AS1109 8-Bit LED Drivers

The ams OSRAM AS1109 is designed to drive up to 8 LEDs through a fast serial interface and features eight constant-current output drivers and an on-chip diagnostic read-back function. The high clock-frequency (up to 50 MHz), adjustable output current, and flexible serial interface make the device perfectly suited for high-volume transmission applications. Output current is adjustable (up to 100 mA/channel) using an external resistor (REXT). The serial interface with Schmitt trigger inputs includes an integrated shift register. Additionally, an internal data register stores the currently displayed data.

The device features integrated diagnostics for overtemperature, open-LED, and shorted-LED conditions. Integrated registers store global fault status information during load, as well as the detailed temperature/open-LED/shorted-LED diagnostics results.

The AS1109 also features a low-current diagnostic mode to minimize display flicker during fault testing. With an operating temperature range from -40°C to +125°C, the AS1109 is ideal for industrial applications. The AS1109 is available in a 16-pin SOIC-150, a 16-pin QFN (4 mm x 4 mm), and the 16-pin QSOP-150 packages.