Isolation power supply circuit based on combination of Boost and common mode inductor

Abstract

The utility model discloses an isolation power supply circuit based on combination of Boost and common mode inductance, which belongs to the field of isolation power supplies and comprises an input filtering module, a Boost module, a common mode inductance module, an output filtering module and a control and feedback module. The input filtering module is connected with an external input power supply, the input filtering module is connected with the Boost module, and the Boost module is electrically connected with the control and feedback module; the input filtering module and the Boost module are both connected with the common mode inductor module, and the common mode inductor module is electrically connected with the output filtering module. According to the utility model, the working efficiency and the power output can meet the requirements of most circuits, the efficient improvement of the voltage is realized, the common-mode noise in the circuit is effectively inhibited, and the electromagnetic compatibility is improved. The electrical isolation between the input end and the output end is realized, and the safety is improved. The utility model has the advantages of compact structure and low cost, and is suitable for miniaturized equipment.

Description

Technical Field

[0001] The utility model relates to the field of isolated power supplies, in particular to an isolated power supply circuit based on the combination of Boost voltage boosting and common mode inductance. Background Art

[0002] The main function of the isolated power supply is to achieve electrical isolation, protect the safety of equipment and personnel, and reduce electromagnetic interference. The isolated power supply isolates the high-voltage power supply from the low-voltage power supply through an isolation transformer or an isolation circuit to form a safe isolation space. Even if a fault occurs, the high-voltage power supply will not cause damage to the low-voltage power supply or the connected equipment. In the power system, the isolated power supply module can ensure that there is no direct connection between strong electricity such as high-voltage power grid and weak electricity such as control signals, avoiding interference and damage of strong electricity to weak electricity. The isolated power supply can effectively prevent the working voltage from damaging low-voltage equipment, avoiding overvoltage damage, heat loss and damage to low-voltage components. In laboratories or high-demand occasions, the isolated power supply is not connected to the ground, and the experimenter will not get an electric shock even if he touches the line, ensuring the safety of personnel. The isolated power supply can suppress electromagnetic interference between power supplies and effectively suppress leakage current, thereby improving the stability and reliability of the equipment. In electronic equipment, the isolated power supply module reduces the impact of noise on the equipment through filtering and shielding measures, especially in the isolation between analog circuits and digital circuits. Isolation power supplies are widely used in electronic devices such as computers, televisions, telephones, and in the installation and maintenance of industrial automation systems and low-voltage circuits. In areas with frequent lightning activity, isolation power supplies can isolate the high voltage and high current introduced by lightning from the internal circuits of the equipment to prevent direct damage to the equipment.

[0003] Existing isolated power supplies generally adopt mature Flyback power supply solutions, but the high cost and difficulty in transformer manufacturing affect the use of isolated power supplies. Utility Model Content

[0004] With regard to the above-mentioned problems existing in the prior art, the purpose of the present invention is to provide an isolated power supply circuit based on the combination of Boost voltage boosting and common-mode inductance, so as to solve the problems raised in the above-mentioned background technology.

[0005] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0006] An isolated power supply circuit based on the combination of Boost boost and common mode inductor, including an input filter module, a Boost boost module, a common mode inductor module, an output filter module and a control and feedback module;

[0007] The input filter module is connected to the external input power supply, the input filter module is connected to the Boost module, and the Boost module is electrically connected to the control and feedback module;

[0008] The input filter module and the Boost module are both connected to the common mode inductor module, and the common mode inductor module and the output filter module are electrically connected.

[0009] As a further solution of the utility model: the input filter module includes a socket CZ1 and a filter capacitor C1.

[0010] As a further solution of the utility model: the Boost module includes a Boost chip U1, a diode D1, a resistor R2, a resistor R3, a resistor R8 and a filter capacitor C3.

[0011] As a further solution of the utility model: the common-mode inductor module includes a common-mode inductor L1.

[0012] As a further solution of the utility model: the output filter module includes a diode D2, a capacitor C2 and a socket CZ2.

