Controller Area Network Transceiver Research Articles

CAN Bus Message Authentication via Co-Channel RF Watermark

Over the past decade, consumer vehicles have increasingly begun to resemble computers on wheels, with many newer vehicles containing over 100 independent electronic control units (ECU) that make independent decisions within the vehicle. Cost and power constraints for the vehicle significantly constrain processing capabilities and limitations on practical cybersecurity measures that may be employed in the vehicle today. Also, as automotive manufacturers are continuous integrators, many legacy communications links within vehicles were originally designed as standalone entities that assumed internal trust of communications between ECUs by virtue of closed bus structures and an emphasis on reliability, but not security. This paper presents a low-cost authentication mechanism to significantly improve message validation on wired message buses such as the Controller Area Network (CAN) bus by employing a co-channel underlay watermark that arrives time-aligned with the primary bus messages. Concept validation using a gate-level Simulink / HDL Coder simulation provided initial feasibility, while a complete CAN bus hardware testbed was constructed with a custom CAN transceiver built on a Red Pitaya software defined radio (SDR) connected to multiple commercial CAN transceivers to validate backwards compatibility. This testbed incorporates a custom transmission security (TRANSEC) engine that supports dynamic variation of the watermark, further improving security during deployment. Finally, this custom CAN testbed with the watermarking CAN transceiver was tested across a range of operational conditions, with initial performance results presented and discussed. Future work describes potential for near-term ruggedization and productization of the watermarking CAN transceiver.

System-Level ESD Protection for Automotive Electronics by Co-Design of TVS and CAN Transceiver Chips

This paper proposed a co-packaged methodology using transient voltage suppressor (TVS) chips and a controller area network (CAN) bus transceiver to ensure IEC 61000-4-2 system-level ESD protection. The design methodology is verified in a high-voltage silicon-on-insulator process for CAN transceiver chip and an 0.8- ${\mu }\text{m}$ bipolar process for TVS chips. The ${I}$ – ${V}$ curves of the TVS and CAN transceiver chip are evaluated by the transmission line pulsing system with the pulse width of 100 ns. The breakdown voltage of the bi-directional TVS chips and CAN transceiver chip are higher than ±80 V compared with the ±70 V fault voltage tolerance requirement. The clamping voltage of the TVS device is lower than ±130 V to discharge ESD current before the CAN transceiver chip breakdown for effective ESD protection. The design target of parasitic inductance by bonding wires is calculated to meet the clamping voltage requirement. The CAN bus transceiver IC with TVS chips co-packaged has been evaluated to pass the IEC61000-4-2 contact ±15-kV stress without any hardware damages and latch-up issues.

A Fabrication and Testing of New RC CMOS Oscillator Insensitive Supply Voltage Variation

A controller area network (CAN) receiver measures differential voltage on a bus to determine the bus level. Since 3.3V transceivers generate the same differential voltage as 5V transceivers (usually ≥1.5V), all transceivers on the bus (regardless of supply voltage) can decipher the message. In fact, the other transceivers cannot even determine or show that there is anything different about the differential voltage levels. A new CMOS RC oscillator insensitive supply voltage for clock generation in a CAN transceiver was fabricated and tested to compensate for this drawback in CAN communication. The system consists of a symmetrical circuit for voltage and current switches, two capacitors, two comparators, and an RS flip-flop. The operational principle is similar to a bistable multivibrator but the oscillation frequency can also be controlled via a bias current and reference voltage. The chip test experimental results show that oscillation frequency and power dissipation are 500 kHz and 5.48 mW, respectively at a supply voltage of 3.3 V. The chip, chip area is 0.021 ㎟, is fabricated with 0.18 μm CMOS technology from SK hynix.

Diagnosis of Local Spot Defects in Analog Circuits

We present a method for diagnosing local spot defects in analog circuits. The method aims to identify a subset of defects that are likely to have occurred and suggests to give them priority in a classical failure analysis. For this purpose, the method relies on a combination of multiclass classifiers that are trained using data from fault simulation. The method is demonstrated on an industrial large-scale case study. The device under consideration is a controller area network transceiver used in automobile systems. This device demands high-quality control due to the reliability requirements of the application wherein it is deployed. The diagnosis problem is discussed by taking into consideration the realities of this case study.

Portable Embedded Data Display and Control Unit using CAN Bus

The development trend and research focus of control system is networked control. The Field Bus Control System (FCS) which is important segment in networked system is widely applied in control system. The CAN (Controller Area Network) bus which has strong fault tolerance, high reliability and low cost plays an important role in FCS. The CAN is a serial communication protocol which efficiently supports distributed real-time control with a very high level of security. Its domain of application ranges from high speed networks to low cost multiplex wiring. In automotive electronics, engine control units, sensors, anti-skid-systems, etc. are connected using CAN with bit rates up to 1M bit/s. This project is to develop an automatic monitor and control of any non-industrial process using a Portable Embedded data display and control unit based on CAN Bus. It is implemented by applying 16 bit RISC key microprocessor technique, embedded software technology, embedded GUI (Graphics User Interface) technology, CAN bus communication technology, information storage and management technology[6]. The Proposed system involves the CAN Protocol to communicate the data. The system consists of many nodes each comprising a PIC microcontroller and a sensor. The data is retrieved from the sensor and forwarded to a PIC microcontroller through a CAN transceiver. The PIC Microcontroller establishes connection with a CAN Protocol and process the sensor data and the data through the CAN Bus which is twisted pair of wires. Another PIC microcontroller at remote end is interfaced with LCD (Liquid Crystal Display) to view the sensor data and send back control signal to the sensor through CAN protocol. The research and development of this project was driven by robustness of CAN communication and its practicality of application.

Modeling IC Snapback Characteristics Under Electrostatic Discharge Stress

This paper presents a novel technique for modeling the electrostatic discharge snapback phenomenon in integrated circuits (ICs). The macromodel is built using standard components: BSIM3v3.2 model for the MOSFET, a bipolar transistor modeled by Mextram 504.7, and a substrate resistor. The IC under test is characterized by its die and package impedance. The model should allow easier simulation program with IC emphasis implementation, high simulation speed, less convergence issues, and wider availability of a gate-grounded n-type MOSFET protection device. Our model determines the interaction between the protection device and the internal circuitry of the IC. The model parameters are extracted with MATLAB script. Simulation results are compared with transmission-line pulsing measurement for a voltage regulator NCV4949 and a controller area network transceiver TLE6250G.

Methodology to Predict EME Effects in CAN Bus Systems Using VHDL-AMS

The electromagnetic emissions (EME) of integrated circuits (ICs) are of increasing importance in the selection of automotive components. Although the IC is treated as the main cause for these emissions, the electrical environment, i.e., the application of an IC including the minimal circuitry on the application board and its layout, as well as the global connection terminals (i.e., supply pins and bus signals) representing the load of an IC are crucial in determining the emission behavior of the entire system. This paper provides application engineers information about different aspects related to the EME of a controller area network (CAN) bus system and how emissions are generated and transformed within the application environment. It presents a methodology to investigate and predict the effects by using Very High-Speed IC Hardware Description Language-Analog Mixed Signal (VHDL-AMS). The description focuses on the interaction between the CAN transceivers and the twisted pair transmission line connecting them. Both common mode and differential mode as well as mode conversion aspects are considered. It highlights the fact that EMEs from a CAN bus system highly depend on the application environment.