CIRCUIT ARRANGEMENT AND METHOD FOR OPERATING SUCH A CIRCUIT ARRANGEMENT

Abstract

Circuit arrangement comprising: - a first electronic switch with an insulated gate; - a second electronic switch with an insulated gate; - a measuring device for determining a charge on the insulated gate of the first electronic switch and on the insulated gate of the second electronic switch; - a power supply unit for providing charge to the insulated gate of the first electronic switch and to the insulated gate of the second electronic switch based on the charge determined by the measuring device; - a logic unit for activating the first electronic switch, both or none of the electronic switches; - wherein the circuit arrangement is configured to be operated in at least one of the following states: - a first ON state in which the insulated gate of the first electronic switch and that of the second electronic switch are supplied with a high amount of charge via the power supply unit; - a second ON state in which the insulated gate of the first electronic switch is supplied with a high amount of charge via the power supply unit; - a first IDLE state in which the insulated gate of the first electronic switch and that of the second electronic switch are supplied with a small amount of charge via the power supply unit; or - an OFF state in which the first electronic switch and the second electronic switch are switched off.

Description

[0001] Embodiments of the present invention relate to a power-optimized control for an electronic switch.

[0002] US 7 576 588 B2 relates to a switching device for an NMOSFET switch, in which the gate voltage of the NMOSFET switch is kept at a level other than zero, which level is just insufficient to switch on the NMOSFET switch.

[0003] One object is, in particular, to create an improved or more efficient possibility for power-optimized operation of an electronic switch or an electronic switch arrangement.

[0004] This object is achieved according to the features of the independent claims. Preferred embodiments can be found in particular in the dependent claims.

[0005] The examples proposed herein may, in particular, be based on at least one of the following solutions. In particular, combinations of the following features could be used to achieve a desired result. The features of the method may be combined with any feature(s) of the device, apparatus, or system, or vice versa.

[0006] A circuit arrangement is specified, comprising - a first electronic switch with an insulated gate; - a second electronic switch with an insulated gate; - a measuring device for determining a charge on the insulated gate of the first electronic switch and on the insulated gate of the second electronic switch; - a power supply unit for providing charge to the insulated gate of the first electronic switch and to the insulated gate of the second electronic switch based on the charge determined by the measuring device; - a logic unit for activating the first electronic switch, both or none of the electronic switches; - wherein the circuit arrangement is configured to be operated in at least one of the following states: - a first ON state in which the insulated gate of the first electronic switch and that of the second electronic switch are supplied with a high amount of charge via the power supply unit; - a second ON state in which the insulated gate of the first electronic switch is supplied with a high amount of charge via the power supply unit; - a first IDLE state in which the insulated gate of the first electronic switch and that of the second electronic switch are supplied with a small amount of charge via the power supply unit; or - an OFF state in which the first electronic switch and the second electronic switch are switched off.

[0007] Therefore, based on the logic unit and based on the measuring device, several states of the circuit arrangement are offered. In a first IDLE state, both electronic switches are active and the measuring device, in combination with the power supply unit, ensures that the charges on the gates do not fall below a predetermined threshold. In a first ON state, both electronic switches are active in a high-current mode. In a second ON state, only one of the electronic switches is active, which supports a low-current mode with the ability to sense a lower current than in the first ON state. In a second IDLE mode, the energy saving of the circuit arrangement is active: only one of the electronic switches is active, and the measuring device, in combination with the power supply unit, ensures that the charges on the gate do not fall below a predetermined threshold.

[0008] The measuring device may comprise at least one measuring device for each of the electronic switches. It is noted that each of the electronic switches, ie, the first electronic switch and / or the second electronic switch, may comprise at least one electronic switch, in particular a plurality of electronic switches.

[0009] The logic unit can activate or deactivate the electronic switches via at least one driver.

[0010] It is a further development that the first electronic switch is a switch with lower power than the second electronic switch.

[0011] The first electronic switch and the second electronic switch may share a chip area (e.g., DMOS area), with the first electronic switch having a smaller portion of this area than the second electronic switch. The ratio between the area used by the first electronic switch and the area used by the second electronic switch may be, for example, 1:200.

[0012] It is a further development that the power supply unit is configured to supply the isolated gates of the electronic switches either with a high amount of charge or with a low amount of charge.

[0013] In the first IDLE state and the second IDLE state, the gates of the electronic switches can be supplied with the small amount of charge. Specifically, in the first IDLE state, the gates of the first and second electronic switches can be supplied with the small amount of charge, while in the second IDLE state, only the gate of the first electronic switch is supplied with the small amount of charge.

[0014] It is a further development that the energy supply unit comprises at least one of the following: - a single charge pump; - a single charge pump with a low energy mode and a high energy mode; - a low-power charge pump and a high-power charge pump; - more than two charge pumps, at least two of which have different power levels; - at least one current source and one current mirror; - a high current path and a low current path, wherein the high current path comprises at least one high current source and the low current path comprises at least one low current source.

[0015] It is a development that the circuit arrangement further comprises a first driver coupled between the power supply unit and the insulated gate of the first electronic switch, and a second driver coupled between the power supply unit and the insulated gate of the second electronic switch.

[0016] It is a further development that the logic unit is configured to directly or indirectly control the energy supply unit of the first electronic switch and the second electronic switch, wherein the measuring device is connected to the logic unit in order to supply the logic unit with the determined charge or information about the determined charge.

[0017] It is a development that the energy supply unit comprises a low-power charge pump and wherein the logic unit is configured to select the low-power charge pump at least partially during at least one IDLE state.

[0018] It is a development that the at least one IDLE state is entered when a device to which the circuit arrangement is connected enters a low-energy mode.

[0019] It is a further development that the electronic switch is temporarily reactivated from the at least one IDLE state when the charge at the isolated gate falls below a predefined threshold.

