Wide DC drive circuit

Abstract

The invention discloses a wide DC drive circuit, which comprises a DC conversion circuit, a controller, an auxiliary power supply circuit, a first interface end and a second interface end, the first interface end is used for connecting the rechargeable battery with the DC conversion circuit, and the second interface end is used for connecting the discharging load or the charging load with the DC conversion circuit; the controller is connected with the adjusting end of the DC conversion circuit, and the controller is used for controlling the working state of the DC conversion circuit; the auxiliary power supply circuit comprises an auxiliary power supply and a power supply processing circuit connected with the auxiliary power supply, and the output end of the power supply processing circuit is connected with the power supply end of the controller so as to provide power needed by work for the controller. According to the wide-width DC driving circuit provided by the technical scheme, the auxiliary power supply circuit provides a stable working power supply for the controller, so that the controller can still operate normally when the voltage output by the battery is as low as 1V, wide-width input is realized, and the wide-width DC driving circuit is particularly suitable for a single low-voltage battery, so that the use scene of the DC driving circuit is expanded.

Description

Technical Field

[0001] The present invention relates to the technical field of DC drive circuits, and in particular to a wide-band DC drive circuit. Background Art

[0002] With the rapid development of portable electronic devices and low-voltage energy storage systems, the demand for low-voltage, high-current DC boost circuits is increasing. However, existing technologies have significant limitations: traditional DC boost circuits are difficult to achieve high-efficiency, high-current output when the input voltage is lower than 3V. This is because the boost chip it relies on requires a voltage of more than 4V to work properly, forcing the energy storage system to increase the voltage through multiple battery groups in series. This method not only increases the size and complexity of the battery pack, but also requires the introduction of a battery balancing management circuit (BMS) to solve the voltage imbalance problem of the series battery pack, resulting in increased system costs and reduced reliability.

[0003] In addition, the existing low-voltage (less than 3V) boost technology only supports one-way energy transmission and cannot realize the reverse charging function. The mainstream bidirectional charging and discharging ICs on the market are mostly adapted to input voltages above 5V, and require the battery pack to consist of at least two cells in series, which limits its application in single-cell battery-powered scenarios. For example, in a single lithium battery (nominal voltage 3.2V) or a low-voltage energy storage module, the existing technology cannot meet the requirements of boost output and reverse charging at the same time, resulting in insufficient system flexibility and difficulty in adapting to the miniaturization trend of portable devices.

[0004] To address the above issues, existing solutions rely on complex peripheral circuits and battery management modules, further increasing design costs and power. Summary of the invention

[0005] The object of the present invention is to provide a wide-range DC drive circuit that is compatible with lower input voltages and supports bidirectional charging and discharging of batteries.

[0006] In order to achieve the above object, the present invention provides a wide-range DC drive circuit, which includes a DC conversion circuit, a controller, an auxiliary power supply circuit, and a first interface terminal and a second interface terminal;

[0007] The first interface terminal is used to connect the rechargeable battery to the DC conversion circuit, and the second interface terminal is used to connect the discharge load or the charging load to the DC conversion circuit;

[0008] The controller is connected to the regulating end of the DC conversion circuit, and the controller is used to control the working state of the DC conversion circuit;

[0009] The auxiliary power supply circuit includes an auxiliary power supply and a power supply processing circuit connected to the auxiliary power supply. The output end of the power supply processing circuit is connected to the power supply end of the controller to provide the controller with power required for operation.

[0010] Preferably, the auxiliary power supply circuit includes a discharge auxiliary power supply circuit and a charge auxiliary power supply circuit;

[0011] The discharge auxiliary power supply circuit comprises a first auxiliary power supply and a first power supply processing circuit connected to the first auxiliary power supply, wherein the output end of the first power supply processing circuit is connected to the power supply end of the controller;

[0012] The charging auxiliary power supply circuit includes a second power supply processing circuit, which is connected to the second interface end to obtain a second auxiliary power supply from a charging load connected to the second interface end, and the output end of the second power supply processing circuit is connected to the power supply end of the controller.

