Preliminary
RT9278
Load Transient Regulation
V
IN
= 1.5V, V
OUT
= 5V, I
LOAD
= 100mA to 300mA
Normal Operation
V
OUT
V
IN
(1V/Div)
Load Current
(mA)
Output Voltage
Deviation (mV)
V
IN
= 4.2V, V
OUT
= 5V, I
LOAD
= 300mA
(10mV/Div)
400
200
0
V
LX
(5V/Div)
50
0
-50
I
I N
(500mA/Div)
Time (1µs/Div)
Time (1ms/Div)
Load Transient Regulation
V
IN
= 4.2V, V
OUT
= 5V, I
LOAD
= 100mA to 400mA
Flash LED
V
IN
= 3.0V, Power LED = 200mA to 700mA
Load Current
(mA)
400
200
0
V
IN
(100mV/Div)
(2V/Div)
GPIO
Output Voltage
Deviation (mV)
100
0
-100
(500mA
/Div)
I
LED
I
I N
Time (1ms/Div)
(500mA/Div)
Time (10ms/Div)
Flash LED
V
IN
= 3.77V, Power LED = 200mA to 700mA
Flash LED
V
IN
= 4.3V, Power LED = 200mA to 700mA
V
IN
(100mV/Div)
(2V/Div)
V
IN
(100mV/Div)
(2V/Div)
GPIO
(500mA
/Div)
GPIO
(500mA/Div)
I
LED
I
I N
(500mA/Div)
Mode Transition
I
LED
I
I N
(500mA/Div)
Time (10ms/Div)
Time (10ms/Div)
DS9278-04 August 2007
www.richtek.com
11
RICHTEK [ RICHTEK TECHNOLOGY CORPORATION ]