[0020] It is a further development that the logic unit is set up, - based on a trigger, to reactivate the electronic switch from the at least one IDLE state by supplying its insulated gate with a higher amount of charge compared to the charge provided during the at least one IDLE state, - to perform a predefined action and - to reactivate at least one IDLE state.

[0021] It is a further development that the trigger is at least one of the following: - an external signal applied to the logic unit; - a detection of an error; - detection of a temperature exceeding a predetermined threshold; - detection of a current exceeding a predetermined threshold; - a trigger provided by a timer or clock.

[0022] It is a further education that the predefined action includes at least one of the following: - sensing a current; - sensing a temperature; - issuing a notice; or - recharging the isolated gate.

[0023] It is a further development that the circuit arrangement further comprises a measuring unit for determining at least one of the following triggers: - a temperature exceeding a predetermined threshold; - a current exceeding a predetermined threshold; - a change of polarity; - a current flowing in the wrong direction, which can be harmful to a logic circuit; - a timer.

[0024] It is a further education that - the power supply unit comprises a high-performance charge pump and - the logic unit is configured to select the high-performance charge pump at least partially during at least one ON state.

[0025] It is a further development that the at least one ON state is entered when a device to which the circuit arrangement is connected enters a normal operating mode.

[0026] It is a further development that the logic unit is configured to switch the electronic switch to the OFF state if a short circuit or overtemperature is detected or if a predefined signal is supplied to the logic unit.

[0027] It is a further development that the measuring device comprises a comparison unit, wherein inputs of the comparison unit are connected to at least one of the first electronic switch or the second electronic switch in order to determine a voltage across terminals of the electronic switch.

[0028] It is a further development that the logic unit initiates a transition from the first ON state to the second ON state if a load current reaches or falls below a predetermined threshold.

[0029] It is a further development that the circuit arrangement is set up to be operated in the following state: - a second IDLE state in which the insulated gate of the first electronic switch is supplied with a small amount of charge via the power supply unit.

[0030] It is a further development that the logic unit initiates a transition from the first ON state to the second IDLE state if a load current is detected that reaches or falls below at least a predetermined threshold, or if no diagnostic or sensing functionality is required.

[0031] It is a further development that the logic unit initiates a transition from the first IDLE state to the second IDLE state if a load current is detected that reaches or falls below at least a predetermined threshold, or if no diagnostic or sensing functionality is required.

[0032] It is a further development that the circuit arrangement comprises a memory unit for storing at least one state.

[0033] It is a further development that the electronic switch comprises at least one of the following: - a transistor, - a PMOS, - an NMOS, - a FET, - a JFET, - an IGBT.

[0034] It is a further development that the electronic switch is an n-channel high-side switch.

[0035] Furthermore, a vehicle is proposed which comprises at least one circuit arrangement as described herein.

[0036] A method is also provided for controlling a first electronic switch with an insulated gate and a second electronic switch with an insulated gate, the method comprising: - detecting charge at the insulated gate of the first electronic switch and at the insulated gate of the second electronic switch; - providing charge to the insulated gate of the first electronic switch and to the insulated gate of the second electronic switch based on the determined charge; - activating either the first electronic switch, both electronic switches or none of the electronic switches; - in which the electronic switches are operated in at least one of the following states: - a first ON state in which the insulated gate of the first electronic switch and that of the second electronic switch are supplied with a high amount of charge via the power supply unit; - a second ON state in which the insulated gate of the first electronic switch is supplied with a high amount of charge via the power supply unit; - a first IDLE state in which the insulated gate of the first electronic switch and that of the second electronic switch are supplied with a small amount of charge via the power supply unit; - an OFF state in which the first electronic switch and the second electronic switch are switched off.

[0037] It is a further development that a transition from the first ON state to the second ON state is carried out if a load current reaches or falls below a predetermined threshold.

[0038] It is a further education that - the first electronic switch and the second electronic switch are reactivated from the first IDLE state to the first ON state when the charge on the insulated gate falls below a predetermined threshold; - the charge on the insulated gate is increased; - the first IDLE state is re-entered.

[0039] It is a further development that the electronic switches are operated in the following state: - a second IDLE state in which the insulated gate of the first electronic switch is supplied with a small amount of charge via the power supply unit.

[0040] It is a further development that a transition from the first ON state to the second IDLE state is performed if a load current reaches or falls below at least a predetermined threshold, or if no diagnostic or sensing functionality is required.

[0041] It is a further development that a transition from the first IDLE state to the second IDLE state is carried out if a load current is detected which at least reaches or falls below a predetermined threshold, or no diagnostic or sensing functionality is required.

[0042] It is a further development that the first IDLE state or the second IDLE state is entered when a device to which the electronic switches are connectable enters a low-power mode.

[0043] It is a further education that - based on a trigger, a state transition is performed from the first IDLE state to the first ON state or from the second IDLE state to the second ON state or from the second IDLE state to the first ON state, - a predefined action is carried out; - the first IDLE state or the second IDLE state is reactivated.

[0044] It is a further development that the trigger is at least one of the following: - an external signal applied to the logic unit; - a detection of an error; - detection of a temperature exceeding a predetermined threshold; - detection of a current exceeding a predetermined threshold; - a trigger provided by a timer or clock.

[0045] It is a further education that the predefined action includes at least one of the following: - sensing a current; - sensing a temperature; - issuing a notice; or - recharging the isolated gate.

[0046] It is a further development that the electronic switch enters the OFF state if a short circuit or overtemperature is detected, or in the case of a predefined signal.

[0047] An electronic circuit arrangement is also specified, comprising: - means for detecting charge at an insulated gate of a first electronic switch and at an insulated gate of a second electronic switch; - means for providing charge to the insulated gate of the first electronic switch and to the insulated gate of the second electronic switch based on the determined charge; - Means for activating either the first electronic switch, both electronic switches or neither of them.

