High-side NMOS drive circuit and electronic device

Abstract

This application provides a high-side NMOS driving circuit and electronic device. The circuit includes a charging power supply module for outputting a charging voltage independent of the main circuit voltage to a bootstrap capacitor module; a lift power supply module for outputting the main circuit voltage to the bootstrap capacitor module; a lift control module for controlling the voltage rise of the bootstrap capacitor module; and a bootstrap capacitor module for outputting a driving voltage to the gate of the NMOS transistor during the voltage rise. During the charging phase, the bootstrap capacitor module is charged to the charging voltage via the charging power supply module. During the lift phase, the bootstrap capacitor module, through the lift power supply module and the lift control module, raises the capacitor voltage to the superposition of the main circuit voltage and the charging voltage to drive the NMOS transistor to conduct. This circuit can still achieve stable NMOS transistor conduction even in scenarios with a wide main circuit power supply voltage range.

Description

Technical Field

[0001] This application relates to the field of electronic circuit technology, and in particular to a high-side NMOS driving circuit and electronic device. Background Technology

[0002] A high-side electronic switch is a power switch located between the positive terminal of a power supply and the load, used to connect and disconnect the load and the power supply. NMOS and PMOS transistors are two common high-side switching devices. In practical applications, NMOS is often the preferred high-side electronic switch for high-current applications to reduce circuit heat generation.

[0003] Currently, the main driving method for using NMOS as a high-side switch in existing technologies is the bootstrap capacitor boost driving method.

[0004] However, the existing bootstrap capacitor boost drive method has strict requirements on the power supply voltage range and poor adaptability. Summary of the Invention

[0005] This application provides a high-side NMOS driving circuit and electronic device to ensure that the driving voltage of the NMOS transistor gate is not affected by fluctuations in the main circuit power supply voltage, thereby enabling the NMOS transistor to conduct stably even when the power supply voltage range is wide.

[0006] In a first aspect, embodiments of this application provide a high-side NMOS driving circuit, comprising:

[0007] A charging power module is connected to the charging terminal of the bootstrap capacitor module and is used to output a charging voltage independent of the main circuit voltage to the bootstrap capacitor module.

[0008] A lifting power module is connected to the lifting end of the bootstrap capacitor module and is used to output the main circuit voltage to the bootstrap capacitor module.

[0009] A lifting control module is connected to the lifting end of the bootstrap capacitor module and is used to control the lifting of the capacitor voltage of the bootstrap capacitor module.

[0010] The output terminal of the bootstrap capacitor module is connected to the gate of the NMOS transistor in the main circuit, and is used to output a drive voltage to the gate of the NMOS transistor when the capacitor voltage rises; wherein, the source of the NMOS transistor is connected to the load, and the drain of the NMOS transistor is connected to the main power supply in the main circuit;

[0011] During the charging phase, the bootstrap capacitor module is charged to the charging voltage through the charging power module;

[0012] During the lift-up phase, the bootstrap capacitor module raises the capacitor voltage to the superposition value of the main circuit voltage and the charging voltage through the lift power module and the lift control module, so as to drive the NMOS transistor to conduct.

[0013] In one possible implementation, the charging power module includes:

[0014] The charging control unit is connected to the base of the first switching transistor via a first resistor; wherein the emitter of the first switching transistor is grounded, and the collector of the first switching transistor is connected to the base of the second switching transistor via a second resistor;

[0015] The charging unit is connected to the emitter of the second switching transistor and is used to output the charging voltage; wherein, the collector of the second switching transistor is connected to the anode of the first diode, and the cathode of the first diode is connected to the charging terminal of the bootstrap capacitor module.

[0016] In one possible implementation, the lifting control module includes: a signal controller, a third resistor, and a third switching transistor;

[0017] The signal controller is connected to the base of the third switching transistor through the third resistor;

[0018] The emitter of the third switch is grounded, and the collector of the third switch is connected to the lift-up terminal of the bootstrap capacitor module.

[0019] In one possible implementation, the bootstrap capacitor module includes: a first capacitor, a second diode, a second capacitor, and a fourth resistor;

[0020] One end of the first capacitor is connected to the collector of the third switching transistor and the lifting power module, and the other end of the first capacitor is connected to the cathode of the first diode.

