Patent Description:
CAN buses can be used for communications within vehicles, in particular within automobiles. It will be appreciated that CAN buses also have application outside of the field of automobiles. A CAN bus network may include multiple bus devices, so called nodes or electronic control units (ECUs), such as an engine control module (ECM), a power train control module (PCM), airbags, antilock brakes, cruise control, electric power steering, audio systems, windows, doors, mirror adjustment, battery and recharging systems for hybrid/electric cars, and many more. A CAN protocol is used to enable communications between the various bus devices. The data link layer of the CAN protocol is standardized as International Standards Organization (ISO) <NUM>-<NUM>:<NUM>. CAN Flexible Data-Rate or "CAN FD," which is an extension of the standardized CAN data link layer protocol and is meanwhile integrated into the ISO11898-<NUM>:<NUM> standard, can provide higher data rates. The standardized CAN data link layer protocol is being further extended to provide even higher data rates. A further extension, referred to as CAN XL, with a new level scheme allowing even higher data rates is in the definition phase discussed under CiA610 (CAN in Automation) and is moving towards standardization in the form of either a further update of the existing ISO11898 standards or a new standard.

<CIT> relates to a communication failure detection device configured to detect a communication failure of a two-wire CAN communication device.

In accordance with a first aspect of the present disclosure, a Controller Area Network, CAN, transceiver is provided. The CAN transceiver comprising: a CAN BUS interface, a transmit data, TXD, interface, a receive data, RXD, interface, a receiver coupled to the CAN BUS interface and the RXD interface, and a transmitter coupled to the TXD interface and the CAN BUS interface, wherein the transceiver is configured to receive, via the TXD interface, from a CAN controller, a digital TXD transmit signal representing a frame comprising a plurality of bits, wherein the transmitter is configured to generate, at the CAN BUS interface, a BUS signal representing the bits of the frame in a sequence, wherein the transceiver is configured to measure an electrical current of the transmitter, referred to as a transmitter current, wherein the transceiver is configured to detect each dominant bit represented by the BUS signal based on the transmitter current, wherein the transceiver is configured to detect an error sequence of at least six consecutive dominant bits being detected based on the transmitter current, and wherein the transceiver is configured to generate a control signal representing a fault of the transmitter in response to a detected error sequence.

In one or more embodiments, the transceiver comprises a first sensor unit, which is arranged and/or configured to measure a first current to supply the transmitter, wherein the first current forms at least a part of the transmitter current.

In one or more embodiments, the transceiver comprises first and second supply terminals for supplying electrical current to the transceiver, wherein the first sensor unit is coupled between the first supply terminal and the transmitter.

In one or more embodiments, the transceiver comprises a second sensor unit, which is arranged and/or configured to measure a second current to supply the transmitter, wherein the transmitter current is based on or formed by a mean value of the first and second current.

In one or more embodiments, the transceiver is configured to detect each dominant bit represented by the BUS signal based on the first and second currents.

In one or more embodiments, the transceiver comprises an evaluation unit connected to the at least one sensor unit such that a sensor signal from each sensor unit can be transmitted to the evaluation unit, wherein the evaluation unit is configured to compare the first current with a predefined first current threshold value and/or the second current with a predefined second current threshold value and wherein the evaluation unit is configured to trigger a positive detection of a dominant bit represented by the BUS signal if the result of the comparison indicates that the first current is greater than the first current threshold value and/or the second current is greater than the second current threshold value.

In one or more embodiments, the transceiver is configured to detect a first time duration of a plurality of successive dominant bits detected based on the transmitter current, wherein the evaluation unit is configured to compare the first time duration with a predefined reference time duration, and wherein the evaluation unit is configured to trigger a positive detection of the error sequence if a result of the comparison indicates that the first time duration is larger than the reference time duration.

In one or more embodiments, the evaluation unit is configured to generate a control signal representing a fault of the transmitter in response to a detected error sequence.

In one or more embodiments, the transceiver comprises at least one shutdown unit configured to at least partially deactivate the transmitter based on the control signal.

In one or more embodiments, the transceiver comprises a first shutdown unit and a second shutdown unit, wherein the two shutdown units are configured to jointly deactivate the transmitter based on the control signal.

In one or more embodiments, the evaluation unit is coupled to each shutdown unit to transmit the control signal to each of the at least one shutdown unit.

In one or more embodiments, the evaluation unit is coupled to the TXD interface to receive the TXD digital transmit signal, wherein the evaluation unit is configured to observe whether a dominant bit represented by the TXD transmit signal is also represented as a dominant bit by the BUS signal, wherein the evaluation unit is configured to trigger a positive detection of a transmission error if the result of the observation indicates that the dominant bit represented by the digital TXD transmission signal is not represented by the BUS signal.

In one or more embodiments, the evaluation unit is configured to generate the control signal in response to a positive detection of the transmission error.

In one or more embodiments, the transceiver is configured to transmit an error signal to the CAN controller via a further interface of the transceiver in response to a detected error sequence or a detected transmission error.

In accordance with a second aspect of the present disclosure, a method for a Controller Area Network, CAN, transceiver is provided, wherein the CAN transceiver comprising a CAN BUS interface, a transmit data, TXD, interface, a receive data, RXD, interface, a receiver coupled to the CAN BUS interface and RXD interface, and a transmitter coupled to the TXD interface and the CAN BUS interface, and wherein the method comprises the steps of:.

Embodiments of the present disclosure will be described in more detail with reference to the appended drawings. Advantages of the subject matter claimed will become apparent to those skilled in the art upon reading this description in conjunction with the accompanying drawings, in which like reference numerals have been used to designate like elements, and in which:.

<FIG> depicts a CAN network <NUM> that includes multiple CAN nodes <NUM>, also referred to as "ECUs," each connected to a CAN bus <NUM>. In the embodiment of <FIG>, each CAN node <NUM> includes a microcontroller <NUM> having an embedded CAN protocol controller <NUM> and a CAN transceiver <NUM>. The CAN protocol controller <NUM> may be referred to as a controller or CAN controller. The CAN transceiver <NUM> may be referred to as a transceiver.

The microcontrollers <NUM> are typically connected to at least one device (not shown) such as a sensor, an actuator, or some other control device and are programmed to determine the meaning of received messages and to generate appropriate outgoing messages. The microcontrollers <NUM>, which may also be referred to as host processors, hosts or digital signal processors (DSPs), are known in the field. In an embodiment, the host supports application software that interacts with the CAN protocol controller <NUM>.

The CAN bus <NUM> carries analog differential signals and includes a first CAN signal line <NUM>, which is also referred to as the CAN high (CANH) bus line <NUM>, and a second CAN signal line <NUM>, which is also referred to as the CAN low (CANL) bus line <NUM>. The CAN bus <NUM> is known in the field.

