Isolated DC-DC circuit and isolated DC-DC power supply

Abstract

The present invention discloses an isolated DC-DC circuit and an isolated DC-DC power supply. The isolated DC-DC circuit includes: a DC voltage input terminal for connecting a first DC voltage; a DC voltage output terminal for outputting a second DC voltage; an electric energy storage device; a main control circuit for outputting a charging control signal and a discharging control signal; a charging control circuit, wherein a controlled terminal of the charging control circuit is connected to a first control terminal of the main control circuit, and an output terminal of the charging control circuit is connected to the electric energy storage device, so as to work when receiving a charging control signal, so as to output the connected DC voltage to the electric energy storage device for energy storage; a discharging control circuit, wherein a controlled terminal of the charging control circuit is connected to a second control terminal of the main control circuit, and an input terminal of the charging control circuit is connected to the electric energy storage device; the discharging control circuit is used to work when receiving a discharging control signal, so as to control the discharging of the electric energy storage device, and output a second DC voltage to the DC voltage output terminal. The isolated DC-DC circuit of the present invention can block the ring loop of noise and floating potential difference.

Description

Technical Field

[0001] The present invention relates to the technical field of power supply, and in particular to an isolated DC-DC circuit and an isolated DC-DC power supply. Background Art

[0002] In current circuits, transformer-based isolated DC-DC circuits are used to achieve electrical isolation between electronic devices. Since the transformer achieves energy exchange between its primary and secondary through electromagnetic conversion, this conversion method will not only couple the noise connected to its primary into the DC power output by its secondary, but also generate electromagnetic noise and couple itself. When the DC power is output to the signal loop, and there is also a transformer in the signal loop and the signal is output to the power supply (the power supply is connected to the primary of the transformer in the isolated DC-DC circuit), a ring loop of noise will be formed, which will continuously affect the quality of the signal output by the signal loop.

[0003] In addition, in existing isolated DC-DC circuits, due to the internal resistance and parasitic distributed parameters of the circuit, there will be a floating potential difference between the primary and secondary of the transformer, and the floating potential difference will also affect the quality of the output signal along the ring loop. Summary of the invention

[0004] The main object of the present invention is to provide an isolated DC-DC circuit for blocking the ring loop of noise and floating potential difference.

[0005] To achieve the above object, the present invention provides an isolated DC-DC circuit. The isolated DC-DC circuit comprises:

[0006] A DC voltage input terminal, used for receiving a first DC voltage;

[0007] A DC voltage output terminal, used for outputting a second DC voltage;

[0008] Electrical energy storage;

[0009] A main control circuit, used for outputting a charging control signal and a discharging control signal;

[0010] A charging control circuit, wherein a controlled end of the charging control circuit is connected to the first control end of the main control circuit, an output end of the charging control circuit is connected to the electric energy storage device, and the charging control circuit is configured to operate upon receiving the charging control signal to output the connected DC voltage to the electric energy storage device for energy storage;

[0011] A discharge control circuit, wherein a controlled end of the discharge control circuit is connected to the second control end of the main control circuit, and an input end of the discharge control circuit is connected to the electric energy storage device; the discharge control circuit is configured to operate upon receiving the discharge control signal to control the discharge of the electric energy storage device and output the second DC voltage to the DC voltage output end.

[0012] Optionally, the charging control circuit includes:

[0013] a first switch circuit, wherein an input end of the first switch circuit is connected to an input end of the charging control circuit, an output end of the first switch circuit is connected to an output end of the charging control circuit, and a controlled end of the first switch circuit is connected to a controlled end of the charging control circuit;

[0014] The discharge control circuit comprises:

[0015] a second switch circuit, wherein the input end of the second switch circuit is connected to the input end of the discharge control circuit, the output end of the second switch circuit is connected to the output end of the discharge control circuit, and the controlled end of the second switch circuit is connected to the controlled end of the discharge control circuit; wherein,

[0016] When receiving the charging control signal, the first switch circuit is closed and the second switch circuit is opened, so as to output the connected DC voltage to the electric energy storage device for energy storage;

[0017] When the discharge control signal is received, the first switch circuit is opened and the second switch circuit is closed to control the discharge of the electric energy storage device and output the second DC voltage to the DC voltage output terminal.

