阅读说明：本技术 一种卫星电源功率使能n沟道mosfet驱动电路 (Satellite power supply power enable N-channel MOSFET drive circuit ) 是由 金家瑶 李小春 吴家旺 朱诚诚 张旭 徐刚 刘高锋 于 2021-06-18 设计创作，主要内容包括：一种卫星电源功率使能N沟道MOSFET驱动电路,包括使能信号输入电路、隔离放大电路和浮地驱动信号生成电路。使能信号输入电路接收外部输入的原始使能信号送至隔离放大电路。隔离放大电路对使能信号进行同相放大后送至浮地驱动信号生成电路,同时对前后两级电路中的电源进行隔离。浮地驱动信号生成电路接收同相放大后的使能信号,并再次进行同相放大后送至N沟道MOSFET的栅极和源极之间,对N沟道MOSFET进行开关控制。本发明可以实现对卫星开关电源的N沟道MOSFET的浮地驱动控制,通过对驱动电路设置使能信号,可以在每一路中控制该路驱动电路输出信号以控制多路浮地开关管的通断。(A satellite power supply power enable N-channel MOSFET driving circuit comprises an enable signal input circuit, an isolation amplifying circuit and a floating ground driving signal generating circuit. The enable signal input circuit receives an original enable signal input from the outside and sends the original enable signal to the isolation amplifying circuit. The isolation amplifying circuit amplifies the enable signal in phase and then sends the enable signal to the floating driving signal generating circuit, and meanwhile, the isolation amplifying circuit isolates power supplies in the front stage circuit and the rear stage circuit. The floating drive signal generation circuit receives the enable signal after in-phase amplification, and sends the enable signal to a position between a grid electrode and a source electrode of the N-channel MOSFET after in-phase amplification again to carry out switch control on the N-channel MOSFET. The invention can realize the floating drive control of the N-channel MOSFET of the satellite switching power supply, and can control the output signal of each driving circuit to control the on-off of a plurality of paths of floating switching tubes by setting the enabling signal for the driving circuits.)

1. A satellite power supply power enabled N-channel MOSFET driver circuit, comprising: enable signal input circuit, isolation amplifier circuit and floating ground drive signal generation circuit, wherein:

an enable signal input circuit: receiving an original enabling signal input from the outside, carrying out phase inversion processing on the original enabling signal, and then sending the original enabling signal to the isolation amplifying circuit to provide a conversion basis for the level change of an output signal of the isolation amplifying circuit;

an isolation amplifying circuit: the output signal of the enabling signal input circuit is subjected to reverse phase amplification, namely the input original enabling signal is subjected to in-phase amplification and then is sent to the floating drive signal generating circuit, and meanwhile, power supplies in the enabling signal input circuit and the floating drive signal generating circuit are isolated;

the floating drive signal generation circuit: receiving the in-phase amplified enable signal, realizing synchronous change of the grid voltage and the enable signal of the N-channel MOSFET through the on-off of the triode, forming a floating driving voltage by the voltage difference between the grid voltage and the source electrode, and performing on-off control on the N-channel MOSFET;

the N-channel MOSFET source is floating ground instead of zero potential ground.

2. The satellite power supply power enabled N-channel MOSFET driver circuit of claim 1, wherein: the enabling signal input circuit comprises an NPN type triode Q1, a base resistor R1, a pull-down resistor R2 and a pull-up resistor R3; the base electrode of the triode Q1 is connected with one end of the base electrode resistor R1 and one end of the pull-down resistor R2, the other end of the base electrode resistor R1 is connected with an original enabling signal input from the outside, the collector electrode of the triode Q1 is connected with one end of the pull-up resistor R3 and serves as the output end of the enabling signal input circuit, the other end of the pull-up resistor R3 is connected with the power VCC, and the emitter electrode of the triode Q1 is connected with the other end of the resistor R2 and the ground GND.

3. The satellite power supply power enabled N-channel MOSFET driver circuit of claim 2, wherein: the isolation amplifying circuit comprises an NPN type triode Q2, an NPN type triode Q3, a base resistor R4, a base resistor R5 and a pull-down resistor R6; the resistor R4 and the resistor R5 are simultaneously connected with the output end of the enable signal input circuit, the other end of the resistor R4 is connected with the base electrode of the triode Q2, the other end of the resistor R5 is simultaneously connected with the base electrode of the triode Q3 and one end of the resistor R6, the emitter electrode of the triode Q3 is connected with the other end of the resistor R6 and the ground GND, the emitter electrode of the triode Q2 is connected with the collector electrode of the triode Q3, and the collector electrode of the triode Q2 serves as the output end of the isolation amplifying circuit.