[0048] Embodiments are presented and illustrated with reference to the drawings. The drawings serve to illustrate the basic principle, so that aspects necessary for understanding the basic principle are presented. The drawings are not to scale. In the drawings, like reference numerals represent like features. Fig. 1 shows a state diagram of a circuit breaker including an OFF state, a first IDLE state, a first ON state, a second IDLE state, and a second ON state; Fig. 2 shows an alternative state diagram for a circuit breaker based on the Fig. 1 shown state diagram; Fig. 3 shows another state diagram for a circuit breaker based on the one shown in Fig. 1 shown state diagram; Fig. Figure 4 shows a summary table of various states of a circuit breaker; Fig. Figure 5 shows a schematic block diagram of a circuit breaker.

[0049] Examples given herein relate to power switches that can be used to replace passive fuses or relays in devices, e.g. in the automotive field, in particular in vehicles such as cars. In the following, the term electronic switch can be used for any type of electronic switching functionality in various use case scenarios. The electronic switch can comprise at least one of the following: a transistor, a PMOS, an NMOS, a FET, a JFET, an IGBT, etc. The electronic switch can have an insulated gate that can serve as a control input. The device described herein can be any device that can be subject to a low-power or standby mode. In particular, the device can be a car, a control unit of a car. Car or vehicle, mentioned below, are examples of such devices.However, the presented solution is not limited to such devices.

[0050] The solution can be used in a high-current switching scenario. The solution can be implemented on a single chip (e.g., a piece of semiconductor) or it can be distributed across various components, e.g., chips.

[0051] The solution can refer to four or five states of a circuit breaker, which include the following: - an OFF state; - a first IDLE state; - a first ON state; - a second ON state; and - optional: a second IDLE state.

[0052] The first ON state can correspond to a high-power ON state that supports a high current (e.g., 30 A). In this context, the first ON state can correspond to the ON state of a relay. When used in an automotive environment, the first ON state of the circuit breaker can be used, e.g., when a vehicle is moving.

[0053] The first IDLE state can support high current, but in this state, the power switch itself consumes only a small amount of energy, e.g., in the range below 100 µA. This can apply—with respect to the automotive scenario—to the vehicle in a parked state.

[0054] A current sensing functionality (also referred to as current measurement functionality) may be provided that enables an autonomous or controlled (e.g., by a microcontroller, processor) transition to another state if a sensed current meets a predetermined condition, e.g., reaches or exceeds a predetermined threshold. In such a case, overcurrent protection may be realized by providing a shutdown functionality, e.g., by entering the OFF state.

[0055] An overcurrent can be detected, e.g. in the (first or second) NO-LOAD state, and this can autonomously lead to a transition to the OFF state, thus providing the functionality of a fuse.

[0056] The overcurrent level for triggering entry into the OFF state can be controlled. This applies to the transition(s) from the ON state and / or the NO-LOAD state and allows the safety functionality to be adjusted according to a load (e.g., a wire).

[0057] Current sensing (also referred to as "measuring a current" or "current sensing") of high currents can be achieved in the first open-circuit state, and current sensing of low currents can be achieved in the second open-circuit state. For example, currents up to 10 mA can be sensed in the second open-circuit state when there should normally be no current at all. According to another example, currents up to 150 A can be sensed in the second open-circuit state. The circuit breaker can thus provide a solution for switching sensed current ranges using either the first open-circuit state or the second open-circuit state.

[0058] Switching between the current detection regions can be achieved by switching between the ON resistances of two switches arranged in parallel, one of which has a low resistance and the other a higher resistance. Preferably, the two switches have different sensing current ratios, comparable to different shunt resistors used for shunt current detection.

[0059] The circuit breaker allows for a high current carrying capacity to be provided without interruption, even when the low-current sensing range is activated. This feature can be achieved by autonomously switching the state of the circuit breaker, i.e., by entering the high-current sensing range when necessary, thus avoiding any damage to the circuit, in particular to the at least one switch of the circuit breaker, and thus simultaneously ensuring a continuous power supply (alternating current) to the load connected to the circuit breaker.

[0060] The different states of the circuit breaker can be controlled via control terminals that can be driven by a microcontroller.

[0061] In the event of a fault and / or if a predetermined threshold is exceeded, the circuit breaker can safely enter a predefined state: For example, the circuit breaker can enter its OFF state if an overcurrent is detected or if a temperature exceeding a predetermined threshold is detected. As another example, a different current sensing range can be autonomously selected if the current exceeds a (different) predefined threshold.

[0062] Optionally, an error flag can be set if the circuit breaker has performed an autonomous state change.

[0063] Another option is for the circuit breaker to remain in the state it was in before the voltage drop after a voltage drop of a predefined magnitude and / or exceeding the predefined magnitude. This can apply to the ON state, the first IDLE state, the second IDLE state, and the OFF state.

[0064] The examples described herein can be applied to, but are not limited to, an automotive scenario. For example, vehicles cycle through various states (e.g., driving, parked, waiting) and may even have multiple levels of standby. These states may require different current carrying capacities as well as different current sensing ranges. Circuit breakers used may need to accommodate these requirements and also consume minimal power when active (depending on the vehicle's state). Circuit breaker operation may function seamlessly without interruptions, providing safety functionality for the vehicle.

[0065] The solution described can be implemented in a single semiconductor chip. In one example, a power switch with multiple states is implemented in a single chip. In particular, several such power switches can be implemented in a single chip. Optionally, other circuitry can also be implemented on the same chip. A logic unit for controlling the power switch, in particular the states and state transitions of the power switch, can also be installed on the semiconductor chip. The logic unit can also be provided separately. One option is for the logic unit to control more than one power switch.