<FIG> depicts an expanded view of one CAN node <NUM> from <FIG>. In the expanded view of <FIG>, the microcontroller <NUM> includes a host <NUM>, which may be, for example, a software application that is stored in a memory of the microcontroller <NUM> and executed by processing circuits of the microcontroller <NUM>. The microcontroller <NUM> and the CAN transceiver <NUM> of the CAN node <NUM> are connected between a first supply voltage, VCC, and as second supply voltage, which is usually ground, GND. For the purpose of the voltage supply, the CAN transceiver <NUM> may comprise a first supply terminal <NUM>, that can be connected to the first supply voltage, and a second supply terminal <NUM>, that can be connected to second supply voltage. The analogous terminals may be provided by the microcontroller <NUM> or may be even combined with the respective terminals of the microcontroller <NUM>. As illustrated in <FIG>, data communicated from CAN protocol controller <NUM> being implemented by the microcontroller <NUM> to the CAN transceiver <NUM> is identified as transmit data (TXD) and data communicated from the CAN transceiver <NUM> to the CAN protocol controller <NUM> being implemented by the microcontroller <NUM> is referred to as receive data (RXD). Throughout the description, TXD is carried on a TXD path and RXD is carried on an RXD path. Data is communicated to and from the CAN bus <NUM> via the CANH and CANL bus lines <NUM> and <NUM>, respectively.

The CAN protocol controller <NUM> is preferably embedded within the microcontroller <NUM>, but may also be implemented external to the microcontroller <NUM> (e.g., a separate IC device). The data link layer operations between the CAN protocol controller <NUM> and the CAN transceiver <NUM> is known in the field.

For example, in receive operations, the CAN protocol controller <NUM> receives from the transceiver <NUM> serial bits in a bit stream, referred to as a RXD stream, via the RXD path. The CAN protocol controller <NUM> may store the received bits until an entire message is available for fetching by the microcontroller <NUM>. The CAN protocol controller <NUM> can also decode the CAN message according to the standardized frame format of the CAN protocol.

In transmit operations, the CAN protocol controller <NUM> receives a message from the microcontroller <NUM> and transmits the message as serial bits in a bit stream, referred to as a TXD stream, via the TXD path in the CAN frame format to the CAN transceiver <NUM>, such that the transceiver receives frames, with each frame comprising several bits.

The CAN transceiver <NUM> is located between the CAN controller <NUM> being implemented by the microcontrollers <NUM> and the CAN bus <NUM>. The CAN transceiver <NUM> is configured to implement physical layer operations as known in the field.

For example, in receive operations, a CAN transceiver <NUM> converts analog differential signals from the CAN bus <NUM> to the RXD stream of serial bits that the CAN protocol controller <NUM> can interpret. The CAN transceiver <NUM> may also protects the CAN protocol controller <NUM> from extreme electrical conditions on the CAN bus <NUM>, e.g., electrical surges.

In transmit operations, the CAN transceiver <NUM> can convert the bits of the frames of the TXD stream received via the TXD path from the CAN protocol controller <NUM> into analog differential signals that are sent on the CAN bus <NUM>.

As noted above, the CAN protocol controller <NUM> can be configured to support the normal mode or the flexible data rate mode. As used herein, "CAN normal mode" (also referred to as "CLASSICAL CAN mode") as well as "CAN FD mode" refer to frames that are formatted according to the ISO <NUM>-<NUM> standard.

<FIG> schematically illustrates an embodiment of the CAN transceiver <NUM> according to the present disclosure.

The CAN transceiver <NUM> comprises a CAN BUS interface <NUM>, a TXD interface <NUM>, an RXD interface <NUM>, a receiver <NUM>, and a transmitter <NUM>. The receiver <NUM> may be formed as a physical unit of the transceiver <NUM> and/or at least partially as a logical unit of the transceiver <NUM>. The transmitter <NUM> may be formed as a physical unit of the transceiver <NUM> and/or at least partially as a logical unit of the transceiver <NUM>.

The receiver <NUM> is coupled between the CAN BUS interface <NUM> and the RXD interface <NUM>. Preferably, the receiver <NUM> is directly coupled to both the CAN BUS interface <NUM> and the RXD interface <NUM>. The transmitter <NUM> is coupled between the TXD interface <NUM> and the CAN BUS interface <NUM>. Preferably, the transmitter <NUM> is directly coupled to both the TXD interface <NUM> and the CAN BUS interface <NUM>. In an example, the transmitter <NUM> is connected to the TXD interface <NUM> via a signal connection. In an example, as shown for example in <FIG>, the transmitter <NUM> is connected to the TXD interface <NUM> via a signal connection <NUM>, a TXD signal error detector <NUM>, and a signal connection <NUM>.

The transceiver <NUM> is configured to receive a digital TXD transmit signal via the TXD interface <NUM>. The TXD transmit signal may also be referred to as the TXD signal. The TXD transmit signal may be transmitted from a CAN controller <NUM> to the TXD interface <NUM> via a signal connection <NUM>. The TXD signal represents at least one frame. Each frame comprising a plurality of digital bits.

As can be seen schematically from <FIG>, the TXD transmit signal can reach the TXD signal error detector <NUM> via the TXD interface <NUM> and the signal connection <NUM>. In an example, the TXD signal error detector <NUM> is configured to detect a sequence of at least six consecutive identical bits in the TXD transmit signal as a TXD error. Further, the TXD signal error detector <NUM> may be configured to stop forwarding the TXD transmit signal to the signal connection <NUM> upon detection of the TXD error. The TXD signal error detector <NUM> may further be configured to forward the TXD transmit signal from the signal connection <NUM> to the signal connection <NUM> if the TXD signal error detector <NUM> does not detect a TXD error. In an example, the TXD signal error detector <NUM> may detect the TXD error based on a timeout of at least six consecutive equal bits. Therefore, in an example, the TXD signal error detector <NUM> may be configured as a timeout detector.

As can also be seen schematically from <FIG>, a frame represented by the TXD transmit signal may reach the transmitter <NUM> via the TXD interface <NUM>. The transmitter <NUM> is configured to generate a CAN BUS signal at the CAN BUS interface <NUM>. The CAN BUS signal may be generated as a differential voltage signal between a first terminal <NUM> of the CAN BUS interface <NUM> and a second terminal <NUM> of the CAN BUS interface <NUM>. In an example, a differential voltage of <NUM> V may represent a recessive bit "<NUM>" and a differential voltage of <NUM> V may represent a dominant bit "<NUM>". The CAN BUS signal may represent the bits of the frame in a sequence.

