CN209896936U

CN209896936U - Rectifier bridge circuit based on MOS power tube

Info

Publication number: CN209896936U
Application number: CN201920716503.7U
Authority: CN
Inventors: 唐俊雄
Original assignee: Hangzhou Tuya Information Technology Co Ltd
Current assignee: Hangzhou Tuya Information Technology Co Ltd
Priority date: 2019-05-17
Filing date: 2019-05-17
Publication date: 2020-01-03
Anticipated expiration: 2029-05-17

Abstract

The utility model relates to a rectifier bridge circuit based on MOS power tube, including first PMOS power tube, second PMOS power tube, third NMOS power tube, fourth NMOS power tube, first to fourth divider circuit, first to fourth one-way switch-on circuit. The utility model discloses a MOS founds full-bridge rectifier, can not only adapt to the not polarity input, moreover because MOS on-resistance is little, can also effectively reduce the power loss of rectifier bridge, reduces the heat dissipation requirement.

Description

Rectifier bridge circuit based on MOS power tube

[ technical field ] A method for producing a semiconductor device

The utility model relates to a power technical field, in particular to rectifier bridge circuit based on MOS power tube.

[ background of the invention ]

In the application of a Powered Device (PD), a Power Sourcing Equipment (PSE) provides a positive pole that may add a Power source output from the PSE to 12 pairs of lines of the PD, a negative pole that may add to 36 pairs of lines of the PD, and a positive pole that may add to 36 pairs of lines of the PD, and a negative pole that may add to 12 pairs of lines of the PD. The PD device is required to be capable of adapting to such input with any polarity, and a scheme of adding a rectifier bridge to the input end of the PD device is adopted to rectify a dc power supply with uncertain polarity direction into a dc power supply with confirmed polarity direction. In the prior art, a silicon diode rectifier bridge is generally adopted, but the forward voltage drop of a silicon diode can reach 0.9-1.5V; in the POE AT protocol, the system power is high, and the current flowing through the rectifier bridge can reach more than 700mA, so that the power loss on the rectifier bridge can reach 0.6-1W; in the future higher specification protocol, the power of the PSE will reach 60W-150W, the current flowing through the rectifier bridge will be larger, and the power loss on the rectifier bridge will be larger. Meanwhile, heat dissipation is needed along with the heating of the rectifier bridge or the diode, the power supply use efficiency is low, and the system reliability is low.

[ Utility model ] content

An object of the utility model is to overcome prior art not enough, provide a rectifier bridge circuit based on MOS power tube, adopt the low on-resistance of MOS power tube to effectively reduce the conduction loss among the rectification process.

The utility model discloses a following technical scheme: a rectifier bridge circuit based on MOS power tube includes: the power supply circuit comprises a first PMOS power tube, a second PMOS power tube, a first NMOS power tube, a second NMOS power tube, a third NMOS power tube, a fourth NMOS power tube, a first voltage division circuit, a second voltage division circuit, a third voltage division circuit, a fourth voltage division circuit, a first one-way conduction circuit, a second one-way conduction circuit, a third one-way conduction circuit and a fourth one-way conduction circuit;

the source electrode of the first PMOS power tube is connected with the drain electrode of the first NMOS power tube and then used as a first input end of the rectifier bridge circuit, and the source electrode of the second PMOS power tube is connected with the drain electrode of the second NMOS power tube and then used as a second input end of the rectifier bridge circuit;

the drain electrode of the first PMOS power tube is connected with the drain electrode of the second PMOS power tube and then used as the positive output end of the rectifier bridge circuit, and the source electrode of the second NMOS power tube is connected with the source electrode of the second NMOS power tube and then used as the negative output end of the rectifier bridge current;

the first voltage division circuit and the first one-way conduction circuit are connected between the first input end and the second input end, when the first one-way conduction circuit is conducted, the first voltage division circuit outputs a first voltage division signal to a grid electrode of the first PMOS power tube, and the first PMOS power tube is conducted;

the second voltage division circuit and the second one-way conduction circuit are connected between the first input end and the second input end, when the second one-way conduction circuit is conducted, the second voltage division circuit outputs a second voltage division signal to a grid electrode of the second PMOS power tube, and the second PMOS power tube is conducted;