4. The satellite power supply power enabled N-channel MOSFET driver circuit of claim 3, wherein: the floating ground driving signal generating circuit comprises a PNP type triode Q4, a PNP type triode Q5, a base resistor R7, a bootstrap resistor R11, a pull-up resistor R10, a base resistor R8 and a bootstrap resistor R9; the base of the triode Q4 is connected with one end of a resistor R7 and one end of a resistor R11 at the same time, the base of the triode Q5 is connected with one end of a resistor R8 and one end of a resistor R9 at the same time, the other end of the resistor R7 and the other end of the resistor R8 are connected with the output end of the isolation amplifying circuit at the same time, the other end of the resistor R9 is connected with the collector of the triode Q4 and the emitter of the triode Q5 at the same time, the collector of the triode Q5 is connected with the source end of the N-channel MOSFET, the other end of the resistor R11 is connected with one end of the resistor R10, the emitter of the triode Q4 and the gate end of the N-channel MOSFET at the same time, and the other end of the resistor R10 is connected with a power supply VCC-GS.

5. The satellite power supply power enabled N-channel MOSFET driver circuit of claim 4, wherein: the voltage of the power supply VCC is 12V, and the voltage of the power supply VCC-GS is the sum of the source voltage of the N-channel MOSFET and 12V.

6. The satellite power supply power enabled N-channel MOSFET driver circuit of claim 5, wherein: the resistance values of the resistor R4 and the resistor R5 are equal.

7. The satellite power supply power enabled N-channel MOSFET driver circuit of claim 5, wherein: the resistance values of the resistor R7 and the resistor R8 are equal.

8. The satellite power supply power enabled N-channel MOSFET driver circuit of claim 5, wherein: the resistance ranges of the resistor R1, the resistor R4, the resistor R5, the resistor R7 and the resistor R8 are 1K-10K.

9. The satellite power supply power enabled N-channel MOSFET driver circuit of claim 5, wherein: the resistance ranges of the resistor R2, the resistor R6, the resistor R9 and the resistor R11 are 10K-100K.

10. The satellite power supply power enabled N-channel MOSFET driver circuit of claim 5, wherein: the resistance ranges of the resistor R3 and the resistor R10 are 1K-10K.

Technical Field

The invention belongs to the technical field of satellite power supplies, and relates to a power-enabled N-channel MOSFET (metal-oxide-semiconductor field effect transistor) driving circuit of a satellite power supply.

Background

In a satellite power supply, a power circuit can be switched between an on state and an off state according to needs so as to realize the power on/off function, and therefore, each input bus needs to be subjected to performance control through an MOSFET.

If the P-channel MOSFET is adopted, the MOSFET is conducted when the grid voltage is lower than the source voltage, the required switching-on voltage can be obtained from the input bus by directly utilizing the voltage-dividing resistor, and the driving mode is more convenient. For the MOSFET that is enabled in the power circuit, the switching frequency is very low and the on-time is long, so the main loss comes from the loss when the MOSFET is turned on. The commonly used P-channel MOSFET of the satellite power supply has large conduction loss, and the requirement that a large-current circuit is applied to a high-efficiency satellite power supply is difficult to meet. Therefore, the enabling switch tube of the high-efficiency large-current circuit is preferably an N-channel MOSFET.

However, the N-channel MOSFET is turned on under the condition that the gate voltage is about 12V higher than the source voltage, and needs to be driven in a floating manner, and cannot be obtained by bus voltage division, and only one path of 12V power supply for floating is additionally provided. Based on the characteristics of high reliability and the like of a satellite power supply, a plurality of paths of power circuits are often connected in parallel to realize high-power output in the satellite power supply, and a plurality of paths of floating driving voltages are generated simultaneously through a plurality of secondary winding transformers. Through the multichannel enabling signal, the function that multichannel power circuit supplied power simultaneously can be realized in order to satisfy satellite power supply work needs.

In the prior art, the MOSFET driving circuit is rarely used for floating ground, or the floating ground is considered, but the P-channel MOSFET which is driven by dividing the source voltage is not considered for the N-channel MOSFET which needs higher voltage to drive the floating ground, and the multi-path floating ground driving voltage is not considered.

