DE102016203421A1 - Method and arrangement for overcurrent protection of an electronic switch - Google Patents

Abstract

The invention relates to a method for overcurrent protection of an electronic switch, in particular a transistor, wherein an electrical size of the switch is determined by a measuring unit and compared with a threshold, wherein the measuring unit generates a signal and is transmitted as an input signal to a signal processing module (200) when the electrical quantity reaches the threshold, wherein a global time management module with a routing unit (240), an input module (210), a multi-channel sequencer module (220) and an output module (230) as a signal processing module ( 200), the input module (210) being communicatively coupled to the multi-channel sequencer module (220) via the routing unit (240), and wherein the multi-channel sequencer module (220) is routed via the routing unit (240 ) is data transmitting connected to the output module (230), wherein the routing unit (240) data transmission of the individual with her data orderly connected modules (210, 220, 230) one after the other in a predetermined order, the input signal being received by the input module (210) and then receiving information from the input module (210) via the routing unit (240) to the multichannel 211), output information being generated by the multi-channel sequencer module (220) in response to the receive information and forwarded to the output module (230) via the routing unit (240) ( 221), wherein the output module (230) outputs an output signal in response to the output information, whereby the switch is driven and a protective measure for overcurrent protection of the switch is performed.

Description

The present invention relates to a method and an arrangement for overcurrent protection of an electronic switch, e.g. in a motor vehicle, and a computer program for its implementation.

State of the art

In motor vehicles mostly transistors such as bipolar transistors or MOSFET transistors (metal oxide semiconductor field effect transistor) are used as switches to control loads such as valves, injectors or actuators. The control of such switches is usually via a microcontroller or a controller. For the fault-free operation of motor vehicles, it is of great importance to protect such switches against overcurrent and thus caused defects.

For example, is from the US 2015/0123629 A1 an overcurrent protection for field effect transistors known. For this purpose, a voltage of a MOSFET is determined, for example a drain-source voltage drop. When the determined voltage reaches a reference value, an overcurrent signal is output and then the MOSFET is turned off.

Disclosure of the invention

According to the invention, a method and an arrangement for overcurrent protection of an electronic switch, in particular a semiconductor switch, (for example in a motor vehicle) and a computer program for carrying it out with the features of the independent patent claims are proposed. Advantageous embodiments are the subject of the dependent claims and the following description.

The arrangement for overcurrent protection is, in particular hardware and / or program technology, configured to perform a preferred embodiment of the method according to the invention. Embodiments of this method and this arrangement for overcurrent protection will become apparent from the following description in an analogous manner.

Conveniently, a transistor, in particular a bipolar transistor or MOSFET transistor, used as an electronic switch and protected in the invention from overcurrent. By means of the switch, in particular a load is actuated during operation, for example a motor vehicle, for example a valve, an injector or an actuator. In particular, the electronic switch is driven by a microcontroller, i. switched on and off. The microcontroller can be integrated in a control unit (of the motor vehicle), for example in an engine control unit.

The core of the invention is to use a so-called global time management module as a signal processing module for overcurrent protection of the particular designed as a transistor switch. Such a global time management module is sold under the name "Global Timer Module" or "Generic Timer Module" (GTM) by the applicant. Under such a global time management module (hereinafter also referred to as GTM) is in particular a timer module or time management module to understand, by means of which a signal processing can be performed both hardware-based and software-based.

For processing an input signal, the GTM includes special hardware modules as well as computational cores, for example so called Reduced Instruction Set Computing (RISC) cores and / or programmable state machines. The GTM module used in the context of the invention comprises at least the following hardware modules: a routing unit (Advanced Routing Unit, ARU), an input module (so-called Timer Input Module, TIM), a multi-channel sequencer module (so-called multi Channel Sequencer, MCS) and an output module (so-called Advanced Timer Output Module, ATOM). Input module TIM and multi-channel sequencer module MCS are connected on the one hand via the routing unit data transmitting to each other and on the other hand, the multichannel sequencer module MCS and the output module ATOM are also connected data transmitting via the routing unit.

The input module TIM is provided in particular as a module for receiving signals. For example, the TIM may be connected to an input or feedback pin of the signal processing module for this purpose.

The output module ATOM is expediently provided as a module for emitting signals. In particular, the electronic switch can be controlled by the emitted signals accordingly. The ATOM expediently has an output pin via which the corresponding signals can be transmitted to components connected to the GTM.

