New Industry Products

austriamicrosystems Offers 16-Channel LED Driver For large-Size LED Displays

January 17, 2008 by Jeff Shepard

austriamicrosystems announced an expansion of its LED driver portfolio with the AS1112, a full color LED driver well suited for full color applications such as LED video displays, LCD TV backlighting, indoor/outdoor full-color LED displays and large-size stadium displays.

The AS1112 full color LED driver offers an integrated PWM of 12-bit with impressive 4,096 grayscale steps per color, reaching up to 68 billion colors with RGB. Additionally, the integrated 6-bit dot-correction allows adjusting the output current in 64 steps compensating for LED luminous mismatch. With an accuracy of ±4.5% between channels and ICs plus the dot-correction the AS1112 is said to dramatically improve the picture quality of LED displays since variations of intensity between LEDs and LED modules completely disappear. The AS1112 also offers line regulation of 2.5% and load regulation of 0.5%.

"Huge volumes of LEDs are required for high quality LED displays such as big stadium displays, commercially used indoor and outdoor displays and displays for public transportation. These top quality displays offer high color depth and brightness, high framerates and excellent contrast ratio in order to be used even in bright sunlight. Additionally, LED error detection is a very important factor in order to optimize maintenance cost and to guarantee high picture quality," said Walter Moshammer, Director Marketing Standard Linear at austriamicrosystems.

"austriamicrosystems’ AS1112 full color LED driver is designed for video displays with fast video action, such as in stadium and sporting event applications, as it provides a very fast refresh rate capability at 30MHz data transfer rate with no delay. Furthermore, AS1112 can be used in LCD TV backlighting where a dynamic dot-correction scheme is required to generate "tunable" white light."

The AS1112 features sixteen regulated current ports which provide constant currents for driving LEDs within a wide range of forward voltages. The company claims that the AS1112’s output ports are guaranteed to endure a maximum voltage of 15V allowing multiple LEDs to be combined in series to a single pixel to increase brightness. Currents can be adjusted from 0 to 80mA via an external resistor which provides utmost flexibility in controlling LED brightness.

Another highlight of the AS1112 is the built-in LED error detection. The AS1112 can detect any open- or short-circuit as well as any over-temperature occurrence. Two temperature thresholds allow detailed thermal surveillance of the system. For immediate detection of errors a global error pin is available. Furthermore, a detailed error report can be read out with the exact position of the broken LED. The AS1112 uses the serial data input/output lines for the detailed error information readback so that no additional PCB tracks are needed for LED error diagnostics.

The fast 30MHz serial interface of the AS1112 ensures high refresh rates even for huge LED display modules. The AS1112 offers very low power consumption, additionally, a power-down function allows reducing the supply current to 40nA in standby mode. With an operating temperature range from -40 to +85°C, the AS1112 is suitable for industrial as well as outdoor applications. The IC is available in the small size, thermally efficient 32-pin TQFN (5x5mm) package, easily handling high output power and allowing a very small pitch between LED pixels.