The MAQ3203 from Micrel is an AEC-Q100 qualified step-down high brightness LED (HBLED) driver for automotive lighting applications. With its hysteretic control architecture and high-side current sense scheme, it is capable of driving multiple HBLEDs in series at more than 90% efficiency with ±5% current accuracy from input voltages of 4,5 V to 42 V. The device’s operating frequency is adjustable up to 1,5 MHz which allows flexibility in the design and offers a frequency dithering feature to mitigate EMI. The IC features a dedicated PWM dimming pin, an enable pin for low-power shutdown, over-temperature protection and an under-voltage lockout. It has an external power switch and requires no external compensation.