R1218X Datasheet, PDF (10/14 Pages) RICOH electronics devices division – Step-up DC/DC converter for Whilte LED Backlight

R1218X
4. Efficiency vs. ILED (6LED) L: LQH32CN220, Diode: CRS02
100
90
80
70
60
50
40
30
20
10
0
0
R1218X062A
VIN=2.7V
LÉ¿LQH32CN220
DiodeɿCRS02
4
8
12
16
20
LED Current ILED (mA)
100
90
80
70
60
50
40
30
20
10
0
0
100
90
80
70
60
50
40
30
20
10
0
0
R1218X062A
VIN=4.2V
LÉ¿LQH32CN220
DiodeɿCRS02 _25℃
4
8
12
16
20
LED Current ILED (mA)
5. PWM Dimming Control (2 LED) VIN=3.6V, R1=10Ω
ç 5-1. Duty vs. LED current
25
22.5
20
17.5
15
12.5
10
7.5
5
2.5
0
0
R1218X021A
20
40
60
DUTY (%)
Topt=25℃
5kHz
1kHz
200Hz
80
100
R1218X062A
VIN=3.6V
4
8
12
16
20
LED Current ILED (mA)
10