144-channel Dot Matrix LED Driver Enables 80% Longer Battery Life

austriamicrosystems' AS1119 LED dot-matrix driver can drive 144 LEDs but requires only 9mm² PCB space. It reduces external component count as well as the connector pin count and requires fewer PCB layers. Benefits for end users include up to 80 percent longer battery life, more colourful effects and smoother running animations. The AS1119 is targeted for dot matrix displays in mobile phones, personal electronics and toys.

The AS1119 leads the industry by driving the most LEDs, each with an 8-bit dimming control. No external resistor is required. Additionally, an 8-bit analog current control allows fine tuning of each matrix to compensate for varying brightness of different colours, 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 precious processing time. The AS1119 also extends battery life by including an on-chip 320mA 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 1MHz 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. The single/bicolour mode can be used to drive the maximum number of LEDs in two 8x9 matrixes; the RGB mode offers a three times 5x6 matrix, allowing white balance by adjusting the analog current in each matrix.

"The AS1119 is the most advanced and smallest dot matrix LED driver available on the market," says Rene Wutte, austriamicrosystems' Marketing Manager for Lighting. "It enables creative light design with the longest battery life through our intelligent power management for mobile applications. It allows our customers to create unique looking devices while minimising design effort by making use of the AS1119's flexibility. The AS1119 also saves space and cost by reducing the external component count, the connector pin count and the number of PCB layers."

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

The AS1119 is available in a 36-pin WL-CSP 3x3mm package and operates over a temperature range of -40°C to 85°C over a wide 2.7V to 5.5V power supply range.

austriamicrosystems AS1119 144-channel dot matrix LED driver

austriamicrosystems