the switch transistor 120, and the second charge pump circuit 132 is further used to receive the second terminal voltage of the switch transistor 120, and raise the preset voltage according to the voltage of the second terminal of the switch transistor 120 to obtain the bias voltage. In this way, the gate voltage of the switch transistor 120 can be adjusted according to the voltage feedback of the input terminal of the controlled component, so that the difference between the gate voltage of the switch transistor 120 and the second terminal voltage is greater than or equal to the preset difference, so as to turn on the switch transistor 120; it should be noted that the preset voltage and the preset difference are equal in value.

[0078] Specifically, the second charge pump circuit 132 is used to increase the voltage of the second end of the switching transistor 120 (i.e., the voltage output by the port 142) by a preset difference (i.e., the value of the preset voltage) to obtain a bias voltage, and apply the bias voltage to the gate end of the switching transistor 120; for example, the voltage of the second end of the switching transistor 120 is 3V, the second charge pump circuit 132 increases the voltage of 3V by 5V, and the obtained bias voltage is 8V, and the bias voltage of 8V is applied to the gate end of the switching transistor 120.

[0079] In the disclosed embodiment, since the switch transistor 120 includes an NMOS tube, the turn-on voltage of the NMOS is usually less than 5V under low voltage conditions, so the preset difference can be greater than 5V, such as 6V, 6.5V, 7V, etc. In other embodiments, it can also be set according to actual conditions. When the second voltage V2 is small, more charge pump circuits can be set to increase the second voltage.

[0080] In the disclosed embodiment, since a driving circuit (i.e., the second charge pump circuit 132) is connected to the gate terminal and the second terminal of the switching transistor, the voltages at the gate terminal and the second terminal of the switching transistor can be controlled by the driving circuit to turn on the switching transistor.

[0081] In the disclosed embodiment, when the high-side switch circuit 100 is turned off, the second power supply 151, the drive circuit 130 and other circuits are all turned off. When the high-side switch circuit 100 is turned on, the second power supply and the first charge pump circuit 131 in the drive circuit 130 are both kept turned on; at this time, when the high-side switch circuit 100 needs to be turned on, the second charge pump circuit 132 in the drive circuit 130 is turned on to drive the high-side switch circuit 100 to work.

[0082] In this way, the switching transistor 120 can be turned on or off only by turning on or off the second charge pump circuit 132. That is to say, during the operation of the high-side switch circuit 100, the second power supply 151 and the first charge pump circuit 131 will not cause any delay, thereby improving the response speed of the high-side switch circuit 100.

[0083] In some embodiments, please refer to Figure 8 The high-side switch circuit 100 further includes a first body-end switch circuit 190, wherein a first end and a second end of the first body-end switch circuit 190 are respectively connected to a gate end and a second end of the switch transistor 120, so as to ensure that the switch transistor 120 is reliably turned on and off.

[0084] It should be noted that the controlled component, the first power supply, the second power supply and the switch circuit can also be set on one IC, or part of them and the switch circuit can be set on one IC. In this case, no external interface is required for connection and they can be directly connected.

[0085] In some embodiments, please refer to Figure 8 The high-side switch circuit 100 further includes a logic control circuit 180, which is connected to the second charge pump circuit 132. The logic control circuit 180 is used to generate a first control signal and transmit the first control signal to the second charge pump circuit 132; when the first control signal is in an enabled state, the second charge pump circuit 132 is turned on and the switch transistor 120 is turned on; when the first control signal is in a disabled state, the second charge pump circuit 132 is turned off and the switch transistor 120 is turned off.

[0086] Here, the output signal of the logic control circuit 180 can be represented by CTRL_IN, which includes the first control signal CTRL_IN <0> .

[0087] In some embodiments, the logic control circuit 180 is also used to control the opening and closing of the second power supply 151 and the first charge pump circuit 131 .

[0088] In some embodiments, the logic control circuit 180 is also used to receive the initial control signal output by the port 182, such as Figure 8The VCC_Ctrl signal is used to generate a first control signal in an enabled state by performing logic processing on the initial control signal VCC_Ctrl and when the initial control signal indicates to turn on the switch transistor 120 .

[0089] It should be noted that the switching transistor 120 in the embodiment of the present disclosure can be a depletion-type NMOS tube or an enhancement-type NMOS tube; wherein, the manufacturing process of the depletion-type NMOS tube is simple; the enhancement-type NMOS tube has a fast switching speed and a stronger driving capability, and can be selected as needed during implementation.

[0090] It should also be noted that when the switching transistor 120 is a PMOS or a triode, the driving circuit 130 may not be added to the high-side switching circuit 100, that is, the switching transistor 120 is directly connected to the second power supply 151, and the second power supply 151 is used to control the opening or closing of the switching transistor (PMOS or triode).

[0091] The above description is only a preferred embodiment of the present disclosure and is not intended to limit the protection scope of the present disclosure.

