Data Sheet
AS1105
Serially Interfaced, 4-Digit LED Driver
1 General Description
2 Key Features
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Cost effective version of AS1100 functionality for
applications up to 4-Digits
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.
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10MHz 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.
Individual LED Segment Control
Decode/No-Decode Digit Selection
20µA Low-Power Shutdown (Data Retained)
Extremely low Operating Current 0.5mA in open
loop
Every individual segment can be addressed and
updated separately. Only one external resistor is
required to set the current through the LED display.
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Digital and Analog Brightness Control
Display Blanked on Power-Up
Drive Common-Cathode LED Display
Software Reset
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.
Optional External clock
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.
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.
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. Typical Application Circuit
+5V
VDD
9.53k
DIFG0-DIG3
ISET
4 Digits
MOSI
µP I/O
SCK
DIN
LOAD
SEG A-G
SEP DP
CLK
GND
8 Segments
GND
4-Digit µP Display
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