the third voltage division circuit and the third one-way conduction circuit are connected between the first input end and the second input end, when the third one-way conduction circuit is conducted, the third voltage division circuit outputs a third voltage division signal to a grid electrode of the third NMOS power tube, and the third NMOS power tube is conducted;

the fourth voltage division circuit and the fourth unidirectional conduction circuit are connected between the first input end and the second input end, when the fourth unidirectional conduction circuit is conducted, the fourth voltage division circuit outputs a fourth voltage division signal to a grid electrode of the fourth NMOS power tube, and the fourth NMOS power tube is conducted;

when the first input end obtains a power supply positive pole and the second input end obtains a power supply negative pole, the first one-way conduction circuit and the fourth one-way conduction circuit are conducted, the first input end obtains the power supply negative pole, the second input end obtains the power supply positive pole, and the second one-way conduction circuit and the third one-way conduction circuit are conducted.

Preferably, the first voltage division circuit comprises a first resistor and a second resistor, a first end of the first resistor is connected to the first input end, a second end of the first resistor is connected to a first end of the second resistor and the gate of the first PMOS power transistor, and a second end of the second resistor is connected to the second input end;

the second voltage division circuit comprises a third resistor and a fourth resistor, wherein the first end of the fourth resistor is connected to the second input end, the second end of the fourth resistor is connected with the first end of the third resistor and the grid electrode of the second PMOS power tube, and the second end of the third resistor is connected with the first input end;

the third voltage division circuit comprises a fifth resistor and a sixth resistor, wherein the first end of the sixth resistor is connected to the second input end, the second end of the sixth resistor is connected to the first end of the fifth resistor and the grid electrode of the third NMOS power tube, and the second end of the fifth resistor is connected to the first input end;

the fourth voltage division circuit comprises a seventh resistor and an eighth resistor, wherein the first end of the seventh resistor is connected to the first input end, the second end of the seventh resistor is connected to the first end of the eighth resistor and the grid electrode of the fourth NMOS power tube, and the second end of the eighth resistor is connected to the second input end.

Preferably, the first unidirectional conducting circuit comprises a first diode, the second end of the second resistor is connected with the anode of the first diode, and the cathode of the first diode is connected with the second input end;

the second unidirectional conduction circuit comprises a second diode, the second end of the third resistor is connected with the anode of the second diode, and the cathode of the second diode is connected with the first input end;

the third unidirectional conducting circuit comprises a third diode, the second end of the fifth resistor is connected with the anode of the third diode, and the cathode of the third diode is connected with the first input end;

the fourth unidirectional conducting circuit comprises a fourth diode, the second end of the eighth resistor is connected with the anode of the fourth diode, and the cathode of the fourth diode is connected with the second input end.

Preferably, the first unidirectional conducting circuit comprises a first diode, the anode of the first diode is connected with the second end of the first resistor, and the cathode of the first diode is connected with the first end of the second resistor;

the second unidirectional conduction circuit comprises a second diode, the anode of the second diode is connected with the second end of the fourth resistor, and the cathode of the second diode is connected with the first end of the third resistor;

the third unidirectional conduction circuit comprises a third diode, the anode of the third diode is connected with the second end of the sixth resistor, and the cathode of the third diode is connected with the first end of the fifth resistor;

the fourth unidirectional conducting circuit comprises a fourth diode, the anode of the fourth diode is connected with the second end of the seventh resistor, and the cathode of the fourth diode is connected with the first end of the eighth resistor.

Preferably, the first unidirectional conducting circuit comprises a first relay, the second end of the second resistor is connected with the first contact of the first relay, the positive control end of the coil of the first relay is connected with the first input end, and the negative control end of the coil and the second contact of the first relay are connected with the second input end;

the second unidirectional conduction circuit comprises a second relay, the second end of the third resistor is connected with the first contact of the second relay, the positive control end of the coil of the second relay is connected with the second input end, and the negative control end of the coil of the second relay and the second contact are connected with the first input end;

the third unidirectional conduction circuit comprises a third relay, the second end of the fifth resistor is connected with the first contact of the third relay, the positive control end of the coil of the third relay is connected with the second input end, and the negative control end of the coil of the third relay and the second contact are connected with the first input end;

the fourth unidirectional conduction circuit comprises a fourth relay, the second end of the eighth resistor is connected with the first contact of the fourth relay, the positive control end of the coil of the fourth relay is connected with the first input end, and the negative control end of the coil of the fourth relay is connected with the second contact to connect the second input end.