The multi-channel sequencer module MCS is provided, in particular, as a data processing module, which processes information from the input module TIM and forwards corresponding results to the ATOM. In particular, the MCS may for this purpose have cores, conveniently RISC cores, as well Storage devices such as RAM or flash memory. Due to the modular design of the GTM, the multi-channel sequencer module MCS has no direct connection to the input or output pin. Input and output modules each serve as an intermediary between the pins and the MCS.

The routing unit ARU is provided for the communication or data transmission of the individual modules of the GTM with each other. For this purpose, the routing unit ARU carries out an arbitration of the modules connected to it with data transmission, that is to say of the input module TIM, of the multichannel sequencer module MCS and of the output module ATOM. In the course of this arbitration, the routing unit ARU manages when the individual modules can communicate with each other and exchange data. The routing unit expediently permits a data transmission of the individual modules connected to it in succession in a defined sequence. By means of the routing unit ARU, the individual modules of the GTM are flexibly and configurably connected to one another and a parallel mode of operation of the individual modules of the GTM is achieved, whereby a high number of requirements can be served within a short time. In particular, the arbitration performed by the ARU can ensure deterministic communication of the individual modules with a maximum latency for the transmission of messages.

For a more detailed explanation of a global time management module GTM at this point on the publication DE 10 2010 003 530 A1 by the Applicant, which generally describes a GTM called "Timer Module".

As part of the method, an electrical size of the switch is determined by a measuring unit and compared with a threshold value. When the electrical quantity reaches or exceeds the threshold value, a signal is generated by the measuring unit and transmitted to the signal processing module designed as a global time management module GTM as an input signal. The measuring unit may preferably be designed as a comparator or comparator.

The input signal is received in the signal processing module from the input module, then a receive information is generated by the input module and forwarded via the routing unit ARU to the multi-channel sequencer module. In particular, the input signal is transmitted to the input or feedback pin of the signal processing module, which is monitored by the input module TIM. For example, when a rising edge is applied to the input pin, a corresponding event is generated in the TIM and the corresponding receive information is generated and forwarded via the routing unit ARU to the multi-channel sequencer module MCS.

Output information is generated by the multi-channel sequencer module MCS in dependence on the received information and forwarded via the routing unit ARU to the output module ATOM. For this purpose can be performed by the MCS process, in particular hardware and / or software-based, which generates the output information and writes in a memory of the MCS, in particular in a RAM memory.

In response to the output information, the output module ATOM generates an output signal, whereby the switch is driven and a protective measure for overcurrent protection of the switch is performed. Advantageously, the switch is turned off as a protective measure to effectively protect it from overcurrent. The output signal is conveniently applied to the output pin connected to the ATOM.

In particular, it is not necessary for the overcurrent protection in the context of the invention to use interrupts. On the other hand, for conventional overcurrent protection measures, interrupts are usually sent to a processor unit of a microcontroller, which is provided to control the switch. However, the processing of such interrupts by the processor unit is generally not deterministic, which is why in the course of conventional overcurrent protection measures it can hardly be ensured that a corresponding countermeasure can be performed in real time or within a predetermined time interval.

In contrast, by using the GTM for overcurrent protection of the switch, in particular, it can be ensured that an overvoltage or an overcurrent is reacted within a predetermined time interval and that the corresponding protective measure is carried out. In particular, the countermeasure can be performed 10 μs after detecting an overcurrent. Since deterministic communication of the individual modules of the GTM with maximum latency can be ensured by the arbitration performed by the routing unit ARU, a maximum reaction time between detecting the input signal at the TIM and the output signal at the ATOM can be guaranteed, in particular between the Generating the event at the input pin and applying the output signal to the output pin.

Furthermore, the microcontroller can be relieved by the use of the global time management module. Thanks to the modular design of the GTM, a high degree of flexibility can be achieved. In particular, the specific configuration of the hardware modules of a GTM can be adapted to the respective requirements or to the operations to be performed by the GTM. The GTM can thus carry out the respective operations necessary for the overcurrent protection, without sending out interrupts to a processor unit of the microcontroller.

The invention is particularly suitable for discrete power amplifiers in the motor vehicle and avoids destruction of such amplifiers in the event of a short circuit. In particular, the invention is suitable for single switch for driving loads, which can not be controlled via integrated power amplifiers. In particular, simple standard switches, suitably standard transistors, can be used as output stage or as output stage transistor, without having to implement complex protective circuits for overcurrent protection.

