Interface circuit, electronic control unit system and method for operating a device using an electronic control unit

Abstract

According to various embodiments, an interface circuit for connection to an electronic control unit (ECU) is provided. The interface circuit can include a first connection circuit, a second connection circuit, and a switch circuit. The first connection circuit can be configured to connect to an external device. The second connection circuit can be configured to provide an input signal to the ECU. The input signal can be indicative of a voltage level at the first connection circuit. The switch circuit can be connected to a first voltage and a second voltage. The switch circuit can be configured to receive a control signal from the ECU and can be further configured to selectively connect the first connection circuit to one of the first voltage and the second voltage based on the received control signal.

Description

Technical Field

[0001] Various embodiments relate to interface circuitry and ECU systems for connection to an electronic control unit (ECU). Various embodiments also relate to methods of operating devices such as sensor devices or load devices using an ECU. Background Technology

[0002] Modern automobiles include multiple ECUs to perform various functions. These ECUs may include, for example, body control modules, zone control modules, etc. ECUs can serve as input interfaces to detect or measure automotive electrical sensors, such as thermostats and switches, such as ignition and control switches. ECUs can also serve as output drivers to drive or actuate electromechanical load devices, such as relays, solenoids, DC motors, lamps, and light-emitting diodes (LEDs). ECUs typically include dedicated input interface circuitry and output driver circuitry for connecting to each electromechanical load device or automotive electrical sensor. For example, an ECU may include input interface circuitry that is active low or active high, depending on the type of sensor to be connected to. Similarly, an ECU may include output driver circuitry that can be either high-side or low-side, depending on the type of load device to be connected to. Each of these individual active low-level input interface circuits, active high-level input interface circuits, high-side output driver circuits, and low-side output driver circuits requires dedicated wiring for connection to sensors or load devices. Therefore, an ECU will require a large cable harness and multiple mating connectors to connect to various types of devices. These large cable harnesses and mating connectors add unwanted weight and cost to vehicles. Furthermore, during new vehicle development, if the ECU's connections need to be rewired from sensors to load devices (or vice versa), significant hardware changes will be required. These hardware changes will involve circuit board layout modifications and re-verification, translating into time and cost impacts for both automakers and ECU suppliers. Summary of the Invention

[0003] According to various embodiments, an interface circuit for connecting to an electronic control unit (ECU) can be provided. The interface circuit may include a first connection circuit, a second connection circuit, and a switching circuit. The first connection circuit may be configured to connect to an external device. The second connection circuit may be configured to provide an input signal to the ECU. The input signal may indicate a voltage level at the first connection circuit. The switching circuit may be connected to a first voltage and a second voltage. The switching circuit may be configured to receive a control signal from the ECU and may be further configured to selectively connect the first connection circuit to one of the first voltage and the second voltage based on the received control signal.

[0004] According to various embodiments, an ECU system can be provided. This ECU system may include the aforementioned interface circuit and an ECU connected to the interface circuit.

[0005] According to various embodiments, a method for operating a sensor device using an ECU can be provided. The method may include connecting the ECU to the aforementioned interface circuit and a first connection circuit connecting the sensor device to the interface circuit. The first connection circuit may be connected to a switching circuit via a wetting current resistor.

[0006] According to various embodiments, a method for operating a load device using an ECU can be provided. The method may include connecting the ECU to the aforementioned interface circuit and a first connection circuit connecting the load device to the interface circuit. The first connection circuit may be connected to a switching circuit via a jumper cable.

[0007] According to various embodiments, a method for diagnosing fault conditions in an external device using an ECU can be provided. This method may include connecting the ECU to the aforementioned interface circuit, connecting the external device to a first connection circuit of the interface circuit, connecting a diagnostic sub-circuit of the interface circuit to a reference voltage, and setting a control signal to a logic low level to disconnect the external device from the power supply.

[0008] Further features of the advantageous embodiments are provided in the dependent claims. Attached Figure Description

[0009] In the accompanying drawings, the same reference numerals generally refer to the same parts in all different views. The drawings are not necessarily to scale, but rather are intended to illustrate the principles of the invention in general. In the following description, various embodiments are described with reference to the following drawings, in which:

[0010] Figure 1 Conceptual diagrams of interface circuits according to various embodiments are shown.

[0011] Figure 2 A schematic diagram of an interface circuit according to various embodiments is shown.

[0012] Figure 3 Circuit diagrams of interface circuits according to various embodiments are shown.

[0013] Figure 4 An ECU system according to various embodiments is shown.

[0014] Figure 5 A flowchart illustrating a method for operating a sensor device using an ECU according to various embodiments is shown.

[0015] Figure 6A The following illustrations show various embodiments of the interface circuitry used to perform... Figure 5The method is an annotated circuit diagram of the interface circuit.

[0016] Figure 6B The following illustrations show various embodiments of the interface circuitry used to perform... Figure 5 The method is an annotated circuit diagram of the interface circuit.

[0017] Figure 6C The following illustrations show various embodiments of the interface circuitry used to perform... Figure 5 The method is an annotated circuit diagram of the interface circuit.

[0018] Figure 7 A flowchart illustrating a method for operating a load device using an ECU according to various embodiments is shown.

[0019] Figure 8A The following illustrations show various embodiments of the interface circuitry used to perform... Figure 7 The method is an annotated circuit diagram of the interface circuit.

[0020] Figure 8B The following illustrations show various embodiments of the interface circuitry used to perform... Figure 7 The method is an annotated circuit diagram of the interface circuit.

[0021] Figure 9 A flowchart illustrating a method for diagnosing fault conditions in an external device using an ECU, according to various embodiments. Detailed Implementation

[0022] The embodiments described below in the context of devices such as interface circuits or electronic control unit systems are similarly effective for the corresponding methods, and vice versa. Furthermore, it should be understood that the embodiments described below can be combined; for example, a portion of one embodiment can be combined with a portion of another embodiment.

[0023] It should be understood that any property described herein for a specific device (e.g., an interface circuit or electronic control unit system) may also apply to any device described herein. Similarly, it should be understood that any property described herein for a specific method may also apply to any method described herein. Furthermore, it should be understood that for any device or method described herein, not all described components or steps must be included in that device or method, but only some (but not all) of them may be included.

[0024] The term “connection” (or “linkage”) in this document may be understood as an electrical or mechanical connection, such as attachment or fixation, or contact without any fixation, and it should be understood that direct or indirect connections may be provided at the same time (in other words: connections that do not involve direct contact).

[0025] In one embodiment, "circuit" can be understood as an electrical circuit or any type of logical implementation entity, which can be a dedicated circuit or a processor executing software stored in memory, firmware, or any combination thereof. Thus, in one embodiment, "circuit" can be a hardwired logic circuit or a programmable logic circuit, such as a programmable processor, such as a microprocessor (e.g., a Complex Instruction Set Computer (CISC) processor or a Reduced Instruction Set Computer (RISC) processor). An electrical circuit, or simply "circuit," can be understood as any type of conductive path, including, for example, wires, input connectors, or output connectors. An electrical circuit can also include one or more electrical components electrically connected by wires. A "circuit" can also be a processor executing software—such as any type of computer program, such as a computer program using virtual machine code like Java. Any other type of implementation of the corresponding functionality, which will be described in more detail below, can also be understood as a "circuit" according to alternative embodiments.