Preferably, the first unidirectional conducting circuit comprises a first relay, a first contact of the first relay is connected with a second end of the first resistor, a second contact of the first relay is connected with a first end of the second resistor, a positive control end of a coil of the first relay is connected with the first input end, and a negative control end of the coil of the first relay is connected with the second input end;

the second unidirectional conduction circuit comprises a second relay, a first contact of the second relay is connected with a second end of the sixth resistor, a second contact of the second relay is connected with a first end of the fifth resistor, a coil positive control end of the second relay is connected with the second input end, and a coil negative control end of the second relay is connected with the first input end;

the third unidirectional conduction circuit comprises a third relay, a first contact of the third relay is connected with the second end of the sixth resistor, a second contact of the third relay is connected with the first end of the fifth resistor, the positive control end of a coil of the third relay is connected with the second input end, and the negative control end of the coil of the third relay is connected with the first input end;

the fourth unidirectional conduction circuit comprises a fourth relay, a first contact of the fourth relay is connected with a second end of the seventh resistor, a second contact of the fourth relay is connected with a first end of the eighth resistor, a coil anode control end of the fourth relay is connected with the first input end, and a coil cathode control end of the fourth relay is connected with the second input end.

Preferably, the first relay, the second relay, the third relay and the fourth relay are normally open type signal relays.

Preferably, the normally open signal relay comprises a housing, and the housing comprises a diode, wherein the anode of the diode is connected to the anode control terminal of the coil, and the cathode of the diode is connected to the cathode control terminal of the coil.

Compared with the prior art, the technical scheme of the utility model, constitute the bridge type bridge circuit through the MOS pipe, the low power dissipation of rectifier bridge has reduced the heat dissipation requirement to the drive circuit of MOS is simple, and occupation space is little, and is with low costs, does benefit to the product miniaturization.

[ description of the drawings ]

Fig. 1 is a circuit diagram of a MOS connection circuit portion of a rectifier bridge circuit based on a MOS power transistor according to an embodiment of the present invention;

fig. 2 is a schematic structural diagram of a MOS driving circuit portion of a rectifier bridge circuit based on a MOS power transistor according to an embodiment of the present invention;

fig. 3 is a circuit diagram of a first embodiment of a MOS driving circuit portion of a rectifier bridge circuit based on a MOS power transistor according to an embodiment of the present invention;

fig. 4 is a circuit diagram of a second embodiment of a MOS driving circuit portion of a rectifier bridge circuit based on a MOS power transistor according to an embodiment of the present invention;

fig. 5 is a circuit diagram of a third embodiment of a MOS driving circuit portion of a rectifier bridge circuit based on a MOS power transistor according to an embodiment of the present invention;

fig. 6 is a circuit diagram of a fourth embodiment of a MOS driver circuit portion of a rectifier bridge circuit based on a MOS power transistor according to an embodiment of the present invention.

[ detailed description ] embodiments

To make the above objects, features and advantages of the present invention more comprehensible. The following detailed description of the embodiments of the present invention will be made with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein, as those skilled in the art will be able to make similar modifications without departing from the spirit and scope of the present invention.

The embodiment of the utility model discloses a rectifier bridge circuit based on MOS power tube divide into MOS connecting circuit part and MOS drive circuit part, the break-make of the MOS in the MOS drive circuit part control MOS connecting circuit part.

As shown in fig. 1, for the MOS connection circuit part of the rectifier bridge circuit based on the MOS power tube of embodiment 1 of the present invention, including first PMOS power tube Q1, second PMOS power tube Q2, first NMOS power tube Q3, second NMOS power tube Q4:

a source electrode of the first PMOS power tube Q1 is connected with a drain electrode of the first NMOS power tube Q3 to serve as a first input end COM1 of the rectifier bridge circuit, and a source electrode of the second PMOS power tube Q2 is connected with a drain electrode of the second NMOS power tube Q4 to serve as a second input end COM2 of the rectifier bridge circuit; the drain of the first PMOS power transistor Q1 is connected to the drain of the second PMOS power transistor Q2 to serve as the positive output terminal VCC of the rectifier bridge circuit, and the source of the second NMOS power transistor Q3 is connected to the source of the second NMOS power transistor Q4 to serve as the negative output terminal GND of the rectifier bridge current;

