New automotive monolithic LED driver ensures stable lighting

ROHM has developed an ultra-compact high output linear LED driver IC (BD18336NUF-M) that gives stable lighting even in the case of battery voltage drops on a single chip, making it excellent for a wide range of socket-type LED lamps employed in vehicle systems, from DRLs and position lighting to rear lamps.

The device adopts a current bypass function that stops LED turn OFF and sustains a brightness of at least 30% at all times by switching the LED current path, even when the battery voltage reduces from 13V to 9V. Also, a high output of 600mA is delivered in an ultra-compact 3mm square package, and mounting area is decreased by approximately 30% over conventional solutions (including the external circuit), making mounting feasible on the 10mm square substrates needed for small socket-type LED lamps.

Conventional products, when configured with no external circuitry, can cause the LED lamps to turn OFF when the battery voltage drops, likely creating an unsafe situation throughout vehicle operation. However, the company's new LED driver IC provides stable lighting while contributing to the greater miniaturisation of socket LED lamps. A function for suppressing LED heat generation is also built-in that supports white LEDs that typically run hot, enabling them to be employed in DRLs and other vehicle lighting systems using white LEDs.