[0013] Preferably, it further comprises a low voltage protection circuit, the input end of the low voltage protection circuit is connected to the first auxiliary power supply, the output end of the low voltage protection circuit is connected to the input end of the first power processing circuit, and the controller is also connected to the first interface end to obtain the port voltage of the rechargeable battery;

[0014] The low voltage protection circuit further includes a control port connected to the controller, and the controller controls an on / off state of the low voltage protection circuit based on the port voltage.

[0015] Preferably, the low voltage protection circuit comprises an input circuit, an output circuit, an operational amplifier and a power regulator;

[0016] One end of the input circuit is connected to a first auxiliary power supply of an external device, the other end of the input circuit is connected to a non-inverting end of the operational amplifier, one end of the output circuit is connected to an inverting end of the operational amplifier, and the other end of the output circuit is connected to the first power processing circuit;

[0017] The power regulator is connected in series in the current loop of the output end of the operational amplifier, the control port is located on the power regulator, and the control port is used to control the on / off of the power regulator;

[0018] The input circuit is used to generate a reference voltage based on an initial voltage provided by the first auxiliary power supply;

[0019] The output circuit is used to generate a sampling voltage based on the target voltage output to the first power processing circuit;

[0020] The operational amplifier is used to generate an error signal based on the reference voltage and the sampled voltage;

[0021] The power regulator can adaptively adjust the working state of the operational amplifier according to the size of the error signal, so that the target voltage output by the output circuit is stabilized at a target level.

[0022] Preferably, the input circuit includes a first resistor and a second resistor connected in series, the first resistor is connected to the first auxiliary power supply, the second resistor is grounded, and a first node between the first resistor and the second resistor is connected to the in-phase terminal of the operational amplifier; the output circuit includes a third resistor and a fourth resistor connected in series, the third resistor is connected to the input terminal of the first power supply processing circuit, the fourth resistor is grounded, and a second node between the third resistor and the third resistor is connected to the inverting terminal of the operational amplifier.

[0023] Preferably, there is a fifth resistor between the in-phase terminal and the output terminal of the operational amplifier; there is a first capacitor between the inverting terminal of the operational amplifier and the ground, and there is a second capacitor between the positive terminal and the negative terminal of the operational amplifier; the output terminal of the operational amplifier is connected to the power regulator through a sixth resistor, and a seventh resistor is also connected between the sixth resistor and the power modulator, and the other end of the seventh resistor is grounded.

[0024] Preferably, the power regulator includes a first power switch tube.

[0025] Preferably, at least one second power switch tube is arranged between the DC conversion circuit and the first interface end, and the control end of the second power switch tube is connected to the controller; the controller is also connected to the first interface end to obtain the port voltage of the rechargeable battery; the controller controls the on / off state of the second power switch tube according to the direction of the port voltage.

[0026] Preferably, a first current detection circuit connected to the controller is further provided between the DC conversion circuit and the first interface end, and a second current detection circuit connected to the controller is further provided between the DC conversion circuit and the second interface end;

[0027] When the second interface terminal is connected to the discharge load, the controller controls the working state of the DC conversion circuit according to the current value detected by the second current detection circuit;

[0028] When the second interface terminal is connected to the charging load, the controller controls the working state of the DC conversion circuit according to the current value detected by the first current detection circuit.

[0029] Preferably, when the second interface terminal is connected to the discharging load, the controller can also control the working state of the DC conversion circuit based on the comparison between the current value detected by the first current detection circuit and the preset first maximum threshold value; when the second interface terminal is connected to the charging load, the controller can control the working state of the DC conversion circuit based on the comparison between the current value detected by the second current detection circuit and the preset second maximum threshold value.

[0030] Compared with the prior art, the wide-range DC drive circuit provided by the above technical solution of the present invention provides a stable working power supply for the controller through an auxiliary power supply circuit, and is suitable for charging mode and discharging mode, so that the controller can maintain normal operation when the voltage output by the battery is as low as 1V. This breaks through the bottleneck that the traditional DC conversion circuit relies on the high voltage of the rechargeable battery connected to it, and realizes a wide input (1V-35V), which is especially suitable for single-cell low-voltage batteries. There is no need for multiple cells to be connected in series for power supply, thereby expanding the use scenarios of the DC drive circuit, and avoiding the introduction of the battery balancing management circuit (BMS) in the traditional solution, significantly reducing the system complexity and cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 4 is a system principle structure diagram of a wide-range DC drive circuit in an embodiment of the present invention.