[0026] The terms "high" and "low" used in the text regarding voltage can be understood as relative terms. In other words, a "high" voltage can have a higher value than a "low" voltage. For example, a high voltage can be 5V and a low voltage can be 0V, or a high voltage can be 10V and a low voltage can be 5V, or a high voltage can be 0V and a low voltage can be -5V.

[0027] Traditional automotive ECUs typically have connection interfaces specifically adapted for the external devices to be connected to them. For example, the connection interface for a sensor device may differ from that of an electromechanical load device. Furthermore, the connection interface for a high-level active sensor device may differ from that of a low-level active sensor device. Similarly, the connection interface for a high-side load device may differ from that of a low-side load device. An ECU may require another connection interface to perform diagnostic tests on external devices. As a result, vehicles may need to be equipped with multiple different mating connector types and cable harnesses to connect various external devices to their respective ECUs. Moreover, if the type of external device connected to the ECU changes, the affected ECU hardware may need to be modified to provide the appropriate connection interface to match the new external device.

[0028] According to various embodiments, the interface circuitry connectable to the ECU can address the aforementioned problems by selectively configuring functions among active-high level input sensing, active-low level input sensing, high-side output driver, low-side output driver, and diagnostic sensing, without any significant hardware changes. By being configurable among various functions without any substantial hardware changes, the interface circuitry reduces the need for hardware modifications to the ECU when it needs to connect to different external devices. Furthermore, it reduces the number of wires and ECU mating connectors required in the vehicle, as the interface circuitry allows the ECU to connect to any of the active-high level input sensors, active-low level input sensors, high-side load devices, and low-side load devices. The interface circuitry can be provided as part of a new ECU that includes the interface circuitry in place of a conventional connection interface. Alternatively, the interface circuitry can be provided as an external component connectable to a conventional ECU.

[0029] To make the invention easy to understand and practice, various embodiments will now be described by way of example rather than limitation and with reference to the accompanying drawings.

[0030] Figure 1 A conceptual diagram of an interface circuit 100 according to various embodiments is shown. The interface circuit 100 can be connected to an ECU. The interface circuit 100 may include a first connection circuit 110, a second connection circuit 120, and a switching circuit 130. The first connection circuit 110 can be configured to connect to an external device 160. The second connection circuit 120 can be configured to provide an input signal 102 to the ECU. The input signal 102 can indicate a voltage level at the first connection circuit 110. The switching circuit 130 can be connected to a first voltage 104 and a second voltage 106. The switching circuit 130 can be configured to receive a control signal 108 from the ECU. The switching circuit 130 can also be configured to selectively connect the first connection circuit 110 to one of the first voltage 104 and the second voltage 106 based on the received control signal 108. The first connection circuit 110, the second connection circuit 120, and the switching circuit 130 can be interconnected, as shown by line 150, for example, an electrical connection (e.g., using a line or cable) and / or a communication connection.

[0031] In other words, interface circuit 100 can be connected to the ECU to receive control signal 108 from the ECU. Interface circuit 100 can also provide input signal 102 to the ECU. Input signal 102 can be provided to the input port of the ECU's microcontroller or central processing unit. Interface circuit 100 may include a first connection circuit 110 and can be connected to an external device 160 via the first connection circuit 110. Interface circuit 100 may also include a switching circuit 130 that can be connected to a first voltage 104 and a second voltage 106. Interface circuit 100 can receive control signals via switching circuit 130. Depending on the received control signal 108, switching circuit 130 can connect the first connection circuit 110 and thus, by connection to the first connection circuit, the external device 160 to the first voltage 104 or the second voltage 106. Interface circuit 100 may also include a second connection circuit 120. Second connection circuit 120 can be coupled to first connection circuit 110. Second connection circuit 120 can receive voltage signals from first connection circuit 110 and can provide input signal 102 based on the received voltage signals. The voltage signal can be the voltage level at the output of the first connection circuit 110. The input signal 102 can indicate the voltage signal.

[0032] The first voltage 104 may have a lower voltage level than the second voltage 106. The first voltage 104 may be electrically grounded, in other words, at least approximately zero volts, for example, in the range of about -0.1V to -1.0V. The second voltage 106 may be supplied by a power source. In an alternative embodiment, the first voltage 104 may be a negative voltage level, while the second voltage 106 may be a positive voltage level.

[0033] When paired with an ECU, the interface circuit 100 can be selectively configured between the functions of active high-level input sensing, active low-level input sensing, high-side output driver, and low-side output driver by using the ECU to adjust the control signal 108 provided to the interface circuit 100.

[0034] According to one embodiment that can be combined with the above embodiments or any further embodiments described below, the switching circuit 130 may include a high-side switch connectable to a second voltage 106 and a low-side switch connectable to a first voltage 104, for example, as Figure 2 As shown. Switching circuit 130 can be configured to selectively turn on only one of the high-side switch and the low-side switch based on the received control signal 108.

[0035] According to one embodiment that can be combined with the above embodiments or any further embodiments described below, the high-side switch may include a first high-side transistor configured to receive a control signal 108 and may further include a second high-side transistor connectable to a second voltage 106, wherein the first high-side transistor may be configured to turn on the second high-side transistor based on the received control signal 108, for example, as... Figure 3 As shown. When the first high-side transistor is turned on, it allows current to flow through itself, causing the second high-side transistor to also turn on.

[0036] According to embodiments that can be combined with any of the above embodiments or any further embodiments described below, each of the first high-side transistor and the second high-side transistor can be a bipolar junction transistor (BJT), for example, as... Figure 3 As shown. The base terminal of the first high-side transistor can be configured to receive the control signal 108, and the collector terminal of the first high-side transistor can be connected to the base terminal of the second high-side transistor. The emitter terminal of the second high-side transistor can be connected to the second voltage 106.

[0037] According to embodiments that can be combined with any of the above embodiments or any further embodiments described below, the low-side switch may include a first low-side transistor configured to receive a control signal 108 and may further include a second low-side transistor connectable to a first voltage 104, for example, as... Figure 3 As shown. The first low-side transistor can be configured to turn on the second low-side transistor based on the received control signal 108.

[0038] According to embodiments that can be combined with any of the above embodiments or any further embodiments described below, each of the first low-side transistor and the second low-side transistor can be a BJT, for example, as... Figure 3 As shown. The base terminal of the first low-side transistor can be configured to receive the control signal 108. The collector terminal of the first low-side transistor can be connected to the base terminal of the second low-side transistor. The emitter terminal of the second low-side transistor can be connected to the first voltage 104.

[0039] According to embodiments that can be combined with any of the above embodiments or any further embodiments described below, the first connection circuit 110 can be connected to the switching circuit 130 via either a wetting current resistor or a jumper cable. The jumper cable can have a very low resistance, such as 0 Ω. Connecting the first connection circuit 110 to the switching circuit 130 via the jumper cable allows current to flow between the first connection circuit 100 and the switching circuit 130 with minimal energy loss, thereby providing higher power to the load device driven by the ECU. On the other hand, when the first connection circuit 100 is connected to a sensor device, connecting the first connection circuit 110 to the switching circuit 130 via the wetting current resistor can provide a small amount of wetting current to the sensor device. The wetting current can overcome the surface film resistance at the electrical contacts connected to or part of the sensor device, allowing current to flow between the sensor device and the first connection circuit 110.

