NMOS tube high-side drive circuit, system and device

Abstract

The present invention discloses a NMOS tube high-side drive circuit, system and device, and relates to the field of electronic circuit technology. The drive circuit includes a voltage regulation circuit, a pulse generating circuit and a boost circuit connected in sequence, and the pulse generating circuit includes a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a first capacitor and a first operational amplifier; one end of the third resistor is connected to the output end of the voltage regulation circuit, and the other end is connected to one end of the fourth resistor, one end of the fifth resistor and the same-direction input end of the first operational amplifier; the other end of the fifth resistor is connected to one end of the sixth resistor and the output end of the first operational amplifier to form the output end of the pulse generating circuit; the other end of the sixth resistor is connected to one end of the first capacitor and the reverse input end of the first operational amplifier. The present application generates a pulse signal through the designed pulse generating circuit, which provides a basis for subsequent driving work and meets actual needs under the premise of effectively controlling costs.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic circuits, and in particular to an NMOS tube high-side drive circuit, system and device. Background Art

[0002] When the NMOS tube outputs high side, the gate voltage driving the NMOS needs to be higher than the drain voltage. Only when it is higher than its conduction threshold voltage can the NMOS tube be turned on. To make the NMOS tube fully turned on, the conduction threshold voltage is generally about 10V, that is, the gate voltage must be about 10V higher than the drain voltage. Only when the MOS tube is fully turned on, its internal resistance is small and it will not heat up. Only when it is fully turned on can the damage to the tube be reduced.

[0003] At present, most of the body control uses high-side output smart MOS tubes. Smart MOS integrates the tube drive circuit. For the tube user, the drive only needs to give a level signal. However, the price of smart MOS tubes is high, the selectivity is poor, and they are monopolized by very few foreign companies. If ordinary MOS tubes are used and the MOS tube high-side drive circuit is designed separately externally, the cost can be effectively reduced and the selection diversity can be enriched. However, there is no technology that can meet the above requirements at this stage.

[0004] Therefore, in order to meet actual needs, an NMOS tube high-side driving technology is now provided. Summary of the invention

[0005] In view of the defects existing in the prior art, the purpose of the present invention is to provide an NMOS tube high-side driving circuit, system and device, which generates a pulse signal through a designed pulse generating circuit to provide a basis for subsequent driving work and meet actual needs under the premise of effectively controlling costs.

[0006] In order to achieve the above purpose, the technical solution adopted by the present invention is:

[0007] In a first aspect, the present application provides an NMOS tube high-side driving circuit, wherein the driving circuit comprises a voltage regulating circuit, a pulse generating circuit and a boosting circuit connected in sequence;

[0008] The pulse generating circuit includes a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a first capacitor and a first operational amplifier;

[0009] One end of the third resistor is connected to the output end of the voltage regulating circuit, and the other end is connected to one end of the fourth resistor, one end of the fifth resistor and the same-direction input end of the first operational amplifier;

[0010] The other end of the fifth resistor is connected to one end of the sixth resistor and the output end of the first operational amplifier to form the output end of the pulse generating circuit;

[0011] The other end of the sixth resistor is connected to one end of the first capacitor and the inverting input end of the first operational amplifier;

[0012] The inverting input terminal of the first operational amplifier is connected to the output terminal of the voltage regulating circuit;

[0013] The other end of the fourth resistor and the other end of the first capacitor are both grounded.

[0014] On the basis of the above technical solution, the voltage regulating circuit includes a first resistor, a second resistor, a third diode and a first NPN transistor;

[0015] One end of the first resistor is connected to the collector of the first NPN transistor and a power supply end;

[0016] The other end of the first resistor is connected to the base of the first NPN transistor, one end of the second resistor and the cathode of the third diode;

[0017] The anode of the third diode and the other end of the second resistor are both grounded;

[0018] The transmitter of the first NPN transistor serves as the output end of the voltage regulating circuit. Based on the above technical solution, the boost circuit includes a second capacitor, a second diode, a first diode and a third capacitor;

[0019] One end of the second capacitor is connected to the output end of the pulse generating circuit;

[0020] The other end of the second capacitor is connected to the cathode of the second diode and the anode of the first diode;

[0021] The anode of the second diode is connected to a preset power supply terminal;

[0022] The cathode of the first diode is connected to one end of the capacitor to form the output end of the boost circuit.