[0032] Figure 2 4 is a schematic diagram of a DC conversion circuit in an embodiment of the present invention.

[0033] Figure 3 FIG. 4 is a schematic diagram of a discharge auxiliary power supply circuit in one embodiment of the present invention.

[0034] Figure 4 It is a principle structure diagram of a charging auxiliary power supply circuit in an embodiment of the present invention.

[0035] Figure 5 FIG. 4 is a schematic structural diagram of a discharge auxiliary power supply circuit in another embodiment of the present invention.

[0036] Figure 6 4 is a circuit schematic diagram of a low voltage protection circuit in an embodiment of the present invention.

[0037] Figure 7 4 is a circuit schematic diagram of a wide-range DC drive circuit in an embodiment of the present invention.

[0038] Figure 8 4 is a pin structure diagram of the controller in an embodiment of the present invention. DETAILED DESCRIPTION

[0039] In order to explain the technical content, structural features, achieved objectives and effects of the present invention in detail, the following is a detailed description in conjunction with the implementation methods and the accompanying drawings.

[0040] This embodiment discloses a wide-range DC driving circuit for DC voltage step-up or step-down to cooperate with the discharge or charge operation of a rechargeable battery BT.

[0041] like Figure 1 The DC drive circuit includes a DC conversion circuit 1, a controller U1, an auxiliary power supply circuit 6, a first interface terminal 2 and a second interface terminal 3.

[0042] The DC conversion circuit 1 is used to step up or step down the voltage of an input electrical signal.

[0043] The first interface terminal 2 is used to connect the rechargeable battery BT to the DC conversion circuit 1 , and the second interface terminal 3 is used to connect the discharging load 4 or the charging load 5 to the DC conversion circuit 1 .

[0044] Specifically, the first interface terminal 2 is connected to the rechargeable battery BT to receive a discharge power signal output by the rechargeable battery BT, or output a charging power signal to the rechargeable battery BT.

[0045] When the second interface terminal 3 is connected to the discharge load 4, the second interface terminal 3 outputs the boosted discharge power signal to the discharge load 4. When the second interface terminal 3 is connected to the charging load 5, the second interface terminal 3 receives the charging power signal provided by the charging load 5 and performs a voltage reduction process.

[0046] The controller U1 is connected to the regulating end of the DC conversion circuit 1 , and the controller U1 is used to control the working state of the DC conversion circuit 1 .

[0047] like Figure 2 The DC conversion circuit 1 in this embodiment performs a voltage step-up or step-down process on the voltage signal based on the transistor group Q and the inductor L. The controller U1 outputs a PWM wave, and controls the on and off states of each transistor in the transistor group Q through the PWM wave to achieve a voltage step-up or step-down effect.

[0048] Specifically, the transistor group Q includes two third power switch tubes Q3, two fourth power switch tubes Q4 and a number of current limiting resistors R8, R9, R10, R11, R12, R13, R14, and R15 respectively arranged at the control ends of the third power switch tubes Q3 and the fourth power switch tubes Q4. The controller U1 alternately controls the on and off of the two third power switch tubes Q3 and the two fourth power switch tubes Q4 and the conduction time through ports TG1 and TG2 to change the working state of the DC conversion circuit 1 to output signals of different voltages and currents.

[0049] Please refer to Figure 1 and Figure 7The auxiliary power supply circuit includes an auxiliary power supply and a power supply processing circuit connected to the auxiliary power supply. The output end of the power supply processing circuit is connected to the power supply end VCC of the controller U1 to provide the controller U1 with the power required for operation.

[0050] In this embodiment, the auxiliary power supply provides a constant working power supply for the controller U1, which is suitable for charging mode and discharging mode, so that the controller U1 can maintain normal operation when the voltage output by the rechargeable battery BT is as low as 1V. This breaks through the bottleneck of the traditional DC conversion circuit 1 relying on the high voltage of the rechargeable battery BT connected thereto, and realizes a wide input range (1V-35V), especially suitable for a single low-voltage battery, without the need for multiple batteries to be connected in series, thereby expanding the use scenarios of the DC drive circuit, and avoiding the introduction of the battery balancing management circuit (BMS) in the traditional solution, significantly reducing the system complexity and cost.

