Latest LED driver family eliminates PWM audible noise

Allegro MicroSystems has announced the A8060x family, its newest generation of advanced LED backlight drivers. The device family is created with an innovative and patented Pre-Emptive Boost (PEB) control, removing noise that is typically audible. PEB control in the family extensively reduces Vout ripple and removes the common problem of audible noise from ceramic output capacitors during PWM dimming, while also needing less output capacitance overall. Systems can produce an LED brightness contrast ratio of 15,000:1 using PWM-only dimming at 200Hz. A higher ratio of 150,000:1 is possible when using a combination of PWM and analogue dimming. “This family of LED drivers alleviates significant customer pain points in the areas of audible noise and device footprint,” explains Mark Gaboriault, Allegro’s marketing director for DC-DC Regulators and LED Drivers. “The A8060x family offers excellent PMW dimming ratios without analogue adjustment and eliminates noise that is emitted from ceramic capacitors, making them perfect for automotive applications.” The A8060x device family is perfect for all types of automotive backlighting, including Audio-Video systems as well as instrument clusters and HUD. These devices allow a wide input range from single power supply from 4.5V to 40V – once started, it can continue to operate down to 3.9V. This enables the parts to withstand stop/start, cold crank, double battery and load dump conditions faced in automotive systems. The series is a robust family with a host of safety and protection features demanded for automotive applications. The ALT80600 and A80603 feature four LED strings, each capable of up to 120mA with total LED current of up to 480mA. The A80601 and A80602 offer a total LED current of up to 840mA, via four or six strings respectively.