AS1112

16-Channel LED Driver with Dot Correction and

Greyscale PWM

Produ ct Brief

www.austriamicrosystems.com

Revision 1.01

1 - 2

1 General Description

The AS1112 is a 16-channel, constant current-sink LED

driver. Each of the 16 channels can be individually

adjusted by 4096-step greyscale PWM brightness con-

trol and 64-step constant-current sink (dot correction).

The dot correction circuitry adjusts the brightness varia-

tions between the AS1112 channels and other LED driv-

ers. Greyscale control and dot correction circuitry are

accessible via the SPI-compatible serial interface. A sin-

gle external resistor sets the maximum current value of

all 16 channels.

The device features two error detection functions. The

open & short LED detection function indicates a broken,

shorted or disconnected LED at one or more of the out-

puts. The overtemperature flag indicates that the device

is in an overtemperature condition.

An additional power-down pin puts the AS1112 into a

40nA standby-mode.

The AS1112 is available in a 32-pin TQFN 5x5 mm

package.

Figure 1. Block Diagram

2 Key Features

!

16 Channels

!

Greyscale PWM Control: 12-Bit (4096 Steps)

!

Dot Correction: 6-Bit (64 Steps)

!

Drive Capability (Constant-Current Sink): 0 to 80mA

!

LED Power Supply Voltage: Up to 15V

!

Supply Voltage Range: 3.0 to 5.5 V

!

SPI-Compatible Serial Interface

!

Controlled In-Rush Current

!

Data Transfer & PWM Clock Rate: up to 30 MHz

!

CMOS Level I/O

!

Diagnostic Features

- LED Open/Short Detection

- Overtemperature Flag

!

32-pin TQFN 5x5 mm Package

3 Applications

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

displays, LED signboards, and display backlights.

AS1112

Max OUTn

Current

27

Status

Open LED Detect,

Overtemperature

Flag, Dot

Correction Data

Thermal

Flag

22

XERR

Open

LED

Detect

26

24

GSCLK

31

OEN

30

GND

23

SDO

.

.

.

Control

12-Bit Greyscale

PWM Control

Constant Current

Driver

Delay

x15

21

OUT15

6-Bit Dot

Correction

Dot Correction

90

Register 95

Greyscale

180 Register191

Control

12-Bit Greyscale

PWM Control

Constant Current

Driver

Delay

x0

Open&Short LED Detection

4

OUT0

6-Bit Dot

Correction

Dot Correction

0

Register

5

Greyscale

0

Register 11

Control

12-Bit Greyscale

PWM Control

Constant Current

Driver

Delay

x1

5

OUT1

6-Bit Dot

Correction

Dot Correction

6

Register

11

Greyscale

12 Register 23

.

.

.

32 LD

Input

Shift

Register

Input

Shift

Register

2 SDI

1 CLK

Greyscale

Counter

Control

1.24V

29 PD

3

MODE

Open&Short LED Detection

Open&Short LED Detection