[0051] On the other hand, the second interface end 3 may be provided with one interface for sharing the discharging load 4 and the charging load 5 , or may be provided with two interfaces for the discharging load 4 and the charging load 5 respectively.

[0052] Preferably, in this embodiment, a first interface 3a and a second interface 3b are provided in parallel, the first interface 3a is used to connect to the discharge load 4, and the second interface 3b is used to connect to the charging load 5. By providing two interfaces, there is no need to provide a corresponding interface control circuit, the structure is simple, and it is easy to implement.

[0053] Regardless of whether the DC drive circuit is in a charging state or a discharging state, the controller U1 can be powered by the same set of auxiliary power circuits 6 , or by two different sets of auxiliary power circuits 6 .

[0054] On the other hand, Figure 3 and Figure 4 In this embodiment, two sets of auxiliary power supplies are configured, that is, the auxiliary power supply circuit 6 includes a discharge auxiliary power supply circuit 60 and a charge auxiliary power supply circuit 61.

[0055] The discharge auxiliary power supply circuit 60 includes a first auxiliary power supply 600 and a first power supply processing circuit 601 connected to the first auxiliary power supply 600 , and an output end of the first power supply processing circuit 601 is connected to a power supply end VCC of the controller U1 .

[0056] The charging auxiliary power supply circuit 61 includes a second power supply processing circuit 610, which is connected to the second interface terminal 3 to obtain a second auxiliary power supply from the charging load 5 connected to the second interface terminal 3, and the output end of the second power supply processing circuit 610 is connected to the power supply terminal VCC of the controller U1. Specifically, the second power supply processing circuit 610 is connected to the second interface 3b.

[0057] In this embodiment, the first auxiliary power supply 600 is an external power supply, such as a battery. The second auxiliary power supply comes from the charging load 5, which is convenient to obtain power. In addition, compared with using the first auxiliary power supply 600 to simultaneously power the controller U1 in the charging and discharging states, the use time of the first auxiliary power supply 600 can be effectively extended.

[0058] On the other hand, to avoid over-discharge of the rechargeable battery BT, Figure 5 The discharge auxiliary power supply circuit 60 in this embodiment also includes a low voltage protection circuit 602, the input end of the low voltage protection circuit 602 is connected to the first auxiliary power supply 600, the output end of the low voltage protection circuit 602 is connected to the input end of the first power supply processing circuit 601, and the controller U1 is also connected to the first interface terminal 2 to obtain the port voltage of the rechargeable battery BT.

[0059] The low voltage protection circuit 602 further includes a control port EN connected to the controller U1 , and the controller U1 controls the on / off state of the low voltage protection circuit 602 based on the port voltage.

[0060] In this embodiment, the first auxiliary power supply 600 is connected to the first power supply processing circuit 601 through the low voltage protection circuit 602, so that when the rechargeable battery BT is in the process of discharging, the controller U1 collects the port voltage of the rechargeable battery BT in real time through the first interface terminal 2, and when the port voltage is lower than the preset value, the low voltage protection circuit 602 is sent a stop working instruction through the control port EN, so that the controller U1 loses power supply and the DC drive circuit stops working.

[0061] like Figure 6 The low voltage protection circuit 602 includes an input circuit S1, an output circuit S2, an operational amplifier U2 and a power regulator Q1.

[0062] One end of the input circuit S1 is connected to the first auxiliary power supply 600 of the peripheral device, and the first auxiliary power supply 600 outputs the initial voltage VC1 to the input circuit S1 and the operational amplifier U2. The other end of the input circuit S1 is connected to the non-inverting end of the operational amplifier U2, one end of the output circuit S2 is connected to the inverting end of the operational amplifier U2, and the other end of the output circuit S2 is connected to the first power processing circuit 601.

[0063] The power regulator Q1 is connected in series in the current loop of the output end of the operational amplifier U2. The control port EN is located on the power regulator Q1. The control port EN is used to control the on / off of the power regulator Q1.

