RT7258
Absolute Maximum Ratings
(Note 1)
Supply Input Voltage, V
IN
------------------------------------------------------------------------------------------
–0.3V
to 26V
Switching Voltage, SW --------------------------------------------------------------------------------------------
–0.3V
to (V
IN
+ 0.3V)
BOOT to SW ---------------------------------------------------------------------------------------------------------
–0.3V
to 6V
All Other Voltage ----------------------------------------------------------------------------------------------------
−0.3V
to 6V
Power Dissipation, P
D
@ T
A
= 25°C
WDFN-14L 4x3 ------------------------------------------------------------------------------------------------------- 1.667W
SOP-8 (Exposed Pad) --------------------------------------------------------------------------------------------- 1.333W
Package Thermal Resistance (Note 2)
WDFN-14L 4x3,
θ
JA
------------------------------------------------------------------------------------------------- 60°C/W
WDFN-14L 4x3,
θ
JC
------------------------------------------------------------------------------------------------- 7.5°C/W
SOP-8 (Exposed Pad),
θ
JA
---------------------------------------------------------------------------------------- 75°C/W
SOP-8 (Exposed Pad),
θ
JC
--------------------------------------------------------------------------------------- 15°C/W
Lead Temperature (Soldering, 10 sec.) ------------------------------------------------------------------------- 260°C
Junction Temperature ----------------------------------------------------------------------------------------------- 150°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 Input Voltage, V
IN
------------------------------------------------------------------------------------------ 4.5V to 24V
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
Shutdown Supply Current
Supply Current
Reference Voltage
Feedback Current
High Side Switch On Resistance
High Side Switch Current Limit
Oscillation Frequency
Short Circuit Oscillation Frequency
Maximum Duty Cycle
Minimum On-Time
Symbol
Test Conditions
V
EN
= 0V
V
EN
= 3V, V
FB
= 1V
Min
--
--
--
--
--
--
--
--
--
4
--
2
--
Typ
1
0.9
10
45
13
600
190
90
100
4.2
400
--
--
Max
--
--
0.82
--
--
--
--
--
--
--
4.4
--
5.5
0.4
Unit
μA
mA
V
nA
mΩ
A
kHz
kHz
%
ns
V
mV
V
V
REF
I
FB
R
DS(ON)
4.5V
≤
V
IN
≤
24V
V
FB
= 0.8V
BOOT
−
SW = 4.8V
0.796 0.808
f
OSC1
f
OSC2
D
MAX
t
ON
V
FB
= 0V
V
FB
= 0.6V
V
FB
= 1V
Input Under Voltage Lockout Threshold V
UVLO
Input Under Voltage Lockout Threshold
ΔV
UVLO
Hysteresis
EN Threshold
Voltage
Logic-High
Logic-Low
V
IH
V
IL
Copyright
©
2012 Richtek Technology Corporation. All rights reserved.
is a registered trademark of Richtek Technology Corporation.
DS7258-00 January 2012
www.richtek.com
5
RICHTEK [ RICHTEK TECHNOLOGY CORPORATION ]