[0018] Optionally, there are multiple electric energy storage devices, and the multiple electric energy storage devices are arranged in parallel.

[0019] Optionally, the number of the first switch circuits and the second switch circuits corresponds to the number of the plurality of electric energy storage devices, and each of the first switch circuits, one electric energy storage device and one second switch circuit constitute an isolated DC-DC unit;

[0020] The isolated DC-DC units are arranged in parallel.

[0021] Optionally, the main control circuit is used to control the first switch circuit to work in time-sharing mode;

[0022] Alternatively, the first switch circuits are controlled to operate simultaneously.

[0023] Optionally, the main control circuit is used to control the second switch circuit to work in time-sharing mode;

[0024] Alternatively, the second switch circuits are controlled to operate simultaneously.

[0025] Optionally, the number of the first switch circuits and the second switch circuits corresponds to the number of the plurality of electric energy storage devices, and each of the first switch circuits, one electric energy storage device and one second switch circuit constitute an isolated DC-DC unit;

[0026] The isolated DC-DC units are arranged in series.

[0027] Optionally, the main control circuit is used to control each of the first switch circuits to work in time-sharing mode; and

[0028] The second switch circuits are controlled to work in time sharing.

[0029] Optionally, the isolated DC-DC circuit also includes a first DC-DC circuit; the input end of the first DC-DC circuit is connected to the DC voltage input end, and the output end of the first DC-DC circuit is connected to the input end of the charging control circuit; the first DC-DC circuit is used to output the connected first DC voltage to the charging control circuit after voltage conversion.

[0030] The present invention also provides an isolated DC-DC power supply, the DC-DC power supply comprising a power supply and the isolated DC-DC circuit as described above;

[0031] The output end of the power supply is connected to the input end of the isolated DC-DC circuit.

[0032] The isolated DC-DC circuit of the present invention is provided with a DC voltage input terminal, a DC voltage output terminal, a main control circuit, an electric energy storage device, a charging control circuit and a second charging and discharging circuit, and outputs a charging control signal and a discharging control signal through a main control board to respectively control the operation of the charging control circuit and the discharging control circuit, so that the charging control circuit can output the connected DC voltage to the electric energy storage device, and the discharging control circuit can control the discharging of the electric energy storage device and output a second DC voltage to the DC voltage output terminal. When the isolated DC-DC circuit of the present invention puts the electric energy storage device in an energy storage state through the charging control circuit, the electric energy storage device is disconnected from the DC voltage output terminal through the discharging control circuit, so that the noise input to the DC voltage input terminal cannot be output to the load through the DC voltage output terminal; and when the electric energy storage device is controlled to discharge through the discharging control circuit, the input terminal of the electric energy storage device is disconnected from the DC voltage input terminal through the charging control circuit, so that the noise in the load connected to the output terminal cannot be reversely transmitted to the power supply connected to the DC voltage input terminal, thereby blocking the noise transmission path between the DC voltage input terminal and the DC voltage output terminal. Since no transformer is used, there will be no floating potential difference and noise generated by electromagnetic conversion, and the noise and floating potential difference generated by the transformer in the signal loop will not continue to be output, thereby blocking the ring loop of transmission noise and floating potential difference. Moreover, after the isolated DC-DC circuit of the present invention is applied to the isolated DC-DC power supply, compared with the traditional DC-DC power supply that uses a transformer to achieve isolation, the isolated DC-DC power supply used by the present invention itself will not generate electromagnetic interference. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0034] Figure 1 It is a functional module schematic diagram of an isolated DC-DC circuit according to an embodiment of the present invention;

[0035] Figure 2 A schematic diagram of the circuit structure of another embodiment of the isolated DC-DC circuit of the present invention;

[0036] Figure 3 A schematic diagram of the circuit structure of another embodiment of the isolated DC-DC circuit of the present invention;

[0037] Figure 4 A schematic diagram of the circuit structure of another embodiment of the isolated DC-DC circuit of the present invention;

[0038] Figure 5 It is a functional module diagram of the latter embodiment of the electromagnetic DC-DC circuit of the prior art;

[0039] Figure 6 It is a functional module diagram of the isolated DC-DC circuit of the present invention applying the latter embodiment.