[0023] On the basis of the above technical solution, the driving circuit further includes:

[0024] The gate drive switch circuit has an input end connected to the output end of the boost circuit.

[0025] On the basis of the above technical solution, the gate drive switch circuit includes a plurality of switch circuits connected in parallel.

[0026] Based on the above technical solution, the third diode is a voltage regulator diode.

[0027] Based on the above technical solution, the resistance values ​​of the third resistor, the fourth resistor and the fifth resistor are the same.

[0028] Based on the above technical solution, the voltage of the power supply end is 12V or 24V or 48V.

[0029] In a second aspect, the present application provides an NMOS tube high-side driving system, the driving system comprising: a shell having a receiving cavity formed therein, and the NMOS tube high-side driving circuit mentioned in the first aspect, arranged in the shell.

[0030] In a third aspect, the present application provides an NMOS tube high-side driving device, wherein the NMOS tube high-side driving device comprises the NMOS tube high-side driving system mentioned in the second aspect.

[0031] Compared with the prior art, the advantages of the present invention are:

[0032] The present invention generates a pulse signal through a designed pulse generating circuit, which provides a basis for subsequent driving work and meets actual needs under the premise of effectively controlling costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0034] Figure 1 The figure is a schematic diagram of the structure of the NMOS tube high-side driving circuit according to an embodiment of the present invention. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0036] The embodiments of the present invention are further described in detail below with reference to the accompanying drawings.

[0037] The embodiments of the present application provide an NMOS tube high-side driving circuit, system and device, which generate a pulse signal through a designed pulse generating circuit, provide a basis for subsequent driving work, and meet actual needs under the premise of effectively controlling costs.

[0038] In order to achieve the above technical effects, the overall idea of ​​this application is as follows:

[0039] An NMOS tube high-side drive circuit, the drive circuit comprising a voltage regulating circuit, a pulse generating circuit and a boosting circuit connected in sequence;

[0040] The pulse generating circuit includes a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a first capacitor and a first operational amplifier;

[0041] One end of the third resistor is connected to the output end of the voltage regulating circuit, and the other end is connected to one end of the fourth resistor, one end of the fifth resistor and the same-direction input end of the first operational amplifier;

[0042] The other end of the fifth resistor is connected to one end of the sixth resistor and the output end of the first operational amplifier to form the output end of the pulse generating circuit;

[0043] The other end of the sixth resistor is connected to one end of the first capacitor and the inverting input end of the first operational amplifier;

[0044] The inverting input terminal of the first operational amplifier is connected to the output terminal of the voltage regulating circuit;

[0045] The other end of the fourth resistor and the other end of the first capacitor are both grounded.

[0046] The embodiments of the present application are further described in detail below in conjunction with the accompanying drawings.

[0047] First, see Figure 1 As shown, an embodiment of the present application provides an NMOS tube high-side driving circuit, wherein the driving circuit includes a voltage regulating circuit, a pulse generating circuit and a boosting circuit connected in sequence;

[0048] The pulse generating circuit includes a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a first capacitor and a first operational amplifier;

[0049] One end of the third resistor is connected to the output end of the voltage regulating circuit, and the other end is connected to one end of the fourth resistor, one end of the fifth resistor and the same-direction input end of the first operational amplifier;

[0050] The other end of the fifth resistor is connected to one end of the sixth resistor and the output end of the first operational amplifier to form the output end of the pulse generating circuit;

[0051] The other end of the sixth resistor is connected to one end of the first capacitor and the inverting input end of the first operational amplifier;

[0052] The inverting input terminal of the first operational amplifier is connected to the output terminal of the voltage regulating circuit;

[0053] The other end of the fourth resistor and the other end of the first capacitor are both grounded.

[0054] It should be noted that the driving circuit in the embodiment of the present application may be a common circuit and, if necessary, may be presented in the form of an integrated circuit.

