How have automotive sensors, cables, storage, connectors, and testing solutions evolved?

The picture above is the product structure of ISA-Weld of ISA-Weld based on welding technology. The BAS shunt in the product display picture above belongs to the Bus-bar connection type (copper busbar mechanical connection installation) product of this product line. In addition to the raw materials, alloy materials, and resistance product structure of the products are completed by ISA-Weld itself (precision alloys, precision and power resistors are ISA-Weld's main business lines), "the biggest feature is the TCR temperature drift of 50ppm, which no other company in the industry can do, and the same type is 200ppm." Its constant current can reach 925A. "It meets the ideal four-wire measurement solution; the raw materials used are still the company's manganese-nickel-copper alloy, so the temperature coefficient is low, the thermal stress is small, and the long-term stability is good; vacuum electron beam welding (the two black lines in the picture above) is more compact than laser welding."

"The biggest feature of Isabelenghuite's products is low temperature drift." This is inseparable from the research on alloy materials. "What is the concept of temperature drift? It is the value that changes with the resistance value. What is the concept of 300ppm? Under a temperature difference of 100℃, the resistance value changes by 3%. If the battery pack of the car manufacturer requires an accuracy of 1%, a 300ppm shunt cannot meet the requirement."

In addition, thermal internal resistance (the resistor itself generates heat, which spreads from the intermediate alloy to the terminals on both sides), power attenuation curve (power attenuates greatly when the terminal temperature reaches a certain value), long-term stability (resistance changes over time), and copper thermoelectric potential (voltage is generated when there is a temperature difference between copper and non-copper materials) are all parameters that need to be considered for sampling resistors. They will be particularly prominent in electric vehicles.

Test solutions for automotive electronics

As a large number of new standards and new technologies emerge for intelligent connected vehicles, test solutions are also changing. Not long ago, we reported on Keysight's test solution for automotive Ethernet and Keysight's latest in-vehicle network security test - this is also an unavoidable topic when intelligent connected vehicles develop to a certain extent in the future. This time, Huang Teng, digital application market and business development manager at Keysight, shared Keysight's bus test solution in automotive electronics.

"Cars are rapidly developing in the direction of today's mobile phones, with global technologies, interfaces, buses, etc." Huang Teng actually mainly shared USB, MIPI and general serial data analysis. Here we only talk about MIPI.

"There are many cars that use the MIPI bus. Cameras need image sensors and are used in all directions of the car. MIPI now has mature solutions in use in cars." "MIPI was originally most typically used in mobile phones. The original goal was to make mobile phones the same as PCs, but it was not achieved in the end. Otherwise, if all components were MIPI, mobile phones could be assembled by themselves."

MIPI D-PHY physical layer test, time parameter test

"This is a characteristic of the MIPI physical layer. This is an intermediate bus that has some characteristics of DDR and some of USB. It switches between Low Power and High Speed ​​modes. When performing MIPI testing, you need to consider testable issues, leave test points at the receiving end, and leave as much ground as possible for the signal, so that you can ensure that the signal is what you want to see during testing."

In the era of automotive electronics, the more representative test is Keysight's automotive Ethernet test. We mentioned in previous articles that due to the use of high-speed buses, signal stability and signal quality issues also need to be reconsidered; cable connectors also need to consider impedance matching, reflection, loss, crosstalk; various DCDC DC conversions, power integrity, etc. For the test solution of automotive Ethernet, the physical layer consistency test mainly includes the transmitter, receiver and link segmentation. Tests including USB, MIPI, Ethernet bus, etc. are playing a role, which is enough to show the changes in the automotive electronics industry.

"The motherboard used to have many discrete devices, but now they are all large-scale integrated circuits. Now we only consider whether there are problems with the PCB and the connector. The testing ratio has been relatively small, and most of the time we do consistency verification, measurement, and analysis. So the three main uses of an oscilloscope are: first, general signal debugging; second, consistency testing (treating the system as a black box) and eye diagram and jitter testing and debugging; third, using the oscilloscope as a digital receiver (radar and coherent optical communications)." said Huang Teng.

Keysight Technologies 3000T X-Series Oscilloscope

Zhang Bin, a technical engineer at ITECH, shared ITECH's automotive electronics testing solutions in a relatively systematic manner. The automotive electronics anti-interference verification test mainly includes the simulation test of the voltage disturbance when the car engine is started. The test plan is to simulate the voltage waveform of the car engine start-up and detect the characteristics of the DUT (device under test) during and after starting; the automotive electronics reset function test simulates different voltage sag curves to test the reset performance of the DUT under different voltage sags; the fuse blowing test simulates the impact of the voltage drop on the automotive electronics when the conventional fuse component in another circuit melts in the automotive circuit; for the LV123 of new energy vehicles, the power supply reliability test of the high-voltage parts of new energy vehicles, etc.

In the automotive power system, power chips or power modules are used for voltage conversion to power automotive electronic devices such as electric vehicle instrument systems, fingerprint locks, and EPS electric power systems. In addition to the anti-interference test at the input end, the output end also needs to simulate the working status of real electrical equipment. For example, the light control module test, the electric window anti-pinch function test, and the laser radar is sensitive to current shock. When the DC power supply is started, there will be a large current overshoot. A large overshoot will break down the laser radar, so the laser sensor power supply test is required...

As the degree of automation and intelligence of smart connected vehicles increases, there will be more control modules, sensors and motors, which are typical test objects in automotive electronics testing. In addition, there are also low-power supply tests (the device is usually in idle or sleep mode and is activated only when needed), charging pile/on-board charger tests (charging output test, low-voltage auxiliary power supply test, harmonic current test, etc.).

ITECH IT-M3600 series regenerative source load system and IT8600 AC/DC electronic load

Therefore, on the road to autonomous driving, the entire vertical field of the automotive industry, and even traditional participants that were not originally in the automotive industry, are preparing to usher in a wave of new vitality due to various technological innovations in automotive networking, intelligence, electrification, and digitization. Even though there are still many pain points in this transitional period of development in the automotive industry, as all speakers at the conference mentioned, the various components of the car have generated new demands and challenges due to the emergence of new opportunities, and the industrial structure is indeed changing, which still makes people full of confidence in the future of intelligent connected vehicles.