LED dot-matrix driver offers high efficiency in small space

austriamicrosystems announces the AS1119, one of the most advanced and smallest LED dot-matrix drivers (channels vs. PCB space) available, according to company sources. The AS1119 drives 144 LEDs but requires only 9 mm² PCB space, reduces external component count, reduces connector pin count, and requires fewer PCB layers. Benefits for end users include up to 80% longer battery lifetime, more colorful effects, and smoother running animations. The AS1119 is targeted for dot matrix displays in mobile phones, personal electronics, and toys.

The AS1119 drives LEDs with an 8-bit dimming control and no external resistor required. Additionally, an 8-bit analog current control allows fine tuning of each matrix to compensate for different brightness of different colors, or to adjust the white balance on RGB LEDs. The AS1119 incorporates six frames of memory for small animations or for use as a buffer to reduce host processor load, thereby saving energy and processing time. The AS1119 also extends battery life by including an on-chip 320 mA charge pump, which is required when LEDs require a higher voltage than the battery can supply, allowing continuous operation even under low battery voltage conditions.

Other features include control via a 1 MHz I²C compatible interface, open and shorted LED error detection, and low-power shutdown current. Two modes of operation are offered making the AS1119 a very flexible part to design with -- single/bicolor mode to drive the maximum number of LEDs in two 8x9 matrix, or the RGB mode offering three times 5x6 matrix, allowing white balance by adjusting the analog current in each matrix.

Only 18 lines are required to drive all 144 LEDs. This is accomplished with a multiplexing technique called cross-plexing, which allows reducing the line count on the PCB as well as fewer pins on the connectors, saving space and costs.

The AS1119 is available in a 36-pin WL-CSP 3x3 mm package and operates over a temperature range of -40° to 85° C over a 2.7 to 5.5 V power supply range.

For more information, contact austriamicrosystems USA Inc., 5201 Great America Parkway, Suite 320, Santa Clara, CA 95054. Phone: (408) 345-1790.

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