RT7251A/B
Absolute Maximum Ratings (Note 1)
z Supply Voltage, VIN ----------------------------------------------------------------------------------------------- −0.3V to 19V
z SW--------------------------------------------------------------------------------------------------------------------- −0.3V to (VIN + 0.3V)
z BOOT to SW -------------------------------------------------------------------------------------------------------- −0.3V to 6V
z All Other Pins ------------------------------------------------------------------------------------------------------- −0.3V to 6V
z Power Dissipation, PD @ TA = 25°C
WDFN-8L 2x2 ------------------------------------------------------------------------------------------------------- 0.833W
z Package Thermal Resistance (Note 2)
WDFN-8L 2x2, θJA -------------------------------------------------------------------------------------------------- 120°C/W
WDFN-8L 2x2, θJC -------------------------------------------------------------------------------------------------- 8.2°C/W
z Lead Temperature (Soldering, 10 sec.)------------------------------------------------------------------------ 260°C
z Junction Temperature ---------------------------------------------------------------------------------------------- 150°C
z Storage Temperature Range ------------------------------------------------------------------------------------- −65°C to 150°C
z ESD Susceptibility (Note 3)
HBM (Human Body Mode) --------------------------------------------------------------------------------------- 2kV
MM (Machine Mode) ----------------------------------------------------------------------------------------------- 200V
Recommended Operating Conditions (Note 4)
z Supply Input Voltage, VIN ---------------------------------------------------------------------------------------- 4V to 17V
z Junction Temperature Range------------------------------------------------------------------------------------- −40°C to 125°C
z Ambient Temperature Range------------------------------------------------------------------------------------- −40°C to 85°C
Electrical Characteristics
(VIN = 12V, TA = 25°C, unless otherwise specified)
Parameter
Shutdown Supply Current
Supply Current
Symbol
Test Conditions
Min
--
Typ
1
Max
Unit
μA
mA
V
I
V
= 0V
5
1
SHDN
EN
I
V
EN
= 3V, V = 0.9V
--
0.6
0.8
10
OUT
FB
Feedback Reference Voltage V
4V ≤ V ≤ 17V
0.788
--
0.812
--
FB
IN
Feedback Current
I
V
FB
= 0.8V
nA
FB
High Side Switch On
Resistance
Low Side Switch On
Resistance
R
R
--
--
145
140
--
--
mΩ
mΩ
DS(ON)1
DS(ON)2
Min. Duty Cycle, V
− V
= 4.8V
SW
BOOT
Upper Switch Current Limit
Lower Switch Current Limit
Oscillation Frequency
--
3
--
A
A
Maximum Loading = 1.5A
From Drain to Source
For RT7251A
--
300
700
--
1
--
380
900
--
340
800
95
f
f
kHz
OSC1
OSC2
For RT7251B
V
= 0V, For RT7251A
= 0V, For RT7251B
= 0.7V, For RT7251A
= 0.7V, For RT7251B
Short-Circuit Oscillation
Frequency
FB
kHz
%
V
FB
--
170
93
--
V
FB
--
--
Maximum Duty Cycle
D
MAX
V
FB
--
84
--
Copyright 2012 Richtek Technology Corporation. All rights reserved.
©
is a registered trademark of Richtek Technology Corporation.
www.richtek.com
4
DS7251A/B-01 April 2012
RICHTEK [ RICHTEK TECHNOLOGY CORPORATION ]
