chrispeng To meet people’s higher demands on vehicle performance and functionality, manufacturers are scrambling to apply advanced Electronic control technology in vehicle design. With the rapid increase of the amount of information exchange in the car, the vehicle serial network system using the multiplex transmission method emerges as the times require. Currently, the CAN (Controller Area Network) protocol has become the standard for the In-Vehicle Network (IVN) protocol. In addition to CAN networks, the industry has also developed the automotive serial protocol LIN (Local Interconnect Network) bus for low-cost applications to support in-vehicle hierarchical networking.
As a leading automotive semiconductor solutions provider with extensive automotive expertise, ON Semiconductor’s broad portfolio of automotive components provides a variety of optimized solutions for in-vehicle networking, including standalone LIN transceivers, standalone CAN transceivers, system-level ICs, as well as FlexRayTM transceivers, provide automakers with a variety of options to improve the performance of automotive electronic systems.
Advantages of in-vehicle networking
With the development of automobile technology and the large-scale application of electronic technology and control technology in automobiles, there are more and more electronic control modules in automobiles. The requirements for data transfer between modules cannot be met. CAN, which is increasingly popular in automobile control systems, helps to transmit the data of automobile control systems at high speed and makes the design of automobile control systems simpler.
At present, the CAN protocol and its network system have been widely adopted by global automobile manufacturers. The CAN protocol clearly defines the content of the data link layer and the physical layer. CAN has very superior characteristics, which can optimize performance, power consumption and electronic control unit (ECU) cost, which is conducive to the realization of body control module, interior temperature control, seat control, electric power steering (EPS), adaptive lighting , rain/light intensity sensor, parking assist and transmission module and other wide range of vehicle applications.
LIN is a low-cost serial communication network used to control distributed electronic systems in automobiles. The goal of LIN is to provide auxiliary functions for existing automotive networks such as the CAN bus, so the LIN bus is an auxiliary bus network. The use of the LIN bus can provide significant cost savings where the bandwidth and versatility of the CAN bus is not required, such as for communication between smart sensors and braking devices.
ON Semiconductor’s In-Vehicle Network Solutions
Today, automakers are leveraging industry-standard interfaces to connect distributed systems. ON Semiconductor offers an innovative portfolio of in-vehicle networking products including CAN, LIN and FlexRay transceivers, all of which are AEC and TS16949 certified. The company also offers system-on-chips that integrate other circuits such as voltage regulators, drivers, transceivers and supervisory functions. Figure 1 is a typical system division of LIN and CAN bus connections and a typical device of ON Semiconductor.
Figure 1: Typical system division for LIN and CAN bus connections
1. Independent CAN transceiver
The latest generation of CAN transceivers enables industry-leading Electrostatic Discharge (ESD) and Electromagnetic Interference (EMI) immunity. These devices from ON Semiconductor utilize proven innovative I3T technology to provide very rugged, high-quality components with a measured failure rate of parts per billion (ppb).
ON Semiconductor’s NCV7341 is a CAN transceiver that acts as the interface between the CAN protocol controller and the physical bus for 12 V and 24 V systems. NCV7341 provides differential transmission function for the bus, and the high common mode range differential receiver with good EMI capability can provide powerful differential reception capability for CAN controller. When the power supply is removed, the NCV7341 has ideal passive characteristics and is fully ISO11898 compliant with rates up to 1 Mb. If a Split Termination voltage source is used, its VSPLIT (Split Termination Voltage) pin stabilizes the idle bus level, further improving Electromagnetic Emissions (EME) performance. The bus topology function of the device can connect up to 110 nodes, the digital interface independent VIO (input output voltage) power supply facilitates communication between CAN controllers and microcontrollers (MCUs) powered by different power supplies, so it is widely used in automotive and industrial network. In addition, the bus pin, VSPLIT pin short-circuit protection, and thermal protection against transients in the automotive environment make this device ideal for automotive applications. Figure 2 is a circuit diagram of a 5V CAN controller application using the NCV7341.
Figure 2: Application circuit diagram of 5V CAN controller using NCV7341
2. Independent LIN transceiver
The LIN bus communication and control unit has a lower data rate (up to 20 kBaud) and is mainly used for applications that are not time-critical functions such as door locks, mirrors, car seats and sunroofs. Each node of the LIN bus protocol uses only a single wire, which minimizes wiring costs. Each node of the LIN bus contains a slave MCU state machine capable of recognizing and converting instructions for specific functions. These products comply with US (SAE J2602-2) and European (LIN Physical Layer Specification Revision 2.1) standards.