[0066] The circuit breaker can cover a current range of, for example, 10 mA to 30 A. Optionally, multiple circuit breakers can be arranged in parallel to cover current ranges of more than 30 A.

[0067] An example use case scenario could be a circuit breaker in a vehicle's electrical system. The circuit breaker provides safety and monitoring functionality. The circuit breaker can be used for both high and low current loads and can support various vehicle states.

[0068] The circuit breaker can be controlled by a processor or microcontroller, e.g., via connectors. This enables flexible and customized applications of the circuit breaker in diverse scenarios. In particular, it is possible to protect current paths to loads in the vehicle's electrical system, even when the vehicle is in different states (e.g., driving, standby, parked, etc.).

[0069] The circuit breaker states can be monitored, and a transition to another state can be triggered based on a predefined condition. This allows both the vehicle and the circuit breaker to be protected.

[0070] Optionally, a feedback mechanism can be provided to detect, for example, a transition between the circuit breaker's states that was triggered internally rather than externally. This allows, for example, an autonomous state transition to be flagged for a microcontroller driving the circuit breaker.

[0071] In particular, the power switch can provide cold start robustness of up to 3.2 V, for example.

[0072] Fig. Figure 1 shows a state diagram of a circuit breaker comprising: - an OFF state 101; - a first IDLE state 102; - a first ON state 103; - a second ON state 105; and - optional: a second IDLE state 104.

[0073] The states of the circuit breaker can be explained in more detail below: (1) OFF state 101: The OFF state 101 can have two internal states: a fault OFF state with a set buffer, and a normal OFF state. If the circuit breaker reaches the OFF state 101 due to an internal safety feature, the fault OFF state indicates via the buffer (which can be implemented as a status indicator that can be set or reset) that the OFF state 101 was reached by internal mechanisms and not by external control. The normal OFF state indicates that the entire switch (e.g., chip if implemented as a single chip) has been deactivated (e.g., due to an external control signal). In the OFF state 101, the switch consumes very little power. (2) first ON state 103: In the first ON state 103, a low drain-source resistance may be enabled, the power switch may have a low DMOS resistance, normal power consumption, and provide full safety functionality. Such safety functionality may include: - Overcurrent protection; - Overtemperature protection; - Polarity protection; and - Protection of the logic circuitry against the wrong current direction. Preferably, the available DMOS area is activated, providing high current carrying capacity. High currents can be sensed. A microcontroller can be supplied with information about the sensed current via at least one pin, which can then be used to simulate a fuse using software, meaning the fuse functionality can depend on the magnitude of the sensed current. This first ON state 103 is used in particular during an active state of a roaming vehicle or during a current sensing functionality provided during a parked state of the vehicle. (3) first IDLE state 102: In the first IDLE state 102, the power switch has a low drain-source resistance and consumes very little power (e.g., approximately 30 µA). The switch can provide basic safety features, such as overvoltage protection (if the drain-source voltage reaches or exceeds a predetermined threshold) and overtemperature protection. The IDLE state 102 may be used when a vehicle is in a long-term parked state. The circuit breaker can transition from the NO-LOAD state 102 to the first ON state 103 and / or the second ON state 105, triggered by a control unit (e.g., a microcontroller) to perform a current sensing. After performing the current sensing, the circuit breaker can return to the NO-LOAD state 102. (4) second ON state 105: In the second ON state 105, the power switch has a higher drain-source resistance than in the first ON state 103, normal power consumption, and limited safety functionality: In case of overcurrent and / or overtemperature, the power switch is turned off. In the second ON state 105, the circuit breaker can sense (e.g., measure or (indirectly) determine) small currents (e.g., 10 mA). This enables the detection of a very low leakage current, which more effectively protects a vehicle's electrical system. A microcontroller can be supplied with the sensed current (or any information related to the sensed current) via at least one terminal and can be used to simulate a fuse in software to protect a low-power load and / or a thin wire, e.g. in the range between 10 mA and 1.5 A. This second ON state 105 can be advantageously used for accurate measurements of small currents, e.g. during a driving state or a parked state of a vehicle. (5) second IDLE state 104: In the second IDLE state 104, the power switch has a higher drain-source resistance than in the first IDLE state 102 and consumes very little power (e.g., approximately 30 µA). The switch can provide basic safety features, such as overvoltage protection (if the drain-source voltage reaches or exceeds a predetermined threshold) and overtemperature protection.

[0074] The second IDLE state 104 may be used when a vehicle is in a long-term parked state, wherein a connection with a thin wire or a high impedance load may be used.

[0075] The circuit breaker can transition from the second IDLE state 104 to the first ON state 103 and / or to the second ON state 105, triggered by a control unit (e.g., a microcontroller) to perform a current sensing. After performing the current sensing, the circuit breaker can return to the second IDLE state 104.

[0076] According to one example, the power switch may include two electronic switches referred to as DMOS A and DMOS B. DMOS A and B may share a DMOS region in a 200:1 (A:B) ratio. In the second IDLE state 104 and the second ON state 105, only DMOS B is enabled, and in the first IDLE state 102 and the first ON state 103, DMOS A and DMOS B are enabled. Each of these electronic switches may include a drain, a source, and a gate terminal. Therefore, DMOS A may be referred to as a high-power DMOS, and DMOS B may be referred to as a low-power DMOS.

[0077] It is noted that other types of electronic switches may also be used. For example, a transistor, a PMOS, an NMOS, a FET, a JFET, an IGBT, etc. Furthermore, it is noted that DMOS A and / or DMOS B may each comprise at least one electronic switch.

[0078] A low power charge pump may be used to drive the electronic switches of the power switch in the first IDLE state 102 and the second IDLE state 104, and a high power charge pump may be used to drive the electronic switches in the first ON state 103 and the second ON state 105.