[0092] It should be noted that in the present disclosure, the terms "include", "comprises" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "includes a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element.

[0093] The serial numbers of the above-mentioned embodiments of the present disclosure are only for description and do not represent the advantages or disadvantages of the embodiments.

[0094] The methods disclosed in several method embodiments provided in the present disclosure can be arbitrarily combined without conflict to obtain new method embodiments.

[0095] The features disclosed in several product embodiments provided in the present disclosure can be arbitrarily combined without conflict to obtain new product embodiments.

[0096] The features disclosed in several method or device embodiments provided in the present disclosure may be arbitrarily combined without conflict to obtain new method embodiments or device embodiments.

[0097] The above is only a specific embodiment of the present disclosure, but the protection scope of the present disclosure is not limited thereto. Any person skilled in the art who is familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present disclosure, which should be included in the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure should be based on the protection scope of the claims.

Claims

1. A switch locking circuit, characterized in that: The switch locking circuit is connected to the control end of the switch transistor, the first end of the switch transistor is connected to the first power supply, and the second end of the switch transistor is used to connect to the controlled component; wherein: The switch locking circuit is used to turn on when the switch transistor is turned off, and limit the control end of the switch transistor to a turn-off voltage to maintain the turn-off state of the switch transistor. The switch locking circuit is also used to turn off when the switch transistor is turned on.

2. The switch locking circuit according to claim 1, characterized in that: The switch locking circuit comprises a first locking circuit; a first end of the first locking circuit is connected to the control end of the switch transistor, and a second end of the first locking circuit is connected to a first shutdown power supply; wherein: The first locking circuit is used to turn on when the switch transistor is turned off, and limit the control terminal of the switch transistor to a turn-off voltage to maintain the turn-off state of the switch transistor, and the first locking circuit is also used to turn off when the switch transistor is turned on; The first shutdown power supply is used to provide the shutdown voltage.

3. The switch locking circuit according to claim 2, characterized in that: The first locking circuit includes a first locking switch and an attenuation module; One end of the attenuation module serves as the first end of the first locking circuit and is connected to the control end of the switch transistor; The other end of the attenuation module is connected to the first end of the first locking switch; the attenuation module is a resistor or an inductor; The second end of the first locking switch is connected to the first shutdown power supply as the second end of the first locking circuit.

4. The switch locking circuit according to claim 3, characterized in that: The switch locking circuit further includes a second locking circuit; a first end of the second locking circuit is connected to the control end of the switch transistor, and a second end of the second locking circuit is connected to a second shutdown power supply; wherein: The second locking circuit is used to turn on after a preset time when the switch transistor is turned off, and limit the control terminal of the switch transistor to the turn-off voltage to maintain the switch transistor in the off state, and the second locking circuit is also used to turn off when the switch transistor is turned on; The second shutdown power supply is used to provide the shutdown voltage.

5. The switch locking circuit according to claim 4, characterized in that: The second locking circuit includes a second locking switch; The first end of the second locking switch serves as the first end of the second locking circuit and is connected to the control end of the switching transistor. The second end of the second locking switch serves as the second end of the second locking circuit and is connected to the second shutdown power supply.

6. The switch locking circuit according to claim 5, characterized in that: The switch transistor is an NMOS tube, and the shutdown voltages provided by the first shutdown power supply and the second shutdown power supply are both less than 300 millivolts.

7. The switch locking circuit according to claim 5, characterized in that: The switch transistor is a PMOS tube, and the shutdown voltages provided by the first shutdown power supply and the second shutdown power supply are both greater than the difference between the voltage of the first power supply and 300 millivolts.

8. The switch locking circuit according to claim 5, characterized in that: The switch transistor is a triode, and the shutdown voltage provided by the first shutdown power supply and the second shutdown power supply is greater than the voltage of the first power supply, or the shutdown voltage is less than the voltage of the controlled component.

9. The switch locking circuit according to any one of claims 5 to 8, characterized in that: The preset time is greater than or equal to 20 nanoseconds and less than or equal to 2 microseconds.

10. The switch locking circuit according to claim 9, characterized in that: The first locking switch and / or the second locking switch is a transistor.

11. A high side switch circuit, characterized in that: A switch transistor and a switch locking circuit as claimed in any one of claims 1 to 10, wherein the switch locking circuit is connected to the control end of the switch transistor, the first end of the switch transistor is connected to a first power supply, and the second end of the switch transistor is connected to a controlled component; wherein, The first power supply is used to provide a first voltage to the switching transistor; The switching transistor is used to transmit the first voltage to the controlled component when the switching transistor is turned on; The switch locking circuit is used to turn on when the switch transistor is turned off, and limit the control end of the switch transistor to a turn-off voltage to maintain the turn-off state of the switch transistor. The switch locking circuit is also used to turn off when the switch transistor is turned on.

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