Power supply unit and power supply system

Abstract

The invention relates to a power supply unit (5) and to a power supply system, the power supply unit comprising a resistor (R), a first switch (T1) and a second switch (T2), and being designed to be connected between a supply voltage (Vbatt) and a load (40) such that a quiescent current is provided to the load (40) via the resistor (R). A first monitoring unit (10) is designed to monitor the current consumption of the load (40) and to generate a first signal (S1) if the current consumption exceeds a quiescent current threshold value. The power supply unit (5) is also designed to switch on the first switch (T1) in response to the first signal (S1) such that an activation current which is greater than the quiescent current is provided to the load (40) via the resistor (R) and the first switch (T1) and to switch on the second switch (T2) after the first switch (T1) in order to supply the load (40) with a full load current which is greater than the activation current. The second monitoring unit (20) is designed to monitor the full load current and to generate a second signal if the full load current exceeds an overload current threshold value. Lastly, the power supply unit (5) is designed to switch off the first switch (T1) and the second switch (T2) in response to the second signal being generated.

Description

[0001] Description

[0002] title

[0003] Power supply unit and a power supply system

[0004] State of the art

[0005] The present invention relates to a power supply unit and a power supply system with such a power supply unit.

[0006] More and more electrical components and / or systems are being permanently powered by electrical energy. This includes, among others, battery-powered consumer systems, remote controls, wearables (i.e., electrical components worn on the body), and systems that must remain functional for extended periods without recharging a battery.

[0007] But applications in the automotive sector are also increasingly affected. In this context, electronic safety systems are one example, which are increasingly replacing conventionally used fuses for overcurrent protection of electrical components.

[0008] One advantage of conventional fuses is that they do not consume any power themselves, which reduces the operating time of battery-powered components.

[0009] Electronic protection systems are known as an alternative in the prior art. These systems, for example, disconnect a load from a power source using semiconductor switches in the event of a short circuit or overcurrent. However, when protecting a large number of individual components (such as multiple control units in a vehicle) with separate electronic protection systems, the power consumption of these systems can be correspondingly high.

[0010] In consumer applications, prior art therefore employs methods such as keeping a system without power until it is awakened by a key press or similar user action, or switching off for specific idle periods, e.g., in the multi-digit millisecond range, and then automatically reactivating itself. Such long idle periods, compared to the active time, ensure low average power consumption.

[0011] Disclosure of the invention

[0012] According to a first aspect of the present invention, a power supply unit is proposed which comprises a resistor, a first switch, a second switch, a first monitoring unit and a second monitoring unit.

[0013] The resistor, the first switch and the second switch are connected in parallel to each other between a first terminal of the power supply unit and a second terminal of the power supply unit.

[0014] The power supply unit is designed to be connected via the first connection to a supply voltage from a voltage source (e.g. a battery, etc.) and via the second connection to a load which is supplied by the supply voltage.

[0015] The power supply unit is further configured to switch the first and second switches off and / or keep them in a switched-off state in a standby mode, so that a quiescent current is supplied to the load via the resistor. To ensure the lowest possible power consumption of the power supply unit according to the invention, the resistor is preferably designed with a correspondingly high resistance. The first monitoring unit is configured, in particular based on a voltage measurement across the resistor, to monitor the current consumption of the load and to generate a first signal when the current consumption exceeds a predefined quiescent current threshold.The predefined quiescent current threshold is therefore preferably determined based on information about the expected quiescent current range of a load supplied by the power supply unit according to the invention. Such a quiescent current range of the load can represent a typical current consumption of the load in a standby mode, where the standby mode of the load can be understood in particular as a state of the load in which at least some of the components contained in the load are deactivated or in which they are operated in a mode with reduced current consumption. Preferably, in such a standby mode of the load, all components are deactivated that are not required for necessary background tasks and / or a wake-up process of the load.

[0016] Preferably, the predefined quiescent current threshold is set higher than the highest expected current consumption in a standby mode of the load, taking into account a safety tolerance.

[0017] The power supply unit is further configured to activate the first switch upon receiving the first signal, so that an activation current, greater than the quiescent current, is supplied to the load via the resistance and switching path of the first switch. The activation current can be understood, in particular, as the current drawn by the load when it exits its standby mode and activates one or more components or subunits that were previously deactivated in standby mode or in a state of reduced current consumption.

