AS1112
16-Channel LED Driver with Dot Correction and
Greyscale PWM
Product Brief
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.
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
Figure 1. Block Diagram
1 CLK
26
I
REF
24
GSCLK
31
OEN
Status
Open LED Detect,
Overtemperature
Flag, Dot
Correction Data
3
MODE
The device is ideal for mono-, multi-, and full-color LED
displays, LED signboards, and display backlights.
2 SDI
32 LD
29 PD
Control
Greyscale
0 Register 11
12-Bit Greyscale
PWM Control
6-Bit Dot
Correction
Constant Current
Driver
4
Delay
x0
OUT0
Max OUTn
Current
V
REF
=
1.24V
Greyscale
Counter
Control
Input
Shift
Register
0
Dot Correction
Register 5
Open&Short LED Detection
Control
Greyscale
12 Register 23
6
Dot Correction
Register 11
12-Bit Greyscale
PWM Control
6-Bit Dot
Correction
Constant Current
Driver
5
Delay
x1
OUT1
.
.
.
Constant Current
Driver
21
Delay
x15
OUT15
.
Thermal
Flag
Open
LED
Detect
Open&Short LED Detection
Control
12-Bit Greyscale
PWM Control
6-Bit Dot
Correction
23
27
V
CC
.
.
Input
Shift
Register
Greyscale
180 Register191
Dot Correction
90 Register 95
22
XERR
30
GND
Open&Short LED Detection
AS1112
SDO
www.austriamicrosystems.com
Revision 1.01
1-2
AMSCO [ AUSTRIAMICROSYSTEMS AG ]