Disclosure of Invention

The technical problem solved by the invention is as follows: the power enable N-channel MOSFET driving circuit of the satellite power supply is provided to realize floating driving control of the N-channel MOSFET of the satellite switching power supply, and the output signals of the driving circuit can be controlled in each path to control the on-off of a plurality of paths of floating switching tubes by setting enable signals for the driving circuit.

The technical solution of the invention is as follows: a satellite power supply power enabled N-channel MOSFET driver circuit, comprising: enable signal input circuit, isolation amplifier circuit and floating ground drive signal generation circuit, wherein:

an enable signal input circuit: receiving an original enabling signal input from the outside, carrying out phase inversion processing on the original enabling signal, and then sending the original enabling signal to the isolation amplifying circuit to provide a conversion basis for the level change of an output signal of the isolation amplifying circuit;

an isolation amplifying circuit: the output signal of the enabling signal input circuit is subjected to reverse phase amplification, namely the input original enabling signal is subjected to in-phase amplification and then is sent to the floating drive signal generating circuit, and meanwhile, power supplies in the enabling signal input circuit and the floating drive signal generating circuit are isolated;

the floating drive signal generation circuit: receiving the in-phase amplified enable signal, realizing synchronous change of the grid voltage and the enable signal of the N-channel MOSFET through the on-off of the triode, forming a floating driving voltage by the voltage difference between the grid voltage and the source electrode, and performing on-off control on the N-channel MOSFET;

the N-channel MOSFET source is floating ground instead of zero potential ground.

Compared with the prior art, the invention has the advantages that: the invention discloses a satellite power supply power enable N-channel MOSFET driving circuit which is used for the first time in the field of space power supplies. The circuit drives the N-channel MOSFET by applying a grid-source voltage, and enables and controls the drive by switching on or off a grid-source triode. Under the condition that the source electrode of the MOSFET is floating, the MOSFET is controlled to be switched on reliably by controlling the triode to be switched off due to insufficient base voltage so as to obtain enough driving voltage, and the MOSFET is switched off reliably by controlling the triode between the grid electrode and the source electrode to be switched on when the triode between the grid electrode and the source electrode is switched on and the voltage of two ends is smaller. The invention realizes the drive control of the N-channel MOSFET for the satellite, has the advantages of effective and high reliability of the circuit proved by the invention, and avoids the problems of large volume, heavy weight and the like caused by adopting a plurality of transformers in multi-path control.

Drawings

FIG. 1 is a schematic diagram of an N-channel MOSFET driver circuit enabling control of multiple discharge circuits;

FIG. 2 is a schematic diagram of a satellite power supply power enable N-channel MOSFET drive circuit of the present invention;

fig. 3 is a schematic diagram of Saber simulation results in an embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in further detail with reference to the accompanying drawings.

As shown in figure 1, the satellite-borne storage battery pack supplies power for a plurality of paths of discharge circuits, each path of discharge circuit takes an N-channel MOSFET as a discharge switch, and each path of discharge circuit is controlled to be switched on and switched off by arranging an enabling drive circuit so as to control each path of discharge circuit to work independently. The invention relates to an enabling drive circuit. When a certain discharge circuit needs to work, the enable signal of the drive circuit is at a high level, the drive circuit correspondingly outputs a drive signal at a high level, the MOSFET of the circuit is switched on, and the storage battery supplies power for the discharge circuit of the circuit; when a certain circuit of discharge circuit needs to stop working, the enable signal of the drive circuit is at low level, the drive circuit correspondingly outputs the drive signal at low level, the MOSFET of the circuit is turned off, the storage battery cannot supply power for the discharge circuit of the circuit, and the corresponding discharge circuit does not work.

