R1218K021A RICOH [RICOH electronics devices division], R1218K021A Datasheet - Page 12

• Manufacturer Part Number: R1218K021A
• Description: Step-up DC/DC converter for White LED Backlight
• Manufacturer: RICOH [RICOH electronics devices division]

12
R1218x
6) PWM Dimming Control (4 LED) V
5-2. Output Voltage Waveform (Topt=25°C)
6-1. Duty vs. LED Current (Topt=25°C)
6-2. Output Voltage Waveform (4 LED) (Topt=25°C)
10
10
20
25.0
22.5
20.0
17.5
15.0
12.5
10.0
5
0
0
7.5
5.0
2.5
0
0
0
0
CE Input Voltage
CE Input Voltage
Output Voltage
Output Voltage
20
0.8
0.8
R1218x021A
R1218x041A
R1218x041A
Time (ms)
Time (ms)
40
1.6
1.6
Duty (%)
60
2.4
2.4
fosc=200Hz
fosc=200Hz
80
5kHz
1kHz
200Hz
IN
3.2
3.2
=3.6V, R1=10Ω
100
10
10
5
0
5
0
10
20
10
5
0
0
0
0
CE Input Voltage
CE Input Voltage
Output Voltage
Output Voltage
0.04
0.04
R1218x021A
R1218x041A
Time (ms)
Time (ms)
0.08
0.08
0.12
0.12
fosc=5kHz
fosc=5kHz
0.16
0.16
10
10
5
0
5
0