rt9278 Richtek Technology Corporation, rt9278 Datasheet - Page 10

• Manufacturer Part Number: rt9278
• Description: High Efficiency Boost Converter High Power White Driver
• Manufacturer: Richtek Technology Corporation

www.richtek.com
10
RT9278
V
3.310
3.305
3.300
3.295
3.290
3.285
3.280
3.275
3.270
3.265
3.260
3.255
3.250
OUT
V
V
100
I
LX
I N
IN
90
80
70
60
50
40
30
20
10
0
1
3 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 4 4.1 4.2 4.3
Power LED Efficiency vs. Input Voltage
V
Vf = 3.5V, I
(10mV/Div)
(5V/Div)
(1V/Div)
(1A/Div)
OUT
Output Voltage vs. Output Current
= 3.3V
LED
Normal Operation
Output Current (mA)
= 200mA, L = 4.7 H
10
V
Input Voltage (V)
Time (1 s/Div)
IN
= 1.5V, V
V
V
V
V
IN
IN
IN
IN
= 3.0V
= 2.5V
= 2.0V
= 1.5V
OUT
= 5V, I
100
LOAD
= 300mA
Preliminary
1000
V
V
4.98
4.97
4.96
4.95
4.94
4.93
4.92
4.91
4.90
4.89
4.88
4.87
4.86
4.85
OUT
OUT
V
V
V
V
I
I
LX
I N
LX
I N
IN
IN
1
V
(10mV/Div)
(5V/Div)
(1V/Div)
(500mA/Div)
(10mV/Div)
(1V/Div)
(5V/Div)
(500mA/Div)
OUT
Output Voltage vs. Output Current
= 5.0V
Normal Operation
Normal Operation
Output Current (mA)
10
V
V
Time (1 s/Div)
IN
IN
Time (1 s/Div)
= 4.2V, V
= 1.5V, V
V
V
V
V
V
V
V
IN
IN
IN
IN
IN
IN
IN
DS9278-04 August 2007
= 4.2V
= 4.0V
= 3.5V
= 3.0V
= 2.5V
= 2.0V
= 1.5V
OUT
OUT
= 5V, I
= 5V, I
100
LOAD
LOAD
= 100mA
= 100mA
1000