Next-generation LED backlight driver uses patented control technology to eliminate PWM audible noise

(Image source: Allegro Microsystems official website)

According to foreign media reports, Allegro Microsystems has launched the A8060x series of LED backlight drivers, which use innovative PEB patented control technology (pre-emptive boost) to successfully eliminate the annoying noise generated by the PWM modulation circuit in the LED driver. Allegro is a supplier of power and sensor solutions for motion control and energy-saving systems.

The A8060x series uses PEB control technology to greatly reduce output voltage ripple and eliminate the common problem of audible noise generated by ceramic output capacitors during PWM dimming, while requiring less output capacitance overall. The system uses 200 Hz PWM dimming to achieve an LED brightness contrast ratio of 15000:1. If PWM and analog dimming are combined, the contrast ratio is even higher, reaching 150000:1.

ALT80600 and A80603 combine a switching converter, a metal oxide semiconductor field effect transistor (MOSFET) and four current receivers. A80601 and A80602 drive external boost field effect transistors to achieve higher output power. All parts can be configured in boost or single-ended main inductor converter (SEPIC) topology to meet different needs. The switching converter is designed for low electromagnetic interference, including programmable switching frequency, controllable switching rate and programmable high-frequency jitter noise processing. In addition, the clock pin allows other switching converters to synchronize to the switching frequency of A8060x to enhance the anti-electromagnetic interference performance of the entire system.

The A8060x series of parts are suitable for all types of automotive backlighting devices, such as audio and video systems, instrument panels, and head-up displays (HUDs). These parts use a single 4.5 to 40 V supply and can continue to operate at a low voltage of 3.9 V once started. Therefore, they can withstand stop/start, cold start, dual battery, and load dump in automotive systems. The A8060x has the safety and protection features required for automotive applications. The ALT80600 and A80603 have four LED strings, each capable of up to 120 mA, with a total current of up to 480 mA. The A80601 and A80602 provide up to 840 mA of LED current through 4 or 6 strings, respectively.