Austriamicrosystems has introduced a constant-current, 16-channel LED driver, the AS1123, with an on-chip diagnostic read-back function for indoor and outdoor public information displays, LED panels, fixed- or slow-rolling displays, large LED video wall and matrix displays, displays in elevators, displays for public transport, in stadia and in other public areas. The driver features an LED supply voltage of three to 5.5V at a temperature range of -40 to +85°C. The driver also features an integrated diagnostics and internal registers to store information about the global fault status, over-temperature, open-LED and shorted-LED conditions for future analysis. It has a low-current diagnostic mode to eliminate display flicker during fault testing. In this mode, a small test current is applied to the display for a short time. As a result, LED testing is not visible and can therefore be applied during normal operation. The output current of the driver is adjustable up to 40mA/channel using an external resistor to ensure good output current accuracy of ±3% between LEDs as well as between ICs. This ensures good picture quality and uniform brightness for an LED display since intensity variations between LEDs and LED modules disappear, claims the company. The driver is available in a 4x4mm thin QFN-24 and a quarter small outline 24 package.
