STMicroelectronics has released a single-chip automotive LED driver, ALED6000 that comes with an integrated DC/DC converter and is the ideal low- BoM (Bill of Materials) solution that offers design flexibility in automotive applications. Ideal to be used in exterior lighting such as daytime running lights, headlights, rear lights, stop lights, turn signals, and interior lighting, the ALED6000 drives a single string of LEDs at up to 3A and has a wide input-voltage range of 4.5V to 61V.
The wide input voltage range of the ALED6000 automotive LED driver makes it an ideal choice for automotive systems. The 250 mV typical RSENSE voltage drop helps in improving the efficiency performance. The dedicated DIM pin helps in applying the PWM control signal and implements digital dimming. Additionally, the device comes with the Enable pin and a Sync pin that ensures low noise in multi-device applications.
The output current of the device is accurate within 3.2% and is monitored efficiently with a sense resistor that has a typical voltage drop of 250mV. The quiescent current is extremely low, at just 2.4mA in operation and 11µA in shutdown. The ALED6000 features a VBIAS auxiliary-input pin and pulse-skipping operation at light load and ensures high efficiency across the load range.
The on-chip converter allows buck, buck/boost, and floating-boost topologies, giving flexibility to power LED strings that require a voltage above or below the input voltage while also handling supply fluctuations. In addition, the converter can operate in a low-dropout mode with close to 100% duty cycle if the input voltage falls near or below the programmed output.
In the event of over-current, the ALED6000 invokes pulse-by-pulse protection to limit the output current at the preset maximum. There is also programmable soft-start circuitry to limit inrush current and thermal protection with auto-recovery. Both the output-current limit and converter switching frequency can be selected using external components, allowing the inductor to be optimized for high energy efficiency, fast dynamic response, small size, and low output ripple in conjunction with a low-ESR capacitor. The AEC-Q100 qualified ALED6000 automotive LED driver is in production now in the HTSSOP16 package and is available at the price range of $2.25 for orders of 1000 pieces.