[0018] The activation current can therefore be considered a current drawn by the load during a transition phase between standby and active modes, in order to switch the load's internal system into active mode. Using the example of a vehicle's control unit, the control unit itself may already be fully energized during such a transition phase, while actuators connected to and supplied by the control unit are still at least partially in a non-activated state. Specifically, for example, during the transition phase, a control unit of an ultrasonic system, which supplies individual ultrasonic sensors of the vehicle with electrical energy, may already be fully energized, while the connected ultrasonic sensors, which typically have a relatively high current draw in active operation, are still deactivated.In fully activated operation of such an ultrasound system, both the control unit and the connected ultrasound sensors would therefore be fully activated and powered.

[0019] The power supply unit is also configured to turn on the second switch after the first switch in order to supply the load with a full load current that is greater than the activation current.

[0020] For example, the time to switch on the second switch after the first switch has been switched on is determined based on information about the duration and / or the respective phases and / or current requirements of a load start-up process.

[0021] Alternatively or additionally, it is possible that the power supply unit is configured to switch on the second switch in response to receiving an activation signal from the load and / or another component.

[0022] Alternatively or additionally, it is possible for the power supply unit to be configured to switch on the second switch when a current drawn by the load exceeds a predefined activation current threshold, which is higher than the quiescent current threshold and lower than the full load current of the load in the fully activated state.

[0023] The second monitoring unit is configured to monitor the full load current and generate a second signal if the full load current exceeds a predefined overcurrent threshold, wherein the second monitoring unit is configured to be activated after the first switch is turned on and wherein the second monitoring unit, when activated, has a higher current consumption than the first monitoring unit.

[0024] The overcurrent threshold is preferably set such that it lies above a typical current draw range of the load during active operation. Furthermore, the overcurrent threshold can advantageously be determined based on the maximum continuous current carrying capacity of the overall system, comprising the power supply system, the load, and the voltage source, or by other means.

[0025] The power supply unit is finally set up to switch off the first switch and the second switch in response to the generation of the second signal.

[0026] Based on the configuration described above, the energy supply unit according to the invention is advantageously set up to provide and monitor the current for a load in a staggered manner in accordance with a respective operating mode of the load.

[0027] This offers the advantage that, in a standby mode where the load draws only a small amount of current, power is supplied via a primary supply path, i.e., via the resistor. This also provides a particularly simple and energy-efficient way to monitor the current in standby mode. A simple comparison circuit, which compares the current draw of the load with the standby current threshold and preferably has low power consumption, is therefore sufficient to operate the power supply unit in the standby mode.

[0028] A particularly simple, cost-effective and energy-saving design of the first monitoring unit can be achieved, for example, by connecting a gate-source path of a field-effect transistor (FET) in parallel with the resistor, so that the field-effect transistor switches on from a certain voltage drop across the resistor, which corresponds to the quiescent current threshold, in order to switch on the first switch via its drain-source path.

[0029] The first signal can therefore be a simple turn-on signal for a control input of the first switch to turn it on. Preferably, the first switch is designed such that it can be turned on using the supply voltage without step-up conversion. In this way, few or no additional circuit components are required to turn on the first switch when the load enters the activation phase, thus saving both costs and the space required for these components.

[0030] The energy supply unit according to the invention, based on its staged power supply and current monitoring, offers the particular advantage that the second switch, which preferably has a higher current-carrying capacity than the first switch, only needs to be activated when a full load current is required at the load. This allows the use of switches for the second switch that require a higher control voltage than the supply voltage, since a voltage converter required for this purpose only needs to be activated, for example, when the transition to the fully activated state of the load is imminent. This prevents unnecessarily high power consumption by the energy supply unit according to the invention in the standby mode and / or activation mode of the load.

[0031] According to the invention, this ensures a particularly low power consumption in the standby mode of the load, which in particular allows battery-operated components to be operated for a particularly long period of time without recharging and / or replacing a battery.

[0032] The staggered monitoring of the current also offers the advantage that overcurrent and / or short-circuit monitoring by the second monitoring unit is only required in the fully active mode of the load with the full load current consumption, so that a potentially complex circuit used within the second monitoring unit, which may have high power consumption, does not have to be permanently operated in the background in the idle mode of the load.