[0055] Furthermore, when the first operational amplifier is working, it will also be connected to the output end of the voltage regulating circuit and will also be grounded to ensure its normal operation.

[0056] It should be noted that in order to deal with the technical problems mentioned above and to reliably drive the NMOS tube, the gate drive voltage and drain voltage must have a constant voltage. No matter how the input voltage changes, the gate drive voltage must be higher than the drain voltage by a full conduction voltage, but cannot be higher than the full conduction voltage limit voltage, which is generally around 20V. Taking a 24V system vehicle as an example, it is necessary to adapt to the power supply voltage in an environment of 18V to 32V to work normally. In this way, the gate drive voltage is required to follow the voltage change and always be higher than and only higher than the full conduction voltage.

[0057] In the embodiment of the present application, a pulse signal is generated by a designed pulse generating circuit, which provides a basis for subsequent driving work and meets actual needs under the premise of effectively controlling costs.

[0058] Further, the voltage regulating circuit includes a first resistor, a second resistor, a third diode and a first NPN transistor;

[0059] One end of the first resistor is connected to the collector of the first NPN transistor and a power supply end;

[0060] The other end of the first resistor is connected to the base of the first NPN transistor, one end of the second resistor and the cathode of the third diode;

[0061] The anode of the third diode and the other end of the second resistor are both grounded;

[0062] The transmitter of the first NPN transistor serves as the output end of the voltage regulating circuit.

[0063] Further, the boost circuit includes a second capacitor, a second diode, a first diode and a third capacitor;

[0064] One end of the second capacitor is connected to the output end of the pulse generating circuit;

[0065] The other end of the second capacitor is connected to the cathode of the second diode and the anode of the first diode;

[0066] The anode of the second diode is connected to a preset power supply terminal;

[0067] The cathode of the first diode is connected to one end of the capacitor to form the output end of the boost circuit.

[0068] Furthermore, the driving circuit further includes:

[0069] The gate drive switch circuit has an input end connected to the output end of the boost circuit.

[0070] Furthermore, the gate drive switch circuit includes a plurality of switch circuits connected in parallel.

[0071] Furthermore, the third diode is a voltage regulator diode.

[0072] Furthermore, the resistance values ​​of the third resistor, the fourth resistor and the fifth resistor are the same.

[0073] Furthermore, the voltage of the power supply end is 12V or 24V or 48V.

[0074] As shown in the attached figure of the specification Figure 1 As shown, the voltage at the power supply end is recorded as VC, and the output voltage of the voltage regulating circuit is recorded as VTH;

[0075] The first resistor is denoted as R1, the second resistor is denoted as R2, the third diode is denoted as D3, and the first NPN transistor is denoted as Q1;

[0076] The third resistor is denoted as R3, the fourth resistor is denoted as R4, the fifth resistor is denoted as R5, the sixth resistor is denoted as R6, the first capacitor is denoted as C1, and the first operational amplifier is denoted as U1;

[0077] The second capacitor is denoted as C2, the second diode is denoted as D2, the first diode is denoted as D1, and the third capacitor is denoted as C3;

[0078] The gate drive switch circuit includes a plurality of switch circuits connected in parallel, which are respectively denoted as K1, K2, ..., Kn.

[0079] Based on the technical solution of the embodiment of the present application, combined with the accompanying drawings of the specification Figure 1 The specific contents are as follows:

[0080] The first part of the attached drawings of the specification, namely the voltage regulating circuit, is mainly used to generate a stable voltage based on the VC voltage at the power supply end. Even if the VC voltage fluctuates, the output voltage VTH generated by it is also a fixed voltage value. The voltage regulating circuit is used to provide a voltage with a constant voltage difference. If necessary, other forms of voltage stabilizing circuits can be used as a substitute.

[0081] The voltage value of VTH is smaller than the regulated voltage of the third diode, and the specific voltage difference is 0.7V. The first resistor R1 and the second resistor R2 are both used as voltage divider resistors.