[0040] According to embodiments that can be combined with any of the above embodiments or any further embodiments described below, the first connection circuit 110 can be configured to at least partially absorb voltage surges. When absorbing voltage surges, the first connection circuit 110 can prevent voltage surges or electrostatic discharges from damaging components of the ECU, such as a microcontroller.

[0041] According to embodiments that can be combined with any of the above embodiments or any further embodiments described below, the second connection circuit 120 may include a level shifter subcircuit configured to convert the voltage level at the first connection circuit 110 into a safe voltage level for the ECU as input signal 102. By converting the voltage level to a safe voltage level for the ECU, the second connection circuit 120 can prevent excessive voltage from reaching the ECU, thus preventing damage to components of the ECU, such as the microcontroller. The second connection circuit 120 can also convert the voltage level at the first connection circuit 110 into a logic voltage level state recognizable by the ECU's microcontroller.

[0042] According to embodiments that can be combined with any of the above embodiments or any further embodiments described below, the second connection circuit 120 may include a diagnostic sub-circuit. This diagnostic sub-circuit may be configured to detect faults at the external device 160 and may be further configured to provide an error signal as input signal 102 based on fault detection. Therefore, the diagnostic sub-circuit enables the interface circuit 100 to perform diagnostic functions in addition to serving as an input interface and driving load devices.

[0043] According to an embodiment that can be combined with any of the above embodiments or any further embodiments described below, the second connection circuit 120 can be connected in series with the first connection circuit 110.

[0044] According to embodiments that can be combined with any of the above embodiments or any further embodiments described below, one or more BJTs in integrated circuit 100 may be replaced by other types of transistors, such as field-effect transistors (FETs), for example, metal-oxide-semiconductor field-effect transistors (MOSFETs). Compared to BJTs, MOSFET transistors are capable of handling higher power.

[0045] Figure 2 A schematic diagram of an interface circuit 100 according to various embodiments is shown. The switching circuit 130 may include a high-side switch 132 and a low-side switch 134. The high-side switch 132 and the low-side switch 134 may be connected in parallel. Each of the high-side switch 132 and the low-side switch 134 may be configured to receive a control signal 108. The high-side switch 132 may be configured to receive a second voltage 106, while the low-side switch 134 may be configured to be connected to a first voltage 104. The first voltage 104 may be lower than the second voltage 106. The first voltage 104 may be an electrically grounded terminal, such as... Figure 2 As shown. In an alternative embodiment, the first voltage 104 may be a negative voltage, while the second voltage 106 may be a positive voltage.

[0046] High-side switch 132 and low-side switch 134 can be configured to turn on based on different voltage levels of control signal 108. High-side switch 132 and low-side switch 134 can be mutually exclusive based on control signal 108. For example, high-side switch 132 can be turned on when control signal 108 is logic HIGH (also referred to herein as "HIGH") and turned off when control signal 108 is logic LOW (also referred to herein as "LOW"). In the same example, low-side switch 134 can be turned on when control signal 108 is LOW and turned off when control signal 108 is logic HIGH. Logic HIGH control signal 108 can have a voltage level greater than 0V—for example, 1 to 10V, such as 5V. Logic LOW control signal 108 can have a voltage level lower than logic HIGH, such as 0V.

[0047] Reference Figure 2 According to various embodiments, the interface circuit 100 may further include a wetting current resistor 304 (in Figure 2 (Represented as "R1" in Chinese). The wetting current resistor 304 can be arranged between the first connection circuit 110 and the switching circuit 130. The wetting current resistor 304 can be connected in series with the first connection circuit 110 and the switching circuit 130.

[0048] Still refer to Figure 2According to various embodiments, the interface circuit 100 may further include a jumper cable 302. The jumper cable 302 may be disposed between the first connection circuit 110 and the switching circuit 130. The jumper cable 302 may be connected in series with the first connection circuit 110 and the switching circuit 130. The jumper cable 302 may be a dedicated cable or any conductive cable.

[0049] According to various embodiments, interface circuit 100 may include a wetting current resistor 304 and a jumper cable 302. The wetting current resistor 304 and the jumper cable 302 may be connected in parallel. Interface circuit 110 may optionally further include a jumper cable switch 306 for selectively connecting or disconnecting the jumper cable 302. When the jumper cable 302 is connected, current between the first connection circuit 110 and the switch circuit 130 may flow through the jumper cable 302. When the jumper cable 302 is disconnected, the current between the first connection circuit 110 and the switch circuit 130 may instead flow through the wetting current resistor 304.

[0050] Still refer to Figure 2 According to various embodiments, the first connection circuit 110 can be configured to at least partially absorb voltage surges. The first connection circuit 110 may include a surge protection sub-circuit 112 that at least partially absorbs electrostatic discharge or voltage level spikes. The first connection circuit 110 may include a connector for electrical connection to an external device such as a sensor device or a load device. Figure 2 (Not shown in the image).

[0051] Still refer to Figure 2 According to various embodiments, the second connection circuit 120 may be connected in series with the first connection circuit 110. The second connection circuit 120 may include a level shifter sub-circuit 122. The level shifter sub-circuit 122 may be configured to receive a first voltage (also referred to herein as a voltage level at the first connection circuit 110) from the first connection circuit 110. The level shifter sub-circuit 122 may be further configured to convert the first voltage to a second voltage and may transmit the second voltage as an input signal 102 to the ECU. The second voltage may be within a safe threshold of the ECU. When the first voltage exceeds the safe voltage level of the ECU, the second voltage may be lower than the first voltage.

[0052] The second connection circuit 120 may further include a diagnostic subcircuit 124. The diagnostic subcircuit 124 may be disposed between the first connection circuit 110 and the level shifter subcircuit 122. The diagnostic subcircuit 124 may be configured to detect an open-load fault, for example, when it detects an open circuit at the first connection circuit 110. The diagnostic subcircuit 124 may be configured to provide an error signal to the level shifter subcircuit 122 based on the detection of an open-load fault. The level shifter subcircuit 122 may receive the error signal from the diagnostic subcircuit 124 and may convert the error signal into a second voltage, which may be transmitted to the ECU as input signal 102.

[0053] Figure 3 A circuit diagram of an interface circuit 100 according to various embodiments is shown. The high-side switch 132 may include a first high-side transistor 430 and a second high-side transistor 432. The first high-side transistor 430 may be configured to receive a control signal 108 and may be further configured to transmit a high-side switch signal to the second high-side transistor 432. The second high-side transistor 432 may be connected to a second voltage 106. The second voltage 106 may be supplied by a circuit including… Figure 3 The Chinese character is represented as "V". BAT "Battery power 462 and Figure 3 The middle is represented as V CC The common-collector power supply 460 provides power. The second high-side transistor 432 can be turned on based on a high-side switching signal. Each of the first high-side transistor 430 and the second high-side transistor 432 can be a BJT. The first high-side transistor 430 can be a negative-positive-negative (NPN) transistor, while the second high-side transistor 432 can be a positive-negative-positive (PNP) transistor. The emitter terminal of the first high-side transistor 430 can be connected to an electrical ground terminal. In use, the base terminal of the first high-side transistor 430 can receive a control signal 108. The collector terminal of the first high-side transistor 430 can be connected to the base terminal of the second high-side transistor 432. In use, the emitter terminal of the second high-side transistor 432 can be connected to a second voltage 106. If the control signal 108 is HIGH, the voltage at the base terminal of the first high-side transistor 430 can be higher than the voltage at the emitter terminal of the first high-side transistor 430. Thus, the first high-side transistor 430 is turned on, and current flows between its collector terminal and emitter terminal. Therefore, the voltage at the base terminal of the second high-side transistor 432 can be lower than the voltage at its emitter terminal, and current flows between its collector terminal and emitter terminal.