The transceiver <NUM> is configured to measure an electrical current of the transmitter <NUM>. This electrical current is also referred to as the transmitter current. In an example, to transmit a dominant bit "<NUM>" over the CAN BUS <NUM>, the transmitter <NUM> may generate the aforementioned differential voltage of <NUM> V between the two terminals <NUM>, <NUM> such that a first actuation current flows over the signal connection <NUM> between the terminal <NUM> of the CAN BUS interface <NUM> and the transmitter <NUM> and a second actuation current flows over the signal connection <NUM> between the terminal <NUM> of the CAN BUS interface <NUM> and the transmitter <NUM>. The first and second actuation currents may flow in reverse directions. To effect these electrical currents, it may further be necessary for a first supply current to flow from the first supply terminal <NUM> of the transceiver <NUM> to the transmitter <NUM> and a second supply current to flow from the second supply terminal <NUM> of the transceiver <NUM> to the transmitter <NUM>. The first and second supply currents may flow in reverse directions. Said currents are significantly higher if a dominant bit is generated at the CAN BUS interface <NUM> instead of a recessive bit. Therefore, based on at least one of said electrical currents flowing into or out of the transmitter <NUM>, it is derivable from at least one of the currents whether the transmitter <NUM> generates a dominant bit at the CAN BUS interface <NUM> or whether the transmitter does not generate a dominant bit, but preferably a recessive bit, at the CAN BUS interface <NUM>.

The transceiver <NUM> is configured to detect each dominant bit that is represented by the CAN BUS signal caused by the transmitter <NUM> based on the measured transmitter current. In an example, the transmitter current may be formed by at least one of the previously mentioned currents. Therefore, for a dominant bit, the transmitter current will be higher than for a recessive bit. The transceiver <NUM> may be configured to detect such a higher current and thereby detect a corresponding dominant bit.

The transceiver <NUM> is further configured to detect an error sequence of at least six consecutive dominant bits, each detected based on the transmitter current. In an example, if CAN BUS signal representing a plurality of bits in a sequence is generated at CAN BUS interface <NUM> by means of transmitter <NUM>, where transceiver <NUM> is configured to detect each dominant bit in said sequence based on the transmitter current, transceiver <NUM> may detect multiple consecutive dominant bits in the bit sequence. The transceiver <NUM> is further configured to detect the error sequence of at least six consecutive dominant bits in the bit sequence, if such an error sequence exists. The error sequence of at least six consecutive dominant bits corresponds to a break of the rules according to the CAN standard referred to in the introduction. Therefore, the error sequence of at least six consecutive dominant bits indicates that there is a fault in the transmitter <NUM>.

The transceiver <NUM> is configured to generate a control signal representing a fault of the transmitter <NUM> in response to a detected error sequence (of at least six consecutive dominant bits). The transceiver <NUM> may be configured to send and/or use the control signal to initiate follow-up actions. For example, based on the control signal, disabling the transmitter <NUM>, the transceiver <NUM> and/or notifying the CAN controller <NUM> of the detected fault. Using the control signal, security of the transceiver <NUM>, the CAN controller <NUM>, the CAN network <NUM>, and/or the nodes <NUM> connected to the CAN network <NUM> may be improved.

As previously discussed, the TXD signal error detector <NUM> may be used to detect a TXD error in the TXD transmit signal. If a TXD error is detected by the TXD signal error detector <NUM>, the TXD signal error detector <NUM> may prevent the TXD transmit signal from being forwarded to the transmitter <NUM>. Thus, if the TXD transmit signal has a TXD error with at least six consecutive dominant bits, the TXD signal error detector <NUM> may effectively prevent the transmitter <NUM> from generating a CAN BUS signal at the CAN BUS <NUM> representing the TXD error.

However, the TXD signal error detector <NUM> is not adapted to prevent or detect a fault of the transmitter <NUM>.

In an example, if the transmitter <NUM> exhibits a fault causing the transmitter <NUM> to generate a CAN BUS signal at the CAN BUS interface <NUM> representing an error sequence of at least six consecutive dominant bits, this fault of the transmitter <NUM> will be detected by the previously explained embodiment of the transceiver <NUM> and based on the transmitter current. The transceiver <NUM> is further configured to generate a control signal representing the detected fault of the transmitter <NUM>. In an example, the transceiver <NUM> may use the control signal to disable the faulty transmitter <NUM>. Alternatively or additionally, the CAN transceiver <NUM> may send the control signal to a CAN controller <NUM> to communicate the fault of the transmitter <NUM>. The CAN controller <NUM> may then initiate follow-up actions.

The transceiver <NUM> is preferably configured to detect a fault of the transmitter <NUM> by detecting the error sequence of at least six consecutive dominant bits represented by the CAN BUS signal. The error sequence may be detected by the transceiver <NUM> based on the transmitter current. Using the transmitter current to detect the error sequence has the advantage of detecting a fault of the transmitter <NUM> only if the error sequence is caused by the transmitter <NUM>. In an example, if a signal is transmitted from a remote node <NUM> to the CAN BUS interface <NUM> of the transceiver <NUM> via the CAN BUS <NUM>, where the signal represents a sequence of at least six consecutive dominant bits, these dominant bits will cause a transmitter current in the transmitter <NUM> with no current, or at most a low current, but not representative of dominant bits generated by the transmitter <NUM> itself. Therefore, the transceiver <NUM> will not detect the at least six consecutive dominant bits received as an error sequence based on the transmitter current. Rather, the transceiver <NUM> is preferably configured to detect an error sequence of at least six consecutive dominant bits based on the transmitter current only if those bits are self-generated by the transmitter <NUM>. Detection of the potential fault of the transmitter <NUM> in response to a detected error sequence is therefore particularly robust to potential interference with and/or errors from remote CAN nodes <NUM>.

In an example, the transceiver <NUM> comprises a first sensor unit <NUM>. The first sensor unit <NUM> is preferably arranged and/or configured to measure a first current to power the transmitter <NUM>. The first current may also be referred to as a first supply current. The first current may form at least a part of the transmitter current of the transmitter <NUM>. In an example, the transmitter current is formed by the first current. The first current is an electrical current. In an example, the transmitter <NUM> may comprise a first driver circuit. The first driver circuit may have a current demand that increases if a dominant bit is generated at the CAN BUS interface <NUM> by means of the transmitter <NUM>. The increased current demand if the dominant bit is generated at the CAN BUS interface <NUM> will therefore be reflected in the value of the first current to supply the transmitter <NUM>. The first current measured by means of the first sensor unit <NUM> may therefore be used to detect whether a dominant bit is generated at the CAN BUS interface <NUM> by means of the transmitter <NUM> or whether no dominant bit, thus in particular a recessive bit, is generated at the CAN BUS interface <NUM> by the transmitter <NUM>. In an example, the transceiver <NUM> may be configured to detect any dominant bit represented by the CAN BUS signal generated by the transmitter <NUM> based on the first current.

