Low-power constant power circuit for intelligent power distribution box and software strategy thereof

Abstract

The application provides a low-power constant-power circuit for an intelligent power distribution box and a software strategy thereof. The low-power constant-power circuit comprises a general power supply circuit, a general eFuse circuit, an electrical device and a controller, the general eFuse circuit is connected between the power supply and the electrical device, and the low-power eFuse circuit is connected to the power supply and the electrical device. The input end of the low-power eFuse circuit is connected to the power supply, and the output end of the low-power eFuse circuit is connected to the electrical device. The controller is electrically connected to the general eFuse circuit and the low-power eFuse circuit. The application solves the technical problems of high power consumption and low flexibility in waking up when the intelligent power distribution box is in sleep.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of vehicle electronic information, in particular to a low-power constant-current circuit for an intelligent power distribution box and a software strategy for the low-power constant-current circuit. BACKGROUND

[0002] With the rapid popularization of new energy vehicles and the rapid increase in the installation rate of vehicle intelligent cockpits and auxiliary / automatic driving systems, the electrification level of vehicles is also rapidly increasing. New electric control modules such as battery management modules BMS, vehicle control modules VCU, vehicle networking modules T-box, body domain controllers, and cockpit domain controllers are beginning to be widely used in new vehicle models. The number of electric control modules and loads of the whole vehicle has increased significantly compared to traditional vehicles. While the number of electrical equipment is increasing, the demand for constant current of the whole vehicle is also rapidly increasing, and the electrical equipment that needs constant current power supply is also rapidly increasing. At present, the number of constant current electrical equipment of new energy vehicles has reached 3 times or even more than that of traditional fuel vehicles, and the working mode of electrical equipment is also more complex. For example, all new energy vehicles need to be equipped with a vehicle networking module T-box. The traditional T-box may only need to work after the vehicle is started. Now, with the development of vehicle networking technology, the T-box needs to be actively awakened under any condition including vehicle hibernation, and then the vehicle information is remotely sent to the platform. Then, according to the user demand of the background, the power demand of the electrical equipment of the whole vehicle is adjusted in real time, such as the sentinel mode, and the user needs to remotely turn on the camera, which poses a challenge to the traditional power distribution box using a traditional fuse.

[0003] At present, an intelligent power distribution box based on eFuse can be used. The intelligent power distribution box uses eFuse to control the electrical equipment loop. The intelligent power distribution box can monitor each electrical equipment in real time, and can report fault information in real time when a fault occurs, thereby greatly reducing the electrical risk. At the same time, the intelligent power distribution box can control the switching of each load, thereby greatly improving the flexibility of vehicle remote control.

[0004] However, the related art has at least one of the following problems: eFuse consumes some current when it is turned on, which is not a problem when the vehicle is powered on. However, in the hibernation case, the problem is very serious: for example, an intelligent power distribution box with 10 eFuse constant current channels consumes 5mA per channel, and 10 channels consume 50mA. This can be ignored for vehicle operation, but in the hibernation case, the static power consumption of the whole vehicle is usually required to be within 25mA, and the power consumption of a single electrical equipment is usually within 5mA. The 10-channel constant current intelligent power distribution box needs 50mA, which is far beyond 5mA, which is unacceptable. SUMMARY

[0005] The present application solves the technical problems of high power consumption and inflexible wake-up of the existing intelligent power distribution box in sleep.

[0006] To solve the above problems, the present application provides a low-power constant power circuit for an intelligent power distribution box, comprising: a general power supply circuit, the general power supply circuit comprising: a power supply, a general eFuse circuit, a power-consuming device and a controller, and the general eFuse circuit being connected between the power supply and the power-consuming device; a low-power eFuse circuit, the input end of the low-power eFuse circuit being connected to the power supply, and the output end of the low-power eFuse circuit being connected to the power-consuming device; wherein the controller is electrically connected to the general eFuse circuit and the low-power eFuse circuit respectively.

[0007] Compared with the prior art, the technical effects achieved by adopting the technical scheme are: the present application adopts a low-power constant power circuit suitable for an intelligent power distribution box, adopts a double eFuse circuit design, i.e., a general eFuse circuit + a low-power eFuse circuit, supports low-power power supply of various loads and constant power channels of the power distribution box, and can realize power supply isolation of multiple loads and support passive wake-up at the same time; the general eFuse circuit adopts an eFuse module in the prior art, the input end of which is connected to the power supply, the output end of which is connected to the power-consuming device, and the control end of which is connected to the controller and controlled by the controller to be turned on or off, which can support the rated current required by the load in normal operation; the low-power eFuse circuit adopts a low-power small-current design, has extremely low static power consumption, and can support low-power constant power supply of 20mA-50mA to the outside, which can fully meet the constant power consumption demand of the whole vehicle in sleep.

[0008] In an example of the present application, when the intelligent power distribution box is in a sleep state, the controller controls the general eFuse circuit to be turned off and controls the low-power eFuse circuit to be turned on; when the intelligent power distribution box is initially powered on or is woken up, the controller controls the general eFuse circuit to be turned on and controls the low-power eFuse circuit to be turned off.