[0054] Conversely, if the control signal 108 is LOW, the voltage at the base terminal of the first high-side transistor 430 can be equal to or lower than the voltage at the emitter terminal of the first high-side transistor 430. Thus, the first high-side transistor 430 is turned off, and current does not flow between its collector and emitter terminals. Therefore, due to the open circuit caused by the first high-side transistor 430 being turned off, the voltage at the base terminal of the second high-side transistor 432 may be infinite. Consequently, the second high-side transistor 432 may also be turned off, and current may not flow between its collector and emitter terminals.

[0055] Still refer to Figure 3 According to various embodiments, the low-side switch 134 may include a first low-side transistor 440 and a second low-side transistor 442. The first low-side transistor 440 may be configured to receive a control signal 108 and may be further configured to transmit a low-side switch signal to the second low-side transistor 442. The second low-side transistor 442 may be connected to a first voltage 104. The second low-side transistor 442 may be turned on based on the low-side switch signal. Each of the first low-side transistor 440 and the second low-side transistor 442 may be a BJT. The first low-side transistor 440 may be a PNP transistor, while the second low-side transistor 442 may be an NPN transistor. The emitter terminal of the first low-side transistor 440 may be connected to a common collector voltage (V). CC In use, the base terminal of the first low-side transistor 440 can receive the control signal 108. The collector terminal of the first low-side transistor 440 can be connected to the base terminal of the second low-side transistor 442. In use, the emitter terminal of the second low-side transistor 442 can be connected to the first voltage 104. If the control signal 108 is LOW, the voltage at the base terminal of the first low-side transistor 440 can be lower than the voltage at the emitter terminal of the first low-side transistor 440, thus turning on the first low-side transistor 440 and allowing current to flow between its collector terminal and emitter terminal. Therefore, the voltage at the base terminal of the second low-side transistor 442 can be higher than the voltage at its emitter terminal, and thus allowing current to flow between its collector terminal and emitter terminal.

[0056] Conversely, if the control signal 108 is HIGH, the voltage at the base terminal of the first low-side transistor 440 can be equal to or higher than the voltage at the emitter terminal of the first low-side transistor 440. Thus, the first low-side transistor 440 is turned off, and current does not flow between its collector and emitter terminals. Therefore, due to the open circuit caused by the first low-side transistor 440 being turned off, the voltage at the base terminal of the second low-side transistor 442 may be infinite. Consequently, the second low-side transistor 442 may also be turned off, and current may not flow between its collector and emitter terminals.

[0057] Still refer to Figure 3 According to various embodiments, the interface circuit 100 may further include a diode device 402 between the switching circuit 130 and the first connection circuit 110. The diode device 402 may be connected between the switching circuit 130 and the wetting current resistor 304. The diode device 402 may also be connected between the switching circuit 130 and the jumper cable 302. The diode device 402 may restrict current flow unidirectionally from the high-side switch 132 to the first connection circuit 110. The diode device 402 may restrict current flow unidirectionally from the first connection circuit 110 to the low-side switch 134. The diode device 402 may include, for example, at least one diode. The diode device 402 may be connected to the respective collector terminals of the second high-side transistor 432 and the second low-side transistor 442.

[0058] Still refer to Figure 3 According to various embodiments, the surge protection subcircuit 112 may include a capacitor 410 and a diode device 412 connected in parallel. The diode device 412 may be a back-to-back transient protection diode. The diode device 412 may be configured to protect the interface circuit 100 from damage in the event of a transient surge in the input voltage supplied to the first connection circuit 112.

[0059] Still refer to Figure 3 According to various embodiments, the diagnostic subcircuit 124 may include a first resistor 422 and a second resistor 424. The diagnostic subcircuit 124 may be configured to detect an open circuit, for example, when the interface circuit 100 is disconnected from a load device or sensor device. The diagnostic subcircuit 124 may include a voltage divider. The diagnostic subcircuit 124 may include components arranged to form the reference numeral V. CC The voltage divider 426 has a first resistor 422 and a second resistor 424. The first resistor 422 can be connected to V... CC426 is connected between the first connection circuit 110 and the first connection circuit 110. A second resistor 424 can be connected between the first connection circuit 110 and the electrical ground terminal. The resistance value of resistor 424 can be selected such that it is much higher than the DC resistance of the load or sensor to minimize the load effect on the output or sensor resistance. If the load device or sensor device is disconnected from the interface circuit 100, in other words, no device is connected to the interface circuit 100, then the input signal 102 can be a voltage divider V. CC The step-down level generated by 426. The diagnostic sub-circuit 124 may further include a diode device 420 connected to the first resistor 422. The diode device 420 may be connected to V... CC Both 426 and the electrical ground terminal. Diode device 420 can limit current from V... CC 426 flows unidirectionally to the first resistor 422. Diode device 420 can limit the current from V... CC The current flows unidirectionally from the first resistor 422 to the first resistor 422. The diode device 420 can also limit the current from the first resistor 422 to the ground terminal.

[0060] Still refer to Figure 3 According to various embodiments, the level shifter subcircuit 122 may include a third resistor 450, a fourth resistor 452, and a capacitor 454. The fourth resistor 452 and the capacitor 454 may be connected in parallel. The third resistor 450 may be connected in series with each of the fourth resistor 452 and the capacitor 454.

[0061] Figure 4 An ECU system 400 according to various embodiments is illustrated. The ECU system 400 may include an interface circuit 100 as described in any of the above embodiments. The ECU system 400 may also include an ECU 202 connected to the interface circuit 100. The ECU system 400 may be connected to an external device 160 via a first connection circuit 110 of the interface circuit 100.

[0062] Figure 5 A flowchart of a method 500 for operating a sensor device using an ECU according to various embodiments is shown. Method 500 may include, at 502, connecting an ECU 202 to an interface circuit 100 as described in any of the above embodiments. Method 500 may include, at 504, connecting a sensor device to a first connection circuit 110 of the interface circuit 100. The first connection circuit 110 may be connected to a switching circuit 130 via a wetting current resistor 304.

[0063] According to an embodiment that can be combined with any of the above embodiments or any further embodiments described below, method 500 may further include receiving a sensor output signal via a first connection circuit 110 and providing an input signal 102 by a second connection circuit 120 based on the received sensor output signal. The input signal 102 may indicate the sensor output signal.

[0064] According to an embodiment that can be combined with any of the above embodiments or any further embodiments described below, method 500 may further include connecting the sensor device to a power supply voltage external to the interface circuit 100 and setting the control signal 108 to logic LOW.

[0065] According to an embodiment that can be combined with any of the above embodiments or any further embodiments described below, method 500 may further include connecting the sensor device to an electrical ground terminal outside the interface circuit 100 and setting the control signal 108 to logic HIGH.

[0066] The various aspects of the described method 500 can also be applied to using any of the above-described interface circuits 100 to operate sensor devices using an ECU.

