Application Solutions of MOSFETs in Automotive LED

LED automotive lights have become a prominent feature in vehicle illumination, utilizing LED technology to provide external lighting and comfortable illumination inside vehicles. In the application of LED automotive lights, challenges such as thermal limits and electromagnetic compatibility (EMC) need to be addressed, along with various complex standards such as unloading load tests.

In the design of LED automotive lights, the active ripple compensation Buck circuit topology plays a crucial role. The reliability of LED lighting systems is significantly affected by the lifespan of electrolytic capacitors, especially in automotive headlights, where the lifespan of the LED driver power circuit is notably shortened due to the influence of engine heat dissipation.

As a mainstream application of LED lighting electronics in automobiles, dedicated driving power supplies are required for LEDs. Enhancing the reliability and lifespan of LED driving power supplies is crucial for the improvement of LED lighting products.

Active Ripple Compensation Buck Circuit

Automotive headlights show a significant feedback loop in the lifespan of LED driver power circuits due to engine heat dissipation. The characteristics of electrolytic capacitors result in a significant decrease in lifespan with increasing operating temperature.

By using the Buck circuit to accomplish efficient energy conversion in switch circuits and suppressing circuit ripple with linear circuits, an active ripple compensation Buck circuit is obtained, achieving reliable and long-lasting LED driving.

The design parameters of the circuit are as follows:

Selection of MOSFETs in LED driving voltage circuits

Effective selection of suitable MOSFETs can reduce the switch loss of the power supply circuit and improve the efficiency of the entire power system.

When selecting MOSFETs for automotive LEDs, several key points need to be considered, including:

Power and voltage requirements: Determine the rated power and voltage tolerance of MOSFETs based on the power requirements and operating voltage of LEDs, ensuring that MOSFETs operate stably within the LED's operating voltage range.

Current carrying capacity: MOSFETs are required to control the current in LED driving circuits, so MOSFETs capable of carrying the required current should be selected to avoid damage from overload.

Switching speed: LED driving requires fast switching to control brightness and flicker characteristics, so the switching speed of MOSFETs (such as turn-on and turn-off times) should be considered during selection to ensure system performance.

Thermal characteristics: MOSFETs generate heat during LED driving, so the thermal conductivity and maximum operating temperature of MOSFETs should be considered to ensure system stability and long-term reliability.

Package type: Considering the vibration and temperature changes in automotive environments, select package types with high temperature resistance and shock resistance, such as TO-220 and DPAK, to ensure the reliability of MOSFETs under harsh conditions.

In automotive environments, stability and durability are crucial, and VBsemi's MOSFET products can maintain stable performance under various harsh conditions, ensuring the long-term reliable operation of LED systems.

In addition, VBsemi's MOSFET products offer a variety of package types and a wide range of model choices, including TO-220, DPAK, and other high-temperature-resistant and shock-resistant package types, meeting the needs of different automotive LED driving systems and providing customers with more choices.