High-side driving circuit of push-pull isolation power supply

Abstract

The utility model discloses a high-side driving circuit of a push-pull isolation power supply, which belongs to the field of power supply circuits and comprises a charging tube QC, a discharging tube QD, resistors R1 to R10, a diode D5, a diode D6, a triode Q1, a triode Q2 and isolation optocoupler elements U5 and U6. The charging tube QC and the discharging tube QD are respectively a charging tube and a discharging tube of a BMS (Battery Management System) applied at a high side, and driving voltages of the charging tube QC and the discharging tube QD are respectively generated by two paths of isolated power supplies; and the driving signals of the push-pull type isolation power supply and the charging and discharging switch signal are respectively from charging and discharging switch signals CHA-DRV and DIS-DRV generated by the AFE chip, and the push-pull type isolation power supply and the charging and discharging switch signal are subjected to charging and discharging switch actions by utilizing an isolation power supply generated by a high-side driving circuit of the push-pull type isolation power supply after being subjected to optocoupler isolation. According to the utility model, the scheme of the push-pull isolated power supply is adopted, the output voltage is flexible and adjustable, 12V can be output to drive an NMOS tube, or 5V can be output to drive gallium nitride, or a high-side SIC can be driven, the high-side opening and closing of the high-voltage battery pack can be easily realized, and the high-side driving scheme has the characteristics of high voltage resistance, strong driving capability and the like.

Description

Technical Field

[0001] The utility model relates to the technical field of power supply circuits, in particular to a high-side driving circuit of a push-pull type isolated power supply. Background Art

[0002] In the application scenario of BMS (BATTERY MANAGEMENT SYSTEM), when the system is not working, it is usually necessary to turn off the power supply to keep the standby power consumption low and extend the standby time.

[0003] In some small application scenarios below 40V, the high-side NMOSFET can be controlled, and the high-side switch can be used to drive the NMOSFET in medium voltage systems of 60V and below. However, in scenarios above 60V and in high-current applications, considering the overvoltage caused by hot plugging, the voltage resistance of these products must be above 120V. In addition to process limitations, there are very few products above 120V on the market. Even if this process is available, the high voltage resistance requires many layers of the BCD process, the chip size is large, and the product cost is high. Utility Model Content

[0004] The utility model aims to provide a high-side driving circuit of a push-pull isolated power supply to solve the problems in the background technology.

[0005] In order to solve the above technical problems, the utility model provides a high-side driving circuit of a push-pull isolated power supply, including a charging tube QC, a discharging tube QD, resistors R1-R10, a diode D5, a diode D6, a transistor Q1, a transistor Q2 and isolated optical coupling elements U5 and U6;

[0006] The first end of the isolation optocoupler element U5 is connected to the 12V voltage through the resistor R6, the second end is connected to the collector of the transistor Q1, the third end is connected to the third end of the charging tube QC, and the fourth end is connected to the isolation power supply 12V1 through the resistor R4; the base of the transistor Q1 is connected to the first end of the resistor R9 and the first end of the resistor R10 at the same time, the second end of the resistor R9 is connected to the charging switch signal CHA-DRV, and the second end of the resistor R10 and the emitter of the transistor Q1 are both grounded;

[0007] The first end of the isolation optical coupling element U6 is connected to the 12V voltage through the resistor R5, the second end is connected to the collector of the transistor Q2, the third end is connected to the third end of the discharge tube QD, and the fourth end is connected to the isolation power supply 12V2 through the resistor R3; the base of the transistor Q2 is connected to the first end of the resistor R7 and the first end of the resistor R8 at the same time, the second end of the resistor R7 is connected to the discharge switch signal DIS-DRV, and the second end of the resistor R8 and the emitter of the transistor Q2 are both grounded;

[0008] The first end of the charging tube QC is connected to the isolated power supply BAT+, the second end is connected to the first end of the resistor R2 and the positive electrode of the diode D6, and the second end of the resistor R2 and the negative electrode of the diode D6 are both connected to the third end of the charging tube QC;

[0009] The first end of the discharge tube QD is connected to the isolation power supply PACK+, the second end is connected to the first end of the resistor R1 and the anode of the diode D5, and the second end of the resistor R1 and the cathode of the diode D5 are both connected to the third end of the discharge tube QD.

[0010] The utility model provides a high-side driving circuit of a push-pull isolated power supply. The output voltage of the push-pull isolated power supply is flexibly adjustable. It can output 12V to drive an NMOS tube, or output 5V to drive gallium nitride, or drive a high-side SIC, etc., and easily realize the high-side opening and closing of a high-voltage battery pack. The high-side driving solution has the characteristics of high voltage resistance and strong driving capability. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 The utility model provides a high-side drive circuit structure diagram of a push-pull isolation power supply.

[0012] Figure 2 This is a circuit diagram for generating 12V isolated power supplies 12V1 and 12V2 from 5V.

[0013] Figure 3 It is a schematic diagram of a chip that implements a one-to-two structure.

[0014] Figure 4 This is a schematic diagram of the structure of using voltage-dividing resistors to power the VCC pin of the MX6501T. DETAILED DESCRIPTION

[0015] The following is a further detailed description of a high-side drive circuit of a push-pull isolated power supply proposed by the utility model in combination with the accompanying drawings and specific embodiments. According to the following description, the advantages and features of the utility model will be clearer. It should be noted that the accompanying drawings are all in a very simplified form and are not in precise proportions, which are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the utility model.