[0067] Figure 6A An annotated circuit diagram of interface circuit 100 is shown when interface circuit 100 is used to perform method 500 according to various embodiments. In the illustrated example, interface circuit 100 may be connected to a high-level active sensor device 504, indicated by switch "SW1". High-level active sensor device 504 may be connected to a power supply voltage 550. High-level active sensor device 504 can transmit a high-voltage sensor signal (represented as V1) to interface circuit 100 during use. Interface circuit 100 may be configured to sense readings from high-level active sensor device 504 by setting control signal 108 to LOW using ECU 202. When control signal 108 is LOW, high-side switch 132 may be turned off. Figure 6A (Displayed in gray), while the low-side switch 134 can be turned on. In other words, the first connection circuit 110 can be connected to the first voltage 104 while being disconnected from the second voltage 106. As a result, the current (denoted as I) SW1 502) can flow from the high-level active sensor device 504 to the first voltage 104. SW1 502 can flow from the high-level active sensor device 504 to the first connection circuit 110, and from the first connection circuit 110 to the low-side switch 134 of the switching circuit 130. The jumper cable 302 can be disconnected, allowing I... SW1 502 flows from the first connection circuit 110 through the wetting current resistor 304 to the switching circuit 130. Current I SW1502 can be represented as:

[0068]

[0069] Where R1 represents the wetting current resistor 304, V IN V1, V FD1 This represents the voltage across diode device 402, V. CE_T2_npn This represents the collector-emitter voltage of the second low-side transistor 442.

[0070] Interface circuit 100 does not need to include diagnostic sub-circuit 124 for performing method 500. First connection circuit 110 can receive sensor signal V1 from high-level active sensor device 504. Second connection circuit 110 can receive the same sensor signal V1 directly from low-level active sensor device 604 or via first connection circuit 110, and can transmit a converted sensor signal V2 to ECU 202 based on sensor signal V1. In other words, input signal 102 can be V2.

[0071] V2 can be represented as:

[0072] and

[0073]

[0074] Where R3 represents the third resistor (450Ω), R4 represents the fourth resistor (452Ω), and V... IH_高 This indicates the highest voltage that ECU202 can receive, V. IH_低 This indicates the lowest voltage that ECU 202 can accept.

[0075] Figure 6B Annotated circuit diagrams of interface circuit 100 are shown when it is used to perform method 500 according to various embodiments. In the illustrated example, interface circuit 100 may be connected to a low-level active sensor device 604, indicated by switch "SW2". Low-level active sensor device 604 may be connected to electrical ground terminal 614. Low-level active sensor device 604, in use, can transmit a low-voltage sensor signal (represented as V1) to interface circuit 100. Interface circuit 100 can be configured to sense readings from low-level active sensor device 604 by setting control signal 108 high using ECU 202. When control signal 108 is high, high-side switch 132 can be turned on, while low-side switch 134 can be turned off. Figure 6B (Displayed in gray). In other words, the first connection circuit 110 can be connected to the second voltage 106 while being disconnected from the first voltage 104. In the circuit providing the second voltage 106, V CC 460 can be disconnected, so that only V is available.BAT 462 remains connected to the high-side switch 132. Disconnect V. CC 460 can prevent attacks from V BAT A current of 462 flows into V CC 460 and caused damage to V CC 460 power supply circuit. As a result of connecting the first connection circuit 110 to the second voltage 106, the current (denoted as I) SW2 512) can flow from the second voltage 106 to the low-level active sensor device 512. SW2 512 can flow from the second voltage 106 to the high-side switch 132 of the switching circuit 130, then from the high-side switch 132 to the first connection circuit 110, and then from the first connection circuit 110 to the electrical ground terminal 614. The jumper cable 302 can be disconnected, allowing I... SW2 512 flows from the switching circuit 130 through the wetting current resistor 304 to the first connection circuit 110. Current I SW2 512 can be represented as:

[0076]

[0077] Where R1 represents the wetting current resistor 304, V BAT V represents BAT The voltage provided by 462, V EC_T1_pnp This represents the emitter-collector voltage of the second high-side transistor 432, V. F_D1 This indicates the voltage across diode device 402.

[0078] Interface circuit 100 does not need to include diagnostic sub-circuit 124 for performing method 500. First connection circuit 110 can receive sensor signal V1 from active-low sensor device 604. Second connection circuit 110 can receive the same sensor signal V1 directly from active-low sensor device 604 or via first connection circuit 110, and can transmit a converted sensor signal V2 to ECU 202 based on sensor signal V1. In other words, input signal 102 can be V2.

[0079] V2 can be represented as:

[0080] and

[0081] V IH_低 ≥V2≥V IH_高 ,

[0082] Where R3 represents the third resistor (450Ω), R4 represents the fourth resistor (452Ω), and V... IH_高 This indicates the highest voltage that ECU 202 can receive, V. IH_低This indicates the minimum voltage that ECU 202 can accept.

[0083] Figure 6C An annotated circuit diagram of interface circuit 100 is shown when interface circuit 100 is used to perform method 500 according to various embodiments. In the example shown, interface circuit 100 can be connected to proportional sensor device 1004. Proportional sensor device 1004 can output a sensor voltage that depends on the changing resistance of proportional sensor device 1004. The resistance of proportional sensor device 1004 can vary depending on the parameter being measured by proportional sensor device 1004. In other words, the voltage level of the sensor voltage can indicate the measurement being performed by proportional sensor device 1004. Interface circuit 100 can be used to perform sensor voltage sensing, that is, to determine the output voltage of proportional sensor device 1004. A well-tuned precision voltage source can be connected to a second voltage 106 to serve as the sensor power supply voltage. Proportional sensor device 1004 can be connected to electrical ground terminal 1014. Reference resistor 1006 can be connected between switching circuit 130 and first connection circuit 110 in place of wetting current resistor 304. Jumper cable 302 can be disconnected, such that I S 1002 flows from the switching circuit 130 to the first connection circuit 110 via the reference resistor 1006. The resistance value of the reference resistor 1006 may be different from that of the wetting current resistor 304. The resistance value of the reference resistor 1006 can be selected based on the resistance value of the proportional sensor device 1004.

[0084] Interface circuit 100 can be configured to sense readings from proportional sensor device 1004 by setting control signal 108 to HIGH. When control signal 108 is HIGH, high-side switch 132 can be turned on, while low-side switch 134 can be turned off. Figure 6C (Displayed in gray). In other words, the first connection circuit 110 can be connected to the second voltage 106 while being disconnected from the first voltage 104. As a result, the current (denoted as I) S 1002) can flow from the second voltage 106 to the ratiometer sensor device 1004. S 1002 can flow from the second voltage 106 to the high-side switch 132 of the switching circuit 130, then from the high-side switch 132 to the first connection circuit 110, and then from the first connection circuit 110 to the proportional sensor device 1004. Current I S 1002 can be represented as:

[0085]

[0086] Where Rref represents the reference resistor 1006V. SS This indicates the sensor power supply voltage provided by the second voltage 106, V.EC_T1_pnp This represents the emitter-collector voltage of the second high-side transistor 432, V. F_D1 This indicates the voltage across diode device 402.

[0087] The first connection circuit 110 can receive sensor signal V1 from the proportional sensor device 1004. The second connection circuit 110 can receive the same sensor signal V1 directly from the low-level active sensor device 604 or via the first connection circuit 110, and can transmit the converted sensor signal V2 as input signal 102 to the ECU 202 based on the sensor signal V1.

