AS1105
Serially Interfaced, 4-Digit LED Driver
www.ams.com/LED-Driver-ICs/AS1105 Revision 1.36 1 - 15
1 General Description
The AS1105 is an LED driver for 7-segment numeric displays of up
to 4 digits. The AS1105 can be programmed via a conventional 4-
wire serial interface.
The device 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 continuous
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.
Figure 1. AS1105 - Typical Application Circuit
2 Key Features
Cost effective version of AS1100 functionality for applications
up to 4-Digits
10MHz Serial Interface
Individual LED Segment Control
Decode/No-Decode Digit Selection
20µA Low-Power Shutdown (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 Display
Software Reset
Optional External clock
20-pin SOIC Package
3 Applications
The AS1105 is an ideal solution for Bar-Graph Displays, Industrial
Controllers, Panel Meters, LED Matrix Displays and White Goods
such as washing machines, dishwasher, etc.
4 Digits
8 Segments
GND
GND
CLK
LOAD
DIN
ISET
VDD
DIFG0-DIG3
SEG A-G
SEP DP
MOSI
µP I/O
SCK
+5V
4-Digit µP Display
9.53k
AS1105
