R1218XXX1A RICOH [RICOH electronics devices division], R1218XXX1A Datasheet - Page 10

• Manufacturer Part Number: R1218XXX1A
• Description: Step-up DC/DC converter for Whilte LED Backlight
• Manufacturer: RICOH [RICOH electronics devices division]

10
4. Efficiency vs. I
5. PWM Dimming Control (2 LED)
R1218X
5-1. Duty vs. LED current
22.5
17.5
12.5
7.5
2.5
25
20
15
10
100
5
0
100
90
80
70
60
50
40
30
20
10
90
80
70
60
50
40
30
20
10
0
0
0
0
0
R1218X021A
20
LED
4
4
(6LED) L: LQH32CN220, Diode: CRS02
LED Current I
LED Current I
R1218X062A
R1218X062A
40
DUTY (%)
8
8
L： ： ： ： LQH32CN220
Diode： ： ： ： CRS02
L： ： ： ： LQH32CN220
Diode： ： ： ： CRS02
LED
LED
60
12
V
12
IN
(mA)
(mA)
=3.6V, R1=10Ω
80
Topt=25 ℃
16
16
V
V
5kHz
1kHz
200Hz
IN
IN
=2.7V
=4.2V
25℃
100
20
20
100
90
80
70
60
50
40
30
20
10
0
0
4
LED Current I
R1218X062A
8
LED
12
(mA)
16
V
IN
=3.6V
20