ON Semiconductor’s feature-rich LIN transceiver, the NCV7321, serves as the interface between the LIN protocol controller and the physical bus in low data rate IVN applications. The NCV7321 features excellent EMC characteristics, robust system-level ESD performance up to 13 kV, no external ESD components, and low power consumption, making it ideal for harsh automotive applications. Figure 3 is a block diagram of the stand-alone LIN transceiver NCV7321.
Figure 3: Standalone LIN transceiver NCV7321
NCV7321 adopts ON Semiconductor’s innovative I3T technology and intelligent power technology, which enables high voltage and sensitive digital technology to coexist on the same chip. It provides customers with an alternative to existing LIN transceiver specifications. Housed in a high-density, space-saving SOIC-8 package, typical applications include a variety of body electronics functions and comfort function applications such as remote door receivers, window and sun shade lifters, alarms, power mirrors, and seats regulators, and other features such as electronic steering locks and tire monitoring electronic control units (ECUs). Figure 4 is a typical LIN circuit based on ON Semiconductor NCV7321.
Figure 4: Typical LIN circuit based on ON Semiconductor NCV7321
The outstanding feature of the NCV7321 is that it satisfies the power saving requirements of automobiles to the greatest extent, and the current consumption in sleep mode is only 10μA. Other key features include thermal shutdown, fuzzy short-circuit protection, and 45 V load dump protection. Notably, the device supports a voltage range of -45 V to 45 V and can withstand ESD pulses rated at 5 kV, providing robust protection.
3. Cost-optimized SoCs
ON Semiconductor has successfully developed a system-on-a-chip (SBC) product portfolio with independent intellectual property rights combined with years of experience in integrated custom circuit design. These SoCs integrate key system components such as LIN, CAN, and voltage regulators provided in the ECU, which can effectively improve system reliability, reduce power consumption, and save board space. Automotive industry-certified linear regulators with extremely low quiescent current and wide linear voltage regulation capability, both with short-circuit and over-temperature protection, can be used for battery load dump transient protection or power post regulation; low RDS (on ) MOSFETs have high current capability and low gate charge; integrated circuit components using self-protected MOSFETs can replace relays and fuses to drive solenoids and lamps; high-voltage rectifiers that eliminate reverse recovery oscillations provide low forward voltage drop and improve efficiency; Highly reliable electronic modules with transient voltage protection enable I/O and sensor protection, load dump protection, network data line protection and load switch protection. Figure 5 is a block diagram of ON Semiconductor’s NCV7420/25 LIN-SBC.
Figure 5: ON Semiconductor’s NCV7420/25 LIN-SBC block diagram
ON Semiconductor’s NCV7420 and NCV7425 integrate a 50 mA regulator, a 150 mA regulator and a LIN transceiver respectively, which can effectively save PCB space, and can also supply power to the MCU alone, effectively suppressing the interference of other modules on the MCU power supply. The cost is also low.
In addition to this, ON Semiconductor is also developing a portfolio of FlexRay v3.0 devices for in-vehicle networking, which is expected to hit the market shortly. Transceivers compliant with the V3.0 specification will provide automakers with enhanced pipeline error detection, faster error control, and more. The next generation of FlexRay products are targeting more powerful features, further improved EMC and higher levels of integration to optimize system cost.
Summarize
As a leading supplier of high-efficiency semiconductor solutions for automotive applications, ON Semiconductor uses advanced technology and rich R&D experience to develop a variety of automotive components, including high-voltage interfaces, intelligent power management, in-vehicle networking, and system-level integration. and sensor interface.
Due to the increasing electronic content of automobiles, electromagnetic compatibility has become an issue that cannot be ignored; in-vehicle network applications require better resistance to ESD pulses and EMI. The state-of-the-art devices offered by ON Semiconductor use I3T50/I3T80 technology, such as deep trench isolation processes, to reduce interference between different cell structures on the chip. In addition to their advanced features, these devices meet the appropriate performance standards set by the automotive industry, helping automakers achieve robust designs.
The Links: BSM200GA120DN2 MG150J1BS11