[0021] The positive terminal of the second diode is connected to the negative terminal of the first diode and the other end of the first capacitor, and the negative terminal of the second diode is connected to one end of the second capacitor and one end of the fourth resistor;

[0022] The other end of the second capacitor is grounded, and the other end of the fourth resistor is connected to the gate of the NMOS transistor.

[0023] In one possible implementation, the lifting power module includes a fifth resistor and the main power supply; the main power supply is connected to one end of the first capacitor and the collector of the third switching transistor through the fifth resistor.

[0024] In one possible implementation, the lift power module includes a fifth resistor; one end of the fifth resistor is connected to one end of the first capacitor and the collector of the third switching transistor, and the other end of the fifth resistor is connected to the source of the NMOS transistor.

[0025] In one possible implementation, the bootstrap capacitor module includes: a first capacitor and a fourth resistor; one end of the first capacitor is connected to the collector of the third switching transistor and the lift-up power supply module, and the other end of the first capacitor is connected to the cathode of the first diode; one end of the fourth resistor is connected to the other end of the first capacitor, and the other end of the fourth resistor is connected to the gate of the NMOS transistor.

[0026] In one possible implementation, the lifting power module includes: a fifth resistor and the main power supply; the main power supply is connected to one end of the first capacitor and the collector of the third switching transistor through the fifth resistor.

[0027] In one possible implementation, the lift power module includes: a fifth resistor; one end of the fifth resistor is connected to one end of the first capacitor and the collector of the third switching transistor, and the other end of the fifth resistor is connected to the source of the NMOS transistor.

[0028] Secondly, embodiments of this application provide an electronic device, including a device body and the aforementioned high-side NMOS driving circuit disposed on the device body.

[0029] The high-side NMOS driving circuit and electronic device provided in this application decouple the charging power supply of the bootstrap capacitor module from the lift power supply, making the charging power supply independent of the main circuit voltage provided by the lift power supply module. This ensures the stability of the gate voltage of the NMOS transistor and prevents it from being affected by fluctuations in the main circuit power supply voltage. As a result, the NMOS transistor can still conduct stably when the main circuit power supply voltage range is wide, improving the adaptability of the high-side NMOS driving circuit in high voltage range scenarios. Attached Figure Description

[0030] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0031] Figure 1 A module frame diagram of the high-side NMOS driving circuit provided in an embodiment of this application;

[0032] Figure 2 This is a schematic diagram of a high-side NMOS driving circuit provided in an embodiment of this application;

[0033] Figure 3A schematic diagram of a high-side NMOS driving circuit provided in another embodiment of this application;

[0034] Figure 4 A schematic diagram of a high-side NMOS driving circuit provided in another embodiment of this application;

[0035] Figure 5 A schematic diagram of a high-side NMOS driving circuit provided in another embodiment of this application.

[0036] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concepts of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0037] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0038] High-side electronic switches are widely used in industrial control, automotive electronics, and consumer electronics to connect and disconnect loads from power sources. For example, in industrial automation equipment, high-side switches control high-current loads such as motors and relays; in automotive electronics, they control lighting systems and power windows; and in consumer electronics, they control power management modules. Because high-side switches are directly connected to the positive terminal of the power supply, their performance directly affects the system's reliability, energy efficiency, and cost.

[0039] In practical applications, N-channel metal-oxide-semiconductor (NMOS) and P-channel metal-oxide-semiconductor (PMOS) transistors are two common high-side switching devices. Because the on-resistance of NMOS devices is significantly lower than that of PMOS devices under equivalent price and rated current conditions, NMOS is often the preferred high-side switching device in high-current applications to reduce circuit heat generation.

[0040] Traditional driving methods for NMOS as high-side switches mainly include: (1) bootstrap capacitor boost driving; (2) transformer isolation driving; and (3) dedicated high-side driver chip. Among them, transformer isolation driving and dedicated high-side driver chip solutions are simple to use but expensive. As for bootstrap capacitor boost driving, either the control voltage of the MOS transistor and the main circuit voltage are heavily dependent, making the circuit unable to meet the requirements of a wide power supply voltage range; or the control voltage of the MOS transistor gradually decreases as a key capacitor in the circuit discharges, eventually leading to natural shutdown, which cannot meet the requirement of long-term MOS transistor operation; or the control circuit is too complex, resulting in high manufacturing costs and short-circuit risks.

