Datasheet
AS1122
12-Channel LED Driver with Dot Correction and Greyscale PWM
1 General Description
The AS1122 is a 12ꢀchannel, constant currentꢀsink LED driver. Each
of the 12 channels can be individually adjusted by 4096ꢀstep
greyscale PWM brightness control and 64ꢀstep constantꢀcurrent sink
(dot correction).
2 Key Features
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Greyscale PWM Control: 12ꢀBit (4096 Steps)
Dot Correction: 6ꢀBit (64 Steps)
Drive Capability (ConstantꢀCurrent Sink): 0 to 40mA
LED Power Supply Voltage: up to 30V
Supply Voltage Range: 2.7V to 3.6V
The dot correction circuitry adjusts the brightness variations between
the AS1122 channels and other LED drivers. Greyscale control and
dot correction circuitry are accessible via a simple SPIꢀcompatible
serial interface.
Output Delay for controlled Inrush Current (factory set, can be
turned off)
The open LED detection function indicates a broken or disconnected
LED at one or more of the outputs. The overtemperature flag indiꢀ
cates that the device is in an overtemperature condition.
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Factory set riseꢀ and fallꢀtime for EMI improvement
Internal PWM Clock: 10 MHz (typ)
Data Transfer Clock Rate: up to 5 MHz
CMOS Level I/O
A single external resistor sets the maximum current value of all 12
channels.
The AS1122 is available in a 24ꢀpin QFN 4x4mm package.
Diagnostic Features
24ꢀpin QFN 4x4mm Package
3 Applications
The device is ideal for monoꢀ, multiꢀ, and fullꢀcolor LED displays,
LED signboards, and display backlights.
Figure 1. AS1122 - Typical Application Diagram
www.austriamicrosystems.com/LEDꢀDriverꢀICs
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