[0040] Description of Figure Numbers:

[0041] Label name Label name 10 DC voltage input terminal 50 Discharge control circuit 20 DC voltage output 51 Second switch circuit C1 Energy storage 60 First DC-DC circuit 30 Main control circuit VCC1 First DC voltage 40 Charging control circuit VCC2 Second DC voltage 41 First switch circuit C2 Second energy storage

[0042] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0043] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0044] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0045] In the present invention, unless otherwise clearly specified and limited, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0046] In addition, in the present invention, descriptions such as "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0047] The present invention provides an isolated DC-DC circuit which can be applied to an isolated switching power supply.

[0048] Reference Figures 1 to 6 In one embodiment of the present invention, the isolated DC-DC circuit comprises:

[0049] A DC voltage input terminal 10, used for receiving a first DC voltage VCC1;

[0050] A DC voltage output terminal 20, used for outputting a second DC voltage VCC2;

[0051] Electric energy storage C1;

[0052] A main control circuit 30, used for outputting a charging control signal and a discharging control signal;

[0053] A charging control circuit 40, wherein a controlled end of the charging control circuit 40 is connected to the first control end of the main control circuit 30, and an output end of the charging control circuit 40 is connected to the electric energy storage C1. The charging control circuit 40 is configured to work upon receiving the charging control signal to output the connected DC voltage to the electric energy storage C1 for energy storage;

[0054] The discharge control circuit 50 has a controlled end connected to the second control end of the main control circuit 30, and an input end of the discharge control circuit 50 is connected to the electric energy storage device C1; the discharge control circuit 50 is used to operate when receiving the discharge control signal to control the discharge of the electric energy storage device C1 and output the second DC voltage VCC2 to the DC voltage output end 20.

[0055] In this embodiment, the DC voltage input terminal 10 can be connected to the output terminal of an AC-DC circuit such as a rectifier circuit or a DC-DC circuit to access the first DC voltage VCC1 outputted therefrom. The DC voltage output terminal 20 can be the output terminal of the isolated DC-DC circuit of the present invention, and can be connected to the power supply terminal of a functional module such as a signal loop.

[0056] The electric energy storage C1 can be implemented by a capacitor or a battery. The electric energy storage C1 can be used to store energy of the connected DC voltage, and can also output the stored electric energy in the form of DC voltage when connected to the discharge circuit.

[0057] The main control circuit 30 can be implemented by a microprocessor such as MCU, DSP or FPG, or can also be a CPU main control chip. The main control circuit 30 can be integrated with corresponding hardware circuits and software programs or algorithms, and store various data, and can be connected to other functional circuits in the isolated DC-DC circuit through a connection port to output corresponding signals to control the operation of other functional circuits. In this embodiment, the charging control signal and the discharging control signal can be current signals or voltage signals in the form of high and low levels. The main control circuit 30 can achieve a variety of output effects of the charging control signal and the discharging control signal by running corresponding programs, such as a timing program; for example, the output time of the charging control signal and the discharging control signal can be set respectively to achieve the effect of time-sharing output and alternating output, or the output time of the two can be set to be simultaneous to achieve the effect of synchronous output.