[0079] Various types of charge pump(s) could be implemented, e.g., two charge pumps as described above, e.g., a high-power charge pump and a low-power charge pump. Alternatively, a single charge (e.g., high-energy) pump could be used. Another option is for the single charge pump to comprise two charge pump functionalities (the low-power and high-power charge pump) as described above, enabling the low-power mode of the electronic switch and the associated components (e.g., driver, comparator, etc.).

[0080] Below are the Fig. 1 shown transitions are described as examples: Transition 106: The state change from the first IDLE state 102 to the OFF state 101 is performed if an external control (e.g. a microcontroller) indicates a rapid shutdown. Transition 150: The state change from the first IDLE state 102 to the OFF state 101 is performed if one of the following conditions occurs: - a drain-source voltage of one of the electronic switches of the power switch exceeds a predetermined threshold, e.g. 100 mV; - an overtemperature condition is met. Transition 107: The power switch remains in the first IDLE state 102 if a high current is to be maintained. The source-drain voltage at the power switch (e.g., at the low-power DMOS B of the power switch) does not exceed a predetermined current and / or temperature protection level. Transitions 113 and 114: Transition 113 from the first IDLE state 102 to the first ON state 103 is performed if the high-load current is still required and diagnostic and sensing functionality is required. Accordingly, transition 114 is performed when the diagnostic and sensing functionality is no longer required. Transitions 111 and 112: Transition 111 from the OFF state 101 to the first ON state 103 is performed if the circuit breaker is activated. Accordingly, transition 112 is performed when the circuit breaker is deactivated (turned off). Transition 151: Transition 151 is the consequence of another autonomous protection feature of the circuit breaker: when an overcurrent protection threshold reaches or exceeds a predetermined limit or when an (over)temperature condition is met, the circuit breaker enters the OFF state 101 from the ON state 103. Transition 108: The circuit breaker remains in the first ON state 103 if the load still requires high current and if full protection and sensing functionality is required. Transition 116: The transition 116 from the first ON state to the second ON state indicates that the load current reaches or falls below a predetermined threshold (e.g., 10 A) and that DMOS A is turned off to activate the low current sensing region. Transition 115: The transition 115 from the second ON state to the first ON state indicates that the load current reaches or exceeds a predetermined threshold (e.g., 2.5 A) and that DMOS A is turned on to activate the high current sensing section and enter a reduced power consumption mode of the power switch. Transition 110: The circuit breaker remains in the second ON state 105 if the load current remains low (e.g., below the 2.5 A threshold) and if full protection and sensing functionality is required. Furthermore, the circuit breaker remains in the low-current sensing range. Transitions 123 and 124: Transition 124 from the second ON state 105 to the second IDLE state 104 is performed if the load current remains low (e.g., below the threshold of 2.5 A) and (e.g., periodic) diagnostic and sensing functionality is not required. Accordingly, transition 123 is performed if diagnostic and sensing functionality is required. Transition 109: The power switch remains in the second IDLE state 104 if the load current remains low (e.g., below the 2.5 A threshold). The source-drain voltage at the power switch (e.g., at the power switch's low-power DMOS B) does not exceed a predetermined current and / or temperature protection level. Transitions 121 and 122: Transition 121 from the second IDLE state 104 to the first ON state 103 is performed if the load current switches between high and low (e.g., greater than 2.5 A or less than 2.5 A, respectively) and if (e.g., periodic) diagnostic and sensing functionality is required. Accordingly, transition 122 is performed if the diagnostic and sensing functionality is not required. Transition 152: The state change from the second IDLE state 104 to the OFF state 101 is performed in the event of one of the following conditions: - a drain-source voltage of one of the electronic switches of the power switch exceeds a predetermined threshold, e.g. 500 mV; - an overtemperature condition is met.

[0081] Transitions 150 to 152 may be a result of the circuit breaker's integrated autonomous protection features. The remaining transitions may be a result of an external trigger or a control signal provided, for example, by a microcontroller.

[0082] Fig. Figure 2 shows an alternative state diagram for a circuit breaker that implements some of the Fig. 1. In addition to the above description concerning Fig. 1 will be in Fig. 2 the following transitions are presented: Transition 202: The transition 202 from the first IDLE state 102 to the second IDLE state 104 is performed when a low load current (e.g., below 2.5 A) is detected. DMOS A is turned off to activate a low-power consumption mode of the power switch. Transition 201: Transition 201 from the second IDLE state 104 to the first IDLE state 102 is performed when a drain-source voltage of one of the electrical switches of the power switch exceeds a predetermined threshold, e.g., 500 mV. DMOS A is turned on to reduce the resistance (drain-source resistance) of the power switch. Transition 203: Transition 203 from the first ON state 103 to the second IDLE state 104 is performed when a low load current (e.g., below 2.5 A) is detected. DMOS A is turned off to activate a low-power mode of the power switch. Transition 154: The state change from the first IDLE state 102 to the first ON state 103 is performed if a drain-source voltage of one of the electrical switches of the power switch exceeds a predetermined threshold, e.g. 100 mV, and the overtemperature condition is met. Transition 155: A state change from the second IDLE state 104 to the first ON state 103 is performed if a drain-source voltage of one of the electrical switches of the power switch exceeds a predetermined threshold, e.g. 500 mV, and the overtemperature condition is met. Transition 156: The state change from the second ON state 105 to the first ON state 103 is carried out in the event of one of the following conditions: - a drain-source voltage of one of the electrical switches of the power switch exceeds a predetermined threshold, e.g. 500 mV; - an overtemperature condition is met.

