Automotive multi-pixel driver with CAN FD Light protocol
The L99LDLH32 linear current regulator from STMicroelectronics delivers a convenient, integrated solution for dynamic automotive lighting controlled using the lightweight CAN FD Light protocol. Ideal for use with OLED lamps that provide bright, homogeneous, and high-contrast lighting from a small surface area, the new multi-pixel driver lets designers produce complex light patterns and effects that enhance safety and styling.
With 32 regulated current sources, independently programmable from 1-mA to 15-mA, the L99LDLH32 multi-pixel driver can drive individual pixels in external and interior lighting applications. Global dimming is also provided, with 8-bit resolution. While powered at the vehicle battery voltage, the driver produces outputs of up to 35 V to cover a wide emitter forward-voltage spread.
The integrated CAN FD Light protocol handler and transceiver simplify connection to the vehicle’s communication infrastructure and controlling domain ECU (electronic control unit). Based on proven industry standards, CAN FD Light’s synchronized commander/responder communication, conceived for controlling simple devices like lights and sensors, saves costly external components such as timing crystals. On the other hand, the data bandwidth of 1 Mbit/s enables designers to create complex animated light patterns and permits smoothly modulated transitions and dimming.
In addition, on-chip memory cells allow programming of parameters such as current level and PWM dimming for stand-alone operation, to provide a failsafe mode to cover malfunctioning of the communication bus or controller. Targeting roles including safety-critical lighting such as taillights, stoplights, and turn indicators, the L99LDLH32 multi-pixel driver provides features for a high level of functional safety. These include a fault-status pin, voltage and temperature monitors, a programmable timeout watchdog, and short-circuit and open-load detection. In addition, frequency dithering minimizes electromagnetic emissions.
Monolithically integrated using ST’s BCD9sL process, the L99LDLH32 multi-pixel driver is AEC-Q100 qualified. It is available as a 7- x 7-mm QFN48 device with wettable flanks and an exposed thermal pad to aid dissipation.