[0064] The input circuit S1 is used to generate a reference voltage Vref based on an initial voltage VC1 provided by the first auxiliary power source 600 .

[0065] The output circuit S2 is used to generate a sampling voltage Vfb based on the target voltage VC2 output to the first power processing circuit 601 .

[0066] The operational amplifier U2 is used to generate an error signal based on the reference voltage Vref and the sampling voltage Vfb.

[0067] The power regulator Q1 can adaptively adjust the working state of the operational amplifier U2 according to the size of the error signal, so that the target voltage VC2 output by the output circuit S2 is stabilized at a target level.

[0068] The low voltage protection circuit 602 in this embodiment is a linear voltage regulated power supply based on an operational amplifier U2, which adjusts the target voltage VC2 output by the output circuit S2 through feedback control of the power regulator Q1.

[0069] During operation, the reference voltage Vref provided by the input circuit S1 sets the reference base of the target voltage VC2. While the output circuit S2 outputs the voltage to the first power processing circuit 601, it also collects the sampled voltage Vfb in real time and sends it to the operational amplifier U2.

[0070] The operational amplifier U2 compares the reference voltage Vref with the sampled voltage Vfb to output an error signal. Then, the state of the operational amplifier U2 can be controlled by controlling the state of the power regulator Q1 according to the error signal, so that the voltage output by the output circuit S2 is stabilized at the target voltage VC2 level. When the target voltage VC2 deviates from the target value due to load changes, the error signal drives the operational amplifier U2 to adjust the output, forcing the target voltage VC2 to return to the set value.

[0071] Specifically, the input circuit S1 includes a first resistor R1 and a second resistor R2 connected in series, the first resistor R1 is connected to the first auxiliary power supply 600, the second resistor R2 is grounded, and a first node J1 between the first resistor R1 and the second resistor R2 is connected to the non-inverting terminal of the operational amplifier U2.

[0072] The output circuit S2 includes a third resistor R3 and a fourth resistor R4 connected in series, the third resistor R3 is connected to the input end of the first power processing circuit 601, the fourth resistor R4 is grounded, and the second node J2 between the third resistor R3 and the third resistor R3 is connected to the inverting end of the operational amplifier U2.

[0073] In this embodiment, the initial voltage VC1 provided by the first auxiliary power source 600 is divided by the first resistor R1 and the second resistor R2 in series to generate a reference voltage Vref at the first node J1.

[0074] Similarly, the third resistor R3 and the fourth resistor R4 are connected in series to divide the voltage, and form a sampling voltage Vfb at the second node J2.

[0075] On the other hand, the power regulator Q1 includes a first power switch tube Q1.

[0076] When the first power switch tube Q1 is an NMOS tube, the G pole of the first power switch tube Q1 is connected to the output end of the operational amplifier U2, the D pole of the first power switch tube Q1 is used as a control port EN and connected to the controller U1, and the S pole of the first power switch tube Q1 is grounded.

[0077] The first power switch tube Q1 is used as a series adjustment tube, and its conduction state directly affects the energy transmission efficiency from the initial voltage VC1 provided by the first auxiliary power supply 600 to the target voltage VC2 output by the output circuit S2. That is, the first power switch tube Q1 dynamically controls the voltage distribution from the initial voltage VC1 to the target voltage VC2 by adjusting its own conduction impedance. When the conduction is enhanced, the voltage drop loss of the initial voltage VC1 is reduced, and the target voltage VC2 rises; when the conduction is weakened, the voltage drop loss increases, and the target voltage VC2 decreases. The closed-loop control logic adjusts the conduction state of the first power switch tube Q1 in real time through the error signal, and finally realizes the precise voltage regulation of the target voltage VC2.

[0078] On the other hand, a fifth resistor R5 is provided between the in-phase terminal and the output terminal of the operational amplifier U2. A first capacitor C1 is provided between the inverting terminal of the operational amplifier U2 and the ground, and a second capacitor C2 is provided between the positive terminal and the negative terminal of the operational amplifier U2. The output terminal of the operational amplifier U2 is connected to the power regulator Q1 through a sixth resistor R6, and a seventh resistor R7 is further connected between the sixth resistor R6 and the power modulator, and the other end of the seventh resistor R7 is grounded.

