Diodes Incorporated announces the expansion of its automotive qualified* product portfolio with the launch of the AL8891Q LED driver. This easy-to-use synchronous buck LED driver features high-side current sensing, drives up to 2A over a wide 4.5V to 65V input voltage range, and supports up to 95% duty cycle to drive long LED chains. The device provides a flexible and efficient solution for automotive lighting applications including daytime running lights (DRL), fog lights, turn signals, brake/parking lights, and interior lighting.
The AL8891Q uses a constant-on-time (COT) control design that allows for simple control loop compensation and cycle-by-cycle current limiting. Fast transient response is achieved without the need for external compensation capacitors. The switching frequency of the device is adjustable from 200kHz to 2.5MHz, helping to improve efficiency or enable smaller inductor size and a compact form factor. The device uses Spectrum Frequency Modulation to improve EMI performance, helping to meet the most stringent CISPR 25 Class 5 standards. .
The AL8891Q has two independent pins (PWM dimming and analog dimming) to enhance the functionality of the device. The PWM dimming range is 0.1kHz to 2kHz for high-resolution dimming, while the analog dimming range is between 0.15V and 2V. The device has a built-in soft-start function that smoothly increases the inductor and switch current to minimize possible overvoltage and overcurrent conditions at the output.
The AL8891Q has a fault reporting function and provides comprehensive protection, including overtemperature shutdown with automatic restart, input and constant current undervoltage lockout (UVLO), cycle-by-cycle current limit, and LED open and short circuit protection to help enhance system robustness.
The AL8891Q is available in a thermally enhanced TSSOP-16EP package and operates over the -40°C to +125°C temperature range. The AL8891 is also available in standard specifications for industrial and commercial product applications.
