A S 11 2 2

1 2 - C h a n n e l L E D D r i v e r w i t h D o t C o r r e c t i o n a n d G r e y s c a l e P W M

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Revision 1.00

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D a ta s h e e t

1 General Description

The AS1122 is a 12-channel, constant current-sink LED driver. Each

of the 12 channels can be individually adjusted by 4096-step

greyscale PWM brightness control and 64-step constant-current sink

(dot correction).

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 SPI-compatible

serial interface.

The open LED detection function indicates a broken or disconnected

LED at one or more of the outputs. The overtemperature flag indi-

cates that the device is in an overtemperature condition.

A single external resistor sets the maximum current value of all 12

channels.

The AS1122 is available in a 24-pin QFN 4x4mm package.

Figure 1. AS1122 - Typical Application Diagram

2 Key Features

Greyscale PWM Control: 12-Bit (4096 Steps)

Dot Correction: 6-Bit (64 Steps)

Drive Capability (Constant-Current Sink): 0 to 40mA

LED Power Supply Voltage: up to 30V

Supply Voltage Range: 2.7V to 3.6V

Output Delay for controlled Inrush Current (factory set, can be

turned off)

Factory set rise- and fall-time for EMI improvement

Internal PWM Clock: 10 MHz (typ)

Data Transfer Clock Rate: up to 5 MHz

CMOS Level I/O

Diagnostic Features

24-pin QFN 4x4mm Package

3 Applications

The device is ideal for mono-, multi-, and full-color LED displays,

LED signboards, and display backlights.