The threshold value of the electrical quantity particularly characterizes a (lower) limit value for the load current through the switch, which corresponds to an overcurrent and from which the switch can be damaged. For example, the limit may be 50 mA. For currents above this limit, in particular, the protective measure is carried out and the switch is preferably switched off. Below this threshold, special measures need not necessarily be taken. It may be sufficient here (for example as a workaround or substitute measure) to limit only the effects of the short circuit. The switch can be used for this purpose, for example, to limit the short-circuit current, for example, by a designed as a transistor switch via a resistor as an analog current source or constant current source limits the short-circuit current.

Conveniently, the GTM may be used as a module within the microcontroller, whereby the CPU of the microcontroller may be relieved of fast and complex real-time control functions that may be performed by parallel operating hardware units of the GTM. The GTM is thus responsible for simple and complex timer inputs and timer outputs.

A GTM is characterized in particular by the fact that functionalities, data processing, processes or arithmetic operations can be hardware-based or executed at hardware level, by the use and special interconnection of hardware components, and not only by running software or microcode. For this purpose, the GTM has in particular Reduced Instruction Set Computing (RISC) cores and / or programmable state machine to perform certain functionalities hardware-based.

Programmable state machines can operate in parallel without affecting the load of processor cores of the microcontroller. A state machine is a sequential system that traverses certain states in a predetermined order. For this purpose, a state machine has in particular memory and combinatorial logic, in particular for detecting inputs or input conditions and generating outputs. By means of the combinational logic, the next state of the state machine is determined, in particular depending on the current state and detected inputs. As combinatorial logic, programmable (and erasable) logic devices (PLD) may be used, for example, based on the use of EPROM or EEPROM memories. Thus, a large number of logical functions can be implemented on a single chip.

RISC cores are used in particular for data processing and the generation of complex output sequences. RISC cores are specially designed processor cores for which a simplified instruction set is used and whose hardware architecture is adapted to this instruction set so that the individual instructions of the instruction set can be executed quickly with high performance. In most cases, only one clock is required to execute a command. Thus, a high clock frequency is possible.

The use of such RISC cores and / or programmable state machines enables effective, parallel data processing, in particular through the use of a plurality of self-sufficient RISC cores, which can access TIM and ATOM directly via the ARU. By arbitration of the modules connected to the ARU and by a defined, fixed round-trip time of the ARU as well as by the determined program execution in the MCS, the deterministic architecture of the GTM can be guaranteed.

Advantageously, the routing unit ARU permits the data transmission of the individual modules (TIM, MCS, ATOM) connected to it in a data-transmitting manner successively in accordance with a round-robin method. In the course of this, the individual modules are assigned one time slot in succession, in the course of which the modules can communicate with one another. In this way the deterministic communication of the modules with each other can be ensured and a so-called "Round Trip Time" (RTT) can be guaranteed as a maximum latency for the data transfer of the modules with each other, this maximum latency depends in particular only on the number of modules connected to the ARU data transmitting , Advantageously, the signal processing module is integrated in a microcontroller or in a control unit of the motor vehicle, preferably in the microcontroller, which is provided for driving the switch. Thus, the overcurrent protection of the processor unit of the microcontroller in the signal processing module can be outsourced, whereby the overcurrent protection can be performed reliably and deterministically, and thereby computing capacity of the processor unit can be provided for other computing operations.

Alternatively or additionally, the measuring unit may preferably be integrated in a microcontroller or in a control unit. For example, a programmable threshold analog-to-digital converter or a programmable comparator may be integrated in the microcontroller for this purpose. Conveniently, both the measuring unit and the signal processing module as well as the switch can be integrated in a control unit, in particular in an engine control unit.

Preferably, a load current through the switch is determined as the electrical size of the switch. For this purpose, a voltage drop across a shunt resistor can be detected and used to determine the load current. If a permissible maximum value of the load current is exceeded as a threshold value, an overcurrent can be deduced and the input signal is generated by the measuring unit.

Preferably, a voltage drop between the drain and source of a switch formed as a MOSFET transistor and / or a voltage drop between the collector and emitter of a switch designed as a bipolar transistor is determined as the electrical size of the switch. In particular, the corresponding threshold characterizes a voltage drop which indicates an overcurrent. The voltage drop is expediently determined only after a predetermined time interval after switching on the switch and in particular only when the switch is activated.

Also, the implementation of the method in the form of a computer program is advantageous because this causes very low costs, especially if an executive controller is still used for other tasks and therefore already exists. Suitable data carriers for providing the computer program are in particular magnetic, optical and electrical memories, such as e.g. Hard drives, flash memory, EEPROMs, DVDs, etc. It is also possible to download a program via computer networks (Internet, intranet, etc.).