[0058] Both the charging control circuit 40 and the discharging control circuit 50 can be constructed and implemented by one or more combinations of electric control switch devices such as relays, contactors, circuit breakers, and reed switches. The charging control circuit 40 can be arranged between the input end of the electric energy storage device C1 and the DC voltage input end 10; and the discharging control circuit 50 can be arranged between the output end of the electric energy storage device C1 and the output end of the DC voltage output end 20. When receiving the corresponding charging / discharging control signal, both the charging control circuit 40 and the discharging control circuit 50 can control the components such as the iron core, the tripping mechanism or the opening and closing mechanism therein to perform corresponding actions to make themselves in the corresponding closed / open state. Among them, the charging control circuit 40 can output the first DC voltage VCC1 connected to the DC voltage input end 10 to the electric energy storage device C1 when closed to charge it. The discharging control circuit 50 is used to connect the electric energy storage device C1 to the DC voltage output end 20 when closed, so that the second DC voltage VCC2 output by the discharge output can be output to the DC voltage output end 20 to power the subsequent functional module functions. Since there is no direct electrical connection between the second DC voltage VCC2 and the first DC voltage VCC1 , an electrical isolation effect can be achieved.

[0059] It is understandable that the charging control circuit 40 and the discharging control circuit 50 can realize various charging and discharging effects of the electric energy storage C1 by cooperating with the main control circuit 30. For example, the charging control signal and the discharging control signal can be outputted in time-sharing manner so that when the charging control circuit 40 is closed, the discharging control circuit 50 is turned on, so that the electric energy storage C1 is only in the charging state at this time; or, when the charging control circuit 40 is turned on, the discharging control circuit 50 is closed, so that the electric energy storage C1 is only in the discharging state at this time; or, after the charging control circuit 40 is turned on, the discharging control circuit 50 is controlled to be closed after a preset time, so as to realize the effect of delayed output. It is also understandable that the main control circuit 30 can also realize the voltage conversion effect of boosting / reducing by controlling the operating frequencies of the charging control circuit 40 and the discharging control circuit 50 respectively.

[0060] In an optional embodiment, a second electric energy storage C2 may be provided between the electric energy storage C1 (explained as "the first electric energy storage C1" in this embodiment) and the DC voltage output terminal 20. In this case, the discharge control circuit 50 is provided between the two electric energy storages. When the discharge control circuit 50 is in operation, the second DC voltage VCC2 discharged and output by the first electric energy storage C1 may be loaded onto the two ends of the second electric energy storage C2 to increase the discharge voltage of the second electric energy storage C2, thereby forming an amplifier circuit.

[0061] The isolated DC-DC circuit of the present invention is provided with a DC voltage input terminal 10, a DC voltage output terminal 20, a main control circuit 30, an electric energy storage device C1, a charging control circuit 40 and a second charging and discharging circuit, and outputs a charging control signal and a discharging control signal through the main control board to control the operation of the charging control circuit 40 and the discharging control circuit 50 respectively, so that the charging control circuit 40 can output the connected DC voltage to the electric energy storage device C1, and the discharging control circuit 50 can control the electric energy storage device C1 to discharge, and output the second DC voltage VCC2 to the DC voltage output terminal 20. When the isolated DC-DC circuit of the present invention puts the electric energy storage device C1 in an energy storage state through the charging control circuit 40, the electric energy storage device C1 is disconnected from the DC voltage output terminal 20 through the discharging control circuit 50, so that the noise input by the DC voltage input terminal 10 cannot be output to the load through the DC voltage output terminal 20; and when the electric energy storage device C1 is controlled to discharge through the discharging control circuit 50, the input terminal of the electric energy storage device C1 is disconnected from the DC voltage input terminal 10 through the charging control circuit 40, so that the noise in the load connected to the output terminal cannot be reversely transmitted to the load connected to the DC voltage input terminal 10. In the power supply, the noise transmission path between the DC voltage input terminal 10 and the DC voltage output terminal 20 is blocked, and since no transformer is used, there will be no floating potential difference and noise generated by electromagnetic conversion, and the noise and floating potential difference generated by the transformer in the signal loop will not continue to be output, thereby blocking the ring loop of transmission noise and floating potential difference. Moreover, after the isolated DC-DC circuit of the present invention is applied to the isolated DC-DC power supply, compared with the traditional DC-DC power supply that uses a transformer to achieve isolation, the isolated DC-DC power supply used by the present invention itself will not generate electromagnetic interference.

