RT8271
Absolute Maximum Ratings
(Note 1)
Supply Voltage, V
IN
-----------------------------------------------------------------------------------------
−0.3V
to 26V
Switching Voltage, SW -------------------------------------------------------------------------------------
−0.3V
to (V
IN
+
0.3V)
BOOT Voltage ------------------------------------------------------------------------------------------------ (V
SW
−
0.3V) to (V
SW
+
6V)
The Other Pins Voltage -------------------------------------------------------------------------------------
−0.3V
to 6V
Power Dissipation, P
D
@ T
A
= 25°C
SOP-8 ---------------------------------------------------------------------------------------------------------- 0.833W
MSOP-10 (Exposed Pad) ---------------------------------------------------------------------------------- 1.163W
Package Thermal Resistance (Note 2)
SOP-8,
θ
JA
---------------------------------------------------------------------------------------------------- 120°C/W
MSOP-10 (Exposed Pad),
θ
JA
---------------------------------------------------------------------------- 86°C/W
MSOP-10 (Exposed Pad),
θ
JC
---------------------------------------------------------------------------- 30°C/W
Junction Temperature --------------------------------------------------------------------------------------- 150°C
Lead Temperature (Soldering, 10 sec.) ----------------------------------------------------------------- 260°C
Storage Temperature Range -------------------------------------------------------------------------------
−65°C
to 150°C
ESD Susceptibility (Note 3)
HBM (Human Body Mode) --------------------------------------------------------------------------------- 2kV
MM (Machine Mode) ---------------------------------------------------------------------------------------- 200V
Recommended Operating Conditions
(Note 4)
Supply Voltage, V
IN
----------------------------------------------------------------------------------------- 4.75V to 24V
Enable Voltage, V
EN
----------------------------------------------------------------------------------------- 0V to 5.5V
Junction Temperature Range ------------------------------------------------------------------------------
−
40°C to 125°C
Ambient Temperature Range ------------------------------------------------------------------------------
−
40°C to 85°C
Electrical Characteristics
(V
IN
= 12V, T
A
= 25°C unless otherwise specified)
Parameter
Feedback Reference Voltage
High Side Switch-On Resistance
Low Side Switch-On Resistance
Switch Leakage
Current Limit
Current Sense Transconductance
Error Amplifier Tansconductance
Oscillator Frequency
Symbol
V
FB
R
DS(ON)1
R
DS(ON)2
Test Conditions
4.75V
≤
V
IN
≤
24V
Min
0.902
--
--
--
--
--
620
--
--
--
--
3.8
--
Typ
0.92
0.18
10
--
3
2.5
920
1.2
440
75
90
4.2
250
Max
0.938
--
--
10
--
--
1220
--
--
--
--
4.5
--
Unit
V
Ω
Ω
μA
A
A/V
μA/V
MHz
kHz
%
ns
V
mV
V
EN
= 0V, V
SW
= 0V
I
LIM
G
CS
G
m
f
SW
V
FB
= 0V
V
FB
= 0.8V
Duty = 75%; V
BOOT−SW
= 4.8V
Output Current to V
COMP
ΔI
C
= ±10μA
Short Circuit Oscillation Frequency
Maximum Duty Cycle
D
MAX
Minimum On-Time
Under Voltage Lockout Threshold
Rising
Under Voltage Lockout Threshold
Hysteresis
t
ON
To be continued
www.richtek.com
4
DS8271-02 March 2011
RICHTEK [ RICHTEK TECHNOLOGY CORPORATION ]