In an example, the transceiver <NUM> comprises a first supply terminal <NUM> and a second supply terminal <NUM> for supplying electrical power to the transceiver <NUM>. As schematically illustrated in an example shown in <FIG>, the first sensor unit <NUM> may be coupled between the first supply terminal <NUM> and the transmitter <NUM>. A first current flowing through the first supply terminal <NUM> to the transmitter <NUM> may be measured by the first sensor unit <NUM>. The signal connection <NUM> may extend from the first supply terminal <NUM> to the first sensor unit <NUM>. Another signal connection <NUM> may extend from the sensor unit <NUM> to the transmitter <NUM>. In an example, the first current may flow from the first supply terminal <NUM> via the signal connection <NUM> to the first sensor unit <NUM> and from the first sensor unit <NUM> via the signal connection <NUM> to the transmitter <NUM>. The preferred arrangement of the first sensor unit <NUM> between the first supply terminal <NUM> and the transmitter <NUM> can ensure that the first current measured by the first sensor unit <NUM> is caused solely by the transmitter <NUM>. Therefore, the first current measurable by the first sensor unit <NUM> can be advantageously used by the transceiver <NUM> to detect whether the CAN BUS signal generated by the transmitter <NUM> represents a dominant bit. The detection is thereby particularly robust to possible bits sent to the transceiver <NUM> by means of a signal over the CAN BUS <NUM> from a remote node <NUM>.

In an example, in particular as shown schematically in <FIG>, the first sensor unit <NUM> is physically separate from the transmitter <NUM>. For example, the first sensor unit <NUM> may be physically separated from the transmitter <NUM> by the signal connection <NUM>. In another example, which is not shown, the first sensor unit <NUM> may be partially or fully integrally formed with the transmitter <NUM>.

In an example, the transceiver <NUM> comprises a second sensor unit <NUM>. The second sensor unit <NUM> is preferably arranged and/or configured to measure a second current to power the transmitter <NUM>. The second current is an electrical current. The second current may also be referred to as a second supply current. The second current may form at least a part of the transmitter current of the transmitter <NUM>. In an example, the transmitter current is formed by the second current. In an example, the transmitter <NUM> may comprise a second driver circuit. The second driver circuit may have a current demand that increases if a dominant bit is generated at the CAN BUS interface <NUM> by means of the transmitter <NUM>. The increased current demand if the dominant bit is generated at the CAN BUS interface <NUM> will therefore be reflected in the value of the second current used to power the transmitter <NUM>. The second current measured by means of the second sensor unit may therefore be used to detect whether a dominant bit is generated at the CAN BUS interface <NUM> by means of the transmitter <NUM> or whether no dominant bit, thus in particular a recessive bit, is generated at the CAN BUS interface <NUM>. In an example, the transceiver <NUM> may be configured to detect any dominant bit represented by the CAN BUS signal generated by the transmitter <NUM> based on the second current.

In an example, the transceiver <NUM> comprises a first supply terminal <NUM> and a second supply terminal <NUM> for supplying electrical power to the transceiver <NUM>. As schematically illustrated in an example shown in <FIG>, the second sensor unit <NUM> may be coupled between the second supply terminal <NUM> and the transmitter <NUM>. A second current flowing through the second supply terminal <NUM> to the transmitter <NUM> may be measured by the second sensor unit <NUM>. The signal connection <NUM> may extend from the second supply terminal <NUM> to the second sensor unit <NUM>. Another signal connection <NUM> may extend from the second sensor unit <NUM> to the transmitter <NUM>. In an example, the second current may flow from the second supply terminal <NUM> to the second sensor unit <NUM> via the signal connection <NUM> and from the second sensor unit <NUM> to the transmitter <NUM> via the signal connection <NUM>. The preferred arrangement of the second sensor unit <NUM> between the second supply terminal <NUM> and the transmitter <NUM> can ensure that the second current measured by the second sensor unit <NUM> is caused solely by the transmitter <NUM>. The second current measurable by the second sensor unit <NUM> may therefore be advantageously used by the transceiver <NUM> to detect whether the CAN BUS signal generated by the transmitter <NUM> represents a dominant bit. In this regard, the detection is particularly robust to possible bits sent to the transceiver <NUM> by means of a signal over the CAN BUS <NUM> from a remote node <NUM>.

In an example, such as that shown schematically in <FIG>, the second sensor unit <NUM> is physically separate from the transmitter <NUM>. For example, the second sensor unit <NUM> may be physically separated from the transmitter <NUM> by the signal connection <NUM>. In another example, not shown, the second sensor unit <NUM> may be partially or fully integrally formed with the transmitter <NUM>.

In an example, the first supply terminal <NUM> of the transceiver <NUM> is supplied with a first supply voltage, VCC. In addition, the second supply terminal <NUM> of the transceiver <NUM> may be supplied with a second supply voltage, in particular ground potential, Ground. If a CAN BUS signal representing a dominant bit is generated by the transmitter <NUM>, the absolute value of the first current measured by the first sensor unit <NUM> may correspond to the absolute value of the second current measured by the second sensor unit. It may therefore be sufficient, in an example, for the transmitter current to be formed by either the first current or, alternatively, the second current.

In an example, the transceiver <NUM> is configured to detect each dominant bit represented by the CAN BUS signal generated by the transmitter <NUM> based on the first current and the second current. Thus, to detect the dominant bit, both the first current and the second current may be considered by the transceiver <NUM>. Thus, the detection may be robust to electromagnetic interference.

In an example, the transceiver <NUM> comprises an evaluation unit <NUM>. The evaluation unit <NUM> is coupled to at least one sensor unit <NUM>, <NUM> of the two sensor units <NUM>, <NUM>. In an example, the evaluation unit <NUM> may be coupled to the first sensor unit <NUM> via a signal connection <NUM>. In an example, the evaluation unit <NUM> may be coupled to the second sensor unit <NUM> via another signal connection <NUM>. The evaluation unit <NUM> may be connected to only one of the two sensor units <NUM>, <NUM> or to both sensor units <NUM>, <NUM>. Each sensor unit <NUM>, <NUM> connected to the evaluation unit <NUM> may transmit a sensor signal to the evaluation unit <NUM>.

In an example, the first sensor unit <NUM> may transmit a first sensor signal representing the first current to the evaluation unit <NUM> via the signal connection <NUM>. The evaluation unit <NUM> may be configured to compare the value of the first current to a predefined first current threshold. Further, the evaluation unit <NUM> may be configured to trigger a positive detection of a dominant bit represented by the CAN BUS signal generated by the transmitter <NUM> if the result of the comparison indicates that the value of the first current is higher than the first current threshold value. In an example, the evaluation unit <NUM> may be configured to not trigger a positive detection of a dominant bit (thus not represented by the CAN BUS signal generated by the transmitter <NUM>) if the result of the comparison indicates that the value of the first current is less than the first current threshold.