as shown in fig. 2, the MOS driving circuit portion of the MOS power transistor-based rectifier bridge circuit according to the embodiment of the present invention includes a first driving circuit 1, a second driving circuit, a third driving circuit, and a fourth driving circuit. The first driving circuit 1, the second driving circuit 2, the third driving circuit 3 and the fourth driving circuit 4 are respectively connected between the first input end COM1 and the second input end COM2, and respectively output a first control signal, a second control signal, a third control signal and a fourth control signal to respectively control the conduction of the first PMOS power tube Q1, the second PMOS power tube Q2, the third NMOS power tube Q3 and the fourth NMOS power tube Q4.

The first driving circuit 1 comprises a first voltage division circuit and a first unidirectional conduction circuit, wherein the first voltage division circuit and the first unidirectional conduction circuit are connected between the first input end COM1 and the second input end COM2, and when the first unidirectional conduction circuit is conducted, the first voltage division circuit outputs a first voltage division signal to the grid electrode of the first PMOS power tube Q1 to control the conduction of the first PMOS power tube Q1; the first divided voltage signal is the first control signal;

the second driving circuit 2 comprises a second voltage division circuit and a second unidirectional conduction circuit, wherein the second voltage division circuit and the second unidirectional conduction circuit are connected between the first input end COM1 and the second input end COM2, and when the second unidirectional conduction circuit is conducted, the second voltage division circuit outputs a second voltage division signal to the grid electrode of the second PMOS power tube Q2 to control the conduction of the second PMOS power tube Q2; the second divided signal is the second control signal;

the third driving circuit 3 comprises a third voltage division circuit and a third unidirectional conduction circuit, which are connected between the first input terminal COM1 and the second input terminal COM2, and when the third unidirectional conduction circuit is turned on, the third voltage division circuit outputs a third voltage division signal to the gate of the third NMOS power transistor Q3 to control the third NMOS power transistor Q3 to be turned on; the third divided voltage signal is the third control signal;

the fourth driving circuit 4 comprises a fourth voltage dividing circuit and a fourth unidirectional conducting circuit, which are connected between the first input terminal COM1 and the second input terminal COM2, and when the fourth unidirectional conducting circuit is conducted, the fourth voltage dividing circuit outputs a fourth voltage dividing signal to the gate of the fourth NMOS power tube Q4 to control the conduction of the fourth NMOS power tube Q4; the fourth voltage division signal is the fourth control signal;

when the first input end obtains a power supply positive pole and the second input end obtains a power supply negative pole, the first one-way conduction circuit and the fourth one-way conduction circuit are conducted, the first input end obtains the power supply negative pole, the second input end obtains the power supply positive pole, and the second one-way conduction circuit and the third one-way conduction circuit are conducted. The power source anode is the anode of the output power source of the PSE device, and the power source anode is the cathode of the output power source of the PSE device.