[0009] Compared with the prior art, the technical effects achieved by adopting the technical scheme are: when the intelligent power distribution box is in a sleep state, only a very small current needs to be provided for the load for sleep, so the low-power eFuse circuit is switched to supply power to the power-consuming device.

[0010] In an example of the present application, the low-power eFuse circuit comprises: a power input interface, an output interface, a control interface and a wake-up interface, the power input interface is connected to a power supply, the output interface is connected to a power-consuming device, the control interface and the wake-up interface are connected to a controller; a first transistor, the first transistor is provided with a first base, a first collector and a first emitter, and the first base is connected to the control interface through a fifth resistor, the first collector is connected to the power input interface through a second resistor, and the first emitter is grounded; a third field effect transistor, the third field effect transistor is provided with a third gate, a third source and a third drain, and the third gate is connected to the power input interface through a second resistor, and the third source is grounded; a fifth field effect transistor, the fifth field effect transistor is provided with a fifth gate, a fifth source and a fifth drain, and the fifth gate is connected to the third drain through a fourth resistor, the fifth source is connected to the power input interface, and the fifth drain is connected to the output interface through a seventh resistor; and a sixth resistor, one end of the sixth resistor is connected to the first base, and the other end of the sixth resistor is grounded.

[0011] Compared with the prior art, the technical effects achieved by adopting the technical scheme are: the control interface is low effective, that is, when the control interface is low, the low-power eFuse circuit is opened, that is, when there is no control signal in the control interface, the low-power eFuse constant power output is effective; when the control interface is high, the low-power eFuse constant power output is closed. In order to reduce the power consumption of the circuit, after the controller is in sleep state, the controller can release the control interface, that is, the control interface is not controlled, at this time, the control signal is invalid, the first base of the first transistor is pulled low by the sixth resistor, at this time, the first transistor is in off state, the third gate of the third field effect transistor is pulled high to the power supply voltage by the second resistor, the third field effect transistor is turned on, the fifth gate of the fifth field effect transistor is pulled low, the fifth field effect transistor is turned on, and the low-power constant power is outputted through the seventh resistor. Since the supply current is small at this time, it is feasible to design a resistor current limiting and voltage dividing. Firstly, the output current size can be limited, and secondly, the fifth field effect transistor is protected from overcurrent when the output interface is short-circuited.

[0012] In an example of the present application, the low-power constant power circuit comprises a first topology architecture; the first topology architecture adopts a low-power eFuse circuit to supply power to a plurality of power-consuming devices, the output interface of the low-power eFuse circuit is connected to the plurality of power-consuming devices through a plurality of diodes, and each power-consuming device is connected to a common eFuse circuit, and the common eFuse circuit and the low-power eFuse circuit are connected through diodes to realize power supply isolation.

[0013] Compared with the prior art, the technical effects achieved by adopting the technical scheme are: in the first topology architecture, the circuit output can be connected in parallel to the common eFuse circuit through a plurality of diodes, and the plurality of power-consuming devices requiring constant power supply can be supplied with constant power during sleep; at the same time, when the common eFuse circuit supplies power, the output is not affected.

[0014] In an example of the present application, the low-power constant-current circuit comprises a second topology architecture; the second topology architecture is configured with a normal eFuse circuit and a low-power eFuse circuit for each power device, and the normal eFuse circuit and the low-power eFuse circuit are connected in parallel to the corresponding power device.

[0015] Compared with the prior art, the technical effects achieved by the technical scheme are as follows: in the second topology architecture, a low-power eFuse circuit is matched for each constant-current load according to different power distribution properties and different load control requirements, each power supply is independently controllable, and independent high-performance power supply and accurate wake-up detection can be provided, but the power consumption and cost are increased; the two topology architectures can meet the constant-current power supply requirements of different power distribution properties, improve the flexibility of the system scheme in consideration of the requirements and cost.

[0016] In an example of the present application, the low-power eFuse circuit further comprises: a seventh field effect transistor, the seventh field effect transistor is provided with a seventh gate, a seventh source and a seventh drain, the seventh gate is connected to the output interface through an eighth resistor, the seventh source is connected to the output interface through a seventh resistor, and the seventh drain is grounded; and a ninth field effect transistor, the ninth field effect transistor is provided with a ninth gate, a ninth source and a ninth drain, the ninth gate is connected to the seventh drain, the ninth source is grounded, and the ninth drain is connected to the wake-up interface.

[0017] Compared with the prior art, the technical effects achieved by the technical scheme are as follows: when the low-power eFuse circuit is turned on, that is, when the output is effective, if the load is abnormally woken up, the current exceeds the power consumption of the whole vehicle, at this time, the output voltage will be pulled down, that is, the gate voltage of the seventh field effect transistor will drop, this voltage will drive the seventh field effect transistor to open, the power supply voltage drives the ninth field effect transistor to open after being divided, the wake-up interface is pulled down, and the wake-up controller is woken up; during this period, the power supply voltage requirements of the power device can still be met.

