SM8134A Datasheet, PDF (16/19 Pages) Nippon Precision Circuits Inc – White LED Driver IC

SM8134A
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.
EN
SDA
Set LED1 to 4 current 30mA
2
F
00 1 01 111
SCK
LED1 to 4
LED5
LED1 to 4 ON
5
8
010 1100 0
Set LED1 to 4 current 12mA
2
6
001 0011 0
Set LED5 current 150mA
4
F
010 01111
Soft start time
30mA
12mA
LED1 to 5 ON
5
A
010 11010
Soft start time
150mA
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
Example 3 input waveform
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