[0016] The utility model provides a high-side drive circuit of a push-pull type isolated power supply, the structure of which is as follows: Figure 1As shown, it includes a charging tube QC, a discharging tube QD, resistors R1-R10, a diode D5, a diode D6, a transistor Q1, a transistor Q2 and isolated optical coupling elements U5 and U6; the first end of the isolated optical coupling element U5 is connected to a 12V voltage through a resistor R6, the second end is connected to the collector of the transistor Q1, the third end is connected to the third end of the charging tube QC, and the fourth end is connected to an isolated power supply 12V1 through a resistor R4; the base of the transistor Q1 is simultaneously connected to the first end of the resistor R9 and the first end of the resistor R10, the second end of the resistor R9 is connected to a charging switch signal CHA-DRV, the second end of the resistor R10 and the emitter of the transistor Q1 are both grounded; the first end of the isolated optical coupling element U6 is connected to a 12V voltage through a resistor R5, and the second end is connected to the collector of the transistor Q2, The third terminal is connected to the third terminal of the discharge tube QD, and the fourth terminal is connected to the voltage 12V2 through the resistor R3; the base of the transistor Q2 is connected to the first end of the resistor R7 and the first end of the resistor R8 at the same time, the second end of the resistor R7 is connected to the discharge switch signal DIS-DRV, and the second end of the resistor R8 and the emitter of the transistor Q2 are both grounded; the first terminal of the charging tube QC is connected to the isolation power supply BAT+, the second end is connected to the first end of the resistor R2 and the positive electrode of the diode D6 at the same time, and the second end of the resistor R2 and the negative electrode of the diode D6 are both connected to the third terminal of the charging tube QC; the first terminal of the discharge tube QD is connected to the isolation power supply PACK+, the second end is connected to the first end of the resistor R1 and the positive electrode of the diode D5 at the same time, and the second end of the resistor R1 and the negative electrode of the diode D5 are both connected to the third terminal of the discharge tube QD.

[0017] like Figure 1 As shown, QC and QD are the charging tube and discharging tube used by the BMS on the high side, and their driving voltages are generated by two isolated power supplies. The driving signals of the charging tube QC and the discharging tube QD come from the charging and discharging switch signals CHA-DRV and DIS-DRV generated by the AFE (ActiveFront End), respectively. After being isolated by optical coupling, the two use the isolated power generated by the high-side driving circuit (MX6501T) of the push-pull isolated power supply of the utility model to perform the charging and discharging switching action. Figure 2 As shown, in this embodiment, 12V is the primary power supply; 12V1 and 12V2 are isolated power supplies after passing through the high-side drive circuits U1 and U2 and the transformer MXPP8 of the push-pull isolated power supply of the utility model.

[0018] The high-side drive circuit (MX6501T) of the push-pull isolated power supply of the utility model can be used in the fields of photovoltaic inverter, isolated communication, electric tools, automotive electronics, etc. in addition to being applied to BMS.

[0019] In addition, if the user needs a smaller MOSFET driving capability and does not require high precision for the driving voltage, the MX6501T+MXPP8-30-1103 chip set can be used to implement a one-to-two 12V to 12V isolated driving solution or the MX6501T+MXPP8-30-1250 chip set can be used to implement a one-to-two 5V to 12V isolated driving solution. The schematic diagram is as follows: Figure 3 shown.

[0020] Since the input voltage limit of MX6501T is 7V, for the 12V input system, it is recommended to use a voltage divider resistor to power the VCC pin of MX6501T, and the transformer drive voltage is still 12V. The internal drive MOS of MX6501T has a withstand voltage of 36V, which can fully meet the 24V withstand voltage requirement of the 12V system, and the efficiency can reach 90%, which is higher than 5V to 12V. The schematic diagram is as follows Figure 4 shown.

[0021] The above description is only a description of the preferred embodiment of the utility model, and is not any limitation on the scope of the utility model. Any changes and modifications made by ordinary technicians in the field of the utility model based on the above disclosure shall fall within the scope of protection of the claims.

Claims

1. A high-side drive circuit of a push-pull isolated power supply, characterized in that: It includes a charging tube QC, a discharging tube QD, resistors R1 to R10, a diode D5, a diode D6, a transistor Q1, a transistor Q2, and isolation optical coupling components U5 and U6; The first end of the isolation optocoupler element U5 is connected to the 12V voltage through the resistor R6, the second end is connected to the collector of the transistor Q1, the third end is connected to the third end of the charging tube QC, and the fourth end is connected to the isolation power supply 12V1 through the resistor R4; the base of the transistor Q1 is connected to the first end of the resistor R9 and the first end of the resistor R10 at the same time, the second end of the resistor R9 is connected to the charging switch signal CHA-DRV, and the second end of the resistor R10 and the emitter of the transistor Q1 are both grounded; The first end of the isolation optical coupling element U6 is connected to the 12V voltage through the resistor R5, the second end is connected to the collector of the transistor Q2, the third end is connected to the third end of the discharge tube QD, and the fourth end is connected to the isolation power supply 12V2 through the resistor R3; the base of the transistor Q2 is connected to the first end of the resistor R7 and the first end of the resistor R8 at the same time, the second end of the resistor R7 is connected to the discharge switch signal DIS-DRV, and the second end of the resistor R8 and the emitter of the transistor Q2 are both grounded; The first end of the charging tube QC is connected to the isolated power supply BAT+, the second end is connected to the first end of the resistor R2 and the positive electrode of the diode D6, and the second end of the resistor R2 and the negative electrode of the diode D6 are both connected to the third end of the charging tube QC; The first end of the discharge tube QD is connected to the isolation power supply PACK+, the second end is connected to the first end of the resistor R1 and the anode of the diode D5, and the second end of the resistor R1 and the cathode of the diode D5 are both connected to the third end of the discharge tube QD.

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