R1218X Datasheet, PDF (12/14 Pages) RICOH electronics devices division – Step-up DC/DC converter for Whilte LED Backlight

R1218X
7. PWM Dimming Control (6 LED) VIN=3.6V,R1=10Ω
7-1. Duty vs. LED Current (Topt=25°C)
25
22.5
20
17.5
15
12.5
10
7.5
5
2.5
0
0
R1218X062A
5kHz
1kHz
200Hz
20
40
60
80
100
DUTY (%)
7-2. Output Voltage Waveform (Topt=25°C)
50
R1218X062A
Fosc=200Hz
10
CE Input Voltage
40
5
30
0
Output Voltage
20
10
0
R1218X062A
50
40
CE Input Voltage
30
20
10
Output Voltage
0
Fosc=5kHz
10
5
0
0
0.8
1.6
2.4
3.2
4
Time (ms)
0
0.04 0.08 0.12 0.16 0.2
Time (ms)
8. VFB Voltage vs. Temperature
0.215
R1218x041A
VIN=3.6V
0.21
0.205
0.2
0.195
0.19
0.185
-50 -25
0
25
50
75 100
Temperature Topt (°C)
9. UVLO Detector Threshold/Released Voltage vs. Temperature
R1218x041A
VIN=3.6V
1.7
1.66
UVLO Released
1.62
1.58
UVLO Detector
1.54
1.5
-50 -25
0
25
50
75 100
Temperature Topt (°C)
12