[0013] As a further solution of the present invention: the control and feedback module includes an internal control circuit of the Boost chip U1 and external feedback resistors R2, R3, R8 and diode D1.

[0014] As a further solution of the utility model: the socket CZ1 in the input filter module is connected to the external input power supply, the port 1 of the socket CZ1 is connected to the port 5 and the port 4 of the Boost chip U1 at the same time, and the port 2 of the socket CZ1 is connected to the ground terminal GND;

[0015] Port 1 and port 2 of the socket CZ1 are provided with a filter capacitor C1 in parallel.

[0016] As a further solution of the utility model: the port 2 of the Boost chip U1 in the Boost module is connected to the ground terminal GND;

[0017] Port 1 of the socket CZ1 is connected to one end of the input side of the common mode inductor L1 , and the other end of the input side of the common mode inductor L1 is connected to port 1 of the Boost chip U1 .

[0018] As a further solution of the utility model: one end of the output side of the common-mode inductor L1 in the common-mode inductor module is connected to the ground terminal GND2; the other end of the output side of the common-mode inductor L1 is connected to the positive electrode of the diode D2.

[0019] As a further solution of the utility model: the cathode of the output filter module diode D2 is connected to the port 1 of the socket CZ2, and the port 2 of the socket CZ2 is connected to the ground terminal GND2;

[0020] One end of the capacitor C2 is connected to the cathode of the diode D2, and the other end of the capacitor C2 is connected to the port 2 of the socket CZ2;

[0021] Socket CZ2 is used for connecting external output loads.

[0022] As a further solution of the utility model: the anode of the diode D1 in the control and feedback module is connected to the port 1 of the Boost chip U1;

[0023] The cathode of the diode D1 is connected to one end of the resistor R3 and one end of the resistor R8 at the same time;

[0024] The other end of the resistor R3 is connected to the port 3 of the Boost chip U1;

[0025] Port 3 of the Boost chip U1 is connected to one end of the resistor R2; the other end of the resistor R2 is connected to the ground terminal GND;

[0026] The other end of the resistor R8 is connected to the ground terminal GND;

[0027] A filter capacitor C3 is connected in parallel between both ends of the resistor R8.

[0028] Compared with the prior art, the beneficial effects of the utility model are:

[0029] The utility model can use all low-cost SMT devices to realize isolated power supply on the target product, and the working efficiency and power output can meet the needs of most circuits. The Boost boost module is used as a flyback chip. The common mode inductor module is used as a high-frequency isolation transformer to improve electromagnetic compatibility. The common mode inductor and output filter module realize electrical isolation between the input and output ends to improve safety. The utility model has a compact structure and low cost and is suitable for miniaturized equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 The schematic diagram of the circuit structure of the isolated power supply circuit based on the combination of Boost boost and common-mode inductance disclosed in the embodiment. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model; it is obvious that the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0032] In the description of the present utility model, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "provided with", "connected", and "connected" should be understood in a broad sense; for example, it can be a fixed connection, a detachable connection, or an integral connection, a mechanical connection, or an electrical connection, a direct connection, or an indirect connection through an intermediate medium, or the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0033] See also Figure 1 , an isolated power supply circuit based on the combination of Boost boost and common mode inductor, including an input filter module, a Boost boost module, a common mode inductor module, an output filter module and a control and feedback module;

[0034] The input filter module is connected to the external input power supply, the input filter module is connected to the Boost module, and the Boost module is electrically connected to the control and feedback module;

[0035] The input filter module and the Boost module are both connected to the common mode inductor module, and the common mode inductor module and the output filter module are electrically connected.

[0036] The input filter module includes a socket CZ1 and a filter capacitor C1. The Boost module includes a Boost chip U1, a diode D1, a resistor R2, a resistor R3, a resistor R8 and a filter capacitor C3. The common mode inductor module includes a common mode inductor L1. The output filter module includes a diode D2, a capacitor C2 and a socket CZ2. The control and feedback module includes an internal control circuit of the Boost chip U1 and external feedback resistors R2, R3 and R8.