[0018] In an example of the present application, the low-power eFuse circuit further comprises: a third resistor, one end of the third resistor is connected to the fifth gate, and the other end of the third resistor is connected to the power input interface; a voltage dividing circuit, one end of the voltage dividing circuit is connected to the seventh drain, and the other end of the voltage dividing circuit is grounded, and the voltage dividing circuit comprises a ninth resistor and a tenth resistor connected in series, and the ninth gate is connected between the ninth resistor and the tenth resistor; a first capacitor, one end of the first capacitor is connected to the ninth gate, and the other end of the first capacitor is grounded; and a second capacitor, one end of the second capacitor is connected to the output interface, and the other end of the second capacitor is grounded.

[0019] Compared with the prior art, the technical effects reached by adopting the technical scheme are as follows: the drain electrode of the seventh field effect tube is connected to the gate electrode of the ninth field effect tube through the voltage division of the ninth resistor and the tenth resistor. The first capacitor is connected to the gate electrode of the ninth field effect tube for filtering, and the output interface is connected to a storage capacitor, i.e., the second capacitor, which provides a certain anti-large-current-impact capability. When the power consumption of the electrical equipment increases instantaneously, the second capacitor provides a larger starting current for the electrical equipment. At the same time, the low-power eFuse circuit detects the current increase event and wakes up the controller to turn on the ordinary eFuse circuit to supply power to the electrical equipment.

[0020] In another aspect, the embodiment of the present application also provides a software strategy for a low-power always-on circuit. The software strategy is applied to the low-power always-on circuit of the intelligent power distribution box according to the first embodiment, and includes the following steps: after the intelligent power distribution box is initially powered on or woken up, the controller controls the ordinary eFuse circuit to be turned on, and controls the low-power eFuse circuit to be turned off; when the vehicle meets the sleep condition, the controller controls the low-power eFuse circuit to be turned on, and controls the ordinary eFuse circuit to be turned off, so that the intelligent power distribution box enters the sleep state; when the intelligent power distribution box is in the sleep state, it is determined whether the controller receives a wake-up signal; in the case that the controller receives the wake-up signal, the intelligent power distribution box is woken up, the ordinary eFuse circuit is turned on, and the low-power eFuse circuit is turned off.

[0021] Compared with the prior art, the technical effects reached by adopting the technical scheme are as follows: after the system is initially powered on or woken up, the ordinary eFuse circuit is turned on to supply power to the always-on electrical equipment; when the sleep condition is met, the low-power eFuse circuit is turned on to supply power to the electrical equipment, and then the ordinary eFuse circuit is turned off, so that the intelligent power distribution box enters the sleep state; if the intelligent power distribution box is woken up due to the fact that a certain hard-wire wake-up signal is valid, a network wake-up signal is valid, or a passive wake-up signal is valid, the intelligent power distribution box is woken up, the ordinary eFuse circuit is turned on to supply power to the electrical equipment, and the low-power eFuse circuit is turned off.

[0022] In an example of the present application, the wake-up signal includes an active wake-up signal and a passive wake-up signal; the active wake-up signal includes a hard-wire wake-up signal and a network wake-up signal; the passive wake-up signal is generated by the low-power eFuse circuit when it detects that the current of the electrical equipment exceeds a preset threshold value, and is sent to the controller.

[0023] Compared with the prior art, the technical effects reached by adopting the technical scheme are as follows: the low-power constant-current circuit also supports active wake-up function and passive wake-up function: the active wake-up can be realized through a hard-wire wake-up signal or network wake-up, that is, if a certain hard-wire wake-up signal is valid or network wake-up is valid, the intelligent power distribution box will be woken up, and after being woken up, the normal eFuse will be immediately opened to supply power to the power-consuming device, and the low-power eFuse is closed; the passive wake-up means that after the power supply current of the constant-current appliance is greatly increased, the low-power eFuse circuit can detect the abnormal current increase event and automatically wake up the controller through the wake-up interface, and the controller opens the normal eFuse circuit to supply power to the power-consuming device.

[0024] After the technical scheme of the present application is adopted, the following technical effects can be achieved:

[0025] (1) The present application adopts a low-power constant-current circuit suitable for an intelligent power distribution box, adopts a double eFuse loop design, that is, a normal eFuse circuit + a low-power eFuse circuit, supports low-power power supply of various loads and constant-current channels of the power distribution box, and can realize power supply isolation of multiple loads and support passive wake-up at the same time.

[0026] (2) The present application provides two topological structures to meet the constant-current power supply requirements of loads with different power distribution properties, improves the flexibility of the system scheme under the condition of considering requirements and costs, and improves the flexibility of the system scheme under the condition of considering requirements and costs.

[0027] (3) The low-power constant-current circuit also supports active wake-up function and passive wake-up function. BRIEF DESCRIPTION OF DRAWINGS

[0028] In order to more clearly illustrate the technical scheme of the embodiments of the present application, the drawings to be used in the embodiment description will be briefly introduced as follows: obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creating laborious work;

[0029] Figure 1 A principle diagram of a low-power eFuse circuit in a low-power constant-current circuit for an intelligent power distribution box provided by the first embodiment of the present application;

[0030] Figure 2 A first topological structure diagram of a low-power constant-current circuit for an intelligent power distribution box provided by the first embodiment of the present application;

[0031] Figure 3 A second topological structure diagram of a low-power constant-current circuit for an intelligent power distribution box provided by the first embodiment of the present application;

[0032] Figure 4This is a detailed flowchart of a software strategy for a low-power constant-current circuit provided in Embodiment 2 of the present invention.