In another example, the second sensor unit <NUM> may transmit a second sensor signal representing the second current to the evaluation unit <NUM> via the further signal connection <NUM>. The evaluation unit <NUM> may be configured to compare the value of the second current to a predefined second current threshold value. Further, the evaluation unit <NUM> may be configured to trigger a positive detection of a dominant bit represented by the CAN BUS signal generated by the transmitter <NUM> if the result of the comparison indicates that the value of the second current is higher than the second current threshold value. In an example, the evaluation unit <NUM> may be configured to not trigger a positive detection of a dominant bit (thus not represented by the CAN BUS signal generated by the transmitter <NUM>) if the result of the comparison indicates that the value of the second current is less than the second current threshold.

In another example, the evaluation unit <NUM> may be configured to trigger a positive detection of a dominant bit represented by the CAN BUS signal generated by the transmitter <NUM> if the result of the comparisons indicates that both the value of the first current is higher than the first current threshold and the value of the second current is higher than the second current threshold. In another example, the evaluation unit <NUM> may be configured not to trigger a positive detection of a dominant bit (thus not represented by the CAN BUS signal generated by the transmitter <NUM>) if the result of the comparisons indicates that the value of the first current is less than the first current threshold and/or the value of the second current is less than the second current threshold.

The CAN BUS signal generated by the transmitter <NUM> is preferably a differential voltage signal. To represent a dominant bit via the CAN BUS signal, in an example, a voltage swing of <NUM> V is required. To produce this voltage swing of <NUM> V, increased currents flow between the transmitter <NUM> and the two terminals <NUM>, <NUM> of the CAN BUS interface <NUM> is required. Therefore, to produce the voltage swing of <NUM> V, the transmitter <NUM> requires increased electrical power consumption, so that a higher first current and a higher second current will also flow. To represent a recessive bit via the CAN BUS signal, in an example, no or almost no voltage swing is required, so that no currents or at most very low currents flow between the transmitter <NUM> and the two terminals <NUM>, <NUM> of the CAN BUS interface <NUM>. Therefore, for the recessive bit, the transmitter <NUM> requires no or at most very low electrical power consumption, so that no or at most a very low first current and also no or at most a very low second current will flow.

In an example, the first current threshold value may be defined such that the value of the first current is higher than the first current threshold value if the CAN BUS signal generated by the transmitter <NUM> represents a dominant bit. In an example, the first current threshold value may be defined such that the value of the first current is lower than the first current threshold value if the CAN BUS signal generated by the transmitter <NUM> represents a recessive bit. In an example, the second current threshold value may be defined such that the value of the second current is higher than second current threshold value if the bus signal generated by the transmitter <NUM> represents a dominant bit. In an example, the second current threshold value may be defined such that the value of the second current is lower than the second current threshold value if the CAN BUS signal generated by the transmitter <NUM> represents a recessive bit. Said values of the first and second currents preferably refer to the respective absolute values.

The evaluation unit <NUM> provides the advantage of being able to detect a dominant bit represented by a CAN BUS signal generated by the transmitter <NUM> based on a comparison of the transmitter current, such as the first current, with a predefined threshold value for the current that would have to flow into or out of the transmitter <NUM> at a minimum to represent said dominant bit via the CAN BUS signal. In an example, the threshold value may be understood as a minimum value for the absolute value of transmitter current above which it is robustly detectable that a dominant bit is being transmitted via the CAN BUS signal generated by the transmitter <NUM>. As a result, the evaluation unit <NUM> may detect the dominant bit based on an excess of the (absolute value) of the transmitter current drawn and/or caused by the transmitter <NUM> above the threshold value.

In an example, the evaluation unit <NUM> of the transceiver <NUM> may be configured to detect each dominant bit represented by the CAN BUS signal generated by the transmitter <NUM> based on the transmitter current, preferably formed by the first current and/or second current.

As previously explained, increased currents flow across the signal connections <NUM>, <NUM> if a CAN BUS signal representing a dominant bit is generated by the transmitter <NUM>. The increased currents are generated and/or caused by the transmitter <NUM>. In an example, the transmitter current of the transmitter <NUM> may be formed by the current between the transmitter <NUM> and the first terminal <NUM> of the CAN BUS interface <NUM> and/or the current between the transmitter <NUM> and the second terminal <NUM> of the CAN BUS interface <NUM>.

<FIG> schematically illustrates an example of a further embodiment of the CAN transceiver <NUM>. In this embodiment, the CAN transceiver <NUM> does not comprise the first sensor unit <NUM> or the second sensor unit <NUM>. However, it should be noted that in an example, the CAN transceiver <NUM> may additionally be equipped with the first sensor unit <NUM> and/or the second sensor unit <NUM>. If the CAN transceiver <NUM> is additionally equipped with the first sensor <NUM> and/or the second sensor <NUM>, reference is made to the preceding explanations, preferred features, advantages and/or technical effects provided in connection with <FIG> in an analogous manner.

The design of the CAN transceiver <NUM> of <FIG> corresponds in many details to the design of the CAN transceiver <NUM> of <FIG>, so that reference for these details to the preceding explanations, preferred features, advantages and/or technical effects provided in connection with <FIG> in an analogous manner.

In an example, the transceiver <NUM> comprises a third sensor unit <NUM>. The third sensor unit <NUM> is preferably arranged and/or configured to measure a third current between the transmitter <NUM> and the first terminal <NUM> of the CAN BUS interface <NUM>. The third current may also be referred to as a third actuation current. The third current may form at least a part of the transmitter current of the transmitter <NUM>. In an example, the third sensor unit <NUM> is coupled between a first output <NUM> of the transmitter <NUM> and the first terminal <NUM> of the CAN BUS interface <NUM>. The CAN transceiver <NUM> may comprise a signal connection <NUM> extending from the first output <NUM> of the transmitter <NUM> to the third sensor unit <NUM>. Further, the CAN transceiver <NUM> may comprise another signal connection <NUM> extending from the third sensor unit <NUM> to the first terminal <NUM> of the CAN BUS interface <NUM>. The signal connection <NUM>, the third sensor unit <NUM>, and the signal connection <NUM> may be connected in series to provide a connection between the first output <NUM> of the transmitter <NUM> and the first terminal <NUM> of the CAN BUS interface <NUM>.

In an example, the transceiver <NUM> comprises a fourth sensor unit <NUM>. The fourth sensor unit <NUM> is preferably arranged and/or configured to measure a fourth current between the transmitter <NUM> and the second terminal <NUM> of the CAN BUS interface <NUM>. The fourth current may also be referred to as a fourth actuation current. The fourth current may form at least a part of the transmitter current of the transmitter <NUM>. In an example, the fourth sensor is coupled between a second output <NUM> of the transmitter <NUM> and the second terminal <NUM> of the CAN BUS interface <NUM>. The CAN transceiver <NUM> may comprise a signal connection <NUM> extending from the first output <NUM> of the transmitter <NUM> to the fourth sensor unit <NUM>. Further, the CAN transceiver <NUM> may comprise another signal connection <NUM> extending from the fourth sensor unit <NUM> to the second terminal <NUM> of the CAN BUS interface <NUM>. The signal connection <NUM>, the fourth sensor unit <NUM>, and the signal connection <NUM> may be connected in series to provide a connection between the second output <NUM> of the transmitter <NUM> and the second terminal <NUM> of the CAN BUS interface <NUM>.