[0088] Figure 7 A flowchart of a method 700 for operating a load device using an ECU according to various embodiments is shown. Method 700 may include, at 702, connecting an ECU 202 to an interface circuit 100 as described in any of the above embodiments. Method 700 may include, at 704, connecting a load device to a first connection circuit 110 of the interface circuit 100. The first connection circuit 110 may be connected to a switching circuit 130 via a jumper cable 302.

[0089] According to an embodiment that can be combined with any of the above embodiments or any further embodiments described below, method 700 may further include connecting a load device to an electrical ground terminal outside the interface circuit 100, and setting the switching circuit 130 to a second voltage 106.

[0090] According to an embodiment that can be combined with any of the above embodiments or any further embodiments described below, method 700 may further include setting control signal 108 to logic HIGH to turn on the load device and setting control signal to logic LOW to turn off the load device.

[0091] According to an embodiment that can be combined with any of the above embodiments or any further embodiments described below, method 700 may further include connecting the load device to a power supply voltage external to the interface circuit 100, and setting the control signal 108 to logic LOW to turn on the load device.

[0092] The above aspects of method 700 can also be applied to using any of the above-described interface circuits 100 to operate the load device using the ECU.

[0093] Figure 8AAnnotated circuit diagrams of interface circuit 100 are shown when it is used to perform method 700 according to various embodiments. In the illustrated example, interface circuit 100 can be used as a high-side output driver to drive load device 804. Load device 804 can be an automotive load device, such as an automotive relay, automotive solenoid, or lamp. When interface circuit 100 is used as a high-side output driver, interface circuit 100 can be connected to a second voltage 106, and load device 804 can be connected to the second voltage 106 via interface circuit 100. Load device 804 can be connected to an electrical ground terminal.

[0094] Interface circuit 100 can be configured to act as a high-side output driver by setting control signal 108 to HIGH using ECU 202. When control signal 108 is HIGH, high-side switch 132 can be turned on, while low-side switch 134 can be turned off. Figure 8A (Displayed in gray).

[0095] In other words, the first connection circuit 110 can be connected to the second voltage 106 while being disconnected from the first voltage 104. As a result, the current (denoted as I) L1 802) can flow from the second voltage 106 to the load device 804. L1 802 can flow from the second voltage 106 to the high-side switch 132 of the switching circuit 130, then from the high-side switch 132 to the first connection circuit 110, and then from the first connection circuit 110 to the load device 804. Therefore, the load device 804 can be energized.

[0096] The wetting current resistor 304 can be disconnected, allowing I to... L1 802 flows from the switching circuit 130 to the first connection circuit 110 via the jumper cable 302. Current I L1 802 can be represented as:

[0097]

[0098] Where R L This indicates the resistance of the load device 804, in V. S This indicates the voltage supplied by power supply 106, V. EC_T1_pnp This represents the emitter-collector voltage of the second high-side transistor 432, V. F_D1 This indicates the voltage across diode device 402.

[0099] To shut down load device 804, control signal 108 can be set to LOW, causing high-side switch 132 to be turned off and load device 804 to be disconnected from power supply 106.

[0100] In one embodiment, for high-side output drive operation, low-side switch 134 can be removed from switch circuit 130 to avoid low-side switch 134 affecting high-side output drive operation and reduce material cost of interface circuit 100.

[0101] Figure 8B Annotated circuit diagrams of interface circuit 100 are shown according to various embodiments when interface circuit 100 is used to perform method 700. In the example shown, interface circuit 100 can be used as a low-side output driver to drive load device 804. When interface circuit 100 is used as a low-side output driver, interface circuit 100 can connect load device 804 to a first voltage 104. Load device 804 can be connected to an external power supply voltage 814. Interface circuit 100 can be configured to act as a low-side output driver by setting control signal 108 to LOW using ECU 202. When control signal 108 is LOW, low-side switch 134 can be turned on, while high-side switch 132 can be turned off. Figure 8B (Displayed in gray). In other words, the first connection circuit 110 can be connected to the first voltage 104 while being disconnected from the second voltage 106. As a result, the current (denoted as I) L2 812) can flow from the load device 804 to the first voltage 104. L2 802 can flow from the external power supply voltage 814 to the load device 804, and from the load device 804 to the low-side switch 134 of the switching circuit 130. As a result, the load device 804 can be energized.

[0102] The wetting current resistor 304 can be disconnected, allowing I to... L2 812 flows from the first connection circuit 110 to the switching circuit 130 via the jumper cable 302. Current I L2 812 can be represented as:

[0103]

[0104] Where R L This indicates the resistance of the load device 804, in V. IN This indicates the voltage supplied by the external power supply 814, in V. FD1 This represents the voltage across diode device 402, V. CE_T2_npn This represents the collector-emitter voltage of the second low-side transistor 442.

[0105] To shut off the load device 804, the control signal 108 can be set to HIGH, causing the low-side switch 134 to be turned off and current to stop flowing due to the resulting open circuit.

[0106] In one embodiment, for low-side output drive operation, the high-side switch 132 can be removed from the switch circuit 130 to avoid the high-side switch 132 affecting the low-side output drive operation and to reduce the material cost of the interface circuit 100.

[0107] Figure 9 A flowchart of a method 900 for diagnosing fault conditions in an external device using an ECU according to various embodiments is shown. The external device may be a sensor device or a load device. Method 900 may include connecting an ECU 202 to an interface circuit 100 as described in any of the above embodiments in step 902. Method 900 may include connecting the external device to a first connection circuit 110 of the interface circuit 100 in step 904. Method 900 may include connecting a diagnostic sub-circuit 124 of the interface circuit 100 to a reference voltage in step 906. Reference will be made to the following paragraphs. Figure 6C , 8A Method 900 is further described in conjunction with 8B.

[0108] According to various embodiments, when the interface circuit 100 is used to perform method 500 or 700, the second connection circuit 120 may optionally further include a diagnostic sub-circuit 124, such that the interface circuit 100 can also perform method 900 to diagnose fault conditions in the external device. The ECU can be in V CC A reference voltage VREF_DIAG is provided to the diagnostic subcircuit 124 at position 426. The diagnostic subcircuit 124 can receive a first signal from the first connection circuit 110. Based on the first signal, the diagnostic subcircuit 124 can transmit a second signal to the level shifter subcircuit 122. The voltage level of the second signal can vary depending on the fault condition of the external device. Based on the second signal, the level shifter subcircuit 122 can transmit an input signal 102 to the ECU. The input signal 102 can therefore indicate the fault condition at the external device.

[0109] Reference Figure 6C Interface circuit 100 can be configured to detect fault conditions when interface circuit 100 is connected to proportional sensor device 1004. Diagnostic subcircuit 124 can be configured to detect faults at proportional sensor device 1004 or connections between proportional sensor device 1004 and interface circuit 100. To perform method 900 on proportional sensor device 1004, component control signal 108 can be set to LOW. Figure 6C (Not shown in the image), causing the proportional sensor device 1004 to disconnect from the second voltage 106. Reference voltage V REF_DIAG It can also be done in V CC 426 points are supplied to the diagnostic sub-circuit 124.

[0110] If the proportional sensor device 1004 or the connection between the first connection circuit and the proportional sensor device 1004 is shorted to the ground terminal, the diagnostic sub-circuit 124 may receive a 0V signal from the first connection circuit 110. Therefore, the input signal 102 may be 0V.

[0111] If the proportional sensor device 1004 or the connection between the first connection circuit and the proportional sensor device 1004 is shorted to the battery, current may flow from the battery to the electrical ground terminal in the diagnostic subcircuit 124. The diagnostic subcircuit 124 may output a large voltage signal. The level shifter subcircuit 122 can convert this large voltage signal into the maximum safe voltage for the ECU port as input signal 102.