[0083] Transitions 151 and 154 to 156 may be a result of the circuit breaker's integrated autonomous protection features. The remaining transitions may be a result of an external trigger or a control signal provided, for example, by a microcontroller.

[0084] Fig. 3 shows another alternative state diagram for a circuit breaker based on the one shown in Fig. 1 shown diagram. In contrast to Fig. 1, state 101 is replaced by state 301, which includes a FAULT-OFF state and an OFF state. Transitions 150 to 152 and transition 157 refer to the FAULT-OFF state, which may include a buffer or a status indicator that allows detection that a transition that triggered state 301 was based on an autonomous protection feature of the circuit breaker. Transitions 106 and 112 refer to the OFF state portion of state 301.

[0085] In addition to the above description regarding Fig. 1 is in Fig. 3 the following transition is presented: Transition 157: When an (over)temperature condition is met, the circuit breaker enters the (FAULT) OFF state 301 from the second ON state 105.

[0086] Before reaching the OFF state, the DMOS devices (drivers) of the power switch can both be enabled, so that both DMOS devices can share the voltage energy.

[0087] Fig. Figure 4 shows a summary table of the various states 101 to 105 with regard to the drain-source resistance (Rds_on) and the protection functions provided for each of the states 101 to 105. The current sensing feature is available in the first and second ON states, respectively, where "kilis" determines a current sense signal ratio (load current divided by sense current). Furthermore, the first and second ON states are capable of detecting a current that exceeds an overcurrent protection threshold (Itrip), which may be, for example, 150 A. In such a case, the circuit breaker can be autonomously opened, setting a buffer memory indicating that the OFF state has been entered due to an internal protection feature.

[0088] In the idle states, detection of the drain-source voltage (Vds) is possible, with different Vds thresholds being applicable. In such a case, the circuit breaker can be autonomously turned off, setting a buffer memory indicating that the OFF state has been entered due to an internal protection feature.

[0089] In the OFF state, an open load can be tested and compared with a predetermined Vds threshold.

[0090] (Over)temperature protection is possible in any of the ON and NO-LOAD states. If an (over)temperature event is detected, the circuit breaker can be autonomously opened, setting a buffer memory indicating that the OFF state has been entered due to an internal protection feature.

[0091] Fig. Figure 5 shows an exemplary block diagram with an n-channel MOSFET M1 driven by a (gate) driver 502 and an n-channel MOSFET M2 driven by a (gate) driver 503. The drain of the MOSFET M1 and the drain of the MOSFET M2 are connected to a node 508, which is connected to a supply voltage 504. The source of the MOSFET M1 is connected to the source of the MOSFET M2. Both source terminals of the MOSFETs M1 and M2 can be connected to a (in Fig. 5 not shown) resistor must be connected to ground.

[0092] It is noted that MOSFET M2 may correspond to high-power DMOS A and MOSFET M1 may correspond to low-power DMOS B (as explained above). Therefore, - in the first NO-LOAD state and in the first ON state both MOSFET M1 and M2 are active, while - in the second IDLE state and in the second ON state only the MOSFET M1 is active.

[0093] A logic unit 501 controls driver 502 and driver 503. Logic unit 501 may be any type of control device, e.g., a microcontroller, a controller, a processor, or the like. Logic unit 501 may control a high-power charge pump 506 and a low-power charge pump 507. High-power charge pump 506 and low-power charge pump 507 are each connected to supply voltage 504 and provide power to drivers 502 and 503 depending on the control signal(s) applied by logic unit 501.

[0094] The logic unit 501 is controlled via a single input contact 505. Optionally, multiple input contacts can be provided (in Fig.1) to supply the logic unit 501 with external signals. The logic unit 501 may be part of a single-chip solution. Alternatively, at least part of the logic unit 501 may be arranged separately, in particular separately from the charge pumps 506, 507, the drivers 502, 503, and / or the switches M1, M2.

[0095] However, instead of a huge number of input contacts, the logic unit 501 may include a decoder capable of decoding various structures (“instructions”), e.g., bit sequences, to determine which decision to make.

[0096] Based on (the number of) input contacts and / or such structures, the user has a high degree of flexibility to apply the various functionalities of the electronic switch and the components driving the electronic switch, especially with regard to low-energy modes.

[0097] The high-power charge pump 506 displays an oscillator signal 601, which is fed into an inverter 602. The output of the inverter 602 is connected to a node 607 via a capacitor C2 and to a node 608 via a series connection comprising an inverter 603 and a capacitor C1. Node 508 is connected to node 607 via a diode 604, and node 607 is connected to node 608 via a diode 605. Node 608 is connected to the driver 502 and to the driver 503 via a diode 606. All diodes 604, 605, and 606 are arranged so that their cathodes point toward the drivers 502, 503, respectively.

[0098] The low-power charge pump 507 displays an oscillator signal 609, which is fed into an inverter 610. The output of the inverter 610 is connected to a node 615 via a capacitor C4 and to a node 616 via a series connection comprising an inverter 611 and a capacitor C3. Node 508 is connected to node 615 via a diode 612, and node 615 is connected to node 616 via a diode 613. Node 616 is connected to driver 502 and driver 503 via a diode 614. All diodes 512, 513, and 514 are arranged so that their cathodes point toward the gate drivers 502, 503, respectively.

[0099] The gate driver 502 comprises two current mirrors 623, 624 and two current sources 621, 622. The logic unit 501 controls the gate driver 502: a signal applied to a node 617 activates either a switch 620 (when the signal output by the logic unit 501 is high) or—via an inverter 618—the switch 619 (when the signal output by the logic unit 501 is low). When the switch 620 is activated, the current from the current source 621 is mirrored to a node 625 and thus used to control the gate of the MOSFET M1. When the switch 619 is activated, the current from the current source 622 is mirrored to the gate of the MOSFET M1. Therefore, the logic unit 501 can indicate to the gate driver whether the gate of the MOSFET M1 is actively charging or discharging.

