Allegro LED Driver ICs Include a Current-Mode Boost Converter, Power Switch, and 2 or 4 Current Sinks
October 30, 2014 by John Day
Allegro MicroSystems, LLC introduces two new devices to complement their existing portfolio of LED Driver ICs for LCD backlighting applications.
Allegro’s A8518 and A8519 devices integrate a current-mode boost converter with internal power switch with either two current sinks (dual string) in their A8518 or four current sinks (quad string) in their A8519.
Both devices target automotive and industrial markets with end applications to include automotive infotainment and instrument cluster LCD backlighting, heads-up displays, interior lighting, accent lighting and robust commercial and industrial backlighting and lighting applications.
In Allegro’s A8518, the boost converter can drive up to 22 white LEDs, 11 LED per string, at 200 mA. The LED sinks can be paralleled together to achieve higher LED currents up to 400 mA. In the A8519, the boost converter can drive up to 44 white LEDs, 11 LED per string, at 100 mA each. The LED sinks can be paralleled together to achieve higher LED currents up to 400 mA.
Both devices contain industry leading features such as high dimming ratio, string current matching, frequency dithering and fault detection. Both devices also contain input current sensing and gate drive to control an optional input disconnect MOSFET. The A8518 and the A8519 are AEC-Q100 qualified and operate from a single power supply with a 4.5 V to 40 V range. This allows each part to withstand load dump and start-stop conditions encountered in automotive systems.
Allegro’s A8518KLPTR-T is available in a 16-contact eTSSOP package (suffix LP) and the A8519KETTR-T is available in a 5 x 5 mm, 28-contact QFN (suffix ET) and a 20-contact eTSSOP package (suffix LP). All packages have an exposed pad for enhanced thermal performance.
Pricing for 1,000 pieces is as follows:
• A8518KLPTR-T: $2.13
• A8519KLPTR-T: $2.24
• A8519KETTR-T: $2.24