LED Display Driver Enhances Illumination Through Constant Current

A new 8-bit serial input, 150-mA LED display driver offers constant current and a low junction to ambient thermal impedance, which equates to cooler operation and higher reliability. With a maximum output current of up to 150 mA, the A6277 provides constant current selectable with a single external resistor for 50% or 100% current. This feature enables the user to keep LEDs at a constant current with a constant level of illumination, independent of variation resulting from component tolerances and power supply fluctuation. A CMOS shift register and latches allow direct interfacing with microprocessor-based systems. Offered in two packages, a 20-pin DIP (A6277EA) and a 20-lead SOIC (A6277ELW), the part is targeted toward LED display manufacturers and is expected to be designed into large signs, vending machines, home and industrial appliances, and gaming equipment. Pricing for the A6277EA is $1.47 each/1,000 and for the A6277ELW, $1.57. ALLEGRO MICROSYSTEMS INC., Worcester, MA. (508) 853-5000.