As shown in fig. 2, which is a schematic block diagram of a satellite power supply power enable N-channel MOSFET driving circuit according to the present invention, the driving circuit includes: the primary enable signal input circuit receives an externally input original enable signal, performs inversion processing on the original enable signal, and then sends the original enable signal to the isolation amplifying circuit to provide a conversion basis for level change of an output signal of the isolation amplifying circuit, and the primary enable signal input circuit comprises an NPN type triode Q1, a triode Q1 base resistor R1, a pull-down resistor R2 and a pull-up resistor R3; the secondary isolation amplifying circuit is used for enhancing the driving capability and simultaneously isolating a primary circuit power supply and a tertiary circuit power supply and comprises NPN type triodes Q2 and Q3, a triode Q2 base resistor R4, a triode Q3 base resistor R5 and a pull-down resistor R6; the three-level floating drive signal generation circuit receives the in-phase amplified enable signal, and under the help that the isolation amplification circuit can provide enough large current and a passive signal, the grid voltage and the enable signal of the N-channel MOSFET are synchronously changed through the on-off of the triode, the voltage difference between the grid voltage and the source forms a floating drive voltage, and the N-channel MOSFET is subjected to switching control and comprises PNP type triodes Q4 and Q5, a triode Q4 base resistor R7, a bootstrap resistor R11, a pull-up resistor R10, a triode Q5 base resistor R8 and a bootstrap resistor R9. The base electrodes of the triodes Q2 and Q3 are connected with the collector electrode of the triode Q1 through respective base electrode resistors, and the emitter electrode of the triode Q2 is connected with the collector electrode of the triode Q3, so that the in-phase amplification change of the signal of the collector electrode of the triode Q2 relative to the signal of the base electrode of the triode Q1 is realized; the triodes Q4 and Q5 are connected with the collector of the triode Q2 through respective base resistors, and the collector of the triode Q4 is connected with the emitter of the triode Q5, so that the in-phase amplification change of the emitter signal of the triode Q4 relative to the base signal of the triode Q1 is realized; the enabling signal is connected to a transistor Q1 through a base resistor R1 of the transistor Q1; when the enable signal is at a high level, the N-channel MOSFET is switched on; when the enable signal is at a low level, the N-channel MOSFET is turned off, and enable control over the N-channel MOSFET is achieved.

In a preferred embodiment of the present invention, the base of the transistor Q1 is connected to one end of the resistor R1 and one end of the resistor R2, the collector of the transistor Q1 is connected to one end of the resistor R3 and one ends of the resistor R4 and the resistor R5, and the emitter of the transistor Q1 is connected to the other end of the resistor R2 and the ground GND. The base of the triode Q2 is connected with the other end of the resistor R4, and the collector of the triode Q2 is connected with one end of the resistor R7 and one end of the resistor R8. The base of the triode Q3 is connected with the other end of the resistor R5 and one end of the resistor R6, and the emitter of the triode Q3 is connected with the other end of the resistor R6 and the ground GND. The base of the triode Q4 is connected with the other end of the resistor R7 and one end of the resistor R11, the collector of the triode Q4 is connected with the emitter of the triode Q5 and one end of the resistor R9, and the emitter of the triode Q4 is connected with the other end of the resistor R11 and one end of the resistor R10. The base electrode of the triode Q5 is connected with the other end of the resistor R8 and the other end of the resistor R9, and the emitter electrode of the triode Q5 is connected with one end of the resistor R9 and the collector electrode of the triode Q4. The voltage VCC is connected to the collector of the transistor Q1 through a resistor R3, and the voltage VCC-GS is connected to the emitter of the transistor Q4 through a resistor R10. The gate G of the N-channel MOSFET is connected with the emitter of the triode Q4, and the source S of the N-channel MOSFET is connected with the collector of the triode Q5. The N-channel MOSFET source S is floating instead of zero potential ground.

In a preferred embodiment of the present invention, in order to ensure the basic consistency of the parameters of the transistor Q2 and the transistor Q3, such as the conduction critical current, R4 is set to R5; in order to ensure the basic consistency of parameters such as conduction critical current of the transistor Q4 and the transistor Q5, R7 is set to R8. In order to meet the requirements of high efficiency and high driving capability of a satellite power supply, the values of the base resistors R1, R4, R5, R7 and R8 of the triodes are in the range of 1K-10K. In order to meet the antistatic requirement of a satellite power supply device, the resistors R2, R6, R9 and R11 between the base electrode and the emitter electrode of the triode have larger values, and the value range is 10K-100K. In order to save power consumption and provide enough drive current and proper switching speed, the values of the pull-up resistors R3 and R10 are set to be in the range of 1K-10K.

The working principle of the satellite power supply power enable N-channel MOSFET driving circuit is explained below.