[0062] Reference Figures 1 to 6 In one embodiment of the present invention, the charging control circuit 40 includes:

[0063] a first switch circuit 41, wherein an input end of the first switch circuit 41 is connected to an input end of the charging control circuit 40, an output end of the first switch circuit 41 is connected to an output end of the charging control circuit 40, and a controlled end of the first switch circuit 41 is connected to a controlled end of the charging control circuit 40;

[0064] The discharge control circuit 50 comprises:

[0065] A second switch circuit 51, wherein the input end of the second switch circuit 51 is connected to the input end of the discharge control circuit 50, the output end of the second switch circuit 51 is connected to the output end of the discharge control circuit 50, and the controlled end of the second switch circuit 51 is connected to the controlled end of the discharge control circuit 50; wherein,

[0066] When receiving the charging control signal, the first switch circuit 41 is closed and the second switch circuit 51 is opened to output the connected DC voltage to the electric energy storage device C1 for energy storage;

[0067] When receiving the discharge control signal, the first switch circuit 41 is opened and the second switch circuit 51 is closed to control the discharge of the electric energy storage C1 and output the second DC voltage VCC2 to the DC voltage output terminal 20 .

[0068] In this embodiment, the charging control signal may include a first charging control signal for controlling the first switch circuit 41 to be closed and a second charging control signal for controlling the first switch circuit 41 to be opened; the discharging control signal may include a first discharging control signal for controlling the second switch circuit 51 to be closed and a second discharging control signal for controlling the second switch circuit 51 to be opened. When the first switch circuit 41 receives the first charging control signal, the main control circuit 30 may simultaneously output the second discharging control signal to the second switch circuit 51 to simultaneously control the first switch circuit 41 to be closed and the second switch circuit 51 to be opened; and when the first switch circuit 41 receives the second charging control signal, the main control circuit 30 may simultaneously output the first discharging control signal to the second switch circuit 51 to simultaneously control the first switch circuit 41 to be opened and the second switch circuit 51 to be closed. Such a setting enables the main control circuit 30 to switch the energy storage state and the discharging state of the electric energy storage device C1 respectively through the charging control signal and the discharging control signal, thereby realizing the isolation and voltage conversion functions of the isolated DC-DC circuit of the present invention.

[0069] In another optional embodiment, the first switch circuit 41 and the second switch circuit 51 can use a mechanical relay with contacts and a contactless optical coupler relay. When a switch device such as a mechanical relay or a reed switch is selected, the switching frequency of the first switch circuit 41 and the second switch circuit 51 should not be too high, otherwise it will affect the life of the above-mentioned switch device, and the withstand voltage of the contacts of the above-mentioned switch device determines the withstand voltage between the DC voltage and the second discharge DC voltage. When an optical coupler relay is selected, its own withstand voltage determines the withstand voltage between the DC voltage and the second discharge DC voltage, and it is preferably an optical coupler relay with low on-resistance, high off-resistance, and low off-capacitance parameters. When the electric energy storage device C1 is constructed by using a capacitor device, the switching frequency of the first switch circuit 41 and the second switch circuit 51 can be adaptively increased; when the electric energy storage device C1 is constructed by using a rechargeable battery, the switching frequency of the first switch circuit 41 and the second switch circuit 51 can be adaptively reduced according to the capacity of the rechargeable battery. Such an arrangement enables the first switch circuit 41 and the second switch circuit 51 to meet the voltage transmission requirements of the electric energy storage device C1 during charging and discharging, thereby preventing the excessive charging and discharging voltage from affecting its lifespan.

[0070] Reference Figures 1 to 6 In one embodiment of the present invention, there are multiple electric energy storage devices C1, and multiple electric energy storage devices C1 are arranged in parallel.

[0071] Furthermore, the number of the first switch circuits 41 and the second switch circuits 51 corresponds to the number of the plurality of electric energy storage devices C1, and each of the first switch circuits 41, one electric energy storage device C1 and one second switch circuit 51 constitutes an isolated DC-DC unit;

[0072] The isolated DC-DC units are arranged in parallel.

