AS1112
16-Channel LED Driver with Dot Correction and
Greyscale PWM
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 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 open & short LED detection function indicates a
broken, shorted or disconnected LED at one or more of
the outputs. The overtemperature flag indicates that the
device is in an overtemperature condition.
Table 1. Standard Products
Model
AS1112
AS1112B
Power-Down
Yes
No
TEST pin
Connect to GND
Connect to V
CC
2 Key Features
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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
!
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
1 CLK
26
I
REF
24
GSCLK
31
OEN
Status
Open LED Detect,
Overtemperature
Flag, Dot
Correction Data
3
MODE
3 Applications
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
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Revision 1.06
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