The basic working principle of the rectifier bridge circuit is as follows: the conducting direction, i.e. the direction of current flow, is assumed that the first input terminal COM1 and the second input terminal COM2 of the rectifier bridge circuit are connected to the positive pole and the negative pole of the PSE output power respectively, i.e. COM1 is connected to the positive pole of the PSE output power and COM2 is connected to the negative pole of the PSE output power. At this time, current flows from COM1 to COM2, due to the one-way conduction characteristic of the one-way conduction circuit, the first one-way conduction circuit and the fourth one-way conduction circuit are conducted, at this time, the first voltage division circuit and the fourth voltage division circuit work to respectively output a first voltage division signal and a fourth voltage division signal to gates of Q1 and Q4, Q1 and Q4 are conducted, so that the conduction of the first PMOS power tube Q1 enables the anode of the PSE output power supply to be communicated with the positive output terminal VCC of the rectifier bridge, and the conduction of the fourth NMOS power tube Q4 enables the cathode of the PSE output power supply to be communicated with the negative output terminal GND of the rectifier bridge; and the second unidirectional turn-on circuit and the third unidirectional turn-on circuit are turned off, the second voltage division circuit and the third voltage division circuit do not work, the third voltage division signal and the fourth voltage division signal cannot be output, and therefore Q2 and Q3 are disconnected. Conversely, if the first input terminal COM1 is connected to the negative terminal of the PSE output power supply, the second input terminal COM2 is connected to the positive terminal of the PSE output power supply, at this time, the second unidirectional conducting circuit and the third unidirectional conducting circuit are turned on, Q2 and Q3 are turned on, the first unidirectional conducting circuit and the fourth unidirectional conducting circuit are turned off, and Q1 and Q4 are turned off, so that after passing through the rectifier bridge circuit, the positive terminal of the PSE output power supply is still connected to the positive output terminal VCC of the rectifier bridge circuit, the first terminal of the negative terminal R11 of the PSE output power supply is directly connected to the first input terminal COM1, the first terminal of the second terminal CON1 connected to R12, the second terminal of R12 is connected to the second input terminal COM2, and the second terminal CON1 of the first resistor R11 is also directly connected to the gate of the first PMOS power transistor Q1; still communicates with the negative output terminal GND of the rectifier bridge circuit. Therefore, the rectifier bridge circuit can well complete rectification, and the PD equipment can meet the application requirement of any polarity input. Those skilled in the art will understand that the present embodiment is not only applicable to PD devices in the ethernet field, but also applicable to powered devices in other fields where the dc input polarity is unknown.

Specifically, as shown in fig. 3, which is a first preferred embodiment of the MOS driver circuit, the first voltage divider circuit includes a first resistor R11 and a second resistor R12,

the second voltage division circuit comprises a third resistor R21 and a fourth resistor R22, a first end of R22 is connected to a second input end COM2, a second end CON2 is connected with a first end of R21 and a gate of the second PMOS power tube Q2, and a second end of R21 is connected with the first input end COM 1;

the third voltage division circuit comprises a fifth resistor R31 and a sixth resistor R32, a first end of R32 is connected to a second input end COM2, a second end CON3 is connected with a first end of R31 and the gate of the third NMOS power tube Q3, and a second end of R31 is connected with the first input end COM 1;

the fourth voltage division circuit comprises a seventh resistor R41 and an eighth resistor R42, a first end of R41 is connected to a first input end COM1, a first end of a second end CON4, which is connected with R42, and a gate of the fourth NMOS power tube Q4, and a second end of R42 is connected with the second input end COM 2.

Preferably, the COM1 and the first end of R11, the CON2 and the gate of Q1, the COM2 and the first end of R22, the CON2 and the gate of Q2, the COM2 and the first end of R32, the CON3 and the gate of Q3, the COM1 and the first end of R41, and the CON4 and the gate of Q4 are directly connected.

The first unidirectional conduction circuit comprises a first diode D1, the second end of the second resistor R12 is connected with the anode of the D1, and the cathode of the D2 is connected with the second input end COM 2;

the second unidirectional conduction circuit comprises a second diode D2, the second end of the third resistor R21 is connected with the anode of the D2, and the cathode of the D2 is connected with the first input end COM 1;

the third unidirectional conduction circuit comprises a third diode D3, the second end of the fifth resistor R31 is connected with the anode of the D3, and the cathode of the D3 is connected with the first input end COM 1;

the fourth unidirectional circuit comprises a fourth diode D4, a second end of the eighth resistor R42 is connected to the anode of the D4, and the cathode of the D4 is connected to the second input terminal COM 2.

That is, there is one diode between the second resistor and COM2, between the third resistor and COM1, between the fifth resistor and COM1, and between the eighth resistor and COM2, which are indirectly connected.

The working principle of the above-described embodiment using the first embodiment is as follows:

assume that the first input terminal COM1 and the second input terminal COM2 of the rectifier bridge circuit are connected to the positive pole and the negative pole of the PSE output power supply, respectively:

at this time, the voltage of COM1 is greater than COM2, D1 and D4 are turned on, and the first voltage dividing circuit operates, so Vcom1> Vcon1> Vcom2, the voltage at CON1 point is the first voltage dividing signal, the fourth voltage dividing circuit operates, Vcom1> Vcon4> Vcom2, and the voltage at CON4 point is the fourth voltage dividing signal; d2 and D3 are turned on, and the second voltage dividing circuit does not operate, so Vcom1> Vcon2 is not Vcom2, and the voltage at CON2 point is not the output when the second voltage dividing circuit operates, i.e. not the second voltage dividing signal, and similarly, the third voltage dividing circuit does not operate, so Vcom1> Vcon3 is not Vcom2, and the voltage at CON3 point is not the output when the third voltage dividing circuit operates, i.e. not the third voltage dividing signal.