[0033] It should be generally noted that the resistor preferably has a higher resistance value than the switching path of the first switch when the first switch is on, and that a switching path of the second switch when on preferably has a lower resistance value than the switching path of the first switch when on.

[0034] This can be achieved, for example, by using transistors with different on-resistances ("RDSON") for the first and second switches, and / or by connecting at least one current-limiting resistor in series with the first switch. This resistor limits the current through the path of the first switch (second supply path) more strongly than the current through the path of the second switch (third supply path) when they are in the on state. In this way, the current can be limited accordingly during the activation phase, so that even in the event of a short circuit in the load, only a limited current can flow.

[0035] It should also be noted that the first switch and / or, in particular, the second switch may each consist of a large number of switches connected in parallel, each of which is controlled uniformly in order to provide a higher overall current-carrying capacity if required.

[0036] In summary, the energy supply unit according to the invention thus enables a power supply and current monitoring with a particularly low self-consumption during a standby mode of a load, which also offers the possibility of a particularly fast disconnection of the load from a voltage supply in the event of an overcurrent, based on the switches used.

[0037] A further advantage arises from the fact that the invention

[0038] In contrast to a conventionally used fuse, the energy supply unit provides a reversible safety function, so that, for example, in a case where an overcurrent occurs only briefly due to a temporary fault, after disconnecting the load from the voltage source, it is possible to re-energize the load based on the energy supply unit according to the invention as soon as the fault is no longer present.

[0039] The dependent claims describe preferred embodiments of the invention.

[0040] Preferably, the first switch and / or the second switch is designed as a semiconductor switch, in particular as a FET, or as an electromechanical switch.

[0041] In an advantageous embodiment of the present invention, the first switch is configured as a p-channel FET and / or the second switch is configured as an n-channel FET. Using an n-channel FET, which typically requires higher control voltages than the p-channel FET, meaning that a given supply voltage may not be directly usable as a control voltage, offers the advantage that, compared to the p-channel FET, it can be configured with a smaller area when switching identical power levels, thereby reducing the area required for the power supply unit according to the invention.

[0042] Furthermore, the resistor can be linear and / or non-linear (e.g., a transistor, a diode, etc.). Alternatively or additionally, the first monitoring unit is advantageously based on a comparator, which allows for low power consumption. The comparator is configured, for example, to compare a voltage drop across the resistor with a reference voltage value that corresponds to the quiescent current threshold. Preferably, in such a case, an output of the comparator is directly connected to the control input of the first switch in order to immediately switch on the first switch when the quiescent current threshold is exceeded.Preferably, the first monitoring unit is configured to generate and not generate the first signal using a hysteresis function, in order to prevent unwanted switching back and forth between the respective switching states of the first switch when the current consumption of the load is near the quiescent current threshold. Alternatively or additionally, a capacitor can be connected in parallel and / or in series with the resistor to smooth the measured current.

[0043] In a further advantageous embodiment of the present invention, the power supply unit is configured to detect a fault (in particular an overcurrent fault and / or a different fault) in standby mode and / or during the activation process and, in the event of a fault detection, to prevent the switching on of the first switch and / or the second switch.

[0044] Alternatively or additionally, it is possible that the supply voltage is lower than a control voltage required to switch on the second switch and / or that the power supply unit is configured to provide the control voltage for switching on the second switch based on a voltage converter which is inactive in the load's standby mode and which is configured to provide the control voltage based on the supply voltage. For example, the power supply unit according to the invention is configured to activate the voltage converter during the transition from standby mode to activation mode or during the load's activation mode, so that the control voltage for the second switch is available in good time before or at the beginning of the switching-on process of the second switch.

[0045] In a further advantageous embodiment of the present invention, the second monitoring unit is configured to monitor the full load current based on an i2t characteristic curve, so that a similar or identical tripping behavior of the protective function of the power supply unit according to the invention is achieved as with a conventional fuse. This can be advantageously used, among other things, when an existing overcurrent protection system based on a fuse with identical tripping behavior is to be replaced by the power supply unit according to the invention and / or to generally provide a certain fault tolerance in the case of short-term overcurrent events.

[0046] Advantageously, the power supply unit further comprises at least one third switch (or a plurality of parallel-connected and identically controlled third switches) on the basis of which the power supply unit is configured to provide the load with an additional current that differs from the quiescent current, the activation current, and the full load current. Furthermore, it is possible to provide a third monitoring unit that monitors the current provided on the basis of the third switch. It is also possible for the second monitoring unit and such a third monitoring unit to form a single monitoring unit.