[0041] Based on the above problems, this application provides a high-side NMOS driving circuit and electronic device. By decoupling the charging power supply and the lift power supply of the capacitor in the bootstrap capacitor driving circuit, the charging power supply does not change with the product's operating power supply, while the lift power supply is the voltage of the main circuit, thereby ensuring at least the gate-source voltage amplitude of the MOS transistor and meeting the wide voltage operating requirements.

[0042] The technical solution of this application and how the technical solution of this application solves the above-mentioned technical problems are described in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. The embodiments of this application will now be described with reference to the accompanying drawings.

[0043] Figure 1 This is a module framework diagram of the high-side NMOS driving circuit provided in the embodiments of this application, as shown below. Figure 1 As shown, it includes a charging power module 11, a lifting power module 12, and a lifting control module 13.

[0044] The charging power module 11 is connected to the charging terminal of the bootstrap capacitor module 10 and is used to output a charging voltage independent of the main circuit voltage to the bootstrap capacitor module 10.

[0045] The lifting power module 12 is connected to the lifting end of the bootstrap capacitor module 10 and is used to output the main circuit voltage to the bootstrap capacitor module 10.

[0046] The lifting control module 13 is connected to the lifting end of the bootstrap capacitor module 10 and is used to control the voltage rise of the bootstrap capacitor module 10.

[0047] The output of the bootstrap capacitor module 10 is connected to the gate of the NMOS transistor in the main circuit, and is used to output a drive voltage to the gate of the NMOS transistor when the capacitor voltage rises.

[0048] In this circuit, the source of the NMOS transistor is connected to the load, and the drain of the NMOS transistor is connected to the main power supply in the main circuit.

[0049] During the charging phase, the bootstrap capacitor module 10 is charged to the charging voltage through the charging power module; while during the lifting phase, the bootstrap capacitor module 10 raises the capacitor voltage to the superposition value of the main circuit voltage and the charging voltage through the lifting power module 12 and the lifting control module 13, so as to drive the NMOS transistor to conduct, thereby realizing the conduction between the main power supply and the load in the main circuit.

[0050] In this circuit, the NMOS is used as a high-side switch, connected between the main power supply and the load. The gate (G) needs to be about 10-15 volts higher than the source to be fully turned on. However, the traditional bootstrap capacitor boost drive method cannot provide a stable gate-source voltage difference for the floating source, making the circuit unable to meet the requirements of a wide power supply voltage range.

[0051] In this embodiment, the charging power module 11 is decoupled from the main power supply, so that the charging power supply does not change with the product's operating power supply.

[0052] In addition, a separate lift-up control module 13 can be configured to enable the NMOS transistor to be turned on for an extended period of time. The lift-up control module 13 can be connected to a square wave signal, and when the signal is low, it can lift the capacitor voltage of the bootstrap capacitor module.

[0053] In this embodiment, the lift capacitor module includes at least one capacitor. At the charging node, the capacitor can be charged by the charging power supply module. During the lift phase, the capacitor voltage is raised by the charging voltage of the charging power supply and the main circuit voltage, and the gate of the NMOS transistor is discharged, so that the NMOS transistor is turned on, thereby realizing the conduction between the main power supply and the load.

[0054] The high-side NMOS driving circuit provided in this application decouples the charging power supply of the bootstrap capacitor module from the lift power supply, making the charging power supply independent of the main circuit voltage provided by the lift power supply module. This ensures the stability of the NMOS gate voltage and prevents it from being affected by fluctuations in the main circuit power supply voltage. As a result, the NMOS can still conduct stably when the main circuit power supply voltage range is wide, improving the adaptability of the high-side NMOS driving circuit in high voltage range scenarios.

[0055] The following describes the solution in detail with reference to circuit diagrams in some embodiments.

[0056] Figure 2 This is a schematic diagram of a high-side NMOS driving circuit provided in an embodiment of this application, as shown below. Figure 2 As shown, the charging power module includes a charging control unit 211 and a charging unit 212.

