JAJU633 October 2018
This reference design describes a high-power (55-W) LED driver for automotive front light application. The design uses a single controller and power stage solution for driving both the high beam and the low beam. Traditional implementation uses two separate controllers and power stages. This new approach minimizes cost and circuitry while providing high-quality lighting solutions in terms of electromagnetic interference, thermal efficiency and light quality.
The design gives a simple, eas- to-adopt implementation for a high-power and output accuracy LED driver with integrated current monitoring. This design uses the TPS92692 multi-topology controller and has an input voltage range from 8 V to 16 V. This design meets CISPR-25 Class 5 EMI standards with shielding, and the switching frequency of the controller operates outside the AM frequency band. The TPS92692 controller offers external frequency synchronization, spread spectrum frequency modulation as well as analog dimmer and PWM dimming features that can be used along with this reference design for a variety of other automotive lighting applications.
The LED current is set nominally to 1.25 A with the switching frequency set at 275 kHz.