In an example, the transceiver <NUM> comprises the evaluation unit <NUM>. The evaluation unit <NUM> may be coupled to at least one sensor unit <NUM>, <NUM> of the first and second sensor units <NUM>, <NUM>. Furthermore, in another example, the evaluation unit <NUM> may be coupled to at least one sensor unit <NUM>, <NUM> of the first and second sensor units <NUM>, <NUM>, although this example will not be further explained for now. The following explanations preferably refer to the embodiment of the CAN transceiver of <FIG>.

In an example, the evaluation unit <NUM> may be connected to the third sensor unit <NUM> via a signal connection <NUM>. In an example, the evaluation unit <NUM> may be connected to the fourth sensor unit <NUM> via another signal connection <NUM>. The evaluation unit <NUM> may be connected to one of the two sensor units <NUM>, <NUM> or to both sensor units <NUM>, <NUM>. Each sensor unit <NUM>, <NUM> connected to the evaluation unit <NUM> may transmit a sensor signal to the evaluation unit <NUM>.

In an example, the third sensor unit <NUM> may transmit via the signal connection <NUM> a third sensor signal representing the third current to the evaluation unit <NUM>. The evaluation unit <NUM> may be configured to compare the value of the third current to a predefined third current threshold value. Further, the evaluation unit <NUM> may be configured to trigger a positive detection of a dominant bit represented by the CAN BUS signal generated by the transmitter <NUM> if the result of the comparison indicates that the value of the third current is higher than the third current threshold value. In an example, the evaluation unit <NUM> may be configured to not trigger a positive detection of a dominant bit (thus not represented by the CAN BUS signal generated by the transmitter <NUM>) if the result of the comparison indicates that the value of the third current is less than the third current threshold value.

In another example, the fourth sensor unit <NUM> may transmit via the further signal connection <NUM> a fourth sensor signal representing the fourth current to the evaluation unit <NUM>. The evaluation unit <NUM> may be configured to compare the value of the fourth current to a predefined fourth current threshold value. Further, the evaluation unit <NUM> may be configured to trigger a positive detection of a dominant bit represented by the CAN BUS signal generated by the transmitter <NUM> if the result of the comparison indicates that the value of the fourth current is higher than the fourth current threshold value. In an example, the evaluation unit <NUM> may be configured to not trigger a positive detection of a dominant bit (thus not represented by the CAN BUS signal generated by the transmitter <NUM>) if the result of the comparison indicates that the value of the fourth current is less than the fourth current threshold value.

In another example, the evaluation unit <NUM> may be configured to trigger a positive detection of a dominant bit represented by the CAN BUS signal generated by the transmitter <NUM> if the result of the comparisons indicates that both the value of the third current is higher than the third current threshold value and the value of the fourth current is higher than the fourth current threshold value. In another example, the evaluation unit <NUM> may be configured not to trigger a positive detection of a dominant bit (thus not represented by the CAN BUS signal generated by the transmitter <NUM>) if the result of the comparisons indicates that the value of the third current is less than the third current threshold and/or if the value of the fourth current is also less than the fourth current threshold.

Furthermore, for the embodiment of the CAN transceiver <NUM> of <FIG>, reference is made to the advantageous explanations, preferred features, advantages and technical effects in an analogous manner as explained for the embodiment of the CAN transceiver <NUM> of <FIG>.

In an example, the transceiver <NUM> is configured to detect a first duration of a plurality of consecutive dominant bits. The bits are dominant bits detected based on the transmitter current generated by the transmitter <NUM>. Preferably, the evaluation unit <NUM> of the transceiver <NUM> is configured to detect the first duration of the plurality of detected, consecutive dominant bits. In an example, the evaluation unit <NUM> is configured to compare the first time duration to a predefined reference time duration. Preferably, the evaluation unit <NUM> is configured to trigger a positive detection of the error sequence (of at least six consecutive dominant bits being detected) if the result of the comparison indicates that the first time duration is larger (longer) than the reference time duration. In an example, the time duration of each bit is approximately the same. In an example, if the evaluation unit <NUM> detects a first time duration that is lager (longer) than five times the time duration of a single bit, it may be derived that the first time duration has the duration of at least six consecutive dominant bits being detected. In an example, the predefined reference duration may be understood as a threshold for the first duration to detect the error sequence of at least six consecutive dominant bits. Preferably, the error sequence is determined by at least six consecutive dominant bits because it is specified in the CAN standard that a maximum of five identical consecutive bits may be generated and/or transmitted during error-free operation. A break of this rule defined in the CAN standard leads to the conclusion that an error is present. In an example, the predefined reference duration is at least five times the time duration of a single bit and preferably less than six times the duration of a single bit. In an example, the predefined reference duration may be <NUM> times the time duration of a single bit. By choosing the lower value of the reference duration to be slightly higher than five times the duration of a single bit, very small variations in the time duration of the dominant bits can be prevented from inadvertently causing a false positive detection of the error sequence. In addition, robust detection of the error sequence can be ensured over the first duration and the predefined reference duration.

In an example, the evaluation unit <NUM> of the transceiver <NUM> is configured to generate the control signal representing a fault of the transmitter <NUM> in response to a detected error sequence. According to the preferred embodiment of the transceiver <NUM> explained previously, the error sequence is detected if a first time duration is higher than the predefined reference time duration. In this case, at least six consecutive dominant bits have represented by a CAN BUS signal been generated by the transmitter <NUM>, such that an erroneous behavior of the transmitter <NUM> is present. The erroneous behavior of the transmitter <NUM> can also be referred to as a fault of the transmitter <NUM>. The control signal may be configured to directly or indirectly represent the fault of the transmitter <NUM>. In an example, the control signal may be sent from the evaluation unit <NUM> of the transceiver <NUM> to the CAN controller <NUM> to inform the CAN controller <NUM> of the fault of the transmitter <NUM>.

<FIG> schematically illustrates an example of a further embodiment of the transceiver <NUM>, wherein the transceiver <NUM> is based on the embodiment of the transceiver <NUM> of <FIG> and/or <FIG>. Therefore, for the embodiment of the transceiver <NUM> of <FIG>, reference is made to the preferred explanations, preferred features, technical effects and advantages as explained for the transceiver <NUM> of <FIG> and/or <FIG>.

