A P-channel MOS tube driving circuit with adaptive input voltage

Abstract

The present invention discloses a P-channel MOS tube driving circuit with adaptive input voltage, comprising a first MOS tube, a triode, a first resistor, a diode, a first constant current switch module, a second constant current switch module and a trigger source, wherein the gate of the first MOS tube is respectively connected to the emitter of the triode and the first constant current switch module, the drain of the first MOS tube is connected to the circuit output end, the source of the first MOS tube is respectively connected to the input end of the circuit and the collector of the triode, the diode is arranged between the emitter and the base of the triode, the base of the triode is respectively connected to the negative electrode of the diode and the second constant current switch module, one end of the first resistor is connected to the circuit input end, the other end of the first resistor is connected to the base of the triode, and the first constant current switch module and the second constant current switch module are both connected to the trigger source. The present invention can adapt to different input voltages and broaden the range of input voltage.

Description

Technical Field

[0001] The invention belongs to the technical field of battery production and manufacturing, and in particular relates to a P-channel MOS tube driving circuit with adaptive input voltage. Background Art

[0002] P-channel MOS transistors are commonly used switching devices. The hole mobility of P-channel MOS transistors is low. Therefore, when the geometric dimensions of MOS transistors and the absolute value of the operating voltage are equal, the transconductance of PMOS transistors is smaller than that of N-channel MOS transistors. In addition, the absolute value of the threshold voltage of P-channel MOS transistors is generally high, requiring a higher operating voltage. The voltage and polarity of its power supply are incompatible with bipolar transistors - transistor logic circuits. Because PMOS circuits are simple in process and cheap in price, some medium-scale and small-scale digital control circuits still use PMOS circuit technology.

[0003] However, the inventors have found that the existing solution still has at least the following defects: due to the gate and source voltage characteristics of the P-channel MOS tube, the driving circuit needs to provide a driving voltage equivalent to the source voltage of the P-channel MOS tube in order to turn off the P-channel MOS tube, resulting in that when the input voltage changes, the driving voltage also changes accordingly, limiting the scope of use of the P-channel MOS tube. Summary of the invention

[0004] The purpose of the present invention is to provide a P-channel MOS tube driving circuit with adaptive input voltage to address the deficiencies of the prior art, solve the problem that the driving voltage of the P-channel MOS tube needs to follow the input voltage change, enable the driving circuit to adapt to different input voltages, and broaden the range of the input voltage.

[0005] In order to achieve the above object, the present invention adopts the following technical solution:

[0006] A P-channel MOS transistor driving circuit with adaptive input voltage comprises a first MOS transistor Q1, a transistor Q2, a first resistor R1, a diode D1, a first constant current switch module, a second constant current switch module and a trigger source, wherein the gate of the first MOS transistor Q1 is respectively connected to the emitter of the transistor Q2 and the first constant current switch module, the drain of the first MOS transistor Q1 is connected to the circuit output end, the source of the first MOS transistor Q1 is respectively connected to the input end of the circuit and the collector of the transistor Q2, the diode D1 is arranged between the emitter and the base of the transistor Q2, the base of the transistor Q2 is respectively connected to the cathode of the diode D1 and the second constant current switch module, one end of the first resistor R1 is connected to the circuit input end, the other end of the first resistor R1 is connected to the base of the transistor Q2, and the first constant current switch module and the second constant current switch module are both connected to the trigger source.

[0007] As an improvement of the P-channel MOS tube driving circuit with adaptive input voltage described in the present invention, the anode of the diode D1 is respectively connected to the gate of the first MOS tube Q1, the emitter of the transistor Q2 and the first constant current switch module, and the cathode of the diode D1 is respectively connected to the first resistor R1 and the second constant current switch module.

[0008] As an improvement of the P-channel MOS transistor driving circuit with adaptive input voltage described in the present invention, the first constant current switch module includes a second resistor R2, a first constant current diode D2 and a second MOS transistor Q3 connected in sequence.

[0009] As an improvement of the P-channel MOS transistor driving circuit with adaptive input voltage described in the present invention, the second constant current switch module includes a third resistor R3, a second constant current diode D3 and a third MOS transistor Q4 connected in sequence.

[0010] As an improvement of the P-channel MOS transistor driving circuit with adaptive input voltage described in the present invention, the gate of the second MOS transistor Q3 is connected to the gate of the third MOS transistor Q4, the source of the second MOS transistor Q3 and the source of the third MOS transistor Q4 are both grounded, and the drain of the second MOS transistor Q3 and the drain of the third MOS transistor Q4 are respectively connected to the first constant current diode D2 and the second constant current diode D3.

[0011] As an improvement of the P-channel MOS transistor driving circuit with adaptive input voltage described in the present invention, one end of the second resistor R2 is connected to the gate of the first MOS transistor Q1, and the other end of the second resistor R2 is connected to the first constant current diode D2.

