![](http://datasheet.mmic.net.cn/390000/LM2781_datasheet_16815485/LM2781_3.png)
Absolute Maximum Ratings
2)
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
(Notes 1,
V
IN
pin: Voltage to GND
SD pin: Voltage to GND
0.3V to 5.8V
-0.3V to
(V
IN
+ 0.3V), with
5.8V max
Output Short-to-GND Duration
(Note 3)
Maximum Junction Temperature
(T
J-MAX
)
Storage Temperature Range
Pad Temperature
(Soldering, 10 sec.)
1 sec.
150C
-65C to +150C
265C
ESD Rating (Note 4)
Human-body model
Machine model
2kV
200V
Operating Ratings
(Notes 1, 2)
Input Voltage Range
Junction Temperature (T
J
) Range
Ambient Temperature (T
A
) Range
(Note 5)
1.8V to 5.5V
-40C to +90C
-40C to +85C
Thermal Properties
Junction-to-Ambient Thermal
Resistance (
θ
JA
), TPA08 Package
(Note 6)
220C/W
Electrical Characteristics
Limits in standard typface are for T
J
= 25C, and limits in
boldface
type apply over the full operating junction temperature
range (-40C
≤
T
≤
+90C). Unless otherwise noted: specifications apply to the LM2781 Typical Application Circuit (pg. 1) with
V
IN
= 5.0V, V(SD) = 0V, and C
IN
= C
OUT
= C1 = C2 = 1μF. (Note 8)
Symbol
Parameter
Conditions
R
OUT
Output Resistance
(Note 9)
I
OUT
= 10mA, C2 removed
I
Q
Supply Current
No load
I
SD
Shutdown Supply Current
V(SD) = 5.0V
F
SW
Switching Frequency
V
SD
Shutdown Pin Logic Levels
Normal Operation
1.8V
≤
V
IN
≤
5.5V
Shutdown Mode
1.8V
≤
V
IN
≤
5.5V
V
OUTp-p
Output Voltage Ripple
V
IN
= 5.0V, I
OUT
= 10mA
P
EFF
Power Efficiency
V
IN
= 5.0V, I
OUT
= 10mA
(Notes 2, 7)
Min
Typ
8
18
0.7
0.1
210
Max
30
40
1.4
0.5
400
Units
mA
μA
kHz
I
OUT
= 10mA, C2 = 1μF
100
0
0.5
V
0.5xV
IN
V
IN
10
92
mV
%
Note 1:
Absolute Maximum Ratings indicate limits beyond which damage to the component may occur. Operating Ratings are conditions under which operation of
the device is guaranteed. Operating Ratings do not imply guaranteed performance limits. For guaranteed performance limits and associated test conditions, see the
Electrical Characteristics table.
Note 2:
All voltages are with respect to the potential at the GND pin.
Note 3:
V
OUT
may be shorted to GND for one second without damage when the ambient temperature is at or below 85C. Prolonged or repeated shorts of V
OUT
to GND may damage the device, and should be avoided.
Note 4:
The human-body model is a 100pF capacitor discharged through a 1.5k
resistor into each pin. The machine model is a 200pF capacitor discharged
directly into each pin.
Note 5:
Maximum ambient temperature (T
A-MAX
) is dependent on the maximum operating junction temperature (T
J-MAX-OP
= 90C), the maximum power dissipation
of the device in the application (P
D-MAX
), and the junction-to-ambient thermal resistance of the part in the application (
JA
), as given by the following equation: T
A-MAX
= T
J-MAX-OP
- (
θ
JA
x P
D-MAX
).
Note 6:
Junction-to-ambient thermal resistance of the micro SMD package is highly application and board-layout dependent.
Note 7:
Max and Min limits are guaranteed by design, test, or statistical analysis. Typical numbers are not guaranteed, but do represent the most likely norm.
Note 8:
C
IN
, C
OUT
, C1, and C2: Low-ESR Surface-Mount Ceramic Capacitors (MLCCs) used in setting electrical characteristics.
Note 9:
Output resistance is a model for the voltage drop at the output, resulting from internal switch resistance, capacitor ESR, and charge pump charge transfer
characteristics. Output voltage can be predicted with the following equation: V
OUT
= -[V
IN
- (I
OUT
x R
OUT
)]
L
www.national.com
3