[0073] In this embodiment, in each isolated DC-DC unit, the input end of the first switch circuit 41 can be connected to the DC voltage input end 10, the output end of the first switch circuit 41 can be connected to the input end of the electric energy storage C1; the output end of the electric energy storage C1 can be connected to the input end of the second switch circuit 51; the output end of the second switch circuit 51 can be connected to the DC voltage output end 20. The main control circuit 30 can achieve different voltage conversion effects by controlling the on / off states of the first switch circuit 41 and the second switch circuit 51 in each isolated DC-DC unit.

[0074] For example: in one control cycle, the main control circuit 30 can output only one set of discharge control signals to one of the multiple isolated DC-DC units at a time to control it to be in a discharge state, and at the same time output charging control signals to other isolated DC-DC units respectively, so that the other isolated DC-DC units are in a charging state at this time, and when the discharge time of the isolated DC-DC unit reaches a preset time, it can switch to control other isolated DC-DC units to enter the discharge state, so that the main control circuit 30 controls all isolated DC-DC units to complete a discharge, and then enters the next control cycle; in this way, each isolated DC-DC unit can be charged and discharged in turn, so that the isolated DC-DC unit connected in parallel can always output the second DC voltage VCC2, and for each additional isolated DC-DC unit set in parallel, the voltage transmission efficiency is doubled. Of course, multiple isolated DC-DC units can also be controlled to discharge at the same time to increase the voltage value of the second DC voltage VCC2 to multiple times when there is only one discharge.

[0075] Reference Figures 1 to 6 In one embodiment of the present invention, the main control circuit 30 is used to control the first switch circuit 41 to work in time-sharing mode;

[0076] Alternatively, the first switch circuits 41 are controlled to work simultaneously.

[0077] Furthermore, the main control circuit 30 is used to control the second switch circuit 51 to work in time-sharing mode;

[0078] Alternatively, the second switch circuits 51 are controlled to work simultaneously.

[0079] In this embodiment, when there are multiple isolated DC-DC units arranged in parallel in the isolated DC-DC circuit of the present invention, the main control circuit 30 can simultaneously output a charging control signal to the first switch circuit 41 in each isolated DC-DC unit to control all the first switch circuits 41 to be opened / closed at the same time; or, it can output a corresponding charging control signal to each first switch circuit 41 to control each first switch circuit 41 to be in a corresponding open / closed state. The control logic of the main control circuit 30 for the second switch circuit 51 can be consistent with the above-mentioned first switch circuit 41, which will not be repeated here. It should be noted that there is no necessary logical relationship between the control of the main control circuit 30 for the two. For example, when the first switch circuit 41 is under simultaneous control, the second switch circuit 51 can be under simultaneous control or under time-sharing control. By making the main control circuit 30 control each first switch circuit 41 and each second switch circuit 51 to work simultaneously / time-sharingly, the energy storage device C1 in each isolated DC-DC unit can be further controlled to be in a corresponding energy storage state or discharge state, thereby achieving a variety of voltage effects of the second DC voltage VCC2 output by the isolated DC-DC circuit of the present invention.

[0080] Reference Figures 1 to 6 In one embodiment of the present invention, the number of the first switch circuits 41 and the first switch circuits 41 corresponds to the number of the plurality of the electric energy storage devices C1, and each of the first switch circuits 41, one of the electric energy storage devices C1 and one of the second switch circuits 51 constitutes an isolated DC-DC unit;

[0081] The isolated DC-DC units are arranged in series.

[0082] In this embodiment, the input end of the first switch circuit 41 in each isolated DC-DC unit is the input end of the isolated DC-DC unit, the output end of the first switch circuit 41 is connected to the input end of the electric energy storage C1, the output end of the electric energy storage C1 is connected to the input end of the second switch circuit 51, and the output end of the second switch circuit 51 is the output end of the isolated DC-DC unit. The input end of each isolated DC-DC unit can be connected to the output end of the previous isolated DC-DC unit, and its output end can be connected to the input end of the next isolated DC-DC to achieve a series arrangement between the units. This embodiment is described by taking each isolated DC-DC unit as an example in which a first switch circuit 41, an electric energy storage C1 and a second switch circuit 51 are provided.