[0012] As an improvement of the P-channel MOS tube driving circuit with adaptive input voltage described in the present invention, one end of the third resistor R3 is connected to the base of the transistor Q2, and the other end of the third resistor R3 is connected to the second constant current diode D3.

[0013] As an improvement of the P-channel MOS transistor driving circuit with adaptive input voltage described in the present invention, the second MOS transistor Q3 and the third MOS transistor Q4 are both N-channel MOS transistors.

[0014] The beneficial effect of the present invention is that the present invention includes a first MOS tube Q1, a transistor Q2, a first resistor R1, a diode D1, a first constant current switch module, a second constant current switch module and a trigger source, the gate of the first MOS tube Q1 is respectively connected to the emitter of the transistor Q2 and the first constant current switch module, the drain of the first MOS tube Q1 is connected to the circuit output end, the source of the first MOS tube Q1 is respectively connected to the input end of the circuit and the collector of the transistor Q2, the diode D1 is arranged between the emitter and the base of the transistor Q2, the base of the transistor Q2 is respectively connected to the cathode of the diode D1 and the second constant current switch module, one end of the first resistor R1 is connected to the circuit input end, the other end of the first resistor R1 is connected to the base of the transistor Q2, and the first constant current switch module and the second constant current switch module are both connected to the trigger source. Due to the gate and source voltage characteristics of the P-channel MOS tube, the driving circuit needs to provide a driving voltage equivalent to the source voltage of the P-channel MOS tube to turn off the P-channel MOS tube, resulting in that when the input voltage changes, the driving voltage also changes accordingly, limiting the use range of the P-channel MOS tube. Therefore, a structure in which both the first constant current switch module and the second constant current switch module are connected to the trigger source is adopted. When the trigger source gives a signal to turn off the first constant current switch module and the second constant current switch module, the voltage difference between the gate and the source of the first MOS tube Q1 is the difference between the input voltage and the base and emitter conduction voltage of the transistor Q2. Since the base and emitter conduction voltage of the transistor Q2 is very small, it is lower than the conduction voltage of the first MOS tube Q1. , and the conduction voltage is equal to the difference between the gate voltage and the source voltage, and because a small current is added to the base of the transistor Q2, a large current can be obtained on the collector, so that the first MOS tube Q1 is quickly cut off and the output is turned off; at the same time, because the base current of the transistor Q2 is very small and can be ignored, the current flowing through R1 at this time is the constant current source current of the second constant current switch module, which is equal to the product of the resistance value of the first resistor R1 and the constant current source current in the second constant current switch module, and the voltage difference between the gate and the source of the first MOS tube Q1 is equal to the sum of the voltage difference of the first resistor R1 and the conduction voltage between the base and the emitter of the transistor Q2. Since the voltage difference of the first resistor R1 and the constant current source current remain unchanged, the voltage difference between the gate and the source of the first MOS tube Q1 remains unchanged. In this way, the input voltage changes, and the voltage difference between the gate and the source of the first MOS tube Q1 remains unchanged, so that the drive circuit can adapt to different input voltages and widen the range of input voltage. The present invention solves the problem that the driving voltage of a P-channel MOS tube needs to follow the change of the input voltage, so that the driving circuit can adapt to different input voltages and widen the range of the input voltage. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 1 is a circuit diagram of embodiment 1 of the present invention.

[0016] Figure 2 This is a circuit diagram of embodiment 2 of the present invention. DETAILED DESCRIPTION

[0017] For example, certain words are used in the specification and claims to refer to specific components. Those skilled in the art should understand that hardware manufacturers may use different terms to refer to the same component. This specification and claims do not use differences in names as a way to distinguish components, but use differences in the functions of components as the criteria for distinction. For example, "including" mentioned throughout the specification and claims is an open term, so it should be interpreted as "including but not limited to". "Approximately" means that within an acceptable error range, those skilled in the art can solve technical problems within a certain error range and basically achieve technical effects.

[0018] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by the terms "up", "down", "front", "back", "left", "right", "horizontal", etc. are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0019] In the invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like 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 the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the invention can be understood according to specific circumstances.

[0020] The following is combined with Figures 1-2 The present invention is further described in detail, but is not intended to limit the present invention.