[0057] Among them, the charging unit 212 outputs the required charging voltage V s For example, Vs The value range can be from 10 to 20 volts. The charging control unit 211 outputs a start / stop signal V. ctrl It can output through the General Purpose Input / Output (GPIO) interface.

[0058] The charging control unit 211 is connected to the base of the first switching transistor Q1 through a first resistor R1. The emitter of the first switching transistor Q1 is grounded, and the collector of the first switching transistor Q1 is connected to the base of the second switching transistor Q2 through a second resistor R2.

[0059] The charging unit 212 is connected to the emitter of the second switching transistor Q2 and is used to output a charging voltage. The collector of the second switching transistor Q2 is connected to the anode of the first diode D1, and the cathode of the first diode D1 is connected to the charging terminal of the bootstrap capacitor C1.

[0060] In this embodiment, when V ctrl When the voltage is high, the first switch Q1 is turned on, and the collector voltage of the second switch Q2 is V. s .

[0061] In this embodiment, the charging unit 212 outputs a charging voltage V. s It is independent of the main circuit voltage V in This ensures that the gate voltage of the NMOS transistor is not affected by the main circuit voltage V. in Fluctuations affect and thus support the main circuit voltage V. in It operates stably within a wide voltage range (e.g., 9V-32V).

[0062] For example, the first switch Q1 and the second switch Q2 can be replaced with switching devices such as metal-oxide-semiconductor field-effect transistors (MOSFETs). Additionally, the first diode D1 can be replaced with a switching device such as a MOSFET.

[0063] Replacing the first switch Q1 and the second switch Q2, as well as the diode, with a MOSFET can reduce conduction losses.

[0064] In this embodiment, both the first resistor and the second resistor can be composed of multiple resistors connected in series or multiple resistors connected in parallel, and their specific number is not limited. Furthermore, the resistance values ​​of the first and second resistors can be selected according to actual conditions.

[0065] In this embodiment of the application, the charging voltage V output by the charging control unit is... s Independent of the main circuit voltage V inThis ensures that the gate voltage of the NMOS transistor is unaffected by the main circuit voltage V. in To mitigate the impact of voltage fluctuations, we ensure the stability of the NMOS gate voltage and enable long-term conduction over a wide voltage range.

[0066] Further, please refer to the above. Figure 2 The lifting control module 22 includes a signal controller, a third resistor R3, and a third switch Q3. The signal controller is connected to the base of the third switch Q3 via the third resistor R3. The emitter of the third switch Q3 is grounded, and the collector of the third switch Q3 is connected to the lifting terminal of the bootstrap capacitor module (i.e., the aforementioned...). Figure 2 One end of the first capacitor C1 in the middle).

[0067] In this embodiment, reference is made to the above. Figure 2 When V ctrl When the voltage is high, the first switch Q1 is turned on, and the collector voltage of the second switch Q2 is V. s If the square wave signal output by the signal controller is high at this time, the third switch Q3 will be turned on, and the lower end of the first capacitor C1 in the bootstrap capacitor module will be connected to ground through a resistor, charging the voltage of the first capacitor C1 to V. s -V D1 .

[0068] Wherein, VD1 is the forward conduction voltage drop of D1.

[0069] In addition, when an electronic device or system with the above-mentioned high-side NMOS drive circuit contains multiple high-side electronic load switches, the same power supply can be used to provide the charging voltage Vs and the square wave signal, thereby reducing system cost and simplifying the circuit structure.

[0070] For example, the third switch Q3 can be replaced with a switching device such as a metal-oxide-semiconductor field-effect transistor (MOSFET). Replacing transistors and diodes with MOSFETs can reduce conduction losses.

[0071] In this embodiment, the third resistor can be composed of multiple resistors connected in series or multiple resistors connected in parallel, and its specific number is not limited. In addition, the resistance value of the third resistor can be selected according to the actual situation.

[0072] Further, please refer to the above. Figure 2 The bootstrap capacitor module includes: a first capacitor C1, a second diode D2, a second capacitor C2, and a fourth resistor R4.

[0073] One end of the first capacitor C1 is connected to the collector of the third switch Q3 and the lifting power module (i.e., connected to...). Figure 2 One end of the fifth resistor R5 in the first capacitor is connected to the negative terminal of the first diode D1.