[0100] The gate driver 503 comprises two current mirrors 633, 634 and two current sources 631, 632. The logic unit 501 controls the gate driver 503: a signal applied to a node 627 activates either a switch 630 (when the signal output by the logic unit 501 is high) or—via an inverter 628—the switch 629 (when the signal output by the logic unit 501 is low). When the switch 630 is activated, the current from the current source 631 is mirrored to a node 635 and thus used to control the gate of the MOSFET M2. When the switch 629 is activated, the current from the current source 632 is mirrored to the gate of the MOSFET M2. Therefore, the logic unit 501 can indicate to the gate driver whether the gate of the MOSFET M2 is actively charging or discharging.

[0101] The charge at the gate of MOSFET M1 can be maintained by the low-power charge pump 507. Furthermore, the charge at the gate of MOSFET M2 can be maintained by the low-power charge pump 507.

[0102] A comparison unit 510 includes a comparator 511 and a reference voltage 512, with the first input of comparator 511 connected to the gate of MOSFET 1 and to the gate of MOSFET M2. The second input of comparator 511 is connected to the source of MOSFET M1 and to the source of MOSFET M2 via the reference voltage 512. The output of comparator 511 is connected to the logic unit 501. The reference voltage 512 enables the adjustment of the deviation between the voltage difference between MOSFETs M1 and M2.

[0103] It is noted that instead of the comparison unit 510, which combines the measurement of the voltage across the MOSFETs M1 and M2, two comparison units may be provided, one for each of the MOSFETs M1 and M2, which provide a voltage difference signal to the logic unit 501.

[0104] The solution presented herein can be used in various scenarios. For example, the circuit breaker can be implemented in devices that operate in various states. One example is a vehicle, which may have different levels of energy consumption that could be associated with the circuit breaker states described herein. Furthermore, the circuit breaker could be used as a disconnect switch, e.g., for power supply units, batteries, or the like. Another alternative for the circuit breaker is to implement a (controlled) fuse and / or any type of relay switching function.

[0105] Although various embodiments of the invention have been disclosed, it will be apparent to those skilled in the art that various changes and modifications may be made that may achieve some advantages of the invention without departing from the spirit and scope of the invention. It will be apparent to those skilled in the art that other components performing the same functions may be suitably substituted. It should be noted that features explained with reference to a specific figure may be combined with features from other figures, even those not explicitly mentioned.Furthermore, the methods of the invention can be implemented either in software implementations using the appropriate processor instructions or in hybrid implementations using a combination of hardware and software logic to achieve the same results. Such modifications to the inventive concept are to be considered covered by the appended claims.

