SM8134A

SEIKO NPC CORPORATION —16

Example 3. Set LED1 to LED4 to 30mA drive, and then change LED 1 to LED4 to12mA

drive and set LED5 to 150mA drive

Input “2FH” (LED1 to 4 current setting 30mA) and “58H” (LED1 to 4 ON) using the serial interface. LED1 to

LED4 turn ON after the soft start ends. Then input “26H” (LED1 to 4 current setting 12mA), the current of

LED1 to LED4 change to 12mA. Moreover input “4FH” (LED5 current setting 150mA) and “5AH” (LED1 to

5 ON), LED5 turns ON in addition to LED1 to LED4. The total current of LED1 to LED5 should be set not

exceeding 200mA.

Example 3 input waveform

EN

0

0

1

0

1

111

0

1

0

1

100

0

LED1 to 4

Soft start time

30mA

Set LED1 to 4 current 30mA

LED1 to 4 ON

SCK

SDA

2F

58

LED5

0

0

1

0

011

0

Set LED1 to 4 current 12mA

26

0

1

0

0

1111

Set LED5 current 150mA

4F

0

1

0

1

1010

LED1 to 5 ON

5A

Soft start time

150mA

12mA

EN = High

Send serial data "2FH"

2: DIN1 to 4 dimming command

F: Dimming data (30mA)

EN = Low

EN = High

Send serial data "58H"

5: LED ON command

8: LED1 to 4 ON

EN = Low

EN = High

Send serial data "26H"

2: DIN1 to 4 dimming command

6: Dimming data (12mA)

EN = Low

EN = High

Send serial data "4FH"

4: DIN5 dimming command

F: Dimming data (150mA)

EN = Low

EN = High

Send serial data "5AH"

5: LED ON command

A: LED1 to 4 ON, LED5 ON

EN = Low