[0033] Explanation of reference numerals in the attached figures:

[0034] 10. Intelligent power distribution box; 110. Power supply; 120. Ordinary eFuse circuit; 131. Primary power user; 132. Secondary power user; 133. Thirdary power user; 140. Controller; 200. Low-power eFuse circuit. Detailed Implementation

[0035] To make the above-mentioned objectives, features, and advantages of the present invention more apparent and understandable, the technical solutions in the embodiments of the present invention are clearly and completely described. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0036] Example 1

[0037] See Figures 1-3 This invention provides a low-power constant-power circuit for a smart power distribution box, comprising: a normal power supply circuit and a low-power eFuse circuit 200. The normal power supply circuit includes: a power supply 110, a normal eFuse circuit 120, a power-consuming device, and a controller 140, wherein the normal eFuse circuit 120 is connected between the power supply 110 and the power-consuming device; the input terminal of the low-power eFuse circuit 200 is connected to the power supply 110, and the output terminal of the low-power eFuse circuit 200 is connected to the power-consuming device; wherein the controller 140 is electrically connected to both the normal eFuse circuit 120 and the low-power eFuse circuit 200.

[0038] In one specific embodiment, U3 is the controller MCU. This invention employs a low-power constant-power circuit suitable for intelligent power distribution boxes, using a dual eFuse loop design: a standard eFuse circuit 120 + a low-power eFuse circuit 200. This supports low-power power supply for various loads and the constant-power channels of the power distribution box, while also achieving power supply isolation for multiple loads and supporting passive wake-up. Furthermore, by replacing the traditional fuse constant-power supply with the standard eFuse circuit 120 + low-power eFuse circuit 200, constant-power loops such as BMS, VCU, T-box, body domain control, and cockpit domain control can be opened or closed as needed when the vehicle is in sleep mode. Simultaneously, it can monitor load current and the power status of electrical equipment in real time, reducing the risk of power consumption during vehicle sleep mode. Additionally, it can dynamically adjust the overall vehicle power demand according to requirements, and independently control the switching of each load, greatly improving the flexibility of remote vehicle control.

[0039] The ordinary eFuse circuit 120 adopts the existing eFuse module. Its input terminal is connected to the power supply 110, its output terminal is connected to the electrical equipment, and its control terminal is connected to the controller 140. It is controlled by the controller 140 to turn on or off and can support the rated current required by the load during normal operation. The ordinary eFuse circuit 120 is used to provide rated current (such as 5A) to the electrical equipment after the vehicle is working normally or is woken up. When the vehicle is working normally or is woken up, the power supply 110 flows through the ordinary eFuse circuit 120 to supply power to the electrical equipment.

[0040] The low-power eFuse circuit 200 adopts a low-power, low-current design with extremely low static power consumption. Compared to the ordinary eFuse circuit 120 with approximately 5mA, the low-power eFuse circuit 200 can achieve an extremely low static power consumption of less than 100µA, which is only 2% of the power consumption of the ordinary eFuse circuit 120. At the same time, it can support low-power constant power supply in the range of 20mA to 50mA, which can fully meet the constant power needs of the vehicle in sleep mode. The low-power eFuse circuit 200 is used to provide low-power constant power to electrical equipment when the vehicle is in sleep mode. When the vehicle is in sleep mode, only a very small current needs to be provided to the load for its sleep mode. Therefore, switching to the low-power eFuse circuit 200 to power electrical equipment can meet the highest requirements of the vehicle's static power consumption.

[0041] For example, the gateway operates at a current of 5A. When the vehicle goes into sleep mode, the gateway switches to sleep mode with a sleep current of <1mA. At this time, its power supply can be switched to the low-power eFuse circuit 200. This eFuse circuit adopts a low-power, low-current design, such as a load capacity of 30mA. Because the load capacity is much smaller than the normal power supply of 5A, the static power consumption is extremely low.

[0042] Furthermore, when the smart power distribution box 10 is in a sleep state, the controller 140 controls the ordinary eFuse circuit 120 to disconnect and controls the low-power eFuse circuit 200 to turn on; when the smart power distribution box 10 is initially powered on or woken up, the controller 140 controls the ordinary eFuse circuit 120 to turn on and controls the low-power eFuse circuit 200 to disconnect.

[0043] Specifically, when the smart power distribution box 10 is in sleep mode, it only needs to provide a very small current to the load for its sleep use. Therefore, it switches to the low-power eFuse circuit 200 to power the electrical equipment. The low-power eFuse circuit 200 adopts a low-power, low-current design and has extremely low power consumption, but it cannot provide a large current to the load for a long time.

[0044] In addition, the low-power eFuse circuit 200 can supply power to multiple electrical devices at the same time. Even if the whole vehicle needs multiple constant power supplies, it can meet the needs. After the vehicle is woken up, the power supply of the low-power eFuse circuit 200 will be automatically turned off and switched to the ordinary eFuse circuit 120 without affecting the normal operation of the load.

