LED driver offers single solution for automotive applications

Infineon / Mitsubishi / Fuji / Semikron / Eupec / IXYS

LED driver offers single solution for automotive applications

Posted Date: 2024-01-25

TS19501 single-channel dimmable LED driver for high-brightness automotive applications. The LED driver handles a wide input voltage (4.2 to 42 V), supports multiple topologies and operating modes, features wide programmable frequency operation with spread-spectrum clocking, and is AEC-Q100 qualified.

Its integrated design makes it suitable for all automotive LED applications such as high and low beams, daytime running lights, direction indicators, position indicators, fog lights, ATV and 4WD lights. This IC is also available in non-automotive versions for classic applications.

Automotive lighting

LED lighting is an enabling technology in the automotive sector: it offers new functionality, increased safety, design flexibility, higher efficiency in lumens per watt, easier integration with control systems and electronics, reliability, better lighting design Free and easier to characterize each carmaker's style and personality.

The main reasons for the success of LED technology are its cooler color temperature (typically 5,000 K), which gives cars a more technological and metallic look, and its versatility, which allows for thin and uniform light guides, making it possible to personalize the aesthetics of the vehicle. .

However, due to their higher light intensity, LEDs can also provide greater projection depth, thus improving safety. LED technology is constantly updated through the development of new features and electronic control systems; as we will see later in this article, today's design involves not only the light source, but also the shape, projection and image of the light itself.

LED driver

LEDs require a constant current to produce the proper light, which is what the required operation of the LED driver depends on. The accuracy of the current supply is what attracts the attention of customers. Current changes in the vehicle that occur with voltage changes must be avoided. Linear regulators perform simple control and do not require the use of electromagnetic interference filters. However, their heat dissipation may become excessive for high-power applications.

"Our customers are always looking for high power levels," said Kevin Parmenter, director of applications engineering at TSMC. "But at the same time, they have to comply with EMC requirements while having flexible equipment. For all electronic equipment in the vehicle, EMC performance is very important."

There is a growing demand for compact, efficient drivers with low electrical noise, high light intensity dimming (dimmer) ratios, and protection features such as polarity protection, short-circuit to GND or Vcc, overcurrent or overvoltage protection, and overtemperature protection. All parameters ensure the correct relationship between current and luminous flux.

LED drivers are essentially power supplies that provide dedicated power (usually a constant current) to the LEDs in a manner suitable for their operation, but this function can be controlled in a more or less advanced way by devices equipped with logic functions.

There are two main types of drives: isolated and non-isolated. In this case, the circuit chain from the AC power source to the LED also includes a transformer, which galvanically isolates the surface of the lamp from the electrical system. In the second case, there is no isolation. For low-power isolated drivers, flyback topology is generally used, while for high-power drivers, the resonant half-bridge LLC topology is recommended. For non-isolated drivers, common circuit types are buck-boost, buck, and SEPIC (Single-Ended Primary Inductor Converter). There are many variations: for example, the flyback topology can also be implemented in a two-stage version including a boost stage. Technical requirements, especially power factor correction,

“LED drivers are designed in a variety of configurations,” Parmenter said. "SepiChas are used in a variety of projects due to their low conducted emissions, as the current draw tends to be very constant compared to other solutions. The choice depends on what you want to do, what the supply voltage is, and the EMI and RFI of the conducted emissions What’s the environment like?”

TSMC’s TS19501 offers designers a number of advantages and improvements over competing devices:

2V to 42V input voltage: One device handles multiple applications
Wide operating temperature:

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