[0047] According to a second aspect of the present invention, a power supply system is proposed which comprises a power supply unit according to the first aspect of the invention, a voltage source and a load, wherein the power supply unit is connected to the voltage source via the first connection, is connected to the load via the second connection and is configured to supply the load with a supply voltage provided by the voltage source.

[0048] Brief description of the drawing

[0049] An embodiment of the invention is described in detail below with reference to the accompanying drawing. The drawing shows:

[0050] Figure 1 shows an exemplary circuit diagram of an energy supply system according to the invention based on an energy supply unit according to the invention.

[0051] embodiment of the invention

[0052] Figure 1 shows an exemplary circuit diagram of a device according to the invention.

[0053] energy supply system based on an inventive device

[0054] Energy supply unit 5. The energy supply unit 5 according to the invention is, for example, an energy supply unit 5 of a (not shown) vehicle, which is configured to supply one or more control units and / or loads of the vehicle other than these with electrical energy.

[0055] The power supply unit 5 is connected via a first connection 30 to a voltage source 60 designed as a vehicle battery, which is set up to provide a supply voltage Vbatt of 12 V.

[0056] The power supply unit 5 is connected via a second connection 32 to a load 40 designed as an ultrasonic control unit, which is supplied by means of the supply voltage Vbatt.

[0057] A high-resistance resistor R, a first switch T1 designed as a p-channel FET and a second switch T2 designed as an n-channel FET are each connected in parallel to each other between the first terminal 30 of the power supply unit 5 and the second terminal 32 of the power supply unit 5.

[0058] The power supply unit 5 is configured to put the first switch T 1 and the second switch T2 into an off state and / or keep them in an off state in a standby mode of the load 40, so that a quiescent current is provided to the load 40 via the resistor R.

[0059] A first monitoring unit 10 of the power supply unit 5, which is designed here as a comparator 50, is set up to monitor the current consumption of the load 40 on the basis of a voltage measurement across the resistor R and to generate a first signal S1 when the current consumption exceeds a predefined quiescent current threshold.

[0060] The power supply unit 5 is further configured to switch on the first switch T1 in response to the generation of the first signal S1, so that an activation current, greater than the quiescent current, is supplied to the load 40 via the resistor R and a switching path of the first switch T1. For this purpose, an output of the comparator 50 is connected to a gate terminal of the first switch T1.

[0061] Furthermore, the power supply unit 5 is configured to switch on the second switch T2 after a predefined period following the switching on of the first switch T 1, in order to supply the load 40 with a full load current at that time, the full load current being greater than the activation current.

[0062] For this purpose, the on-resistance of the second switch T2 is designed to be lower than the on-resistance of the first switch T1, so that a correspondingly higher current can be supplied to the load 40 via the second switch T2. The delayed on-delivery of the second switch T2 in response to the first signal S1, relative to the first switch T1, is achieved by a delay element 70, which transmits the first signal S1 to a second monitoring unit 20 of the power supply unit 5 according to the invention with a delay of the predefined period.

[0063] The delay time realized by the delay element 70 is set in such a way as to correspond to a start behavior of the load 40 that the full load current is only provided immediately before the activation of a large number of (not shown) ultrasonic control devices, which are activated and supplied with electrical energy via the ultrasonic control device during the start process.

[0064] The second monitoring unit 20 is intended here, firstly, for monitoring the current consumption of the load 40 in the fully activated state of the load 40, but it also functions here as a control unit, which is set up to specify the respective switching states of the first switch T 1 and the second switch T2.

[0065] For this purpose, the second monitoring unit 20 is electrically connected to a control input of an auxiliary switch TA, via which the second control unit 20 is configured to control the first switch T1 independently of the generation of the first signal S1. Furthermore, the second monitoring unit 20 is electrically connected to a gate terminal of the second switch T2 and configured to provide a control voltage for the second switch T2 that is higher than the supply voltage Vbatt.

[0066] The monitoring of the current consumption of load 40 in the fully activated state of load 40 is carried out in the second monitoring unit 20 by means of a

[0067] Voltage measurement across a drain-source path of the second switch T2. The load 40 is configured to generate a second signal if the full load current exceeds a predefined overcurrent threshold. Since the second signal S2 is generated and processed within the second monitoring unit 20, it is not identified by a reference symbol in the figure.