[0021] Embodiment 1

[0022] like Figure 1As shown, a P-channel MOS transistor driving circuit with adaptive input voltage includes a first MOS transistor Q1, a transistor Q2, a first resistor R1, a diode D1, a first constant current switch module, a second constant current switch module and a trigger source, wherein the gate of the first MOS transistor Q1 is respectively connected to the emitter of the transistor Q2 and the first constant current switch module, the drain of the first MOS transistor Q1 is connected to the circuit output end, the source of the first MOS transistor Q1 is respectively connected to the input end of the circuit and the collector of the transistor Q2, the diode D1 is arranged between the emitter and the base of the transistor Q2, the base of the transistor Q2 is respectively connected to the cathode of the diode D1 and the second constant current switch module, one end of the first resistor R1 is connected to the circuit input end, the other end of the first resistor R1 is connected to the base of the transistor Q2, and the first constant current switch module and the second constant current switch module are both connected to the trigger source. Due to the gate and source voltage characteristics of the P-channel MOS tube, the driving circuit needs to provide a driving voltage equivalent to the source voltage of the P-channel MOS tube to turn off the P-channel MOS tube, resulting in that when the input voltage changes, the driving voltage also changes accordingly, limiting the use range of the P-channel MOS tube. Therefore, a structure in which both the first constant current switch module and the second constant current switch module are connected to the trigger source is adopted. When the trigger source gives a signal to turn off the first constant current switch module and the second constant current switch module, the voltage difference between the gate and the source of the first MOS tube Q1 is the difference between the input voltage and the base and emitter conduction voltage of the transistor Q2. Since the base and emitter conduction voltage of the transistor Q2 is very small, it is lower than the conduction voltage of the first MOS tube Q1. , and the conduction voltage is equal to the difference between the gate voltage and the source voltage, and because a small current is added to the base of the transistor Q2, a large current can be obtained on the collector, so that the first MOS tube Q1 is quickly cut off and the output is turned off; at the same time, because the base current of the transistor Q2 is very small and can be ignored, the current flowing through R1 at this time is the constant current source current of the second constant current switch module, which is equal to the product of the resistance value of the first resistor R1 and the constant current source current in the second constant current switch module, and the voltage difference between the gate and the source of the first MOS tube Q1 is equal to the sum of the voltage difference of the first resistor R1 and the conduction voltage between the base and the emitter of the transistor Q2. Since the voltage difference of the first resistor R1 and the constant current source current remain unchanged, the voltage difference between the gate and the source of the first MOS tube Q1 remains unchanged. In this way, the input voltage changes, and the voltage difference between the gate and the source of the first MOS tube Q1 remains unchanged, so that the drive circuit can adapt to different input voltages and widen the range of input voltage.

[0023] In this embodiment, the constant current is 5.6 mA, so that the voltage of the first resistor R1 remains unchanged, and the voltage of the first resistor R1 = 680Ω*0.0056 mA = 3.808 V. The on-voltage of the first MOS tube Q1 is equal to the sum of the voltage difference of the first resistor R1 and the on-voltage of the triode Q2, and the on-voltage of the first MOS tube Q1 = -3.808-0.7 = -4.508 V. Since the voltage difference of the first resistor R1 and the constant current source current remain unchanged, the on-voltage of the first MOS tube Q1 remains unchanged at -4.508 V, so that the input voltage changes, and the voltage difference between the gate and the source of the first MOS tube Q1 remains unchanged, so that the drive circuit can adapt to different input voltages and widen the range of input voltage.

[0024] The working principle of the present invention is:

[0025] Due to the gate and source voltage characteristics of the P-channel MOS tube, the driving circuit needs to provide a driving voltage equivalent to the source voltage of the P-channel MOS tube to turn off the P-channel MOS tube, resulting in that when the input voltage changes, the driving voltage also changes accordingly, limiting the use range of the P-channel MOS tube. Therefore, a structure in which both the first constant current switch module and the second constant current switch module are connected to the trigger source is adopted. When the trigger source gives a signal to turn off the first constant current switch module and the second constant current switch module, the voltage difference between the gate and the source of the first MOS tube Q1 is the difference between the input voltage and the base and emitter conduction voltage of the transistor Q2. Since the base and emitter conduction voltage of the transistor Q2 is very small and lower than the conduction voltage of the first MOS tube Q1, The conduction voltage is equal to the difference between the gate voltage and the source voltage, and since a small current is added to the base of the transistor Q2, a large current can be obtained on the collector, so that the first MOS tube Q1 is quickly cut off and the output is turned off; at the same time, since the base current of the transistor Q2 is very small and can be ignored, the current flowing through R1 at this time is the constant current source current in the second constant current switch module, which is equal to the product of the resistance value of the first resistor R1 and the constant current source current in the second constant current switch module. The voltage difference between the gate and the source of the first MOS tube Q1 is equal to the sum of the voltage difference of the first resistor R1 and the conduction voltage between the base and the emitter of the transistor Q2. Since the voltage difference of the first resistor R1 and the constant current source current remain unchanged, the voltage difference between the gate and the source of the first MOS tube Q1 remains unchanged. In this way, the input voltage changes, and the voltage difference between the gate and the source of the first MOS tube Q1 remains unchanged, so that the drive circuit can adapt to different input voltages and widen the range of input voltage.

