The use of LEDs in automotive lighting is critical for array management

If you plan to buy a car, what indicators are you most concerned about? It is estimated that 100% of people will say safety and price. So, on the premise of ensuring safety and reasonable prices, what other indicators will you pay attention to? It is estimated that which one is good to choose at this time, so the current car design is increasingly pursuing a sense of fashion. LED lighting can bring a more intuitive and cool experience to cars, and has better energy-saving effects, so it is more and more widely used, including car headlights, car taillights, car window lighting, functional lighting, advanced lighting, etc. Statistics from Strategy Analytics show that safety and brand effect are to improve the LED’s level of

If you plan to buy a car, what indicators are you most concerned about? It is estimated that 100% of people will say safety and price. So, on the premise of ensuring safety and reasonable prices, what other indicators will you pay attention to? It is estimated that which one is good to choose at this time, so the current car design is increasingly pursuing a sense of fashion. LED lighting can bring a more intuitive and cool experience to cars, and has better energy-saving effects, so it is more and more widely used, including car headlights, car taillights, car window lighting, functional lighting, advanced lighting, etc. Statistics from Strategy Analytics show that safety and brand effect are the two main factors that increase the acceptance of LEDs in the automotive front lamp platform. The current annual growth rate of the program is 30%.

The use of LEDs in automotive lighting is critical for array management

Figure 1 Application of LED lighting in automobiles

However, LED lighting designers are also facing many challenges, such as: space, cost, and design complexity requirements are greatly increased, and the overall BOM cost needs to be reduced; high-power applications require higher efficiency and need to be equipped with high-efficiency devices; design needs to be flexible It is necessary to make full use of platform design to solve the problem of reusability; suppress EMI as much as possible to ensure system safety. In response to these problems, Maxim has introduced a brand-new solution. Tamer Kira, Director of Business Management of its Automotive Products Division, introduced, “Our chip integration is getting higher and higher, which can help users reduce BOM costs; high-efficiency synchronous rectification devices can help Users reduce power consumption; multi-topology devices are easy to use, which can improve design flexibility; integrated spread spectrum function, reduce transient noise, thereby suppressing EMI.”

As a car needs to be equipped with multiple sets of LED lighting products, OEM manufacturers are introducing advanced safety management for LED and matrix lighting designs. Maxim’s MAX20092 is a 12-channel switch matrix manager, Tamer Kira said, “This device enables high-performance LED array car lights and adaptive beam adjustment designs to meet the needs of higher current equipment, while reducing solution size and increasing flexibility. Performance. The on-resistance of the matrix switch is the lowest in the industry. This IC can minimize the heating of the LED array lighting, which is 65% lower than the closest competing solution.”

The use of LEDs in automotive lighting is critical for array management

Figure 2 LED lighting applications based on MAX20096 and MAX20092

Highly integrated, single chip step-up and step-down to achieve seamless switching

Integrating multiple functions is a major trend in chip design in the future. The advantage of integration is that a single chip can perform multiple functions, and engineers do not need to add other circuits, thereby reducing BOM costs. In the automotive system, there must be a buck-boost function. The traditional method is completed by a boost chip and a buck chip respectively, and Maxim integrates these two topologies on a single chip.

Of course, some companies can also implement this kind of integration scheme. The difference is that their scheme needs to go through an intermediate state when switching between boost and buck, which will cause a large voltage drop, while Maxim’s scheme can increase Seamless switching between voltage and buck, so the output voltage is more stable. Tamer Kira explained by taking MAX20092 as an example, “When the number of LEDs is relatively large, the required voltage is relatively high, and a step-up solution can be used. When the voltage is very low, a step-down solution can be used. MAX20092 can support 1-4 strings of LEDs, and you can use Buck. /Bootst buck-boost meets the configuration of different LED numbers, with greater flexibility, and meets the needs of reusability.”

Narrow frequency fast response, lower EMI

When a car is driving, whether the lights can send out signals accurately and in real time is related to the safety of the owner. Therefore, real-time monitoring of lights failure is an important part of ensuring driving safety. MAX20092 can be widely used in matrix LED lighting management modules such as headlights and turn signals. As shown in Figure 2, the battery voltage of a car is 12V, which is increased to 60V through MAX16990/2, and then stepped down through MAX20096 to provide a suitable LED matrix. Voltage. MAX20092 has advanced fault protection and open circuit, short circuit and disconnection LED detection management to ensure driving safety.

If you want to manage multiple LED lights, you need MCU to control one by one through the SPI bus. Frequent switching will increase the bus pressure. The MAX20092 integrates a 12-way switch matrix, and you can control the LEDs connected to the switch through the 12-way switches. And each switch can be controlled individually. Tamer Kira introduced the advantage of separate management: “When the system switches from lighting 1 LED light to lighting 12 LED lights, it can be controlled by MAX20092. If lighting one LED light requires 4V voltage, lighting 12 LEDs requires When the voltage is increased to 48V, the new control architecture of MAX20096 can respond quickly. Such fast response switching frequency changes are very narrow. Similar products have a wide range of switching frequency from 4V to 48V conversion output, and it is difficult to achieve filtering. EMI is very large, we need to respond quickly, and also need to ensure that the switching frequency change range is very narrow within this response time, so as to achieve lower EMI interference, MAX20096 slew rate control can reduce EMI and noise. In addition, MAX20092 also uses With RDS_ON as low as 70 milliohms, it supports LED current drive up to 1.5A, which can achieve low power consumption and high efficiency.”

Multiple devices work in parallel to achieve large pixel array control

One MAX20092 can control 12 LED lights. If multiple groups are needed, can multiple MAX20092s be connected in parallel? Tamer Kira analyzes, “MAX20092 can connect up to 27 MAX20092 devices in parallel, without daisy chaining, managing a large pixel array of up to 324 LEDs; allowing designers to configure 1 (string) x 12 series switches, 2 (String) x 6 switches in series, and 4 (string) x 3 switches in series. It can be seen that multiple groups of LEDs can be controlled on the same SPI bus. OME manufacturers can flexibly increase or decrease the number of modules to meet The differentiated needs of different automakers.”

In addition, Maxim also introduced MAX20096 and MAX20097 dual-channel, synchronous buck high-brightness LED controllers, working in conjunction with MAX20092 to help designers improve the transient response of LED lighting. MAX20096 and MAX20097 can achieve ultra-fast transient response, with Maxim’s unique average current mode control to achieve close to a fixed frequency, minimize EMI, and support reliable high-performance design.

The Links:   CM10MD-24H NL160120BC27-14

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