[0083] Since each series-connected isolated DC-DC unit can perform corresponding step-up / step-down conversion under the control of the main control circuit 30, multiple series-connected isolated DC-DC units can further perform multi-stage step-up conversion or multi-stage step-down conversion on the first DC voltage VCC1 connected to the first isolated DC-DC unit and then output it under the control of the main control circuit 30. It can also be understood that each isolated DC-DC unit is used to output the connected first DC voltage VCC1 in the form of a second DC voltage VCC2 after electrical isolation and voltage conversion, and the second DC voltage VCC2 output by the previous isolated DC-DC unit is the first DC voltage VCC1 connected to the next isolated DC-DC unit. Therefore, by arranging the isolated DC-DC units in series, the first DC voltage VCC1 connected to the first isolated DC-DC unit can be output after multi-stage electrical isolation to achieve a better electrical isolation effect.

[0084] Of course, in other optional embodiments, each isolated DC-DC unit arranged in series may also include multiple isolated DC-DC branches arranged in parallel (each isolated DC-DC branch may include a first switch circuit 41, an energy storage device C1 and a second switch circuit 51 arranged in series in sequence), that is, in addition to the function of electrical isolation, each isolated DC-DC unit can also realize uninterrupted power transmission of each isolated DC-DC unit under the control of the main control circuit 30, thereby improving the overall transmission efficiency after series connection.

[0085] Reference Figures 1 to 6 In one embodiment of the present invention, the isolated DC-DC circuit further includes a first DC-DC circuit 60; an input end of the first DC-DC circuit 60 is connected to the DC voltage input end 10, and an output end of the first DC-DC circuit 60 is connected to an input end of the charging control circuit 40; the first DC-DC circuit 60 is used to output the connected first DC voltage VCC1 to the charging control circuit 40 after voltage conversion.

[0086] In this embodiment, the first DC-DC circuit 60 can be implemented by an isolated DC-DC circuit of the type such as an electromagnetic DC-DC circuit or an optically coupled DC-DC circuit. When the first DC-DC circuit 60 uses an optically coupled DC-DC circuit, the first DC-DC circuit 60 can output the DC voltage outputted from the DC voltage output terminal 20 to the input terminal of the charging control circuit 40 after preliminary voltage conversion, so that the withstand voltage of the first switch circuit 41 and the second switch circuit 51 only needs to meet the voltage outputted by the first DC-DC circuit 60, which can greatly reduce the withstand voltage level of the switch devices used in the first switch circuit 41 and the second switch circuit 51, which is conducive to expanding the selection of switch devices in the first switch circuit 41 and the second switch circuit 51 while reducing the circuit cost.

[0087] When an electromagnetic DC-DC circuit is used to realize the above, the electromagnetic DC-DC circuit is used to output the DC voltage connected to the primary through the secondary through the DC voltage input terminal 10 to the first switch circuit 41 after electromagnetic conversion. When the first switch circuit 41 receives the charging control signal, it outputs the DC voltage to the energy storage device C1. At this time, since no transformer is used and there is no electromagnetic conversion process, the noise and floating potential difference brought by the electromagnetic DC-DC circuit will not be output to the subsequent circuit through the energy storage device C1, thereby solving the problem that the noise and floating potential difference brought by the electromagnetic DC-DC circuit affect the output signal.

[0088] The present invention also provides an isolated DC-DC power supply, the DC-DC power supply comprising a power supply and the isolated DC-DC circuit as described above;

[0089] The output end of the power supply is connected to the input end of the isolated DC-DC circuit.

[0090] The detailed structure of the isolated DC-DC circuit can refer to the above-mentioned embodiment, which will not be described in detail here; it can be understood that since the above-mentioned isolated DC-DC circuit is used in the isolated DC-DC power supply, the embodiment of the isolated DC-DC power supply includes all the technical solutions of all the embodiments of the above-mentioned isolated DC-DC circuit, and the technical effects achieved are also exactly the same, which will not be described in detail here.