[0074] The positive terminal of the second diode D2 is connected to the negative terminal of the first diode D1 and the other end of the first capacitor C1, while the negative terminal of the second diode D2 is connected to one end of the second capacitor C2 and one end of the fourth resistor R4.

[0075] The other end of the second capacitor C2 is grounded, and the other end of the fourth resistor R4 is connected to the gate of the NMOS transistor M1.

[0076] In this embodiment, when V ctrl When the voltage is high, the first switch Q1 is turned on, and the collector voltage of the second switch Q2 is V. s If the square wave signal output by the signal controller is high at this time, the third switch Q3 is turned on, and the lower end of the first capacitor C1 can be connected to ground through a resistor, charging the capacitor voltage of the first capacitor C1 to V. s -V D1 Meanwhile, the second capacitor C2 charges the gate of the NMOS transistor M1.

[0077] When the square wave signal output by the signal controller goes low, the third switch Q3 is turned off, and the lower end of the first capacitor C1 is connected to the main circuit voltage V. in This causes the potential at the lower end of the first capacitor C1 to be pulled up and raised to the main circuit voltage V. in Due to the characteristic that the voltage across a capacitor cannot change abruptly, the upper potential of the first capacitor C1 is also simultaneously raised by the same potential, ultimately achieving the bootstrap voltage boosting process of the first capacitor C1. If the voltage across the first capacitor C1 is higher than that of the second capacitor C2 at this time, the first capacitor C1 will discharge to the second capacitor C2 and simultaneously charge the gate of the NMOS transistor M1; otherwise, only the second capacitor C2 will charge the gate of the NMOS transistor M1. During this process, the second capacitor C2 stores the charge from the first capacitor C1, playing a role in stabilizing the gate voltage of the NMOS transistor M1.

[0078] Continue to refer to the above. Figure 2 After several square wave cycles, the voltage across the second capacitor C2 will rise to V. in +V s -V D1 -V D2 This causes the voltage difference between the gate and source of NMOS transistor M1 to reach V. s -V D1 -V D2 This allows the NMOS transistor M1 to conduct for an extended period. When V... ctrlWhen the voltage is low, the first switch Q1 is off, the NMOS transistor M1 is also off, and the output voltage is 0.

[0079] Among them, V D2 This is the forward conduction voltage drop of D2. The square wave signal can be generated by a microcontroller unit (MCU) or a circuit such as a 555 timer.

[0080] In some embodiments, the first capacitor C1 can be replaced with a supercapacitor or an electrolytic capacitor to extend the energy storage time, thereby maintaining gate voltage stability under lower frequency square wave signals, reducing the frequency requirements of the MCU or 555 timer, and further simplifying the control circuit.

[0081] In this embodiment, by utilizing the energy storage function of the second capacitor C2, the gate voltage of the NMOS transistor M1 can be stabilized, avoiding voltage drop due to the discharge of the first capacitor C1, and enabling the NMOS transistor M1 to conduct for a long time.

[0082] Further, please refer to the above. Figure 2 The lifting power module 23 includes a fifth resistor R5 and a main power supply. The main power supply is connected to one end of the first capacitor C1 and the collector of the third switching transistor Q3 through the fifth resistor R5.

[0083] The fifth resistor can be composed of multiple resistors connected in series or in parallel, and its specific number is not limited. Furthermore, the resistance value of the fifth resistor can be selected according to the actual situation.

[0084] Refer to the above Figure 2 When the square wave signal output by the signal controller goes low, the third switch Q3 is turned off, and the lower end of the first capacitor C1 is connected to the main circuit voltage V output by the main power supply. in This causes the potential at the lower end of the first capacitor C1 to be pulled up and raised to the main circuit voltage V. in Due to the characteristic that the voltage across a capacitor cannot change abruptly, the voltage at the upper end of the first capacitor C1 is also raised by the same voltage, thus realizing the bootstrap voltage boosting process of the first capacitor C1.