Further advantages and embodiments of the invention will become apparent from the description and the accompanying drawings.

The invention is illustrated schematically by means of embodiments in the drawing and will be described below with reference to the drawing.

Brief description of the drawings

1 schematically shows control devices of a motor vehicle, each with a preferred embodiment of an inventive arrangement, which is adapted to perform a preferred embodiment of a method according to the invention.

2 schematically shows a signal processing module of a preferred embodiment of an inventive arrangement, which is adapted to perform a preferred embodiment of a method according to the invention.

Embodiment (s) of the invention

Identical reference numerals in the figures designate the same or equivalent elements.

In the 1a and 1b is each a control unit 100 respectively. 100 ' of a motor vehicle shown schematically. For example, the controller 100 respectively. 100 ' each be designed as an engine control unit.

The control unit 100 respectively. 100 ' has an electronic switch designed as a MOSFET transistor 110 on top of which a load 101 , For example, an injector of an internal combustion engine, can be controlled. At this tick is the transistor 110 from a microcontroller 130 activated accordingly, ie switched on and off.

To overcurrent protection of the transistor 110 to ensure is the microcontroller 130 adapted to carry out a preferred embodiment of a method according to the invention. For this purpose, the microcontroller points 130 a signal processing module 200 and the controller 100 a measuring unit designed as a comparator 120 on.

In the course of the procedure, the comparator determines 120 an electrical size of the transistor 110 and compares it to a threshold. The threshold characterizes a maximum permissible current through the transistor 110 , from which a protective measure for overcurrent protection of the transistor 110 to be carried out.

When the electrical quantity reaches or exceeds the threshold, the comparator generates 120 an input signal and transmits this to an input or feedback pin 131 of the microcontroller 130 , This input signal is from the signal processing module 200 evaluated, whereby an output signal is generated and sent to an output pin 132 of the microcontroller 130 is created.

By the at the output pin 132 applied output signal is the transistor 110 controlled so that the protective measure for overcurrent protection is performed and the transistor 110 is switched off.

In the control unit according to 1a is the transistor 110 in series with a shunt resistor 125 connected. The measuring unit 120 determined in this case, according to a preferred embodiment of the method, a load current through the transistor 110 as electrical size. For this purpose, a voltage drop across the shunt resistor 125 metrologically recorded and from this the load current is determined. If the load current exceeds a corresponding threshold value or permissible maximum value, the comparator transmits 120 the input signal to the microcontroller 130 out.

In the control unit 100 ' according to 1b is in contrast to the example of 1a No shunt resistor provided. The measuring unit 120 In this case, it is arranged between the load and the transistor and, according to a further preferred embodiment, determines a voltage drop between the drain and source of the MOSFET transistor 110 as electrical size. If this voltage drop exceeds a threshold or maximum value, the input signal is sent out.

In 2 is the signal processing module 200 shown schematically in a preferred embodiment. In relation to 2 is explained below as the input signal from the signal processing module 200 processed in the course of the proceedings.

The signal processing module 200 is designed as a Global Time Module (Generic Timer Module, GTM). This GTM 200 has a routing unit (Advanced Routing Unit, ARU) 240 on which for the communication of the individual modules of the GTM 200 is provided with each other.

A multi-channel sequencer module (Multi Channel Sequencer, MCS) 220 is intended for performing arithmetic operations or application software and may have one or more processor cores, eg RISC cores, as well as a memory unit, in particular a RAM memory.

Via the routing unit ARU 240 is the multichannel sequencer module MCS 220 with an input module (Timer Input Module, TIM) 210 and an output module (Advanced Timer Output Module, ATOM) 230 data transmitting connected.

For data transfer between TIM 210 , MCS 220 and ATOM 230 leads the routing unit ARU 240 an arbitration of the individual modules 210 . 220 and 230 by. For this purpose, the routing unit ARU 240 each of the modules 210 . 220 and 230 in the course of a round trip method, a time slot during which individual modules can communicate with each other. In this way, a deterministic communication of the individual modules 210 . 220 and 230 guaranteed with a maximum latency for the transmission of messages.

