Preliminary
Absolute Maximum Ratings
l
l
l
l
RT9278
(Note 1)
l
l
l
l
l
Supply Voltage, V
DD
------------------------------------------------------------------------------------------------- 7V
LX Pin Voltage --------------------------------------------------------------------------------------------------------
−
0.3V to 7V
The Other pins --------------------------------------------------------------------------------------------------------
−
0.3V to 7V
Power Dissipation, P
D
@ T
A
= 25°C
VDFN-10L 3x3 -------------------------------------------------------------------------------------------------------- 1.43W
Package Thermal Resistance (Note 4)
VDFN-10L 3x3,
θ
JA
--------------------------------------------------------------------------------------------------- 70°C/W
Lead Temperature (Soldering, 10 sec.)-------------------------------------------------------------------------- 260°C
Operation Temperature Range ------------------------------------------------------------------------------------
−40°C
to 85°C
Storage Temperature Range ---------------------------------------------------------------------------------------
−
65°C to 150°C
ESD Susceptibility (Note 2)
HBM (Human Body Mode) ----------------------------------------------------------------------------------------- 2kV
Recommended Operating Conditions
l
l
(Note 3)
Ambient Temperature Range -------------------------------------------------------------------------------------- 0°C to 70°C
Junction Temperature Range -------------------------------------------------------------------------------------- 0°C to 125°C
Electrical Characteristics
(V
BAT
= 1.8V, V
OUT
= 3.3V, T
A
= 25°C, unless otherwise specified)
Parameter
Start-Up Voltage
Operating Voltage Range, After start-up
VOUT Output Voltage Range
VOUT Over Voltage Protection
Switch-off Current I (V
BAT
)
Shutdown Current
Feedback Reference Voltage
Switching Frequency
Maximum Duty
SWN Switch ON Resistance
SWP Switch ON Resistance
Current Limit Setting
Error Amplifier
GM
Compensation Source Current
Compensation Sink Current
Symbol
V
ST
V
BAT
V
OUT_ADJ
I
SW OFF
I
OFF
V
FB
F
S
D
(MAX)
Test Conditions
I
L
= 1mA
Min
--
1.1
2.4
--
--
--
0.784
--
--
--
--
--
Typ
1.5
--
--
6.5
200
0.01
0.8
650
85
210
240
2
Max
--
5.5
5.5
--
350
1
0.816
--
--
--
--
--
Units
V
V
V
V
µA
µA
V
kHz
%
mΩ
mΩ
A
V
OUT
= 3.3V, V
FB
= 0.9V
EN Pin = 0V, Open Loop
Close Loop, V
OUT
= 3.3V
V
OUT
= 3.3V
V
OUT
= 3.3V
I
SW
V
OUT
= 3.3V
--
--
--
0.2
22
22
--
--
--
ms
uA
uA
To be continued
DS9278-04 August 2007
www.richtek.com
7
RICHTEK [ RICHTEK TECHNOLOGY CORPORATION ]