[0045] Furthermore, the low-power eFuse circuit 200 includes: a power input interface, an output interface, a control interface, and a wake-up interface. The power input interface is connected to the power supply 110, the output interface is connected to the power-consuming device, and the control interface and wake-up interface are connected to the controller 140; a first transistor, a third field-effect transistor, a fifth field-effect transistor, and a sixth resistor. The first transistor has a first base, a first collector, and a first emitter, and the first base is connected to the control interface via the fifth resistor. The first collector is connected to the power input interface via a second resistor, and the first emitter is grounded. The third field-effect transistor has a third gate, a third source, and a third drain, and the third gate is connected to the power input interface via the second resistor, and the third source is grounded. The fifth field-effect transistor has a fifth gate, a fifth source, and a fifth drain, and the fifth gate is connected to the third drain via a fourth resistor. The fifth source is connected to the power input interface, and the fifth drain is connected to the output interface via a seventh resistor. One end of the sixth resistor is connected to the first base, and the other end of the sixth resistor is grounded.

[0046] Specifically, A is the power input interface, B is the output interface, C is the control interface, and D is the wake-up interface; Q1 is the first transistor; Q3 is the third field-effect transistor, which is an N-MOSFET; Q5 is the fifth field-effect transistor, which is a P-MOSFET; R2 is the second resistor, R4 is the fourth resistor, R5 is the fifth resistor, R6 is the sixth resistor, and R7 is the seventh resistor. The power input interface is connected to the source of Q5, and then outputs low-power constant power through the current-limiting resistor R7. The drain of Q5 is connected to one end of R7, and the other end of R7 is connected to the output interface. The gate of Q5 is pulled up to the power input interface through R3, and is also connected to the drain of Q3 through R4. The source of Q3 is grounded, and the gate is pulled up to the power input interface through R2, and is also connected to the collector of Q1. The emitter of Q1 is grounded, and the base is connected to the control interface through R5, and is also pulled down to ground through R6. One end of R5 is connected to the control interface, and the other end of R5 is connected to the first base of Q1, which is responsible for isolating the low-power eFuse circuit 200 from the MCU.

[0047] The control interface is active low, meaning the low-power eFuse circuit 200 is enabled when the control interface is low. In other words, the low-power eFuse constant power output is active when there is no control signal at the control interface; when the control interface is high, the low-power eFuse constant power output is disabled. To reduce circuit power consumption, after the controller 140 enters sleep mode, the controller 140 can release the control interface, meaning it does not control the control interface. At this time, the control signal is invalid, R6 pulls Q1 low, putting Q1 off. The gate of Q3 is pulled high by R2 to the power supply voltage 110, turning Q3 on and pulling the gate of Q5 low, turning Q5 on. Low-power constant power is then output through R7. Since the supply current is relatively small at this time, a resistor-limited current-dividing design is feasible. Firstly, it limits the output current; secondly, it provides overcurrent protection for Q5 when the output interface is short-circuited.

[0048] Taking a 24V system as an example, if the static power consumption of the entire vehicle is 25mA, and R7 is selected as 10Ω, the output voltage will be: 24V-25mA. 10Ω = 23.75V, while the 24V system requires a power supply voltage range of 16V to 32V, and 23.75V can meet the power supply voltage requirements; if the control interface is high, Q1 is turned on, pulling the gate of Q3 low, Q3 is turned off, then the gate of Q5 is pulled high, Q5 is turned off, and the low-power eFuse output is turned off.

[0049] Further, see Figure 2The low-power constant-power circuit includes a first topology architecture; the first topology architecture uses a low-power eFuse circuit 200 to power multiple electrical devices. The output interface of the low-power eFuse circuit 200 is connected to multiple electrical devices through multiple diodes. Each electrical device is connected to a regular eFuse circuit 120. The regular eFuse circuit 120 and the low-power eFuse circuit 200 are isolated from each other by diodes.

[0050] Specifically, in the first topology, when the vehicle is working normally, the controller 140 controls multiple ordinary eFuse circuits 120 to be turned on and controls the low-power eFuse circuit 200 to be turned off; when the vehicle is in sleep mode, the controller 140 controls the low-power eFuse circuit 200 to be turned on, supplies power to multiple electrical devices through multiple diodes, and controls multiple ordinary eFuse circuits 120 to be turned off.

[0051] The circuit output can be connected in parallel with a standard eFuse circuit 120 via multiple diodes, allowing for continuous power supply to multiple appliances requiring constant power during sleep mode; simultaneously, the output remains unaffected when the standard eFuse circuit 120 is powered. For example... Figure 2 As shown, U2 is a low-power eFuse circuit 200, and U4-U6 are ordinary eFuse circuits 120. When the system is initially powered on or woken up, the controller 140 controls the ordinary eFuse circuits U4, U5, and U6 to power the first power-consuming device 131, the second power-consuming device 132, and the third power-consuming device 133. The low-power eFuse circuit 200 is in the off state, the ordinary eFuse circuit outputs a higher voltage, and the diodes D1, D2, and D3 are reverse-biased and cut off. The low-power eFuse circuit 200 does not affect the power supply of the ordinary eFuse circuit.