[0112] If the proportional sensor device 1004 is disconnected from the first connection circuit 110, i.e., an open circuit exists at the interface circuit 100, then the diagnostic sub-circuit 124 can output a value based on V based on its first resistor 422 and second resistor 424. REF_DIAG The input signal 102 is a second signal for the division. Therefore, the input signal 102 can be higher than the load voltage level at the maximum load DC resistance value. The input signal 102 can have different voltage levels under different fault conditions, thus providing an indication of the connection status with the proportional sensor device 1004. The ECU 202 can diagnose the condition of the proportional sensor device 1004 connected to the interface circuit 100 based on the input signal 102.

[0113] Reference Figure 8A When the interface circuit 100 is used to operate the high-side output drive, the diagnostic sub-circuit 124 can be used before the load device 804 is powered on—that is, when the control signal 108 is LOW. Figure 8A (Not shown in the image) — Perform high-side output diagnostics.

[0114] If the connection between the load device 804 or the first connection circuit and the load device 804 is shorted to the ground terminal, the diagnostic sub-circuit 124 may receive a 0V signal from the first connection circuit 110. Therefore, the input signal 102 may be 0V.

[0115] If the load device 804 or the connection between the first connection circuit and the load device 804 is shorted to the battery, current may flow from the battery to the electrical ground terminal in the diagnostic subcircuit 124. The diagnostic subcircuit 124 can output a large voltage signal. The level shifter subcircuit 122 can convert the large voltage signal into the maximum safe voltage for the ECU port as input signal 102.

[0116] If the load device 804 is disconnected from the first connection circuit 110, i.e., an open circuit exists at the interface circuit 100, then the diagnostic sub-circuit 124 can output based on V based on its first resistor 422 and second resistor 424. REF_DIAG The input signal 102 is the second signal for the division. Therefore, the input signal 102 can be higher than the load voltage level at the maximum load DC resistance value. The input signal 102 can have different voltage levels under different fault conditions, and thus provide an indication of the connection status with the load device 804. The ECU 202 can diagnose the condition of the load device 804 connected to the interface circuit 100 based on the input signal 102.

[0117] Reference Figure 8B When interface circuit 100 is used to operate the low-side output drive, diagnostic sub-circuit 124 can be used before load device 804 is powered on—that is, when control signal 108 is HIGH. Figure 8B (Not shown in the image) — Perform low-side output diagnostics.

[0118] If the connection between the load device 804 or the first connection circuit and the load device 804 is shorted to the ground terminal, the diagnostic sub-circuit 124 may receive a 0V signal from the first connection circuit 110. Therefore, the input signal 102 may be 0V.

[0119] If the load device 804 or the connection between the first connection circuit and the load device 804 is short-circuited to the battery, the diagnostic sub-circuit 124 may receive a voltage signal higher than the voltage level when the load device 804 is not short-circuited due to the DC resistance of the load device 804. The diagnostic sub-circuit 124 may output a second signal based on the received higher voltage signal.

[0120] If the load device 804 is disconnected from the first connection circuit 110, i.e., an open circuit exists at the interface circuit 100, then the diagnostic sub-circuit 124 can output based on V based on its first resistor 422 and second resistor 424. REF_DIAG The input signal 102 is the second signal for the division. Therefore, the input signal 102 can be higher than the load voltage level at the maximum load DC resistance value. The input signal 102 can have different voltage levels under different fault conditions, thereby providing an indication of the connection status with the load device 804. The ECU 202 can diagnose the condition of the load device 804 connected to the interface circuit 100 based on the input signal 102.

[0121] The following examples further illustrate the technical aspects of the devices, systems, and methods described above, and should not be construed as claims.

[0122] The following examples can be combined with any of the devices, systems, and methods described above, as well as any of the initially filed claims.

[0123] Example 1 is an interface circuit for connection to an electronic control unit, the interface circuit comprising: a first connection circuit configured to connect to an external device; a second connection circuit configured to provide an input signal to the electronic control unit, the input signal indicating a voltage level at the first connection circuit; and a switching circuit capable of connecting to a first voltage and a second voltage, wherein the switching circuit is configured to receive a control signal from the electronic control unit and is further configured to selectively connect the first connection circuit to one of the second voltage and the first voltage based on the received control signal.

[0124] In Example 2, the subject matter of Example 1 may optionally include: a switching circuit comprising a high-side switch that can be connected to a second voltage and a low-side switch that can be connected to a first voltage, wherein the switching circuit is configured to selectively turn on only one of the high-side switch and the low-side switch based on a received control signal.

[0125] In Example 3, the subject matter of Example 2 may optionally include: a high-side switch including a first high-side transistor configured to receive a control signal and further including a second high-side transistor capable of being connected to a second voltage, wherein the first high-side transistor is configured to turn on the second high-side transistor based on the received control signal.

[0126] In Example 4, the subject matter of Example 3 may optionally include: each of the first high-side transistor and the second high-side transistor is a bipolar junction transistor, wherein the base terminal of the first high-side transistor is configured to receive a control signal, wherein the collector terminal of the first high-side transistor is connected to the base terminal of the second high-side transistor, and wherein the emitter terminal of the second high-side transistor can be connected to a second voltage.

[0127] In Example 5, the subject matter of any one of Examples 2 to 4 may optionally include: a low-side switch including a first low-side transistor configured to receive a control signal and further including a second low-side transistor capable of being connected to a first voltage, wherein the first low-side transistor is configured to turn on the second low-side transistor based on the received control signal.

[0128] In Example 6, the subject matter of Example 5 may optionally include: each of the first low-side transistor and the second low-side transistor is a bipolar junction transistor, wherein the base terminal of the first low-side transistor is configured to receive a control signal, wherein the collector terminal of the first low-side transistor is connected to the base terminal of the second low-side transistor, and wherein the emitter terminal of the second low-side transistor can be connected to a first voltage.

[0129] In Example 7, the subject matter of any of Examples 1 to 6 may optionally include: a first connection circuit connected to a switching circuit via a wetting current resistor and a jumper cable.

[0130] In Example 8, the subject matter of any of Examples 1 through 7 may optionally include: the first connection circuit is configured to at least partially absorb voltage surges.

[0131] In Example 9, the subject matter of any of Examples 1 to 8 may optionally include: a second connection circuit including a level shifter sub-circuit configured to convert the voltage level at the first connection circuit to a safe voltage level for the electronic control unit as an input signal.

[0132] In Example 10, the subject matter of any of Examples 1 to 9 may optionally include: a second connection circuit including a diagnostic sub-circuit configured to detect a fault at an external device and further configured to provide an error signal as an input signal based on the fault detection.

[0133] Example 11 is an electronic control unit system comprising: an interface circuit of any one of Examples 1 to 10; and an electronic control unit connected to the interface circuit.

[0134] Example 12 is a method of operating a sensor device using an electronic control unit, the method comprising: connecting the electronic control unit to an interface circuit of any one of Examples 1 to 10; and connecting the sensor device to a first connection circuit, wherein the first connection circuit is connected to a switching circuit via a wetting current resistor.

[0135] In Example 13, the subject matter of Example 12 may optionally include: receiving a sensor output signal via a first connection circuit; and providing an input signal to an electronic control unit based on the received sensor output signal via a second connection circuit, wherein the input signal indicates the sensor output signal.