For Q1, the gate G of Q1 is connected to CON1, i.e., VG1 of Q1 is Vcon1, the source S of Q1 is connected to COM1, i.e., VS1 of Q1 is Vcom1, and it is known that Vcom1> Vcon1> Vcom2, so VG1 of the first PMOS power transistor Q1 < VS 1. It is known that the PMOS power transistor has a turn-on preset voltage VGSth, and when a voltage difference VGs (negative voltage) between VG and VS is smaller than VGSth, the PMOS power transistor is turned on. In this embodiment, by selecting appropriate R11 and R12, the voltage difference between CON1 and COM1 is smaller than VGSth of the first PMOS power transistor Q1, i.e. the first PMOS power transistor Q1 is made to conduct stably, so that the positive electrode of the PE output power supply is connected to the positive output terminal VCC of the rectifier bridge circuit.

For Q4, since the conduction of Q1 causes the current to flow from COM1 to VCC and then to GND, Q4 is pre-conducted by its body diode, and the current flows from GND to COM2 from the body diode of Q4, the voltage Vgnd of GND is Vcom2, GND is connected to the source S of Q4, that is, VS4 of Q4 is Vgnd Vcom2, the gate G of Q4 is connected to CON4, that is, VG4 of Q4 is Vcon4, and Vcom1> Vcon4> Vcom2 is known, so VG4 VS > 4 of the fourth NMOS power tube Q4. It is known that the NMOS power transistor has a turn-on preset voltage VGSth, and when a voltage difference VGs (positive voltage) between VG and VS is greater than VGSth, the NMOS power transistor is turned on. In the embodiment, the voltage difference between CON4 and COM2 is larger than VGSth of the fourth NMOS power tube Q4 by selecting appropriate R41 and R42, that is, the fourth PMOS power tube Q4 is stably conducted, so that the negative pole of the PSE output power supply is communicated with the negative output terminal GND of the rectifier bridge circuit.

For Q2, the gate G of Q2 is connected to CON2, i.e., VG2 — Vcon2 of Q2, the source S of Q2 is connected to COM2, i.e., VS2 — Vcom2, Vcom1> Vcon2 — Vcom2 is known, so VG2 — VS2 of Q2, VGs 0 of Q2, and Q2 is off.

For Q3, the gate G of Q3 is connected to CON3, i.e., VG3 and Vcon3 of Q3, the source S of Q3 is connected to GND, i.e., VS3 and Vgnd, Vgnd and Vcom2 are known from Q4, Vcom1> Vcon3 and Vcom2 are known, so VG3 and Vcon3 and Vcom2 and Vgnd VS3, VGs of Q3 and Q3 are off.

It should be noted that the selection of the two resistors in the voltage divider circuit also needs to satisfy that VGS of the PMOS is greater than the maximum withstanding voltage VGSmax (negative value), VGS of the NMOS is less than the maximum withstanding voltage VGSmax (positive value), otherwise the MOS power transistor will be damaged.

Conversely, if the first input terminal COM1 is connected to the negative electrode of the PSE output power supply, and the second input terminal COM2 is connected to the positive electrode of the PSE output power supply, at this time, D2 and D3 are turned on, D1 and D4 are turned off, Q2 and Q3 are turned on, and Q1 and Q4 are turned off, which is the same as the above and will not be described again. After passing through the rectifier bridge circuit, the anode of the output power supply of the PSE is still communicated with the positive output end VCC of the rectifier bridge circuit, and the cathode of the output power supply of the PSE is still communicated with the negative output end GND of the rectifier bridge circuit.

