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

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

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

0010

GND

V

DD

0011

GND

V

0100

V

GND

0101

V

V

0110

V

V

DD

0111

V

V

1000

V

DD

GND

1001

V

DD

V

1010

V

DD

V

DD

1011

V

DD

V

1100

V

GND

1101

V

V

1110

V

V

DD

1111 (reserved)

V

V

Matrix configuration

DIV

24x1

GND

24 x2

V

24x4

V

DD

16x8

V