The input module TIM 210 monitors the input pin 131 of the microcontroller. When the input signal at the input pin 131 is present, for example, when a rising edge at the input pin 131 is present in the input module TIM 210 generates a corresponding event. In particular, receive information from the input module TIM 210 generated and via the routing unit ARU 240 to the multi-channel sequencer module MCS 220 forwarded, indicated by reference numerals 211 ,

Depending on the receive information, the multichannel sequencer module MCS 220 generates output information and via the routing unit ARU 240 to the output module ATOM 230 forwarded, indicated by reference numerals 221 ,

Depending on the output information, the output module generates ATOM 230 an output signal and passes this to the output pin 132 continue, causing the switch 110 is controlled accordingly and switched off.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• US 2015/0123629 A1 [0003]
• DE 102010003530 A1 [0013]

Claims (12)

Method for overcurrent protection of an electronic switch ( 110 ), in particular a transistor, wherein an electrical size of the switch ( 110 ) of a measuring unit ( 120 ) and compared with a threshold, wherein the measuring unit ( 120 ) generates a signal and as input to a signal processing module ( 200 ) is transmitted when the electrical quantity reaches the threshold, wherein a global time management module with a routing unit ( 240 ), an input module ( 210 ), a multichannel sequencer module ( 220 ) and an output module ( 230 ) as a signal processing module ( 200 ) is used, wherein the input module ( 210 ) via the routing unit ( 240 ) with the multichannel sequencer module ( 220 ) and wherein the multichannel sequencer module ( 220 ) via the routing unit ( 240 ) with the output module ( 230 ) is data transmitting connected, wherein the routing unit ( 240 ) a data transmission of the individual modules connected with their data transmission ( 210 . 220 . 230 ) in succession in a predetermined order, the input signal from the input module ( 210 ) is received, and then receiving information from the input module ( 210 ) via the routing unit ( 240 ) to the multichannel sequencer module ( 220 ) is forwarded ( 211 ), whereby the multichannel sequencer module ( 220 ) generates an output information in dependence on the received information and via the routing unit ( 240 ) to the output module ( 230 ) is forwarded ( 221 ), the output module ( 230 ) outputs an output signal in dependence on the output information, whereby the switch ( 110 ) and a protective measure for overcurrent protection of the switch ( 110 ) is carried out. Method according to claim 1, wherein the routing unit ( 240 ) the data transmission of the individual modules ( 210 . 220 . 230 ) are allowed successively according to a concentricity method. Method according to claim 1 or 2, wherein a load current through the switch ( 110 ) as electrical size of the switch ( 110 ) is determined. Method according to one of the preceding claims, wherein a voltage drop between the drain and source of a MOSFET transistor formed as switch and / or a voltage drop between the collector and emitter of a bipolar transistor formed as a switch ( 110 ) as electrical size of the switch ( 110 ). Method according to one of the preceding claims, wherein the output module ( 230 ) in dependence on the output signal the switch ( 110 ) as a protective measure. Arrangement for overcurrent protection of an electronic switch ( 110 ), in particular a transistor, with a measuring unit ( 120 ) and a signal processing module ( 200 ), the signal processing module ( 200 ) with the measuring unit ( 120 ) and the switch ( 110 ), the signal processing module ( 200 ) as a global time management module with a routing unit ( 240 ), an input module ( 210 ), a multichannel sequencer module ( 220 ) and an output module ( 230 ), wherein the input module ( 210 ) via the routing unit ( 240 ) with the multichannel sequencer module ( 220 ) and wherein the multichannel sequencer module ( 220 ) via the routing unit ( 240 ) with the output module ( 230 ) is data transmitting connected, wherein the routing unit ( 240 ) is adapted to a data transmission of the individual modules connected with their data transmission ( 210 . 220 . 230 ) successively in a predetermined order and wherein the arrangement is arranged to perform a method according to any one of the preceding claims. Arrangement according to claim 6, wherein the routing unit ( 240 ) is adapted to the data transmission of the individual modules ( 210 . 220 . 230 ) successively according to a concentricity method. Arrangement according to claim 6 or 7, wherein the signal processing module ( 200 ) and / or the measuring unit ( 120 ) into a microcontroller ( 100 . 100 ' ) of the vehicle are integrated. Arrangement according to one of claims 6 to 8, wherein the measuring unit ( 120 ) is formed as a comparator. Arrangement according to one of claims 6 to 9, wherein the switch ( 110 ) is formed as a semiconductor switch or transistor, in particular a bipolar transistor or a MOSFET transistor. A computer program which causes an overcurrent protection arrangement to perform a method according to any one of claims 1 to 5 when carried out on the overcurrent protection arrangement. Machine-readable storage medium with a computer program stored thereon according to claim 11.

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