[0079] The fifth resistor R5 is used to adjust the gain or phase characteristics of the operational amplifier U2 to enhance stability. The first capacitor C1 is a power decoupling capacitor to filter power supply noise. At the same time, the fifth resistor R5 and the first capacitor C1 cooperate to optimize the dynamic response of the operational amplifier U2 to ensure rapid convergence.

[0080] The second capacitor C2 is used to suppress high-frequency interference and prevent the amplifier from self-oscillating.

[0081] The sixth resistor R6 limits the driving current of the control end of the power regulator Q1 , and the seventh resistor R7 is a pull-down resistor to ensure that the power regulator Q1 is turned off when there is no driving to avoid false triggering.

[0082] On the other hand, Figure 7At least one second power switch tube Q2 is also provided between the DC conversion circuit 1 and the first interface terminal 2, and the control end of the second power switch tube Q2 is connected to the controller U1. The controller U1 is also connected to the first interface terminal 2 to obtain the port voltage of the rechargeable battery BT. The controller U1 controls the on / off state of the second power switch tube Q2 according to the direction of the port voltage. Specifically, the second power switch tube Q2 is connected to the port pin BG1 of the controller U1. The voltage node on the first open end 2 corresponding to the port voltage of the rechargeable battery BT is connected to the port pin IN of the controller.

[0083] In this embodiment, two second power switch tubes Q2 are arranged in parallel. When the rechargeable battery BT is connected to the first interface terminal 2 in reverse, the port voltage direction detected by the controller U1 is different from the preset value, and the two second power switch tubes Q2 will not be turned on, so that the reverse power signal cannot flow to the lower level to the DC conversion circuit 1. When the controller U1 detects that the port voltage direction is the same as the preset value, it means that the rechargeable battery BT is connected correctly, and then the two second power switch tubes Q2 are turned on, so that the power signal enters the DC conversion circuit 1.

[0084] On the other hand, a first current detection circuit 7 connected to the controller U1 is provided between the DC conversion circuit 1 and the first interface terminal 2 , and a second current detection circuit 8 connected to the controller U1 is provided between the DC conversion circuit 1 and the second interface terminal 3 .

[0085] When the second interface terminal 3 is connected to the discharge load 4 , the controller U1 controls the working state of the DC conversion circuit 1 according to the current value detected by the second current detection circuit 8 , so that the current signal output by the DC conversion circuit 1 to the second interface terminal 3 meets the requirements.

[0086] When the second interface terminal 3 is connected to the charging load 5 , the controller U1 controls the working state of the DC conversion circuit 1 according to the current value detected by the first current detection circuit 7 , so that the current signal output by the DC conversion circuit 1 to the first interface terminal 2 meets the requirements.

[0087] In addition, the above-mentioned adjustment of the output current of the DC conversion circuit 1 is a post-adjustment, and the output current abnormality needs to be detected before adjustment. In this way, if the detected output current is too large, it will cause damage to the subsequent components before the adjustment is completed. Therefore, further improvements are made:

[0088] When the second interface terminal 3 is connected to the discharge load 4 , the controller U1 can also control the working state of the DC conversion circuit 1 according to the comparison between the current value detected by the first current detection circuit 7 and the preset first maximum threshold value.

[0089] When the second interface terminal 3 is connected to the charging load 5 , the controller U1 controls the working state of the DC conversion circuit 1 according to the comparison between the current value detected by the second current detection circuit 8 and the preset second maximum threshold value.

[0090] In this embodiment, during the discharge process, if the current output by the rechargeable battery BT exceeds the first maximum threshold, the working state of the DC conversion circuit 1 will be adjusted in advance to avoid the DC conversion circuit 1 outputting a large current signal instantaneously and damaging the discharge load 4.

[0091] Similarly, during the charging process, if the current output by the charging load 5 exceeds the second maximum threshold, the working state of the DC conversion circuit 1 will be adjusted in advance to prevent the DC conversion circuit 1 from instantly outputting a large current signal and damaging the rechargeable battery BT.