In an example, the transceiver <NUM> comprises another signal interface <NUM>. The transceiver <NUM> may further comprise a signal connection <NUM> extending from the evaluation unit <NUM> to the signal interface <NUM>. The evaluation unit <NUM> is preferably configured to direct the control signal to the signal interface <NUM> via the signal connection <NUM>, such that the control signal may be transmitted via the signal interface <NUM>. In an example, the CAN controller <NUM> is coupled to the signal interface <NUM> of the transceiver <NUM> via another signal connection <NUM>. In this case, the evaluation unit <NUM> may send the control signal to the CAN controller <NUM> via the signal connection <NUM>, the signal interface <NUM>, and the signal connection <NUM>. As previously explained in an example, the control signal may represent the faulty state of the transmitter <NUM>. The CAN controller <NUM> may be informed of the fault of the transmitter <NUM> of the transceiver <NUM> via the control signal. The CAN controller <NUM> may initiate follow-up actions in response to the fault of the transmitter <NUM>. In an example, in response to the fault of the transmitter <NUM>, the CAN controller <NUM> may interrupt and/or block the transmission of a TXD transmission signal to the TXD interface <NUM> of the transceiver and/or the reception of an RXD signal from the RXD interface <NUM>. Alternatively or additionally, in an example, the CAN controller <NUM> may inform a higher-level control unit (not shown) in response to the fault of the transmitter <NUM>.

In another example, the CAN controller <NUM> and the CAN transceiver <NUM> may be comprised by a CAN system <NUM>.

<FIG> and <FIG> each schematically illustrate an example of a further embodiment of the transceiver <NUM>, preferably based on the embodiment of the transceiver <NUM> of <FIG> and/or <FIG>. Therefore, for the embodiment of the transceiver <NUM> of <FIG> and/or <FIG>, reference is made in each case to the preferred explanations, preferred features, technical effects and advantages as explained for the transceiver <NUM> of <FIG> and/or <FIG>. Purely as a precaution, it is pointed out that the embodiment of the transceiver <NUM> of <FIG> may, in an example, further comprise the features of the transceiver <NUM> previously mentioned in connection with <FIG>.

In an example, the evaluation unit <NUM> may be configured to generate the control signal in response to a detected error sequence such that the fault of the transmitter <NUM> is indirectly represented by the control signal. For example, the control signal may represent a control command to disable the transmitter <NUM> and/or a control command to activate a shutdown unit to disable the transmitter <NUM>.

In an example, the transceiver <NUM> comprises at least one shutdown unit <NUM>, <NUM>. Preferably, each shutdown unit <NUM>, <NUM> is configured to at least partially disable the transmitter <NUM> based on the control signal.

In an example, the evaluation unit <NUM> is coupled to each shutdown unit <NUM>, <NUM> to send the control signal to each of the at least one shutdown unit <NUM>, <NUM>.

In an example, a first shutdown unit <NUM> is integrated into the first sensor unit <NUM>. In an example (not shown), a first shutdown unit <NUM> is not or not fully integrated into the first sensor unit <NUM>. Preferably, the transceiver <NUM> comprises another signal connection <NUM> extending from the evaluation unit <NUM> to the first shutdown unit <NUM>. In an example, the evaluation unit <NUM> may be configured to send the control signal to the first shutdown unit <NUM> via the signal connection <NUM>. In an example, the first shutdown unit <NUM> is configured to interrupt the electrical connection between the first supply terminal <NUM> of the transceiver <NUM> and the transmitter <NUM> based on the control signal. In an example, if the control signal represents a control command to disable the transmitter <NUM>, and thus indirectly represents a fault of the transmitter <NUM>, the first shutdown unit <NUM> may interrupt the electrical connection between the first supply terminal <NUM> of the transceiver <NUM> and the transmitter <NUM> in response to the received control signal. In another example, if the control signal does not represent a control command to disable the transmitter <NUM> or if no control command is generated by the evaluation unit <NUM>, the first shutdown unit <NUM> may be configured in this case to not interrupt the electrical connection between the first supply terminal <NUM> of the transceiver <NUM> and the transmitter <NUM>.

In an example, a second shutdown unit <NUM> is integrated into the second sensor unit <NUM>. In an example (not shown), a second shutdown unit <NUM> is not or not fully integrated into the second sensor unit <NUM>. Preferably, the transceiver <NUM> comprises another signal connection <NUM> extending from the evaluation unit <NUM> to the second shutdown unit <NUM>. In an example, the evaluation unit <NUM> may be configured to send the control signal to the second shutdown unit <NUM> via the signal connection <NUM>. In an example, the second shutdown unit <NUM> is configured to interrupt the electrical connection between the second supply terminal <NUM> of the transceiver <NUM> and the transmitter <NUM> based on the control signal. In an example, if the control signal represents a control command to disable the transmitter <NUM>, and thus indirectly represents a fault of the transmitter <NUM>, the second shutdown unit <NUM> may interrupt the electrical connection between the second supply terminal <NUM> of the transceiver <NUM> and the transmitter <NUM> in response to the received control signal. In another example, if the control signal does not represent a control command to disable the transmitter <NUM> or if no control command is generated by the evaluation unit <NUM>, the second shutdown unit <NUM> may be configured in this case to not interrupt the electrical connection between the first supply terminal <NUM> of the transceiver <NUM> and the transmitter <NUM>.

In an example, the CAN transceiver <NUM> comprises the first shutdown unit <NUM> and the second shutdown unit <NUM>, wherein the two shutdown units <NUM>, <NUM> are configured to jointly disable the transmitter <NUM> based on the control signal. In an example, the two shutdown units <NUM>, <NUM> may be configured to jointly completely interrupt the transmitter <NUM> from the first and second supply terminals <NUM>, <NUM> based on the control signal.

In an example, if an error sequence is detected by means of the evaluation unit <NUM> and, inferred therefrom, a fault of the transmitter <NUM> is detected, the evaluation unit <NUM> may control the first and second shutdown units <NUM>, <NUM> via the control signal so that the two shutdown units <NUM>, <NUM> fully disable the transmitter <NUM>. The disabling can effectively prevent the (faulty) transmitter <NUM> from blocking the CAN BUS <NUM> by sending out dominant bits or adversely affecting nodes <NUM> coupled to the CAN BUS <NUM>.

In an example the CAN transmitter <NUM> may remain disabled until a next power cycle of the transceiver <NUM>. In another example, the evaluation unit may reset the control signal upon a predefined interruption time. The evaluation unit <NUM> may be configured to check again, whether the fault of the transmitter <NUM> disappeared. If not, the evaluation unit <NUM> may change into a locked state, where the evaluation unit sends out the control signal independent of whether the transmitter <NUM> recovers.

In an example, after disabling the transmitter <NUM> the CAN transceiver <NUM> may be configured to re-enabling the transmitter <NUM> again after a predefined waiting period (following the disabling of the transmitter <NUM>) and preferably also configured to check if the fault of the transmitter <NUM> occurs again. The number of re-enablings may be limited to a predefined number.