[0136] Example 14 is a method of operating a load device using an electronic control unit, the method comprising: connecting the electronic control unit to an interface circuit of any one of Examples 1 to 10; and connecting the load device to a first connection circuit, wherein the first connection circuit is connected to a switching circuit via a jumper cable.

[0137] Example 15 is a method for diagnosing fault conditions in an external device using an electronic control unit, the method comprising: connecting the electronic control unit to an interface circuit of any one of Examples 1 to 10; connecting the external device to a first connection circuit; and connecting a diagnostic sub-circuit of the interface circuit to a reference voltage.

[0138] Although embodiments of the invention have been specifically shown and described with reference to specific examples, those skilled in the art will understand that various changes in form and detail may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. The scope of the invention is thus indicated by the appended claims, and all changes falling within the meaning and scope of the equivalents of the claims are therefore intended to be included. It should be understood that common reference numerals used in the related drawings refer to parts used for similar or identical purposes.

[0139] Those skilled in the art will understand that the terminology used herein is for the purpose of describing various embodiments only and is not intended to limit the invention. As used herein, the singular forms “a,” “an,” and “the” are also intended to include the plural forms unless the context clearly indicates otherwise. It will also be understood that the terms “comprising” and / or “including” are used in this specification to indicate the presence of said features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or combinations thereof.

[0140] It should be understood that the specific order and hierarchy of the boxes in the disclosed process / flowchart are illustrative of exemplary approaches. Based on design preferences, it should be understood that the specific order or hierarchy of the boxes in the process / flowchart may be rearranged. Furthermore, some boxes may be combined or omitted. The appended method claims present the elements of the various boxes in an exemplary order and are not intended to limit one to the specific order or hierarchy presented.

[0141] The foregoing description is provided to enable those skilled in the art to implement the various aspects described herein. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein may apply to other aspects. Therefore, the claims are not intended to limit the aspects presented herein, but are to be consistent with the full scope of the language of the claims, wherein references to elements in the singular are not intended to mean “one and only one”, unless specifically indicated otherwise, but rather “one or more”. The term “exemplary” is used herein to mean “serving as an example, illustration, or illustration.” Any aspect described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other aspects. Unless otherwise specified, the term “some” refers to one or more. Combinations such as “at least one of A, B, or C,” “one or more of A, B, or C,” “at least one of A, B, and C,” “one or more of A, B, and C,” and “A, B, C, or any combination thereof” include any combination of A, B, and / or C, and may include multiples of A, multiples of B, or multiples of C. Specifically, combinations such as "at least one of A, B, or C", "one or more of A, B, or C", "at least one of A, B, and C", "one or more of A, B, and C", and "A, B, C, or any combination thereof" can be A only, B only, C only, A and B, A and C, B and C, or A and B and C, wherein any such combination may include one or more members of A, B, or C. All structural and functional equivalents of the elements of the various aspects described throughout this disclosure that are known to those skilled in the art or will become known hereafter are expressly incorporated herein by reference and are intended to be covered by the claims.

Claims

1. An interface circuit (100) for connection to an electronic control unit, the interface circuit (100) comprising: A first connection circuit (110) configured to connect to an external device (160), wherein the first connection circuit (110) includes a surge protection sub-circuit (112) for at least partially absorbing voltage surges and a connector for electrical connection to the external device (160); A second connection circuit (120) configured to provide an input signal to an electronic control unit, the input signal indicating a voltage level at the first connection circuit (110), the second connection circuit (120) including a level shifter sub-circuit (122) and a diagnostic sub-circuit (124), the level shifter sub-circuit (122) being configured to convert the voltage level at the first connection circuit (110) to a safe voltage level for the electronic control unit as the input signal (102), the diagnostic sub-circuit (124) being configured to detect faults at the external device (160) and being further configured to provide an error signal based on fault detection as the input signal (102); and A switching circuit (130) that can be connected to a first voltage (104) and a second voltage (106), The switching circuit (130) is configured to receive a control signal (108) from the electronic control unit, and is further configured to selectively connect the first connection circuit (110) to one of the second voltage (106) and the first voltage (104) based on the received control signal (108).

2. The interface circuit (100) according to claim 1, wherein, The switching circuit (130) includes a high-side switch (132) that can be connected to the second voltage (106) and a low-side switch (134) that can be connected to the first voltage (104), wherein the switching circuit (130) is configured to selectively turn on only one of the high-side switch (132) and the low-side switch (134) based on a received control signal (108).

3. The interface circuit (100) according to claim 2, wherein, The high-side switch (132) includes a first high-side transistor (430) configured to receive the control signal (108) and further includes a second high-side transistor (432) capable of being connected to the second voltage (106), wherein the first high-side transistor (430) is configured to turn on the second high-side transistor (432) based on the received control signal (108).

4. The interface circuit (100) according to claim 3, wherein, Each of the first high-side transistor (430) and the second high-side transistor (432) is a bipolar junction transistor, wherein the base terminal of the first high-side transistor is configured to receive the control signal (108), wherein the collector terminal of the first high-side transistor (430) is connected to the base terminal of the second high-side transistor (432), and wherein the emitter terminal of the second high-side transistor (432) can be connected to the second voltage (106).

5. The interface circuit (100) according to any one of claims 2 to 4, wherein, The low-side switch (134) includes a first low-side transistor (440) configured to receive the control signal (108) and further includes a second low-side transistor (442) connectable to the first voltage (104), wherein the first low-side transistor (440) is configured to turn on the second low-side transistor (442) based on the received control signal (108).

6. The interface circuit (100) according to claim 5, wherein, Each of the first low-side transistor (440) and the second low-side transistor (442) is a bipolar junction transistor, wherein the base terminal of the first low-side transistor (440) is configured to receive the control signal (108), wherein the collector terminal of the first low-side transistor (440) is connected to the base terminal of the second low-side transistor (442), and wherein the emitter terminal of the second low-side transistor (442) can be connected to the first voltage (104).

7. The interface circuit (100) according to claim 1, wherein, The first connection circuit (110) is connected to the switching circuit (130) via one of the wetting current resistor (304) and the jumper cable (302).

8. An electronic control unit system (400), comprising: The interface circuit (100) according to any one of claims 1 to 7; and An electronic control unit (202) is connected to the interface circuit (100).

9. A method for operating a sensor device using an electronic control unit, the method comprising: Connect the electronic control unit to the interface circuit according to any one of claims 1 to 7; as well as The sensor device is connected to the first connection circuit, wherein the first connection circuit is connected to the switching circuit via a wetting current resistor.

10. The method of claim 9, further comprising: The sensor output signal is received via the first connection circuit; as well as The second connection circuit provides the input signal to the electronic control unit based on the received sensor output signal, wherein the input signal indicates the sensor output signal.

11. A method for operating a load device using an electronic control unit, the method comprising: Connect the electronic control unit to the interface circuit according to any one of claims 1 to 7; as well as The load device is connected to the first connection circuit, wherein the first connection circuit is connected to the switch circuit via a jumper cable.

12. A method for diagnosing fault conditions in an external device using an electronic control unit, the method comprising: Connect the electronic control unit to the interface circuit according to any one of claims 1 to 7; Connect the external device to the first connection circuit; as well as Connect the diagnostic sub-circuit of the interface circuit to the reference voltage.

Images