[0092] Specifically, the first current detection circuit 8 includes resistors R19, R20, R21 and capacitor C3, the resistor R19 is connected in series in the current loop between the second interface terminal 3 and the DC conversion circuit, the resistors R20 and R21 are connected in parallel at both ends of the resistor R19, R20 and R21 are respectively connected to the signal pins ISP2 and ISN2 of the controller U1, and the two ends of the capacitor C4 are respectively connected to the ends of the resistors R19 and R20 connected to the controller U1. The controller U1 obtains the voltage signal from the signal pins ISP2 and ISN2, and then converts it into a current signal.

[0093] In summary, if Figures 1 to 8 The present invention discloses a wide-range DC driving circuit for charging or discharging a rechargeable battery.

[0094] When discharging:

[0095] The controller U1 turns on the first power switch tube Q1 in the low voltage protection circuit 602 through the control port EN to start the discharge auxiliary power supply circuit 60 to provide power supply for the controller U1 .

[0096] The electrical signal output by the rechargeable battery BT enters the first interface terminal 2 and the first current detection circuit 7. When the controller U1 detects through the port pin IN that the rechargeable battery BT is connected reversely, the two second power switch tubes Q2 are controlled to remain closed; when the rechargeable battery BT is correctly connected to the first interface terminal 2, the controller U1 turns on the second power switch tube Q2, and then the electrical signal enters the DC conversion circuit 1.

[0097] The processed electrical signal output by the DC conversion circuit 1 reaches the second interface terminal 3 via the second current detection circuit 8 and is transmitted to the discharge load 4 via the first interface 3a.

[0098] During this process, the controller U1 controls the working state of the DC conversion circuit in real time according to the current value detected by the second current detection circuit 8, so that the discharge load 4 obtains an electrical signal of required specifications.

[0099] While charging:

[0100] The controller U1 turns off the first power switch tube Q1 in the low voltage protection circuit 602 through the control port EN to shut down the discharge auxiliary power supply circuit 60 to provide power supply for the controller U1.

[0101] At this time, the charging load 5 is connected to the second interface 3b of the second open end 3, and the charging load 5 provides the second auxiliary power VC3 for the second power processing circuit 610 of the charging auxiliary power circuit 61, and the second power processing circuit 610 provides power supply for the controller U1.

[0102] The charging signal enters the DC conversion circuit 2 via the second current detection circuit 8 , is processed by the DC conversion circuit 1 and enters the first current detection circuit 7 via the second power switch tube Q2 , and then enters the rechargeable battery BT via the first opening end 2 .

[0103] During this process, the controller U1 controls the working state of the DC conversion circuit 1 in real time according to the detection value of the first current detection circuit 7 to ensure that the electrical signal entering the rechargeable battery BT meets the requirements.

[0104] It should be noted that the specific structure of the first power processing circuit 601 in the discharge auxiliary power circuit 60 and the second power processing circuit 610 in the charging auxiliary power circuit 61 in the above embodiment belongs to the conventional technology in the field and will not be repeated here. It can be implemented by a commonly used power management chip.

[0105] The above disclosure is only the preferred embodiment of the present invention, which certainly cannot be used to limit the scope of rights of the present invention. Therefore, equivalent changes made according to the scope of the patent application of the present invention are still within the scope covered by the present invention.

Claims

1. A wide-band DC drive circuit, characterized in that: It includes a DC conversion circuit, a controller, an auxiliary power supply circuit, a first interface terminal and a second interface terminal; The first interface terminal is used to connect the rechargeable battery to the DC conversion circuit, and the second interface terminal is used to connect the discharge load or the charging load to the DC conversion circuit; The controller is connected to the regulating end of the DC conversion circuit, and the controller is used to control the working state of the DC conversion circuit; The auxiliary power supply circuit includes an auxiliary power supply and a power supply processing circuit connected to the auxiliary power supply. The output end of the power supply processing circuit is connected to the power supply end of the controller to provide the controller with power required for operation.

2. The wide-band DC driving circuit according to claim 1, characterized in that: The auxiliary power supply circuit includes a discharge auxiliary power supply circuit and a charge auxiliary power supply circuit; The discharge auxiliary power supply circuit comprises a first auxiliary power supply and a first power supply processing circuit connected to the first auxiliary power supply, wherein the output end of the first power supply processing circuit is connected to the power supply end of the controller; The charging auxiliary power supply circuit includes a second power supply processing circuit, which is connected to the second interface end to obtain a second auxiliary power supply from a charging load connected to the second interface end, and the output end of the second power supply processing circuit is connected to the power supply end of the controller.