[0085] Figure 3 A schematic diagram of a high-side NMOS driving circuit provided in another embodiment of this application is shown below. Figure 3 As shown, the connection method of the fifth resistor can be adjusted. One end of the fifth resistor is connected to one end of the first capacitor and the collector of the third switching transistor, and the other end of the fifth resistor is connected to the source of the NMOS transistor.

[0086] In this embodiment, Figure 3 Compared to Figure 2In this case, the connection position of the fifth resistor has changed. The right end of the fifth resistor R5 is now connected to the source of the NMOS transistor M1, which changes the way the bootstrap capacitor raises the voltage.

[0087] Figure 4 A schematic diagram of a high-side NMOS driving circuit provided in another embodiment of this application is shown below. Figure 4 As shown, the original second diode D2 and second capacitor C2 can be removed to obtain a new bootstrap capacitor module 41, which includes the remaining first capacitor C1 and fourth resistor R4.

[0088] One end of the first capacitor C1 is connected to the lifting control module and the lifting power module (i.e., Figure 4 The collector of the third switch Q3 and the fifth resistor R5 are connected to the collector of the first capacitor C1 and the cathode of the first diode D1.

[0089] One end of the fourth resistor R4 is connected to the other end of the first capacitor C1, and the other end of the fourth resistor R4 is connected to the gate of the NMOS transistor.

[0090] In this embodiment, after removing the second capacitor C2 and the second diode D2, the first capacitor C1 is directly connected to the gate of the NMOS transistor M1 through the fourth resistor R4.

[0091] The signal controller controls the switching on and off of the third switch Q3 by outputting a square wave signal to raise the capacitor voltage of the first capacitor C1. After the capacitor voltage is raised, it directly provides a drive voltage to the gate of the NMOS transistor M1, so that the NMOS transistor M1 is turned on, thereby enabling the main power supply and load R to switch on and off. L The connection is established between them.

[0092] In this embodiment, the fourth resistor can be composed of multiple resistors connected in series or multiple resistors connected in parallel, and its specific number is not limited. In addition, the resistance value of the fourth resistor can be selected according to the actual situation.

[0093] Continue to refer to the above. Figure 4 In some embodiments, the lifting power module includes a fifth resistor R5 and a main power supply. The main power supply V... in The fifth resistor R5 connects one end of the first capacitor C1 to the collector of the third switch Q3.

[0094] In this embodiment, when the square wave signal is high and the third switch Q3 is turned on, the fifth resistor R5 can prevent the output voltage from being directly short-circuited to ground, thus playing a current-limiting role.

[0095] The fifth resistor, R5, can be composed of multiple resistors connected in series or in parallel; its specific number is not limited. Furthermore, the resistance value of the fifth resistor, R5, can be selected according to the actual situation.

[0096] Refer to the above Figure 4 When the square wave signal output by the signal controller becomes low, the third switch Q3 is turned off, and the lower end of the first capacitor C1 is connected to the main circuit voltage Vin output by the main power supply, which pulls up the potential of the lower end of the first capacitor C1 to the main circuit voltage Vin. Due to the characteristic that the voltage across the capacitor cannot change abruptly, the potential of the upper end of the first capacitor C1 is also raised by the same potential at the same time, thus realizing the bootstrap voltage boosting process of the first capacitor C1.

[0097] Figure 5 A schematic diagram of a high-side NMOS driving circuit provided in another embodiment of this application is shown below. Figure 5 As shown, the connection method of the fifth resistor can be adjusted, that is, one end of the fifth resistor R5 is connected to one end of the first capacitor C1 and the collector of the third switch Q3, and the other end of the fifth resistor R5 is connected to the source of the NMOS transistor.

[0098] In this embodiment, Figure 5 Compared to Figure 4 In this case, the connection position of the fifth resistor R5 has changed. The right end of the fifth resistor R5 is now connected to the source of the NMOS transistor M1, which changes the boost path of the bootstrap capacitor.

[0099] This application also provides an electronic device, including a device body and the aforementioned high-side NMOS driving circuit disposed on the device body.

[0100] In this context, electronic equipment can refer to industrial automation equipment that uses NMOS as a high-side switch, suitable for high-current loads such as motors and relays. Additionally, in automotive electronics, electronic equipment can be lighting systems or power windows and doors, among other things.

[0101] In this application, the division of units is merely a logical functional division. In actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed.

