LED control chips enable more efficient automotive lighting designs

November 12, 2014 // By Christoph Hammerschmidt
With two new chips ON Semiconductor joins the trend towards LED lighting in the car. At the electronica exhibition, the manufacturer of power devices introduced the NCV78763, a smart power ballast and dual-channel LED driver, and the NCV7691, a current controller for LEDs.

Capable of driving two strings of LEDs up to 60 V, the NCV78763 provides an efficient single-chip automotive lighting solution. Each output supports a DC current of 1.6 A. An integrated current-mode voltage booster controller enables input current filtering. Dimming is also supported via pulse-width modulation of the supply current at frequencies up to 4 kHz. In addition, the device also can feed the PWM signal directly from the external microcontroller.

Optimized for front lighting applications, the NCV78763 can be employed in high beam, low beam, turn indicator, static cornering, fog and daytime running lights. Each individual LED channel is equipped with an independent buck switch output, through which both the output current and voltage can be set to meet specific application criteria. Configuration is done via the device's serial peripheral interface (SPI).

Integrated diagnostic features offload the system microcontroller, which improves the overall effectiveness of the lighting design. If more than two LED channels are required on one lighting module, then multiple NCV78763 devices can be combined together. Due to the serial peripheral interface (SPI) programmability, this solution is highly flexible - permitting the scaling up of designs so that more LED strings can be utilized. This results in multiple system configurations, which are able to address an expansive range of automobile models, with significantly faster design cycles and lower engineering overheads. The NCV78763 supports high operating frequencies and thus permits specification of smaller inductors which in turn translates into lower bill of materials costs.