3. The wide-band DC driving circuit according to claim 2, characterized in that: It also includes a low voltage protection circuit, the input end of the low voltage protection circuit is connected to the first auxiliary power supply, the output end of the low voltage protection circuit is connected to the input end of the first power processing circuit, and the controller is also connected to the first interface end to obtain the port voltage of the rechargeable battery; The low voltage protection circuit further includes a control port connected to the controller, and the controller controls an on / off state of the low voltage protection circuit based on the port voltage.

4. The wide-band DC driving circuit according to claim 3, characterized in that: The low voltage protection circuit includes an input circuit, an output circuit, an operational amplifier and a power regulator; One end of the input circuit is connected to a first auxiliary power supply of an external device, the other end of the input circuit is connected to a non-inverting end of the operational amplifier, one end of the output circuit is connected to an inverting end of the operational amplifier, and the other end of the output circuit is connected to the first power processing circuit; The power regulator is connected in series in the current loop of the output end of the operational amplifier, the control port is located on the power regulator, and the control port is used to control the on / off of the power regulator; The input circuit is used to generate a reference voltage based on an initial voltage provided by the first auxiliary power supply; The output circuit is used to generate a sampling voltage based on the target voltage output to the first power processing circuit; The operational amplifier is used to generate an error signal based on the reference voltage and the sampled voltage; The power regulator can adaptively adjust the working state of the operational amplifier according to the size of the error signal, so that the target voltage output by the output circuit is stabilized at a target level.

5. The wide-band DC driving circuit according to claim 4, characterized in that: The input circuit includes a first resistor and a second resistor connected in series, the first resistor is connected to the first auxiliary power supply, the second resistor is grounded, and a first node between the first resistor and the second resistor is connected to the in-phase terminal of the operational amplifier; the output circuit includes a third resistor and a fourth resistor connected in series, the third resistor is connected to the input terminal of the first power supply processing circuit, the fourth resistor is grounded, and a second node between the third resistor and the third resistor is connected to the inverting terminal of the operational amplifier.

6. The wide-band DC driving circuit according to claim 4, characterized in that: A fifth resistor is provided between the in-phase terminal and the output terminal of the operational amplifier; a first capacitor is provided between the inverting terminal and the ground, and a second capacitor is provided between the positive terminal and the negative terminal of the operational amplifier; the output terminal of the operational amplifier is connected to the power regulator through a sixth resistor, and a seventh resistor is also connected between the sixth resistor and the power modulator, and the other end of the seventh resistor is grounded.

7. The wide-band DC driving circuit according to claim 4, characterized in that: The power regulator includes a first power switch tube.

8. The wide-band DC driving circuit according to claim 1, characterized in that: At least one second power switch tube is also arranged between the DC conversion circuit and the first interface end, and the control end of the second power switch tube is connected to the controller; the controller is also connected to the first interface end to obtain the port voltage of the rechargeable battery; the controller controls the on / off state of the second power switch tube according to the direction of the port voltage.

9. The wide-band DC driving circuit according to claim 1, characterized in that: A first current detection circuit connected to the controller is further provided between the DC conversion circuit and the first interface end, and a second current detection circuit connected to the controller is further provided between the DC conversion circuit and the second interface end; When the second interface terminal is connected to the discharge load, the controller controls the working state of the DC conversion circuit according to the current value detected by the second current detection circuit; When the second interface terminal is connected to the charging load, the controller controls the working state of the DC conversion circuit according to the current value detected by the first current detection circuit.

10. The wide-band DC driving circuit according to claim 9, characterized in that: When the second interface terminal is connected to the discharging load, the controller can also control the working state of the DC conversion circuit based on the comparison between the current value detected by the first current detection circuit and the preset first maximum threshold value; when the second interface terminal is connected to the charging load, the controller can control the working state of the DC conversion circuit based on the comparison between the current value detected by the second current detection circuit and the preset second maximum threshold value.

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