[0082] The fourth part of the drawings of the specification, i.e., the pulse generating circuit, generates a pulse signal, self-oscillation, the peak-to-peak value of the pulse voltage is VTH, and the frequency is adjusted by the sixth resistor R6 and the first capacitor C1;

[0083] The sixth resistor R6 is used as an oscillation resistor, and the first capacitor C1 is used as an oscillation capacitor to adjust the oscillation frequency, and the amplitude is determined by VTH;

[0084] The fifth resistor R5 is used as a feedback resistor, and the third resistor R3 and the fourth resistor R4 are used as input resistors of the positive electrode of the first operational amplifier U1.

[0085] Specifically, the working circuit of the pulse generating circuit is as follows:

[0086] When the values ​​of the third resistor R3, the fourth resistor R4 and the fourth resistor R5 are the same, at the beginning, the voltage of the negative electrode of the first operational amplifier U1 is 0, the voltage of the positive electrode of the first operational amplifier U1 is VTH / 2 voltage, and the first operational amplifier U1 outputs a high level with an amplitude of VTH, and the first capacitor C1 is charged at this time;

[0087] When the voltage on the first capacitor C1 rises higher than 2 / 3 of the VTH voltage, the voltage of the negative electrode of the first operational amplifier U1 is higher than the voltage of the positive electrode of the first operational amplifier U1, and the first operational amplifier U1 no longer outputs a voltage;

[0088] The first capacitor C1 starts to discharge, and the voltage at the negative terminal of the operational amplifier starts to drop. When the voltage drops below 1 / 3 of the VTH voltage, the first operational amplifier U1 outputs a high level again.

[0089] Working in this way, the first operational amplifier U1 generates a pulse signal.

[0090] The second part of the accompanying drawings of the specification, namely the boost circuit, has the main purpose of boosting a constant voltage based on the VC voltage, and the constant voltage is determined by the peak-to-peak value of the pulse voltage VTH and the frequency.

[0091] The working process of the boost circuit is as follows:

[0092] The pulse signal generated by the pulse generating circuit enters the cathode of the second diode D2 through the second capacitor C2, and the VC voltage also enters the cathode of the second diode D2 through D2 (if the second diode D2 is made of silicon material, the voltage drops by about 0.7V). When the pulse signal voltage is 0V low level, the voltage at the positive end of D1 is about VC voltage, and when the pulse signal voltage is VTH high level, the voltage at the positive end of D1 is about VC+VTH voltage. In this way, the pulse signal at the cathode of the second diode D2 is superimposed on the VC voltage.

[0093] After filtering by the first diode D1 and the third capacitor C3, the pulse signal is converted into a DC signal. The voltage at this time is higher than the VC voltage, that is, a boost occurs, and the boost voltage value remains constant regardless of how the VC voltage fluctuates. In this way, the difference between the gate drive voltage of the NMOS tube and the drain voltage value remains unchanged, thereby protecting the safe and reliable driving of the NMOS.

[0094] In the third part of the drawings of the specification, the gate drive switch circuit may include a plurality of switch circuits connected in parallel, and the switch circuit may be a plurality of electronic switches.

[0095] It should be noted that the advantages of the technical solution of the embodiment of the present application are:

[0096] Only the VC voltage is required from the power supply end to provide the gate drive voltage, and no other components (such as the microprocessor MCU work processing) are required. First, the static power consumption of the entire product can be lower; second, in some special cases, such as in vehicles, the power output in the normal ignition state, when the vehicle ACC switch and ON switch are both turned off, only the battery voltage is supplying power, and some automotive components still need to work, such as monitoring, recorders, door and window control, fire protection systems, etc., and it is necessary to control the MOS tube to power these components, that is, the MOS tube provides these components with normal ignition output, and these normal ignition outputs can be powered and controlled by the digital distribution box or body controller of the vehicle body. When the vehicle is only in the normal ignition state, the microprocessors of the digital distribution box and the body controller are not working or dormant. At this time, it is necessary to complete the function of controlling the power output of the MOS tube in the normal ignition state.