[0091] In this embodiment, the output end of the power supply can be connected to the input end of the isolated DC-DC circuit, that is, connected to the DC voltage input end 10 in the isolated DC-DC circuit, so as to output a DC voltage to the DC voltage input end 10 .

[0092] The above descriptions are only optional embodiments of the present invention, and are not intended to limit the patent scope of the present invention. All equivalent structural changes made using the contents of the present invention's specification and drawings, or directly / indirectly applied in other related technical fields, are included in the patent protection scope of the present invention.

Claims

1. An isolated DC-DC circuit, characterized in that: The isolated DC-DC circuit comprises: A DC voltage input terminal, used for receiving a first DC voltage; A DC voltage output terminal, used for outputting a second DC voltage; Electrical energy storage; A main control circuit, used for outputting a charging control signal and a discharging control signal; A charging control circuit, wherein a controlled end of the charging control circuit is connected to the first control end of the main control circuit, an output end of the charging control circuit is connected to the electric energy storage device, and the charging control circuit is configured to operate upon receiving the charging control signal to output the connected DC voltage to the electric energy storage device for energy storage; a discharge control circuit, wherein a controlled end of the discharge control circuit is connected to the second control end of the main control circuit, and an input end of the discharge control circuit is connected to the electric energy storage device; the discharge control circuit is configured to operate upon receiving the discharge control signal to control the discharge of the electric energy storage device and output the second DC voltage to the DC voltage output end; To block the loop of transmission noise and floating potential difference; Wherein, the charging control circuit comprises: a first switch circuit, wherein an input end of the first switch circuit is connected to an input end of the charging control circuit, an output end of the first switch circuit is connected to an output end of the charging control circuit, and a controlled end of the first switch circuit is connected to a controlled end of the charging control circuit; The discharge control circuit comprises: a second switch circuit, wherein the input end of the second switch circuit is connected to the input end of the discharge control circuit, the output end of the second switch circuit is connected to the output end of the discharge control circuit, and the controlled end of the second switch circuit is connected to the controlled end of the discharge control circuit; wherein, When receiving the charging control signal, the first switch circuit is closed and the second switch circuit is opened, so as to output the connected DC voltage to the electric energy storage device for energy storage; When receiving the discharge control signal, the first switch circuit is opened and the second switch circuit is closed to control the discharge of the electric energy storage device and output the second DC voltage to the DC voltage output terminal; The number of the electric energy storage devices is multiple, and the multiple electric energy storage devices are arranged in parallel or in series; The number of the first switch circuits and the second switch circuits corresponds to the number of the plurality of electric energy storage devices, and each of the first switch circuits, one electric energy storage device and one second switch circuit constitute an isolated DC-DC unit; The isolated DC-DC units are arranged in parallel or in series; When the isolated DC-DC units are arranged in parallel, the main control circuit is used to control the first switch circuit to work in time-sharing mode; Alternatively, controlling the first switch circuits to work simultaneously; When the isolated DC-DC units are arranged in parallel, the main control circuit is used to control the second switch circuit to work in time sharing; Alternatively, controlling the second switch circuits to work simultaneously; When the isolated DC-DC units are arranged in series, the main control circuit is used to control the first switch circuits to work in time-sharing mode; and The second switch circuits are controlled to work in time sharing.

2. The isolated DC-DC circuit according to claim 1, characterized in that: The isolated DC-DC circuit also includes a first DC-DC circuit; the input end of the first DC-DC circuit is connected to the DC voltage input end, and the output end of the first DC-DC circuit is connected to the input end of the charging control circuit; the first DC-DC circuit is used to output the connected first DC voltage to the charging control circuit after voltage conversion.

3. An isolated DC-DC power supply, characterized in that: The DC-DC power supply comprises a power supply and an isolated DC-DC circuit as claimed in any one of claims 1 to 2; The output end of the power supply is connected to the input end of the isolated DC-DC circuit.

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