R1218X Datasheet, PDF (11/14 Pages) RICOH electronics devices division – Step-up DC/DC converter for Whilte LED Backlight

5-2. Output Voltage Waveform (Topt=25°C)
25
R1218X021A
Fosc=200Hz
10
CE Input Voltage
20
5
15
0
10
Output Voltage
5
0
0
0.8
1.6Time _(m2s.4)
3.2
4
6. PWM Dimming Control (4 LED) VIN=3.6V, R1=10Ω
6-1. Duty vs. LED Current (Topt=25°C)
25
22.5
20
17.5
15
12.5
10
7.5
5
2.5
0
0
R1218X041A
5kHz
1kHz
200Hz
20
40
60
80
100
DUTY (%)
6-2. Output Voltage Waveform
50
R1218X041A
Fosc=200Hz
10
CE Input Voltage
40
5
30
0
20
Output Voltage
10
0
0
0.8
1.6
2.4
3.2
4
Time (ms)
R1218X
R1218X021A
25
CE Input Voltage
20
15
10
Output Voltage
5
0
Fosc=5kHz
10
5
0
0
0.04 0.08 0.12 0.16 0.2
Time (ms)
50
R1218X041A
Fosc=5kH
10
CE Input Voltage
40
5
30
0
20
Output Voltage
10
0
0
0.04 0.08 0.12 0.16 0.2
Time (ms)
11