[0052] When the sleep conditions are met, the controller 140 turns on the low-power eFuse circuit 200 to supply power to the electrical devices through D1, D2, and D3 respectively, and then turns off the ordinary eFuse circuits U4, U5, and U6. The controller 140 enters the sleep state to reduce system power consumption. At this time, the diodes are forward-biased to achieve low-power power supply.

[0053] If any of the first power-consuming device 131, the second power-consuming device 132, or the third power-consuming device 133 is awakened, its operating current will increase significantly compared to its dormant current. At this time, the low-power eFuse circuit 200 can wake up the controller 140 through the wake-up interface. After the controller 140 is awakened, it will turn on the ordinary eFuse circuit 120 to supply power to the load and turn off the low-power eFuse circuit 200. Of course, the constantly powered devices can also wake up the smart distribution box 10 through network or hard-wired signals. After being awakened, the controller 140 will turn on the ordinary eFuse circuit 120 to supply power to the load and turn off the low-power eFuse circuit 200.

[0054] Further, see Figure 3 The low-power constant-current circuit includes a second topology architecture; the second topology architecture configures a normal eFuse circuit 120 and a low-power eFuse circuit 200 for each power-consuming device, and the normal eFuse circuit 120 and the low-power eFuse circuit 200 are connected in parallel to the corresponding power-consuming device.

[0055] Specifically, in the second topology, when the vehicle is working normally, the controller 140 controls the ordinary eFuse circuit 120 corresponding to each electrical device to be turned on, and controls the low-power eFuse circuit 200 corresponding to each electrical device to be turned off; when the vehicle is in sleep mode, the controller 140 controls the low-power eFuse circuit 200 corresponding to each electrical device to be turned on, and controls the ordinary eFuse circuit 120 corresponding to each electrical device to be turned off.

[0056] To address different power distribution attributes and load control requirements, a low-power eFuse circuit 200 is paired with each constantly powered load. Each power supply is independently controllable and can provide independent high-performance power supply and accurate wake-up detection. However, this will correspondingly increase power consumption and cost. Figure 3 As shown, U7-U9 are low-power eFuse circuits 200, and U4-U6 are ordinary eFuse circuits 120. Ordinary eFuses U4, U5, and U6 supply power to the first power-consuming device 131, the second power-consuming device 132, and the third power-consuming device 133. Low-power eFuse circuits 200 U7, U8, and U9 are connected in parallel with U4, U5, and U6 respectively, that is, each constant power supply uses two independent eFuses to supply power.

[0057] In the wake-up state, U4, U5, and U6 provide constant power to the first power user 131, the second power user 132, and the third power user 133. In the sleep state, U7, U8, and U9 provide low-power constant power to the first power user 131, the second power user 132, and the third power user 133, respectively. If any power user, such as the first power user 131, is woken up, the controller 140 will be woken up and will turn on the corresponding constant power eFuse, such as U4, to supply power to it, while turning off U7.

[0058] This invention provides two topologies: The first topology uses a low-power eFuse circuit 200 to provide constant power to multiple power supply loops, but the power supply capacity will be reduced, and accurate wake-up detection cannot be provided. This topology is simpler, has lower power consumption, and lower overall cost. The second topology uses a low-power eFuse circuit 200 for each device, with each power supply being independently controllable and providing independent power supply and accurate wake-up detection. However, power consumption and cost will increase accordingly. Both topologies can meet the constant power supply requirements of loads with different power distribution attributes, improving the flexibility of the system solution while balancing demand and cost.

[0059] Furthermore, the low-power eFuse circuit 200 also includes a seventh field-effect transistor and a ninth field-effect transistor. The seventh field-effect transistor has a seventh gate, a seventh source, and a seventh drain. The seventh gate is connected to the output interface via an eighth resistor, the seventh source is connected to the output interface via a seventh resistor, and the seventh drain is grounded. The ninth field-effect transistor has a ninth gate, a ninth source, and a ninth drain. The ninth gate is connected to the seventh drain, the ninth source is grounded, and the ninth drain is connected to the wake-up interface.

[0060] Specifically, Q7 is the seventh field-effect transistor, a P-MOSFET; Q9 is the ninth field-effect transistor, an N-MOSFET; and R8 is the eighth resistor. The drain of Q5 is connected to the source of Q7, and the gate of Q7 is connected to the output interface via R8 for output voltage detection. The drain of Q7 is connected to the gate of Q9, and the drain of Q9 is connected to the wake-up interface, while its source is grounded.

[0061] When the low-power eFuse circuit 200 is turned on, i.e., when the output is valid, if the downstream load wakes up abnormally and the current exceeds the vehicle's power consumption, for example, increasing from 20mA to 400mA, the output voltage will be pulled down to: 24V-400mA. 10Ω = 20V, which means that the gate voltage of Q7 drops from 23.75V to 20V, a decrease of 3.75V. This voltage will drive Q7 to turn on, and the voltage of power supply 110 will drive Q9 to turn on after being divided, pulling the wake-up interface low and waking up controller 140. During this period, the supply voltage drops to 20V, but it can still meet the power supply voltage requirements of the electrical equipment.