<FIG> schematically illustrates an example of a further embodiment of the transceiver <NUM>, preferably based on the embodiment of the transceiver <NUM> of any of <FIG>. Therefore, for the embodiment of the transceiver <NUM> of <FIG>, reference is made to the preferred explanations, preferred features, technical effects and advantages as explained for the transceiver <NUM> to the previous figures.

In connection with <FIG>, it was explained in an example that the transceiver <NUM> may comprise a TXD signal error detector <NUM>. As can be seen schematically from <FIG>, the TXD transmit signal from the CAN controller <NUM> can reach the TXD signal error detector <NUM> via the TXD interface <NUM> and the signal connection <NUM>. In an example, the TXD signal error detector <NUM> is configured to detect a sequence of at least six consecutive identical bits in the TXD transmit signal as a TXD error. Further, the TXD signal error detector <NUM> may be configured to stop forwarding the TXD transmit signal to the signal connection <NUM> upon detecting the TXD error. The TXD signal error detector <NUM> may further be configured to forward the TXD transmit signal from the signal connection <NUM> to the signal connection <NUM> if the TXD signal error detector <NUM> does not detect a TXD error. The TXD signal error detector <NUM> has the advantage that preferably no erroneous TXD transmit signal reaches the transmitter <NUM>. If, nevertheless, a CAN BUS signal is generated by the transmitter <NUM> that represents a sequence of six consecutive dominant bits, it can be derived that there is a fault of the transmitter <NUM>. This fault of the transmitter <NUM> may be detected by means of an embodiment of the transceiver <NUM>, as previously explained with reference to <FIG>.

In an example, a further fault of the transmitter <NUM> may occur if the TXD transmit signal arriving at the transmitter <NUM> via the signal connection <NUM> represents a dominant bit, but a CAN BUS signal is generated by the transmitter <NUM> that does not represent said dominant bit.

In an example, the evaluation unit <NUM> is coupled to the TXD interface <NUM> of the transceiver <NUM> to receive the digital TXD transmit signal. In an example, the transceiver <NUM> may comprise another signal connection <NUM> extending from the signal connection <NUM> to the evaluation unit <NUM>. As a result the digital TXD transmit signal preferably reaches both the transmitter <NUM> and the evaluation unit <NUM>.

In an example, the evaluation unit <NUM> is configured to observe whether a dominant bit represented by the TXD transmit signal is also represented as a dominant bit by the CAN BUS signal. As previously explained, the evaluation unit <NUM> is preferably configured to detect any dominant bit represented by the CAN BUS signal based on the transmitter current. Preferably, the evaluation unit <NUM> is configured to detect each dominant bit that is represented by the TXD transmit signal. In an example, the evaluation unit <NUM> may be configured to observe whether a dominant bit detected in the TXD transmit signal is also represented as a dominant bit by the CAN BUS signal.

In an example, the evaluation unit <NUM> is configured to trigger a positive detection of a transmission error if the result of the observation indicates that a dominant bit represented by the TXD digital transmit signal is not also represented by the CAN BUS signal. In an example, the transmission error may be another example of an fault of the transmitter <NUM>.

In an example, the evaluation unit <NUM> of the transceiver <NUM> may be configured to (also) generate the control signal in response to a positive detection of the transmission error. Also in this case, the control signal may directly or indirectly represent the fault of the transmitter <NUM>. Preferably, reference is made with respect to the control signal to the preferred explanations, preferred features, technical effects and advantages as previously explained, for example, in connection with <FIG>.

In an example, the transceiver <NUM>, and preferably the evaluation unit <NUM> of the transceiver <NUM>, is configured to send an error signal to the CAN controller <NUM> via the interface <NUM> of the transceiver <NUM> in response to a detected error sequence and/or in response to a detected transmission error. The error signal may differ from the control signal. The error signal may directly or indirectly represent the detected error sequence, the detected transmission error, and/or generally the fault of the transmitter <NUM>.

In an example, the transceiver <NUM>, and preferably the evaluation unit <NUM> of the transceiver <NUM>, is configured to generate the control signal in response to the detected error sequence and/or in response to a detected transmission error. Further, the evaluation unit <NUM> may be configured to control the at least one shutdown unit <NUM>, <NUM> via the control signal such that the respective shutdown unit <NUM>, <NUM> fully or at least partially disables the transmitter <NUM> in response to the control signal.

<FIG> schematically illustrates an example of an embodiment of the method according to the present disclosure. The method is for a CAN transceiver <NUM> having a CAN BUS interface <NUM>, a TXD interface <NUM>, an RXD interface <NUM>, a receiver <NUM> coupled to the CAN BUS interface <NUM> and the RXD interface <NUM>, and a transmitter <NUM> coupled to the TXD interface <NUM> and the CAN BUS interface <NUM>, the method comprising the following steps a) through f): a) Receiving a digital TXD transmit signal, representing a frame comprising a plurality of bits, over the TXD interface <NUM> from a CAN controller <NUM>; b) Generate a CAN BUS signal that represents the bits of the frame in a sequence at the CAN BUS interface <NUM>; c) Measuring an electrical current of the transmitter <NUM>, referred to as the transmitter current; d) Detect each dominant bit represented by the CAN BUS signal based on the transmitter current; e) Detecting an error sequence of at least six consecutive dominant bits known based on the transmitter current; and f) Generating a control signal in response to a detected error sequence, the control signal representing a fault of the transmitter <NUM>.

With respect to the method, reference is made to the preferred explanations, preferred features, technical effects and advantages in an analogous manner as previously explained for the CAN transceiver <NUM> in connection with <FIG>.

The methods described herein may at least partially be embodied by a computer program or a plurality of computer programs, which may exist in a variety of forms both active and inactive in a single computer system or across multiple computer systems. For example, they may exist as software program(s) comprised of program instructions in source code, object code, executable code or other formats for performing some of the steps. Any of the above may be embodied on a computer-readable medium, which may include storage devices and signals, in compressed or uncompressed form.

Claim 1:
A Controller Area Network, CAN, transceiver (<NUM>), comprising: a CAN BUS interface (<NUM>), a transmit data, TXD, interface (<NUM>), a receive data, RXD, interface (<NUM>), a receiver (<NUM>) coupled to the CAN BUS interface and the RXD interface, and a transmitter (<NUM>) coupled to the TXD interface and the CAN BUS interface, wherein the transceiver is configured to receive, via the TXD interface, from a CAN controller (<NUM>), a digital TXD transmit signal representing a frame comprising a plurality of bits, wherein the transmitter is configured to generate, at the CAN BUS interface, a BUS signal representing the bits of the frame in a sequence, wherein the transceiver is configured to measure an electrical current for powering the transmitter, referred to as a transmitter current, wherein the transceiver is configured to detect each dominant bit represented by the BUS signal based on the transmitter current, wherein the transceiver is configured to detect an error sequence of at least six consecutive dominant bits being detected based on the transmitter current, and wherein the transceiver is configured to generate a control signal representing a fault of the transmitter in response to a detected error sequence.