Specifically, referring to fig. 4, a second embodiment of the MOS driver circuit portion, the second embodiment is different from the first embodiment only in the connection manner of D1, D2, D3 and D4, and the circuit connections of the rest are completely the same, and the connection manner of D1 to D4 of the second embodiment is as follows:

the anode of the D1 is connected to the second terminal CON1 of the first resistor R11, and the cathode is connected to the first terminal of the second resistor R12;

the anode of the D2 is connected to the second terminal CON2 of the fourth resistor R22, and the cathode is connected to the first terminal of the third resistor R21;

the anode of the D3 is connected to the second terminal CON3 of the sixth resistor R32, and the cathode is connected to the first terminal of the fifth resistor R31;

the anode of the D4 is connected to the second terminal CON4 of the seventh resistor R41, and the cathode is connected to the first terminal of the eighth resistor R42.

Namely, one resistor is arranged between the first resistor and the second resistor, between the third resistor and the fourth resistor, between the fifth resistor and the sixth resistor, and between the seventh resistor and the eighth resistor, and the resistors are indirectly connected.

The utility model discloses an adopt the theory of operation of the MOS drive circuit's of second embodiment, it is the same with the above-mentioned theory of operation that adopts first embodiment completely, no longer give consideration to here. Therefore, the rectifier bridge circuit can well complete rectification, and the PD equipment can meet the application requirement of any polarity input.

Specifically, referring to fig. 5, a third embodiment of the MOS driving circuit portion is different from the first embodiment only in that the specific first to fourth unidirectional circuits are different, and the circuit connections of the rest portions are completely the same, and the first to fourth unidirectional circuits of the third embodiment are as follows:

the first unidirectional conduction circuit comprises a first relay J1, a second end of the second resistor R12 is connected with a first contact of the first relay, a coil positive control end of the first relay is connected with the first input end COM1, and a coil negative control end and a second contact of the first relay are connected with the second input end COM 2;

the second unidirectional conduction circuit comprises a second relay J2, a second end of the third resistor R21 is connected with a first contact of the J2, a coil positive control end of the J2 is connected with the second input end COM2, and a coil negative control end and a second contact of the J2 are connected with the first input end COM 1;

the third unidirectional conduction circuit comprises a third relay J3, a second end of the fifth resistor R31 is connected with a first contact of the J3, a coil positive control end of the J3 is connected with the second input end COM2, and a coil negative control end and a second contact of the J3 are connected with the first input end COM 1;

the fourth unidirectional conduction circuit comprises a fourth relay J4, a second end of the eighth resistor R42 is connected with a first contact of the J4, a coil positive control end of the J4 is connected with the first input end COM1, and a coil negative control end and a second contact of the J4 are connected with the second input end COM 2; .

The above JI-J4 is a normally open type signal relay, which comprises a case having a coil and a diode connected in series inside the case between a positive control terminal of the coil and a negative control terminal of the coil, the positive terminal of the diode being connected to the positive control terminal of the coil, the negative terminal of the diode being connected to the negative control terminal of the coil, whereby the relay is a one-way conductive element. The relay comprises a shell, a switch K and a control circuit, wherein the switch K is in a static normally open state inside the shell, a moving contact of the switch K is connected to a first contact, a normally open contact of the switch K is connected to a second contact, or the moving contact is connected to the second contact, and the normally open contact is connected to the first contact. When the voltage of the coil anode control end of the relay is greater than the coil cathode control end and is greater than the coil control voltage of the relay, the internal diode is conducted, and when the current flows from the coil anode control end of the relay to the coil cathode control end, the coil flows through the current and generates force to attract the iron switch K to be closed, namely, the movable contact is electrically contacted with the normally open contact, so that the second contact is conducted between the first contacts, and the relay is conducted; when the voltage of the coil anode control end of the relay is smaller than that of the coil cathode control end, the internal diode is cut off, the switch K is switched off, and therefore the relay is cut off.

The operation principle of the third embodiment is as follows:

assuming that a first input terminal COM1 and a second input terminal COM2 of the rectifier bridge circuit are respectively connected to the positive pole and the negative pole of the PSE output power supply, the voltage of COM1 is larger than COM2, J1 and J4 are conducted, Q1 and Q4 are conducted, J2 and J3 are disconnected, and Q2 and Q3 are disconnected; on the contrary, assuming that the first input terminal COM1 and the second input terminal COM2 of the rectifier bridge circuit are respectively connected to the negative electrode and the positive electrode of the PSE output power supply, the voltage of COM2 is greater than COM1, J2 and J3 are turned on, Q2 and Q3 are turned on, J1 and J4 are turned off, and Q1 and Q4 are turned off, the operation principle is basically the same as that of the first embodiment, and will not be described herein again. After passing through the rectifier bridge circuit, the anode of the output power supply of the PSE is still communicated with the positive output end VCC of the rectifier bridge circuit, and the cathode of the output power supply of the PSE is still communicated with the negative output end GND of the rectifier bridge circuit.

