AS1108 LED Driver IC

Description

The AS1108 is a compact display driver for 7-segment numeric displays of up to 4 digits. The device can be programmed via SPI, QSPI, and Microwire as well as a conventional 4-wire serial interface.

The device includes an integrated BCD code-B/HEX decoder, multiplex scan circuitry, segment and display drivers, and a 32-bit memory. Internal memory stores the LED settings, eliminating the need for continuous device reprogramming.

Every segment can be individually addressed and updated separately. Only one external resistor (RSET) is required to set the current through the LED display. LED brightness can be controlled by analog or digital means. The device can be programmed to use the internal code-B/HEX decoder to display numeric digits or to directly address each segment.

The AS1108 features an extremely low shutdown current of typically 3µA, and an operational current of less than 500µA. 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.

The AS1108 provides several test modes for easy application debugging.

The device is available in a 20-pin DIP and a 20-pin SOIC package.

Key Features

• 10MHz SPI-, QSPI-, Microwire-Compatible Serial I/O
• Individual LED Segment Control
• Segment Blinking Control (can be synchronized across multiple drivers)
• Hexadecimal- or BCD-Code/No-Decode Digit Selection
• 3µA Low-Power Shutdown Current (typ; data retained)
• Extremely Low Operating Current 0.5mA in Open-Loop
• Digital and Analog Brightness Control
• Display Blanked on Power-Up
• Drive Common-Cathode LED Displays
• Supply Voltage Range: +2.7 to +5.5V
• Software Reset
• Optional External Clock
• Packages:
  • 20-pin DIP
  • 20-pin SOIC

Applications

The AS1108 is ideal for bar-graph displays, instrumentpanel meters, LED matrix displays, dot matrix displays, set-top boxes, white goods, professional audio equipment, medical equipment, industrial controllers and panel meters.

Block Diagram