[0062] Furthermore, the low-power eFuse circuit 200 also includes: a third resistor, a voltage divider circuit, a first capacitor, and a second capacitor. One end of the third resistor is connected to the fifth gate, and the other end of the third resistor is connected to the power input interface. One end of the voltage divider circuit is connected to the seventh drain, and the other end of the voltage divider circuit is grounded. The voltage divider circuit includes a ninth resistor and a tenth resistor connected in series, and the ninth gate is connected between the ninth resistor and the tenth resistor. One end of the first capacitor is connected to the ninth gate, and the other end of the first capacitor is grounded. One end of the second capacitor is connected to the output interface, and the other end of the second capacitor is grounded.

[0063] Specifically, R9 is the ninth resistor, and R10 is the tenth resistor; the drain of Q7 is connected to the gate of Q9 after voltage division by resistors R9 and R10. C1 is the first capacitor, and C2 is the second capacitor; C1 is connected to the gate of Q9 for filtering, and the output interface is connected to an energy storage capacitor C2, which can provide instantaneous high current power supply capability for normally powered electrical appliances.

[0064] The low-power constant-current circuit of this invention is constructed entirely using discrete components such as MOSFETs, transistors, resistors, and capacitors. The circuit is simple, highly reliable, widely applicable, and low in cost.

[0065]

Example 2

[0066] See Figure 4 This embodiment also provides a software strategy for the low-power constant-current circuit applied to the first embodiment above. The software strategy includes:

[0067] S1: After the smart power distribution box is initially powered on or woken up, the controller controls the ordinary eFuse circuit to be turned on, and at the same time controls the low-power eFuse circuit to be turned off.

[0068] S2: When the vehicle meets the sleep conditions, the controller controls the low-power eFuse circuit to turn on and controls the ordinary eFuse circuit to turn off, and the smart power distribution box enters the sleep state.

[0069] S3: When the smart power distribution box is in sleep mode, determine whether the controller has received a wake-up signal;

[0070] S4: When the controller receives a wake-up signal, the smart power distribution box is woken up, controls the ordinary eFuse circuit to turn on, and at the same time controls the low-power eFuse circuit to turn off.

[0071] In one specific embodiment, after the smart power distribution box is initially powered on or woken up, the controller first performs initialization operations, including detecting the status of each interface and initializing control signals. After initialization, the controller controls the ordinary eFuse circuit to conduct to supply power to the electrical equipment, while controlling the low-power eFuse circuit to disconnect to ensure that the electrical equipment receives sufficient rated current during normal operation. The controller monitors the working status of the smart power distribution box and each electrical equipment in real time to determine whether the sleep conditions are met. The sleep conditions include that the smart power distribution box has not received any working instructions (such as remote control instructions, vehicle operation instructions, etc.) within a preset time (such as 30 minutes), and all electrical equipment is in a sleep state (determined by detecting the current or status signals of each electrical equipment). When the sleep conditions are met, the controller first controls the low-power eFuse circuit to conduct to provide low-power constant power to the electrical equipment. After the low-power eFuse circuit stabilizes, the controller controls the ordinary eFuse circuit to disconnect. At this time, the smart power distribution box enters a sleep state to reduce overall power consumption. In the sleep state, the controller is in a low-power mode, but still maintains monitoring of the wake-up signal.

[0072] Furthermore, the wake-up signal includes active wake-up signal and passive wake-up signal; active wake-up signal includes hard-wired wake-up signal and network wake-up signal; passive wake-up signal is generated by low-power eFuse circuit when it detects that the current of the power device exceeds a preset threshold and is sent to the controller.

[0073] Specifically, the low-power constant-power circuit also supports active wake-up and passive wake-up functions: active wake-up can be achieved through a hard-wired wake-up signal or network wake-up. That is, in sleep mode, if a hard-wired wake-up signal or network wake-up is valid, the smart distribution box will be woken up. After being woken up, the ordinary eFuse will be turned on to supply power to the electrical equipment, while the low-power eFuse will be turned off (that is, the constant-power supply of the low-power eFuse circuit will automatically switch to the power supply of the ordinary eFuse circuit).

[0074] Passive wake-up occurs when the power supply current of a normally powered appliance increases significantly (i.e., the appliance is woken up before the smart distribution box is activated, at which point the current of the appliance will increase sharply). At this time, the low-power eFuse circuit can detect the abnormal current increase event and automatically wake up the controller through the wake-up interface. The controller then turns on the ordinary eFuse circuit to supply power to the appliance.

[0075] In sleep mode, if a device switches to normal operating mode without waking the smart distribution box, its current will increase dramatically. For example, the gateway's current might increase from 0.5mA in sleep mode to 300mA after waking. The low-power eFuse circuit can detect this abnormal current increase and automatically wake up the MCU. The MCU then activates the regular eFuse circuit to supply power to the device, increasing the power supply capacity to 5A, meeting the device's normal operating requirements. Besides passive wake-up, the smart distribution box also supports conventional network wake-up or signal wake-up. If a hard-wired wake-up signal or network wake-up is valid, the smart distribution box can be woken up. After waking, the MCU will activate the regular eFuse circuit to supply power to the device while simultaneously disabling the low-power eFuse circuit.

