SM8134A Datasheet, PDF (15/19 Pages) Nippon Precision Circuits Inc – White LED Driver IC

SM8134A
Example 2. Set LED1 to LED4 to 20mA and LED5 to 120mA drive
Input “2AH” (LED1 to 4 current setting 20mA), “4CH” (LED5 current setting 120mA), “58H” (LED1 to 4
ON) on successive EN cycles using the serial interface. LED1 to LED4 turn ON after the soft start ends. Then
input “5AH” (LED1 to 5 ON) and in addition to LED1 to LED4, LED5 turns ON.
EN
SDA
Set LED1 to 4 current 20mA
2
A
00 1 01 0 1 0
SCK
LED1 to 4
LED5
LED1 to 4 ON
5
8
010 1100 0
Set LED5 current 120mA
4
C
01 0 01 1 0 0
Soft start time
20mA
LED1 to 5 ON
5
A
01 0 11 0 1 0
Soft start time
120mA
EN = High
Send serial data "2AH"
2: DIN1 to 4 dimming command
A: Dimming data (20mA)
EN = Low
EN = High
Send serial data "58H"
5: LED ON command
8: LED1 to 4 ON
EN = Low
EN = High
Send serial data "4CH"
4: DIN5 dimming command
C: Dimming data (120mA)
EN = Low
EN = High
Send serial data "5AH"
5: LED ON command
A: LED1 to 4 ON, LED5 ON
EN = Low
Example 2 input waveform
SEIKO NPC CORPORATION —15