Specifically, referring to fig. 6, a fourth embodiment of the MOS drive circuit section is different from the third embodiment only in that the first contact and the second contact of the first relay J1 to the fourth relay are connected in a different manner, and the rest of the circuit connections are completely the same, and the connection manner of the fourth embodiment J1-J4 is as follows:

the first contact of the J1 is connected with the second end CON1 of the first resistor R11, and the second contact is connected with the first end of the second resistor R12;

the first contact of the J2 is connected with the second end CON2 of the fourth resistor R22, and the second contact is connected with the first end of the third resistor R21;

the first contact of the J3 is connected with the second end CON3 of the sixth resistor R32, and the second contact is connected with the first end of the fifth resistor R31;

the first contact of the J4 is connected to the second terminal CON4 of the seventh resistor R41, and the second contact is connected to the first terminal of the eighth resistor R42.

The utility model discloses a theory of operation of the embodiment of fourth embodiment is the same with the theory of operation of above-mentioned third embodiment completely, and is no longer repeated here. Therefore, the rectifier bridge circuit can well complete rectification, and the PD equipment can meet the application requirement of any polarity input.

Although particular embodiments of the present invention have been described above, it will be appreciated by those skilled in the art that this is merely an illustration of distances and that the scope of protection of the present invention is defined by the appended claims. Various changes and modifications to these embodiments may be made by those skilled in the art without departing from the spirit and the principles of the present invention, and these changes and modifications are all within the scope of the present invention.

Claims

1. A rectifier bridge circuit based on MOS power tube, characterized by that, includes: the power supply circuit comprises a first PMOS power tube, a second PMOS power tube, a first NMOS power tube, a second NMOS power tube, a third NMOS power tube, a fourth NMOS power tube, a first voltage division circuit, a second voltage division circuit, a third voltage division circuit, a fourth voltage division circuit, a first one-way conduction circuit, a second one-way conduction circuit, a third one-way conduction circuit and a fourth one-way conduction circuit;

2. The MOS power transistor-based rectifier bridge circuit of claim 1, wherein:

the first voltage division circuit comprises a first resistor and a second resistor, wherein a first end of the first resistor is connected to a first input end, a second end of the first resistor is connected to a first end of the second resistor and a grid electrode of the first PMOS power tube, and a second end of the second resistor is connected to the second input end;

3. The MOS power transistor-based rectifier bridge circuit of claim 2, wherein:

the first unidirectional conducting circuit comprises a first diode, the second end of the second resistor is connected with the anode of the first diode, and the cathode of the first diode is connected with the second input end;

4. The MOS power transistor-based rectifier bridge circuit of claim 2, wherein:

the first unidirectional conducting circuit comprises a first diode, the anode of the first diode is connected with the second end of the first resistor, and the cathode of the first diode is connected with the first end of the second resistor;

5. The MOS power transistor-based rectifier bridge circuit of claim 2, wherein:

the first unidirectional conduction circuit comprises a first relay, the second end of the second resistor is connected with a first contact of the first relay, the positive control end of the coil of the first relay is connected with the first input end, and the negative control end of the coil of the first relay and the second contact are connected with the second input end;

6. The MOS power transistor-based rectifier bridge circuit of claim 2, wherein:

the first unidirectional conduction circuit comprises a first relay, a first contact of the first relay is connected with a second end of the first resistor, a second contact of the first relay is connected with a first end of the second resistor, a coil positive control end of the first relay is connected with the first input end, and a coil negative control end of the first relay is connected with the second input end;

7. The rectifier bridge circuit based on the MOS power tube, as recited in claim 5 or 6, wherein the first relay, the second relay, the third relay and the fourth relay are normally open type signal relays.

8. The MOS power transistor-based rectifier bridge circuit of claim 7, wherein the normally-open signal relay includes a housing, the housing including a diode, the diode having an anode connected to the coil anode control terminal and a cathode connected to the coil cathode control terminal.