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 AS1108 4-Digit LED Display Driver 1 General Description 2 Key Features 10MHz SPI-, QSPI-, Microwire-Compatible The AS1108 is a compact display driver for 7-segment Serial I/O numeric displays of up to 4 digits. The device can be programmed via SPI, QSPI, and Microwire as well as a Individual LED Segment Control conventional 4-wire serial interface. Segment Blinking Control (can be synchronized across multiple drivers) The device includes an integrated BCD code-B/HEX Hexadecimal- or BCD-Code/No-Decode decoder, multiplex scan circuitry, segment and display Digit Selection drivers, and a 32-bit memory. Internal memory stores the LED settings, eliminating the need for continuous 3A Low-Power Shutdown Current (typ device reprogramming. data retained) Extremely Low Operating Current 0.5mA in Every segment can be individually addressed and Open-Loop updated separately. Only one external resistor (RSET) is required to set the current through the LED display. LED Digital and Analog Brightness Control brightness can be controlled by analog or digital means. Display Blanked on Power-Up The device can be programmed to use the internal Drive Common-Cathode LED Displays code-B/HEX decoder to display numeric digits or to Supply Voltage Range: +2.7 to +5.5V directly address each segment. Software Reset The AS1108 features an extremely low shutdown cur- Optional External Clock rent of typically 3A, and an operational current of less SOIC 20-pin package than 500A. The number of digits can be programmed, the device can be reset by software, and an external clock is also supported. Additionally, segment blinking can be synchronized across multiple drivers. 3 Applications The AS1108 provides several test modes for easy appli- cation debugging. The AS1108 is ideal for bar-graph displays, instrument- panel meters, LED matrix displays, dot matrix displays, The device is available in a SOIC 20-pin package. set-top boxes, white goods, professional audio equip- ment, medical equipment, industrial controllers and panel meters. Figure 1. AS1108 - Typical Application Diagram +5V VDD 9.53k 4 Digits ISET DIG0 to DIG3 DIN I/O 8 Segments LOAD/CSN AS1108 I/O CLK SEG A to G SCK SEP DP GND Micro- processor GND 4-Digit Microprocessor Display www.austriamicrosystems.com/LED-Driver-ICs/AS1108 Revision 2.13 1 - 20 ams AG Technical content still valid