AS1105,pdf (4-Digit LED Driver

The AS1105 is a LED driver for 7 segment numeric displays of up to 4 digits. The AS1105 can be programmed via a conventional 4 wire serial interface. It includes a BCD code- B decoder, a multiplex scan circuitry, segment and display drivers and a 32 Bit memory. The memory is used to store the LED settings, so that continuos reprogramming is not necessary. Every individual segment can be addressed and updated separately. Only one external resistor is required to set the current through the LED display. Brightness can be controlled either in an analog or digital way.

The user can choose the internal code-B decoder to display numeric digits or to address each segment directly. The AS1105 features an extremely low shutdown current of only 20µA and an operational current of less than 500µA. The number of visible digits can be programmed as well. The AS1105 can be reset by software and an external clock can be used. Several test modes support easy debugging. AS1105 is offered in a 20 pin SOIC package.