[0097] Furthermore, in actual use, the technical solution of the embodiment of the present application can generate a voltage with a constant voltage difference relative to the power supply voltage VC, and change with the change of the VC voltage;

[0098] In addition, multiple NMOS tubes can be powered and driven centrally.

[0099] In a second aspect, an embodiment of the present application provides an NMOS tube high-side driving system, which includes: a shell with a receiving cavity formed inside, and the NMOS tube high-side driving circuit mentioned in the first aspect, which is arranged in the shell.

[0100] The NMOS tube high-side drive system provided in the embodiment of the present application and the NMOS tube high-side drive circuit mentioned in the first aspect have the same technical solutions, solved technical problems and obtained technical effects at the technical principle level, and will not be elaborated here.

[0101] In a third aspect, an embodiment of the present application provides an NMOS tube high-side driving device, and the NMOS tube high-side driving device includes the NMOS tube high-side driving system mentioned in the second aspect.

[0102] The NMOS tube high-side driving device provided in the embodiment of the present application and the NMOS tube high-side driving circuit mentioned in the first aspect and the NMOS tube high-side driving system mentioned in the second aspect have the same technical solutions, solved technical problems and obtained technical effects at the technical principle level, and will not be elaborated here.

[0103] In the description of the present application, it should be noted that the terms "upper", "lower", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. Unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be a connection between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances.

[0104] It should be noted that, in this application, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" 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 other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0105] The above description is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest range consistent with the principles and novel features applied for herein.

Claims

1. An NMOS tube high-side drive circuit, characterized in that: The driving circuit comprises a voltage regulating circuit, a pulse generating circuit and a voltage boosting circuit connected in sequence; The pulse generating circuit includes a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a first capacitor and a first operational amplifier; One end of the third resistor is connected to the output end of the voltage regulating circuit, and the other end is connected to one end of the fourth resistor, one end of the fifth resistor and the same-direction input end of the first operational amplifier; The other end of the fifth resistor is connected to one end of the sixth resistor and the output end of the first operational amplifier to form the output end of the pulse generating circuit; The other end of the sixth resistor is connected to one end of the first capacitor and the inverting input end of the first operational amplifier; The other end of the fourth resistor and the other end of the first capacitor are both grounded; The voltage regulating circuit includes a first resistor, a second resistor, a third diode and a first NPN transistor; One end of the first resistor is connected to the collector of the first NPN transistor and a power supply end; The other end of the first resistor is connected to the base of the first NPN transistor, one end of the second resistor and the cathode of the third diode; The anode of the third diode and the other end of the second resistor are both grounded; The emitter of the first NPN transistor serves as the output end of the voltage regulating circuit; The boost circuit includes a second capacitor, a second diode, a first diode and a third capacitor; One end of the second capacitor is connected to the output end of the pulse generating circuit; The other end of the second capacitor is connected to the cathode of the second diode and the anode of the first diode; The anode of the second diode is connected to a preset power supply terminal; The cathode of the first diode is connected to one end of the third capacitor to form the output end of the boost circuit, and the other end of the third capacitor is grounded.

2. The NMOS tube high-side driving circuit according to claim 1, characterized in that: The driving circuit further includes: The gate drive switch circuit has an input end connected to the output end of the boost circuit.

3. The NMOS tube high-side driving circuit according to claim 2, characterized in that: The gate driving switch circuit includes a plurality of switch circuits connected in parallel.

4. The NMOS tube high-side driving circuit according to claim 1, characterized in that: The third diode is a voltage regulator diode.

5. The NMOS tube high-side driving circuit according to claim 1, characterized in that: The third resistor, the fourth resistor and the fifth resistor have the same resistance value.

6. The NMOS tube high-side driving circuit according to claim 1, characterized in that: The voltage of the power supply end is 12V or 24V or 48V.

7. An NMOS tube high-side drive system, characterized in that: The driving system comprises: a shell with a receiving cavity formed therein, and the NMOS tube high-side driving circuit according to any one of claims 1 to 6, which is arranged in the shell.

8. An NMOS tube high-side driver, characterized in that: The NMOS tube high-side driving device comprises the system according to claim 7.

Images