austriamicrosystems AG is now ams AG The technical content of this austriamicrosystems datasheet is still valid. Contact information: Headquarters: ams AG Tobelbaderstrasse 30 8141 Unterpremstaetten, Austria Tel: +43 (0) 3136 500 0 e-Mail: ams sales ams.com Please visit our website at www.ams.com Datasheet AS1123 Consta nt-Current, 16 -Channe l LED Driver w ith Diagno stics 1 General Description 2 Key Features 16 Constant-Current Output Channels The AS1123 is designed to drive up to 16 LEDs through a fast serial interface and features 16 output constant current drivers and an on- Excellent Output Current Accuracy chip diagnostic read-back function. - Between Channels: <3% The high clock-frequency (up to 50MHz), adjustable output current, - Between Devices: <3% and flexible serial interface makes the device perfectly suited for Output Current Per Channel: 0.5mA to 40mA high-volume transmission applications. Over-Temperature, Open-LED, Shorted-LED Output current is adjustable (up to 40mA/channel) using an external Diagnostic Functions resistor (REXT). The serial interface with Schmitt trigger inputs includes an integrated Low-Current Test Mode shift register. Additionally, an internal data register stores the cur- Global Fault Monitoring rently displayed data. Fast Serial Interface: 50MHz The device features integrated diagnostics for over- Cascaded Configuration temperature, open-LED, and shorted-LED conditions. Integrated registers store global fault status information during load as well as Extremely Fast Output Drivers Suitable for PWM the detailed temperature/open-LED/shorted-LED diagnostics results. Output Delay for controlling Inrush Current (on request) The AS1123 also features a low-current diagnostic mode to minimize 24-pin QSOP and 24-pin TQFN (4x4mm) Package display flicker during fault testing. The AS1123 is available in a 24-pin QSOP and a 24-pin TQFN (4x4mm) package. 3 Applications The device is ideal for fixed- or slow-rolling displays using static or multiplexed LED matrix and dimming functions, large LED matrix dis- plays, mixed LED display and switch monitoring, displays in eleva- tors, public transports (underground, trains, buses, taxis, airplanes, etc.), large displays in stadiums and public areas, price indicators in retail stores, promotional panels, bar-graph displays, industrial con- troller displays, white good panels, emergency light indicators, and traffic signs. Figure 1. AS1123 - Typical Application Diagram +VLED AS1123 SDI SDO CLK LD OEN REXT GND VDD www.austriamicrosystems.com/LED-Driver-ICs Revision 1.00 1 - 24 ams AG Technical content still valid OUTN0 OUTN1 OUTN2 OUTN3 OUTN4 OUTN5 OUTN6 OUTN7 OUTN8 OUTN9 OUTN10 OUTN11 OUTN12 OUTN13 OUTN14 OUTN15