LED Control IC W2RG012RN 5
Operation
■ Functional Overview
LEDs in 24 systems are driven at a constant current or voltage. Also, LEDs connected in a matrix form can be lit dynamically (pulse lighting). For
dynamic lighting, LEDs in 48 systems (divided into 2 parts), 96 systems (divided into 4 parts), or 128 systems (divided into 8 parts) can be gradation
controlled individually.
Command Reception
An LED lighting command is received via serial communication. Regarding communication method, the product can adapt to three kinds of serial
communication with address, and I
2
C-based serial communication. LED lighting data for up to 128 units can be transmitted continuously. As only
a single operation is required for designation of a start signal or a device address, the overall volume of communication can be reduced.
Gradation Control
A 256-gradation can be used for lighting. Each gradation is allocated to a duty ratio based on the exponential function, to enable lighting design
suited to human visual sensation.
Matrix Control
The product is adapted to connection of 24x1, 24x2, 24x4 and 16x8 matrix. Also, lighting errors at switching can be controlled by controlling switch
timing for dynamic lighting.
Power-saving Control
For driving, power consumption for LED lighting is controlled to 75%/50%25% of the normal level. Collective switching via communication command
can be executed, permitting easy switching between normal and power-saving operations. Either current control or duty ratio control can be select-
ed as control method. For current control, the output current is changed to a 75%/50%/25% level, with the current set with current setting terminal
REXTR/REXTG/REXTB as reference. For duty ratio control, the output duty ratio is changed to a 75%/50%/25% level, with the duty ratio allocated
to a gradation as reference.
Number of Control Systems
Up to 15 devices can be connected through address designation. This permits the control of LEDs in up to 1,920 systems. Additional devices can
be connected by switching the CE terminal.
■ Description of Terminals
Setting By Inputting Resistance Partial Pressure
Device address setting terminal (ADR1/ADR0), division mode setting terminal (DIV), and communication mode setting terminal (COM) are level
input terminals with an A/D converter built in internal IC. One of 4 voltage levels (GND, V
DD
x 1/3, V
DD
x 2/3, and V
DD
) is set by inputting resistance
partial pressure.
Device Address Setting
The device address is set by inputting resistance partial pressure to
device address setting terminal (ADR1/ADR0). The address is cho-
sen from among 15 addresses from “0000” to “1110”. “1111” cannot
be designated to any device, as it is used for collective designation to
all devices in communication. The relationship between device
address and ADR terminal voltage is shown in the table below.
Selection of Division Mode
The matrix configuration for connected LEDs is set by inputting resis-
tance partial pressure to devision mode setting terminal (DIV). The
relationship between matrix configuration and DIV terminal voltage is
shown in the table below.
Device Address ADR1 ADR0
0000 GND GND
0001
GND V
DD
x 1/3
0010
GND V
DD
0011
GND V
DD
x 2/3
0100
V
DD
x 1/3 GND
0101
V
DD
x 1/3 V
DD
x 1/3
0110
V
DD
x 1/3 V
DD
0111
V
DD
x 1/3 V
DD
x 2/3
1000
V
DD
GND
1001
V
DD
V
DD
x 1/3
1010
V
DD
V
DD
1011
V
DD
V
DD
x 2/3
1100
V
DD
x 2/3 GND
1101
V
DD
x 2/3 V
DD
x 1/3
1110
V
DD
x 2/3 V
DD
1111 (reserved)
V
DD
x 2/3 V
DD
x 2/3
Matrix configuration DIV
24x1 GND
24 x2
V
DD
x 1/3
24x4
V
DD
16x8
V
DD
x 2/3
