Absolute Maximum Ratings
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
(Note 1)
V
IN
SW Voltage
FB Voltage
SHDN Voltage
Maximum Junction Temp. T
J
(Note 2)
Lead Temperature
(Soldering 10 sec.)
Vapor Phase
(60 sec.)
7.5V
21V
2V
7.5V
150C
300C
215C
Infrared
(15 sec.)
ESD Ratings (Note 3)
Human Body Model
Machine Model (Note 4)
220C
2kV
200V
Operating Conditions
Junction Temperature
(Note 5)
Supply Voltage
SW Voltage Max.
40C to +125C
2.2V to 7V
20.5V
Electrical Characteristics
Specifications in standard type face are for T
J
= 25C and those in
boldface type
apply over the full
Operating Temperature
Range
(T
J
= 40C to +125C). Unless otherwise specified V
IN
=2.2V.
Symbol
Parameter
Conditions
Min
(Note 5)
Typ
(Note 6)
40
235
0.01
1.237
150
Max
(Note 5)
70
300
2.5
1.269
175
180
120
7.0
1.6
Units
I
Q
Device Disabled
Device Enabled
Shutdown
FeedbackTrip Point
Switch Current Limit
FB = 1.3V
FB = 1.2V
SHDN = 0V
μA
V
FB
I
CL
1.189
110
100
V
mA
I
B
V
IN
R
DSON
T
OFF
I
SD
FB Pin Bias Current
Input Voltage Range
Switch R
DSON
Switch Off Time
SHDN Pin Current
FB = 1.23V (Note 7)
30
nA
V
ns
2.2
0.7
400
0
15
0
0.05
1.8
8
SHDN = V
IN
, T
J
= 25C
SHDN = V
IN
, T
J
= 125C
SHDN = GND
V
SW
= 20V
ON/OFF Threshold
80
nA
I
L
UVP
V
FB
Hysteresis
SHDN
Threshold
θ
JA
Switch Leakage Current
Input Undervoltage Lockout
Feedback Hysteresis
5
μA
V
mV
SHDN low
SHDN High
Thermal Resistance
0.7
0.7
220
0.3
V
1.1
C/W
Note 1:
Absolute maximum ratings are limits beyond which damage to the device may occur. Operating Ratings are conditions for which the device is intended to
be functional, but device parameter specifications may not be guaranteed. For guaranteed specifications and test conditions, see the Electrical Characteristics.
Note 2:
The maximum allowable power dissipation is a function of the maximum junction temperature, T
J
(MAX), the junction-to-ambient thermal resistance,
θ
JA
,
and the ambient temperature, T
A
. See the Electrical Characteristics table for the thermal resistance. The maximum allowable power dissipation at any ambient
temperature is calculated using: P
D
(MAX) = (T
J(MAX)
T
A
)/
θ
JA
. Exceeding the maximum allowable power dissipation will cause excessive die temperature.
Note 3:
The human body model is a 100 pF capacitor discharged through a 1.5 k
resistor into each pin. The machine model is a 200 pF capacitor discharged
directly into each pin.
Note 4:
ESD susceptibility using the machine model is 150V for SW pin.
Note 5:
All limits guaranteed at room temperature (standard typeface) and at temperature extremes (bold typeface). All room temperature limits are 100%
production tested or guaranteed through statistical analysis. All limits at temperature extremes are guaranteed via correlation using standard Statistical Quality
Control (SQC) methods. All limits are used to calculate Average Outgoing Quality Level (AOQL).
Note 6:
Typical numbers are at 25C and represent the most likely norm.
Note 7:
Feedback current flows into the pin.
L
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