RT8289
Absolute Maximum Ratings
(Note 1)
Supply Voltage, V
IN
----------------------------------------------------------------------------------------- 0.3V to 34V
Switching Voltage, SW (Note 2) ------------------------------------------------------------------------
−0.6V
to (V
IN
+
0.3V)
BOOT Voltage ------------------------------------------------------------------------------------------------ (V
SW
−
0.3V) to (V
SW
+
6V)
Other Pins Voltage ------------------------------------------------------------------------------------------
−0.3V
to 6V
Power Dissipation, P
D
@ T
A
= 25°C
SOP-8 (Exposed Pad) -------------------------------------------------------------------------------------- 1.333W
Package Thermal Resistance (Note 3)
SOP-8 (Exposed Pad),
θ
JA
-------------------------------------------------------------------------------- 75°C/W
SOP-8 (Exposed Pad),
θ
JC
-------------------------------------------------------------------------------- 15°C/W
Junction Temperature --------------------------------------------------------------------------------------- 150°C
Lead Temperature (Soldering, 10 sec.) ----------------------------------------------------------------- 260°C
Storage Temperature Range -------------------------------------------------------------------------------
−65°C
to 150°C
ESD Susceptibility (Note 4)
HBM (Human Body Mode) --------------------------------------------------------------------------------- 2kV
MM (Machine Mode) ---------------------------------------------------------------------------------------- 200V
Recommended Operating Conditions
(Note 5)
Supply Voltage, V
IN
----------------------------------------------------------------------------------------- 5.5V to 32V
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
Upper Switch Leakage
Current Limit
Current Sense Transconductance
Oscillator Frequency
Short Circuit Oscillation Frequency
Maximum Duty Cycle
Minimum On-Time
Under Voltage Lockout Threshold
Rising
Under Voltage Lockout Threshold
Hysteresis
En Threshold
Logic Low Voltage
Logic High Voltage
Symbol
V
FB
R
DS(ON)1
R
DS(ON)2
Test Conditions
5.5V
≦
V
IN
≦
32V
Min
1.202
--
--
--
--
--
--
--
--
--
--
--
Typ
100
10
0
6.8
5.5
500
120
90
100
4.2
200
--
--
1
Max
--
--
10
--
--
--
--
--
--
--
--
0.4
5.5
--
Unit
V
mΩ
Ω
μA
A
A/V
kHz
kHz
%
ns
V
mV
V
μA
1.222 1.239
V
EN
= 0V, V
SW
= 0V
I
LIM
G
CS
f
SW
V
FB
= 0V
D
MAX
t
ON
V
FB
= 1V
Duty = 90%; V
BOOT−SW
= 4.8V
Output Current to V
COMP
V
IL
V
IH
--
1.4
--
Enable Pull Up Current
To be continued
DS8289-01 March 2011
www.richtek.com
3
RICHTEK [ RICHTEK TECHNOLOGY CORPORATION ]