Claims

[1] Circuit arrangement comprising: - a first electronic switch with an insulated gate; - a second electronic switch with an insulated gate; - a measuring device for determining a charge on the insulated gate of the first electronic switch and on the insulated gate of the second electronic switch; - a power supply unit for providing charge to the insulated gate of the first electronic switch and to the insulated gate of the second electronic switch based on the charge determined by the measuring device; - a logic unit for activating the first electronic switch, both or none of the electronic switches; - wherein the circuit arrangement is configured to be operated in at least one of the following states: - a first ON state in which the insulated gate of the first electronic switch and that of the second electronic switch are supplied with a high amount of charge via the power supply unit; - a second ON state in which the insulated gate of the first electronic switch is supplied with a high amount of charge via the power supply unit; - a first IDLE state in which the insulated gate of the first electronic switch and that of the second electronic switch are supplied with a small amount of charge via the power supply unit; or - an OFF state in which the first electronic switch and the second electronic switch are switched off. [2] Circuit arrangement according to claim 1, wherein the first electronic switch is a switch with lower power than the second electronic switch. [3] Circuit arrangement according to one of the preceding claims, in which the power supply unit is arranged to supply the insulated gates of the electronic switches either with a high amount of charge or with a low amount of charge. [4] Circuit arrangement according to one of the preceding claims, in which the power supply unit comprises at least one of the following: - a single charge pump; - a single charge pump with a low energy mode and a high energy mode; - a low-power charge pump and a high-power charge pump; - more than two charge pumps, at least two of which have different power levels; - at least one current source and one current mirror; - a high current path and a low current path, wherein the high current path comprises at least one high current source and the low current path comprises at least one low current source. [5] Circuit arrangement according to one of the preceding claims, further comprising a first driver coupled between the power supply unit and the insulated gate of the first electronic switch, and a second driver coupled between the power supply unit and the insulated gate of the second electronic switch. [6] Circuit arrangement according to one of the preceding claims, in which the logic unit is arranged to directly or indirectly control the power supply unit of the first electronic switch and the second electronic switch, wherein the measuring device is connected to the logic unit in order to supply the logic unit with the determined charge or information about the determined charge. [7] Circuit arrangement according to one of the preceding claims, wherein the power supply unit comprises a low-power charge pump and wherein the logic unit is arranged to select the low-power charge pump at least partially during at least one IDLE state. [8] The circuit arrangement of claim 7, wherein the at least one IDLE state is entered when a device to which the circuit arrangement is connected enters a low power mode. [9] Circuit arrangement according to one of claims 7 or 8, wherein the electronic switch is temporarily reactivated from the at least one IDLE state when the charge on the insulated gate falls below a predefined threshold. [10] Circuit arrangement according to one of claims 7 to 9, in which the logic unit is arranged - based on a trigger, to reactivate the electronic switch from the at least one IDLE state by supplying its insulated gate with a higher amount of charge compared to the charge provided during the at least one IDLE state, - to perform a predefined action and - to reactivate at least one IDLE state. [11] A circuit arrangement according to claim 10, wherein the trigger is at least one of the following: - an external signal applied to the logic unit; - a detection of an error; - detection of a temperature exceeding a predetermined threshold; - detection of a current exceeding a predetermined threshold; - a trigger provided by a timer or clock. [12] Circuit arrangement according to one of claims 10 or 11, wherein the predefined action comprises at least one of the following: - sensing a current; - sensing a temperature; - issuing a notice; or - recharging the isolated gate. [13] Circuit arrangement according to one of claims 10 to 12, further comprising a measuring unit for determining at least one of the following triggers: - a temperature exceeding a predetermined threshold; - a current exceeding a predetermined threshold; - a change of polarity; - a current flowing in the wrong direction, which can be harmful to a logic circuit; - a timer. [14] Circuit arrangement according to one of the preceding claims, - in which the energy supply unit comprises a high-performance charge pump and - wherein the logic unit is configured to select the high-power charge pump at least partially during at least one ON state. [15] A circuit arrangement according to claim 14, wherein the at least one ON state is entered when a device to which the circuit arrangement is connected enters a normal operating mode. [16] Circuit arrangement according to one of the preceding claims, in which the logic unit is arranged to switch the electronic switch to the OFF state if a short circuit or an overtemperature is detected or if a predefined signal is supplied to the logic unit. [17] Circuit arrangement according to one of the preceding claims, wherein the measuring device comprises a comparison unit, wherein inputs of the comparison unit are connected to at least one of the first electronic switch or the second electronic switch in order to determine a voltage across terminals of the electronic switch. [18] Circuit arrangement according to one of the preceding claims, in which the logic unit initiates a transition from the first ON state to the second ON state if a load current reaches or falls below a predetermined threshold. [19] Circuit arrangement according to one of the preceding claims, in which the circuit arrangement is arranged to be operated in the following state: - a second IDLE state in which the insulated gate of the first electronic switch is supplied with a small amount of charge via the power supply unit. [20] The circuit arrangement of claim 19, wherein the logic unit initiates a transition from the first ON state to the second IDLE state if a load current is detected that meets or falls below at least a predetermined threshold, or if no diagnostic or sensing functionality is required. [21] Circuit arrangement according to one of claims 19 or 20, wherein the logic unit initiates a transition from the first IDLE state to the second IDLE state if a load current is detected which reaches or falls below at least a predetermined threshold, or if no diagnostic or sensing functionality is required. [22] Circuit arrangement according to one of the preceding claims, comprising a memory unit for storing at least one state. [23] Circuit arrangement according to one of the preceding claims, in which the electronic switch comprises at least one of the following: - a transistor, - a PMOS, - an NMOS, - a FET, - a JFET, - an IGBT. [24] Circuit arrangement according to one of the preceding claims, in which the electronic switch is an n-channel high-side switch. [25] Vehicle comprising at least one circuit arrangement according to one of the preceding claims. [26] A method of controlling a first electronic switch having an insulated gate and a second electronic switch having an insulated gate, the method comprising: - detecting charge at the insulated gate of the first electronic switch and at the insulated gate of the second electronic switch; - providing charge to the insulated gate of the first electronic switch and to the insulated gate of the second electronic switch based on the determined charge; - activating either the first electronic switch, both electronic switches or none of the electronic switches; - in which the electronic switches are operated in at least one of the following states: - a first ON state in which the insulated gate of the first electronic switch and that of the second electronic switch are supplied with a high amount of charge via the power supply unit; - a second ON state in which the insulated gate of the first electronic switch is supplied with a high amount of charge via the power supply unit; - a first IDLE state in which the insulated gate of the first electronic switch and that of the second electronic switch are supplied with a small amount of charge via the power supply unit; - an OFF state in which the first electronic switch and the second electronic switch are switched off. [27] A method according to claim 26, wherein a transition from the first ON state to the second ON state is performed if a load current reaches or falls below a predetermined threshold. [28] A method according to any one of claims 26 or 27, wherein - the first electronic switch and the second electronic switch are reactivated from the first IDLE state to the first ON state when the charge on the insulated gate falls below a predetermined threshold; - the charge on the insulated gate is increased; - the first IDLE state is re-entered. [29] A method according to any one of claims 26 to 28, wherein the electronic switches are operated in the following state: - a second IDLE state in which the insulated gate of the first electronic switch is supplied with a small amount of charge via the power supply unit. [30] The method of claim 29, wherein a transition from the first ON state to the second IDLE state is performed if a load current at least reaches or falls below a predetermined threshold, or if no diagnostic or sensing functionality is required. [31] A method according to any one of claims 29 or 30, wherein a transition from the first IDLE state to the second IDLE state is performed if a load current is detected which at least reaches or falls below a predetermined threshold, or no diagnostic or sensing functionality is required. [32] A method according to any one of claims 29 to 31, wherein the first IDLE state or the second IDLE state is entered when a device to which the electronic switches are connectable enters a low power mode. [33] Method according to one of claims 29 to 32, in which - based on a trigger, a state transition is performed from the first IDLE state to the first ON state or from the second IDLE state to the second ON state or from the second IDLE state to the first ON state, - a predefined action is carried out; - the first IDLE state or the second IDLE state is reactivated. [34] A method according to claim 33, wherein the trigger is at least one of the following: - an external signal applied to the logic unit; - a detection of an error; - detection of a temperature exceeding a predetermined threshold; - detection of a current exceeding a predetermined threshold; - a trigger provided by a timer or clock. [35] A method according to any one of claims 33 or 34, wherein the predefined action comprises at least one of the following: - sensing a current; - sensing a temperature; - issuing a notice; or - recharging the isolated gate. [36] Method according to one of claims 26 to 35, wherein the electronic switch enters the OFF state if a short circuit or an overtemperature is detected, or in the case of a predefined signal.

Images