[0026] Embodiment 2

[0027] like Figure 2As shown, the difference from the embodiment 1 is that the first constant current switch module of the embodiment includes a second resistor R2, a first constant current diode D2 and a second MOS transistor Q3 connected in sequence, the gate of the second MOS transistor Q3 is connected to the gate of the third MOS transistor Q4, the source of the second MOS transistor Q3 and the source of the third MOS transistor Q4 are both grounded, the drain of the second MOS transistor Q3 is connected to the first constant current diode D2, one end of the second resistor R2 is connected to the gate of the first MOS transistor Q1, the other end of the second resistor R2 is connected to the first constant current diode D2, the resistance of the second resistor R2 is 51Ω, the model of the first constant current diode D2 is S-103T, and the second MOS transistor Q3 is an N-channel MOS transistor. When the trigger source gives a signal to turn on the first constant current switch module and the second constant current switch module, since the anode voltage and cathode voltage of the diode D1 are higher than the conduction voltage of the diode D1, the current of the gate of the first MOS transistor Q1 is discharged through the diode D1 and the second resistor R2, thereby accelerating the conduction speed of the first MOS transistor Q1. When the anode voltage and cathode voltage of the diode D1 are lower than the conduction voltage of the diode D1, the diode D1 is cut off. At this time, the first MOS tube Q1 is fully turned on. Because of the constant current effect of the constant current source in the first constant current switch module, the discharge speed of the gate current of the first MOS tube Q1 is consistent, so that the conduction time of Q1 will not change due to the change of the input voltage.

[0028] The other structures are the same as those in Embodiment 1 and will not be described again here.

[0029] According to the disclosure and teaching of the above description, those skilled in the art to which the present invention belongs can also change and modify the above embodiment. Therefore, the present invention is not limited to the above specific embodiment, and any obvious improvement, replacement or modification made by those skilled in the art on the basis of the present invention belongs to the protection scope of the present invention. In addition, although some specific terms are used in this specification, these terms are only for the convenience of description and do not constitute any limitation to the present invention.

Claims

1. A P-channel MOS tube driving circuit with adaptive input voltage, characterized in that: The invention comprises a first MOS tube Q1, a triode Q2, a first resistor R1, a diode D1, a first constant current switch module, a second constant current switch module and a trigger source, wherein the gate of the first MOS tube Q1 is respectively connected to the emitter of the triode Q2 and the first constant current switch module, the drain of the first MOS tube Q1 is connected to the circuit output end, the source of the first MOS tube Q1 is respectively connected to the input end of the circuit and the collector of the triode Q2, the diode D1 is arranged between the emitter and the base of the triode Q2, and the base of the triode Q2 is respectively connected to the collector of the triode Q2. The cathode of the diode D1 and the second constant current switch module are connected respectively, the anode of the diode D1 is connected respectively to the gate of the first MOS tube Q1, the emitter of the transistor Q2 and the first constant current switch module, the cathode of the diode D1 is connected respectively to the first resistor R1 and the second constant current switch module, one end of the first resistor R1 is connected to the circuit input end, the other end of the first resistor R1 is connected to the base of the transistor Q2, and the first constant current switch module and the second constant current switch module are both connected to the trigger source; The first constant current switch module includes a second resistor R2, a first constant current diode D2 and a second MOS transistor Q3 connected in sequence, and the model of the first constant current diode D2 is S-103T.

2. The P-channel MOS transistor driving circuit with adaptive input voltage according to claim 1, characterized in that: The second constant current switch module includes a third resistor R3, a second constant current diode D3 and a third MOS transistor Q4 which are connected in sequence.

3. The P-channel MOS transistor driving circuit with adaptive input voltage as claimed in claim 2, characterized in that: The gate of the second MOS transistor Q3 is connected to the gate of the third MOS transistor Q4, the source of the second MOS transistor Q3 and the source of the third MOS transistor Q4 are grounded, and the drain of the second MOS transistor Q3 and the drain of the third MOS transistor Q4 are connected to the first constant current diode D2 and the second constant current diode D3 respectively.

4. The P-channel MOS transistor driving circuit with adaptive input voltage according to claim 2, characterized in that: One end of the second resistor R2 is connected to the gate of the first MOS transistor Q1 , and the other end of the second resistor R2 is connected to the first constant current diode D2 .

5. The P-channel MOS transistor driving circuit with adaptive input voltage as claimed in claim 2, characterized in that: One end of the third resistor R3 is connected to the base of the transistor Q2, and the other end of the third resistor R3 is connected to the second constant current diode D3.

6. The P-channel MOS transistor driving circuit with adaptive input voltage as claimed in claim 2, characterized in that: The second MOS transistor Q3 and the third MOS transistor Q4 are both N-channel MOS transistors.

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