A. When the enable signal is at high level, the base of the NPN transistor Q1 is at high level, the transistor Q1 is turned on, the collector voltage of the transistor Q1 is at low level, and a large current flows through the resistor R3. At this time, the bases of the NPN transistor Q2 and the transistor Q3 are at a low level and thus are not turned on, and no current flows. Therefore, the bases of the PNP transistor Q4 and the transistor Q5 are high and are not conductive. At this time, the voltage VCC-GS is directly applied to the gate of the N-channel MOSFET after passing through the resistor R10, and the gate-source voltage difference of the N-channel MOSFET turns on the N-channel MOSFET.

B. When the enable signal is at low level, the base of the NPN transistor Q1 is at low level, the transistor Q1 is not turned on, and the collector voltage of the transistor Q1 is at high level. At this time, the voltage VCC is connected to the base resistors of the NPN transistor Q2 and the transistor Q3 through the resistor R3, and the bases of the transistor Q2 and the transistor Q3 are turned on at a high level. Therefore, the bases of the PNP transistor Q4 and the transistor Q5 are low-level conducting. At this time, the voltage difference between the gate and the source of the N-channel MOSFET is the voltage difference between the emitter of the transistor Q4 and the collector of the transistor Q5 after they are turned on, and the voltage difference is low, so the N-channel MOSFET is turned off.

It should be noted that the voltage VCC is 12V and the voltage VCC-GS is the magnitude of the MOSFET source voltage plus 12V. The emitter of the transistor Q1 is grounded to GND of the emitter of the transistor Q3 and the ground GND of the discharge circuit, but not to the source of the N-channel MOSFET, i.e., the MOSFET source is floating. The resistor between the base and the emitter of the transistor Q1, the transistor Q3 and the transistor Q5 prevents the electrostatic damage to the transistor.

Based on the above principle discussion, the following description will take the driving of a certain satellite-borne constant-current power supply power input MOS switch tube as an example.

The input of a certain satellite-borne constant current power supply is adjustable voltage and can provide 20A constant output current, an input switch tube of the satellite-borne constant current power supply adopts an N-channel MOSFET enabling control power loop passage, and an enabling driving circuit adopts the implementation circuit of the invention. The enabling signal working mode is as follows: period 2s, enable time 1s, high level 12V, low level 0V. The simulation results of the drive circuit Saber are shown in fig. 3.

VCC is set to 12V, the bus voltage is 42V, and VCC _ GS is 54V. As shown in fig. 3, the first waveform "Enable Signal" is an Enable Signal waveform, the second waveform "Q1 _ C" is a voltage waveform of a collector of the transistor Q1, the third waveform "Q2 _ C" is a voltage waveform of a collector of the transistor Q2, and the fourth waveform "GS" is a MOSFET driving waveform, i.e., a voltage waveform between a gate and a source. When the enable signal is at a high level, the voltage of the collector of the transistor Q1 is at a low level because the transistor Q1 is turned on, the transistors Q2 and Q3 are not turned on, and the collector of the transistor Q2 has no current. Therefore, the transistor Q4 is not turned on, no current flows through the resistor R10, the VCC _ GS voltage 54V is directly applied to the collector of the transistor Q2, the gate voltage of the MOSFET is VCC _ GS, the voltage difference between the gate and the source is 12V, and the N-channel MOSFET is turned on. When the enable signal is at a low level, the voltage of the collector of the transistor Q1 is at a high level because the transistor Q1 is not conductive, the transistors Q2 and Q3 are conductive, and the current flows through the collector of the transistor Q2. The transistor Q4 is turned on because the emitter voltage is higher than the base voltage, and a current flows through the resistor R10. At this time, the difference between the gate and source voltages is the conduction voltage drop of the transistor Q4 and the transistor Q5, which is very small and close to 0, and the N-channel MOSFET is turned off.

Simulation results show that the satellite power supply power enable N-channel MOSFET driving circuit is feasible.

The power-enabled N-channel MOSFET driving circuit of the satellite power supply is applied to a certain satellite model and belongs to the field of space power supplies for the first time. Through a series of space environment identification tests, the satellite power supply power enabling N-channel MOSFET driving circuit is excellent in performance, is suitable for enabling and driving the N-channel MOSFET in a high-efficiency large-current satellite-borne power supply, and has feasibility and high reliability.

The above description is only for the best mode of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention.

Those skilled in the art will appreciate that those matters not described in detail in the present specification are well known in the art.