[0037] The socket CZ1 is connected to the external input power supply, the port 1 of the socket CZ1 is connected to the port 5 and the port 4 of the Boost chip U1, and the port 2 of the socket CZ1 is connected to the ground terminal GND; the main function of the Boost chip U1 is to increase the input voltage to a higher output voltage. It increases the lower input voltage such as the battery voltage to the higher voltage required by the device. The Boost chip U1 used in the utility model is mainly used as a flyback chip.

[0038] Port 1 and port 2 of the socket CZ1 are connected in parallel with a filter capacitor C1; the input voltage enters the circuit through the socket CZ1, and the filter capacitor C1 filters out high-frequency noise in the input power supply.

[0039] Port 2 of the Boost chip U1 is connected to the ground terminal GND;

[0040] Port 1 of the socket CZ1 is connected to one end of the input side of the common-mode inductor L1, and the other end of the input side of the common-mode inductor L1 is connected to port 1 of the Boost chip U1; the input voltage enters the Boost module through the common-mode inductor L1, and the common-mode inductor L1 serves as a high-frequency isolation transformer.

[0041] One end of the output side of the common mode inductor L1 is connected to the ground terminal GND2; the other end of the output side of the common mode inductor L1 is connected to the positive electrode of the diode D2;

[0042] The cathode of the diode D2 is connected to the port 1 of the socket CZ2, and the port 2 of the socket CZ2 is connected to the ground terminal GND2;

[0043] One end of the capacitor C2 is connected to the cathode of the diode D2, and the other end of the capacitor C2 is connected to the port 2 of the socket CZ2;

[0044] Socket CZ2 is connected to an external output load and used for output power supply. The Boost module increases the input voltage to the required voltage through the switch action of the Boost chip U1. The boosted voltage is transmitted to the output end through the diode D2 and the capacitor C2, and the filter capacitor C2 filters out the high-frequency noise at the output end.

[0045] The anode of the diode D1 is connected to port 1 of the Boost chip U1;

[0046] The cathode of the diode D1 is connected to one end of the resistor R3 and one end of the resistor R8 at the same time;

[0047] The other end of the resistor R3 is connected to the port 3 of the Boost chip U1;

[0048] Port 3 of the Boost chip U1 is connected to one end of the resistor R2; the other end of the resistor R2 is connected to the ground terminal GND;

[0049] The other end of the resistor R8 is connected to the ground terminal GND;

[0050] A filter capacitor C3 is connected in parallel at both ends of the resistor R8;

[0051] The control and feedback module detects the output voltage through resistors R2, R3, and R8, and adjusts the working state of the Boost chip U1 to keep the output voltage stable. The socket CZ1 inputs a 5V power supply, which is filtered by the filter capacitor C1 and input to the power pin and enable pin of the Boost chip U1. The Boost switch output pin of the Boost chip U1 is connected to a small common-mode filter inductor L1. According to the classic Boost principle, a higher voltage can be output at the cathode of the diode D1. In this design, the voltage value is 0.6V divided by resistors R3 and R2 and sent to the feedback single end of the Boost chip U1, and finally the voltage is stabilized at 12V, and filtered by the filter capacitor C3 for other devices that need 10V. If the power output of the filter capacitor C3 has no load, a dummy load R8=1kΩ needs to be added to discharge the power supply of the filter capacitor C3 to avoid the power supply of the filter capacitor C3 maintaining a high level and causing no continuous output on the isolated secondary side.

[0052] Since L1 is a common-mode inductor, if we regard it as a transformer, its two terminals with the same name are at the same end, for example, both on the right. The voltage output on the primary side is 10V, which is 5V higher than the 5V power input terminal. A 5V power output is also generated on the secondary side at capacitor C2, and the GND2 of capacitor C2 is isolated from the GND of the primary side. This can meet some low-power scenarios.

