Austriamicrosystems recently introduced the AS1109 8-channel constant current LED driver. Designed for open and shorted LEDs, this driver features advanced error diagnostics. The AS1109 uses a serial data input/output line for error information readback, eliminating the need for additional PCB board traces that diagnose LED errors.
Walter Moshammer, director of marketing for Standard Linears at austriamicrosystems, said: "As the resolution of LED displays increases, the market needs more accurate and smaller packaged LED drivers. In addition, applications such as safety-related traffic signs, and information like LED error detection is becoming more and more important for more commercial applications such as display or video walls that require optimized maintenance costs. The AS1109 is available in a small package that delivers superior performance, best-in-class accuracy and unique LED error detection. Can meet the current market demand."
The AS1109 has eight regulated current ports that provide constant current for driving LEDs over a wide range of forward voltage variations. The AS1109 output port can withstand voltages up to 15V. The current can be adjusted from 0.5 to 100 mA through an external resistor, providing great flexibility for LED brightness control. The transmission accuracy between the channel and IC of the AS1109 is as high as 2%, and the difference in intensity between the LED and the LED module has completely disappeared, which can further improve the picture quality of the LED display.
Another feature of the AS1109 is the built-in LED error detection feature. This feature is simple and intuitive to use, even when the drive is working properly, without having to switch to a separate detection mode. This makes the software interface easier to use and the detection is very fast. The AS1109 can detect any open, short, and overheat conditions. In order to detect these errors quickly and accurately, the error flag function of the serial data output can be used. In addition, the exact location of the LED damage can be read from the detailed error report.
To prevent LED display flicker during error detection, austriamicrosystems has also introduced a unique low current diagnostic mode. In this mode, the display will use a test current of only 0.6mA in a short period of time. Therefore, the LED test is not obvious and can be used while the drive is operating normally.
The 30MHz serial interface ensures high refresh rates, even for large LED display modules. Suitable for use in temperatures from -40Â°C to +85Â°C, the AS1109 is ideal for industrial and outdoor applications. The device is available in 16-lead SOIC-150, SSOP-150 and small 16-pin QFN (4x4mm) packages with very small pixel spacing, making it ideal for indoor LED displays.