[0068] Finally, the power supply unit 5 is set up on the basis of the second monitoring unit 20 to switch off the first switch T1 and the second switch T2 in response to the generation of the second signal in order to provide a safety function in case of an overcurrent.

Claims

Claims 1. Energy supply unit (5) comprising: - a resistance (R), - a first switch (T1), - a second switch (T2), - a first monitoring unit (10), and - a second monitoring unit (20), wherein - the resistor (R), the first switch (T1) and the second switch (T2) are connected in parallel to each other between a first terminal (30) of the power supply unit (5) and a second terminal (32) of the power supply unit (5), - the power supply unit (5) is set up, - to be connected to a supply voltage (Vbatt) via the first terminal (30), - to be connected via the second terminal (32) to a load (40) which is supplied by the supply voltage (Vbatt), - in a standby mode of the load (40) to put the first switch (T1) and the second switch (T2) into an off state and / or keep them in an off state, so that a quiescent current is supplied to the load (40) via the resistor (R), - the first monitoring unit (10) is set up, in particular on the basis of a voltage measurement across the resistance (R), to monitor the current consumption of the load (40) and to generate a first signal (S1) when the current consumption exceeds a predefined quiescent current threshold, - the power supply unit (5) is set up, - to switch on the first switch (T1) in response to the generation of the first signal (S1), so that the load (40) is connected via the A resistance (R) and a switching path of the first switch (T1) provide an activation current which is greater than the quiescent current, and - to switch on the second switch (T2) after the first switch (T1) in order to supply the load (40) with a full load current that is greater than the activation current, - the second monitoring unit (20) is configured to monitor the full load current and generate a second signal if the full load current exceeds a predefined overcurrent threshold, wherein the second monitoring unit (20) - is set up to be activated after the first switch (T1) is turned on, and - in the activated state has a higher current consumption than the first monitoring unit (10), and - the power supply unit (5) is set up to switch off the first switch (T1) and the second switch (T2) in response to the generation of the second signal.

2. Power supply unit (5) according to one of the preceding claims, wherein the first switch (T1) and / or the second switch (T2) is configured as - Semiconductor switches, especially FETs, or - is designed as an electromechanical switch.

3. Energy supply unit (5) according to claim 2, wherein - the first switch (T1) is designed as a p-channel FET, and / or - the second switch (T2) is designed as an n-channel FET.

4. Energy supply unit (5) according to one of the preceding claims, wherein - the resistance (R) is a linear and / or a non-linear resistance, and / or - the first monitoring unit (10) is trained on the basis of a comparator (50).

5. Energy supply unit (5) according to one of the preceding claims, wherein - the first monitoring unit (10) is set up to generate and not generate the first signal (S1) using a hysteresis function, and / or - a capacitor (C) is connected in parallel and / or in series with the resistor (R).

6. Power supply unit (5) according to one of the preceding claims, wherein the power supply unit (5) is configured, - to detect an error in sleep mode and / or during the activation process, and - to prevent the first switch (T1) and / or the second switch (T2) from being switched on in the event of a fault detection.

7. Energy supply unit (5) according to one of the preceding claims, wherein - the supply voltage (Vbatt) is lower than a control voltage required to switch on the second switch (T2), and / or - the power supply unit (5) is configured to provide the control voltage for switching on the second switch (T2) based on a voltage converter which is inactive in the idle mode of the load (40) and which is configured to provide the control voltage based on the supply voltage (Vbatt).

8. Power supply unit (5) according to one of the preceding claims, wherein the second monitoring unit (20) is configured to monitor the full load current based on an i 2 To monitor the t-characteristic curve.

9. Power supply unit (5) according to one of the preceding claims further comprising at least a third switch, on the basis of which the power supply unit (5) is configured to provide the load (40) with a further current different from the quiescent current, the activation current and the full load current.

10. Equipping an energy supply system: - a power supply unit (5) according to any one of the preceding claims, - a voltage source (60), and - a load (40), wherein the power supply unit (5) - is connected to the voltage source (60) via the first connection (30), - is connected to the load (40) via the second connection (32), and - is set up to supply the load (40) with a supply voltage (Vbatt) provided by the voltage source (60).

Images