[0053] The utility model can use all low-cost SMT components to realize isolated power supply on the target product, and the working efficiency and power output can basically meet most requirements. The voltage is efficiently increased through the Boost step-up module. The common-mode inductor L1 is used as a high-frequency isolation transformer, and the common-mode inductor and the output filter module are used to achieve electrical isolation between the input and output ends, thereby improving safety. The utility model has a compact circuit structure and low cost, and is suitable for miniaturized equipment.

[0054] It is obvious to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention, and any figure mark in the claims should not be regarded as limiting the claims involved.

[0055] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. An isolated power supply circuit based on Boost boost and common mode inductance, characterized in that: It includes input filter module, Boost module, common mode inductor module, output filter module and control and feedback module; The input filter module is connected to the external input power supply, the input filter module is connected to the Boost module, and the Boost module is electrically connected to the control and feedback module; The input filter module and the Boost module are both connected to the common mode inductor module, and the common mode inductor module and the output filter module are electrically connected.

2. The isolated power supply circuit based on Boost and common mode inductance according to claim 1 is characterized in that: The input filter module includes a socket CZ1 and a filter capacitor C1.

3. The isolated power supply circuit based on Boost and common mode inductance according to claim 2 is characterized in that: The Boost module includes a Boost chip U1, a diode D1, a resistor R2, a resistor R3, a resistor R8 and a filter capacitor C3, and the control and feedback module includes an internal control circuit of the Boost chip U1 and external feedback resistors R2, R3, R8 and a diode D1.

4. The isolated power supply circuit based on Boost and common mode inductance according to claim 3 is characterized in that: The common-mode inductor module includes a common-mode inductor L1.

5. The isolated power supply circuit based on Boost and common mode inductance according to claim 4 is characterized in that: The output filter module includes a diode D2, a capacitor C2 and a socket CZ2.

6. The isolated power supply circuit based on Boost voltage boost and common mode inductance according to claim 5, characterized in that: The socket CZ1 in the input filter module is connected to the external input power supply, the port 1 of the socket CZ1 is connected to the port 5 and the port 4 of the Boost chip U1, and the port 2 of the socket CZ1 is connected to the ground terminal GND; Port 1 and port 2 of the socket CZ1 are connected in parallel with a filter capacitor C1.

7. The isolated power supply circuit based on Boost and common mode inductance according to claim 6, characterized in that: Port 2 of the Boost chip U1 in the Boost module is connected to the ground terminal GND; Port 1 of the socket CZ1 is connected to one end of the input side of the common mode inductor L1 , and the other end of the input side of the common mode inductor L1 is connected to port 1 of the Boost chip U1 .

8. The isolated power supply circuit based on Boost and common mode inductance according to claim 7, characterized in that: One end of the output side of the common-mode inductor L1 in the common-mode inductor module is connected to the ground terminal GND2; the other end of the output side of the common-mode inductor L1 is connected to the anode of the diode D2.

9. The isolated power supply circuit based on Boost voltage boost and common mode inductance according to claim 8, characterized in that: The cathode of the output filter module diode D2 is connected to the port 1 of the socket CZ2, and the port 2 of the socket CZ2 is connected to the ground terminal GND2; One end of the capacitor C2 is connected to the cathode of the diode D2, and the other end of the capacitor C2 is connected to the port 2 of the socket CZ2; Socket CZ2 is used for connecting external output loads.

10. The isolated power supply circuit based on Boost voltage boost and common mode inductance according to claim 9, characterized in that: The anode of the diode D1 in the control and feedback module is connected to the port 1 of the Boost chip U1; The cathode of the diode D1 is connected to one end of the resistor R3 and one end of the resistor R8 at the same time; The other end of the resistor R3 is connected to the port 3 of the Boost chip U1; Port 3 of the Boost chip U1 is connected to one end of the resistor R2; the other end of the resistor R2 is connected to the ground terminal GND; The other end of the resistor R8 is connected to the ground terminal GND; A filter capacitor C3 is connected in parallel between both ends of the resistor R8.

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