Preliminary
RT9261B
Absolute Maximum Ratings
z Output Voltage -------------------------------------------------------------------------------------------------------- 8V
z LX Pin Voltage--------------------------------------------------------------------------------------------------------- 8V
z EN Pin Voltage(1) ------------------------------------------------------------------------------------------------------ −0.3 to VOUT +0.3V
z LX Pin Output Current ----------------------------------------------------------------------------------------------- 400mA
z Power Dissipation, PD @ TA = 25°C
SOT-89 ------------------------------------------------------------------------------------------------------------------ 0.5W
SOT-23-5 --------------------------------------------------------------------------------------------------------------- 0.25W
z Package Thermal Resistance
SOT-89, θJC ------------------------------------------------------------------------------------------------------------ 100°C/W
SOT-89, θJA ------------------------------------------------------------------------------------------------------------ 300°C/W
SOT-23-5, θJA ---------------------------------------------------------------------------------------------------------- 250°C/W
z Operating Temperature Range ------------------------------------------------------------------------------------- −20 to +85°C
z Storage Temperature Range --------------------------------------------------------------------------------------- −65°C to 150°C
z Lead Temperature (Soldering, 10 sec.)-------------------------------------------------------------------------- 260°C
Notes: (1)Applicable to RT9261B-xxCB
Electrical Characteristics (Refer to Figure 1)
Parameter
Output Voltage Accuracy
Input Voltage
Symbol
Test Conditions
Min Typ Max Units
-2
--
--
--
+2
7
%
V
V
V
ΔV
OUT
V
V
V
IN
Start-up Voltage
Hold-on Voltage
V
--
0.8
--
1
I
I
= 1mA, V : 0 → 2V
ST
OUT
IN
0.7
--
--
= 1mA, V : 2 → 0V
HO
OUT
IN
≤ 3.5V (1)
24
36
36
45
OUT
To be measured at V in
IN
Input Current 1
μA
μA
3.5V < V
≤ 5V (2)
continuous switching
--
OUT
To be measured at V
switch off condition
in
Input Current 2 (1) (2)
--
6.5
10
OUT
--
--
18
20
36
45
V
≤ 3.5V (1)
OUT
To be measured at V in no
load (guaranteed by I1 and I2)
IN
Input Current 3
μA
3.5V < V
≤ 5V (2)
OUT
120
160
--
--
--
--
V
≤ 3.5V (1)
OUT
LX Switching Current
LX Leakage Current
mA
I
I
V
= 0.4V
= 6V
SWITCHING
LX
3.5V < V
≤ 5V (2)
OUT
--
--
0.5
V
V
V
μA
LEAKAGE
LX
140 190 240 kHz
140 190 320 kHz
= 2.5V to 5V
OUT
OUT
Maximum Oscillator Frequency
F
MAX
= 1.5V to 2.4V
Oscillator Duty Cycle
Efficiency
65
--
75
80
85
--
%
%
V
D
On (V “L”) side
OSC
LX
LX switch on
0.65 0.8
1.0
V
LX
Voltage Limit
Notes:
(1) VIN = 1.8V, VSS = 0V, IOUT = 1mA, Topt = 25°C, and use External Circuit of Typical Application
(2) VIN = 3V, VSS = 0V, IOUT = 1mA, Topt= 25°C, and External Circuit of Typical Application
DS9261B-12 March 2007
www.richtek.com
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RICHTEK [ RICHTEK TECHNOLOGY CORPORATION ]
