rt9903 Richtek Technology Corporation, rt9903 Datasheet - Page 8

• Manufacturer Part Number: rt9903
• Description: Channel Dc/dc Converters With High-efficiency Step-up
• Manufacturer: Richtek Technology Corporation

RT9903
www.richtek.com
8
100
95
90
85
80
75
2
4 series WLED, I
V
V
BAT
BAT
CH3 Efficiency vs. Input Voltage
= 3.8V, V
= 2.5V, V
2.4
V
V
LX2
LX2
DD
DD
2.8
Input Voltage (V)
LED
= 3.3V, @I
= 3.3V, @I
Time (1us/Div)
Time (1us/Div)
&
&
= 20mA
Output Ripple
Output Ripple
3.2
OUT
OUT
= 30mA
= 30mA
3.6
4
Preliminary
4.4
V
V
V
BAT
BAT
BAT
= 4.2V, V
= 3V, V
= 2.5V, V
V
V
V
DD
LX2
LX3
LX2
DD
DD
= 3.3V, @I
= 3.3V, @I
= 3.3V, @I
Time (1us/Div)
Time (1us/Div)
Time (1us/Div)
&
&
&
Output Ripple
Output Ripple
Output Ripple
DS9903-07 August 2007
OUT
OUT
OUT
= 30mA
= 30mA
= 20mA