A S 111 2

1 6 - 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

www.austriamicrosystems.com/LED-Driver-ICs/AS1112

Revision 1.13

1 - 19

D a ta s h e e t

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 control and 64-step constant-current sink

(dot correction).

The dot correction circuitry adjusts the brightness variations between

the AS1112 channels and other LED drivers. Greyscale control and

dot correction circuitry are accessible via the SPI-compatible serial

interface. A single external resistor sets the maximum current value

of all 16 channels.

The open & short LED detection function indicates a broken, shorted

or disconnected LED at one or more of the outputs. The overtemper-

ature flag indicates that the device is in an overtemperature condi-

tion.

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. AS1112 - 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 100mA

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.

Table 1. Standard Products

Model

Power-Down

TEST pin

Output Delay

AS1112

Yes

Connect to GND

Yes

AS1112B

No

Yes

AS1112C

No

No

AS1112

Max OUTn

Current

27

VCC

Status

Open LED Detect,

Overtemperature

Flag, Dot

Correction Data

Thermal

Flag

22

XERR

Open

LED

Detect

26

IREF

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

* not for AS1112C