[0076] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A low-power constant-current circuit for a smart power distribution box, characterized in that, The low-power constant-current circuit includes: A normal power supply circuit includes: a power supply (110), a normal eFuse circuit (120), electrical equipment and a controller (140), and the normal eFuse circuit (120) is connected between the power supply (110) and the electrical equipment; A low-power eFuse circuit (200) is provided, wherein the input terminal of the low-power eFuse circuit (200) is connected to the power supply (110), and the output terminal of the low-power eFuse circuit (200) is connected to the electrical device. The controller (140) is electrically connected to the ordinary eFuse circuit (120) and the low-power eFuse circuit (200), respectively. The low-power eFuse circuit (200) includes: The device includes a power input interface, an output interface, a control interface, and a wake-up interface. The power input interface is connected to the power supply (110), the output interface is connected to the electrical device, and the control interface and the wake-up interface are connected to the controller (140). The first transistor has a first base, a first collector, and a first emitter. The first base is connected to the control interface via a fifth resistor, the first collector is connected to the power input interface via a second resistor, and the first emitter is grounded. The third field-effect transistor has a third gate, a third source, and a third drain, and the third gate is connected to the power input interface via the second resistor, and the third source is grounded; The fifth field-effect transistor has a fifth gate, a fifth source, and a fifth drain. The fifth gate is connected to the third drain via a fourth resistor, the fifth source is connected to the power input interface, and the fifth drain is connected to the output interface via a seventh resistor. A sixth resistor, one end of which is connected to the first base, and the other end of which is grounded; A third resistor, one end of which is connected to the fifth gate, and the other end of which is connected to the power input interface.

2. The low-power constant-current circuit according to claim 1, characterized in that, When the smart power distribution box (10) is in a sleep state, the controller (140) controls the ordinary eFuse circuit (120) to disconnect and controls the low-power eFuse circuit (200) to turn on; When the smart power distribution box (10) is initially powered on or woken up, the controller (140) controls the ordinary eFuse circuit (120) to turn on and controls the low-power eFuse circuit (200) to turn off.

3. The low-power constant-current circuit according to claim 1, characterized in that, The low-power constant-current circuit includes a first topology. The first topology uses a low-power eFuse circuit (200) to power multiple electrical devices. The output interface of the low-power eFuse circuit (200) is connected to multiple electrical devices through multiple diodes. Each electrical device is connected to a regular eFuse circuit (120). The regular eFuse circuit (120) and the low-power eFuse circuit (200) are isolated from each other by the diodes.

4. The low-power constant-current circuit according to claim 1, characterized in that, The low-power constant-current circuit includes a second topology. The second topology is that each of the electrical devices is configured with a normal eFuse circuit (120) and a low-power eFuse circuit (200), and the normal eFuse circuit (120) and the low-power eFuse circuit (200) are connected in parallel to the corresponding electrical device.

5. The low-power constant-current circuit according to claim 1, characterized in that, The low-power eFuse circuit (200) also includes: The seventh field-effect transistor has a seventh gate, a seventh source, and a seventh drain. The seventh gate is connected to the output interface via an eighth resistor, the seventh source is connected to the output interface via the seventh resistor, and the seventh drain is grounded. The ninth field-effect transistor has a ninth gate, a ninth source, and a ninth drain. The ninth gate is connected to the seventh drain, the ninth source is grounded, and the ninth drain is connected to the wake-up interface.

6. The low-power constant-current circuit according to claim 5, characterized in that, The low-power eFuse circuit (200) also includes: A voltage divider circuit is provided, one end of which is connected to the seventh drain, and the other end of which is grounded. The voltage divider circuit includes a ninth resistor and a tenth resistor connected in series, and the ninth gate is connected between the ninth resistor and the tenth resistor. A first capacitor, one end of which is connected to the ninth gate, and the other end of which is grounded; The second capacitor has one end connected to the output interface and the other end grounded.

7. A software strategy for low-power constant-current circuits, characterized in that, The software strategy is applied to the low-power constant-current circuit for a smart power distribution box as described in claims 1-6, and the software strategy includes: After the smart power distribution box is initially powered on or woken up, the controller controls the ordinary eFuse circuit to turn on and the low-power eFuse circuit to turn off. When the vehicle meets the sleep conditions, the controller controls the low-power eFuse circuit to turn on and controls the ordinary eFuse circuit to turn off, and the smart power distribution box enters the sleep state. When the smart power distribution box is in sleep mode, it is determined whether the controller has received a wake-up signal; When the controller receives the wake-up signal, the smart power distribution box is woken up, controls the ordinary eFuse circuit to turn on, and simultaneously controls the low-power eFuse circuit to turn off.

8. The software strategy according to claim 7, characterized in that, The wake-up signal includes an active wake-up signal and a passive wake-up signal; The active wake-up signal includes: a hard-wired wake-up signal and a network wake-up signal; The passive wake-up signal is generated by the low-power eFuse circuit when it detects that the current of the electrical device exceeds a preset threshold and is sent to the controller.

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