[0102] In addition, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0103] Finally, it should be noted that other embodiments of the invention will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This invention is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein, and is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of the invention is limited only by the appended claims.

Claims

1. A high-side NMOS driving circuit, characterized in that, include: A charging power module is connected to the charging terminal of the bootstrap capacitor module and is used to output a charging voltage independent of the main circuit voltage to the bootstrap capacitor module. A lifting power module is connected to the lifting end of the bootstrap capacitor module and is used to output the main circuit voltage to the bootstrap capacitor module. A lifting control module is connected to the lifting end of the bootstrap capacitor module and is used to control the lifting of the capacitor voltage of the bootstrap capacitor module. The output terminal of the bootstrap capacitor module is connected to the gate of the NMOS transistor in the main circuit, and is used to output a drive voltage to the gate of the NMOS transistor when the capacitor voltage rises; wherein, the source of the NMOS transistor is connected to the load, and the drain of the NMOS transistor is connected to the main power supply in the main circuit; During the charging phase, the bootstrap capacitor module is charged to the charging voltage through the charging power module; During the lift-up phase, the bootstrap capacitor module raises the capacitor voltage to the superposition value of the main circuit voltage and the charging voltage through the lift power module and the lift control module, so as to drive the NMOS transistor to conduct.

2. The circuit according to claim 1, characterized in that, The charging power module includes: The charging control unit is connected to the base of the first switching transistor via a first resistor; wherein the emitter of the first switching transistor is grounded, and the collector of the first switching transistor is connected to the base of the second switching transistor via a second resistor; The charging unit is connected to the emitter of the second switching transistor and is used to output the charging voltage; wherein, the collector of the second switching transistor is connected to the anode of the first diode, and the cathode of the first diode is connected to the charging terminal of the bootstrap capacitor module.

3. The circuit according to claim 2, characterized in that, The lifting control module includes: a signal controller, a third resistor, and a third switching transistor; The signal controller is connected to the base of the third switching transistor through the third resistor; The emitter of the third switch is grounded, and the collector of the third switch is connected to the lift-up terminal of the bootstrap capacitor module.

4. The circuit according to claim 3, characterized in that, The bootstrap capacitor module includes: a first capacitor, a second diode, a second capacitor, and a fourth resistor; One end of the first capacitor is connected to the collector of the third switching transistor and the lifting power module, and the other end of the first capacitor is connected to the cathode of the first diode. The positive terminal of the second diode is connected to the negative terminal of the first diode and the other end of the first capacitor, and the negative terminal of the second diode is connected to one end of the second capacitor and one end of the fourth resistor; The other end of the second capacitor is grounded, and the other end of the fourth resistor is connected to the gate of the NMOS transistor.

5. The circuit according to claim 4, characterized in that, The lifting power module includes a fifth resistor and the main power supply; The main power supply is connected to one end of the first capacitor and the collector of the third switching transistor through the fifth resistor.

6. The circuit according to claim 4, characterized in that, The lifting power module includes a fifth resistor; One end of the fifth resistor is connected to one end of the first capacitor and the collector of the third switching transistor, and the other end of the fifth resistor is connected to the source of the NMOS transistor.

7. The circuit according to claim 3, characterized in that, The bootstrap capacitor module includes: a first capacitor and a fourth resistor; One end of the first capacitor is connected to the collector of the third switching transistor and the lifting power module, and the other end of the first capacitor is connected to the cathode of the first diode. One end of the fourth resistor is connected to the other end of the first capacitor, and the other end of the fourth resistor is connected to the gate of the NMOS transistor.

8. The circuit according to claim 7, characterized in that, The lifting power module includes: a fifth resistor and the main power supply; The main power supply is connected to one end of the first capacitor and the collector of the third switching transistor through the fifth resistor.

9. The circuit according to claim 7, characterized in that, The lifting power module includes: a fifth resistor; One end of the fifth resistor is connected to one end of the first capacitor and the collector of the third switching transistor, and the other end of the fifth resistor is connected to the source of the NMOS transistor.

10. An electronic device, characterized in that, Includes a device body and a high-side NMOS driving circuit as described in any one of claims 1-9 disposed on the device body.

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