If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
Storage Temperature Range
Operating Junction Temperature
Range
Lead Temperature
(Soldering, 5 sec.)
ESD Rating (Note 2)
−65˚C to +150˚C
−40˚C to +125˚C
260˚C
2 kV
Power Dissipation (Note 3)
Input Supply Voltage (Survival)
Input Supply Voltage (Operating)
Shutdown Input Voltage (Survival)
Output Voltage (Survival, (Note 4))
I
OUT
(Survival)
Input-Output Voltage
(Survival, (Note 5))
Internally Limited
−0.3V to +16V
2.1V to +16V
−0.3V to +16V
−0.3V to +9V
Short Circuit Protected
−0.3V to +16V
Electrical Characteristics
Limits in standard typeface are for T
J
= 25˚C, and limits in
boldface type
applyover the full operating temperature range. Un-
less otherwise specified: V
IN
= V
O(NOM)
+ 1V, C
IN
= 1 µF, I
L
= 1 mA, C
OUT
= 4.7 µF,V
ON/OFF
= 2V.
Symbol
Parameter
Conditions
Typ
LP2981AI-XX
(Note 6)
Min
∆V
O
Output Voltage
Tolerance
I
L
= 1mA
1 mA
<
I
L
<
100 mA
Output Voltage
Line Regulation
V
IN
–V
O
Dropout Voltage
(Note 7)
I
L
= 1 mA
I
L
= 25 mA
I
L
= 100 mA
I
GND
Ground Pin Current
I
L
= 0
I
L
= 1 mA
I
L
= 25 mA
I
L
= 100 mA
V
ON/OFF
<
0.3V
V
ON/OFF
<
0.15V
V
ON/OFF
I
ON/OFF
I
O(PK)
e
n
ON/OFF Input Voltage
(Note 8)
ON/OFF Input Current
Peak Output Current
Output Noise
Voltage (RMS)
Ripple Rejection
High = O/P ON
Low = O/P OFF
V
ON/OFF
= 0
V
ON/OFF
= 5V
V
OUT
≥
V
O(NOM)
− 5%
BW = 300 Hz–50 kHz,
C
OUT
= 10 µF
f = 1 kHz
C
OUT
= 10 µF
I
O(MAX)
Short Circuit Current
R
L
= 0 (Steady State)
(Note 9)
150
mA
63
dB
7
70
200
65
80
200
600
0.01
0.05
1.4
0.50
0.01
5
400
160
150
1.6
0.15
−1
15
150
V
O(NOM)
+ 1V
≤
V
IN
≤
16V
I
L
= 0
1
0.007
−0.75
−1.0
−2.5
Max
0.75
1.0
2.5
0.014
0.032
3
5
10
15
100
150
250
375
95
125
110
170
300
550
800
1500
0.8
2
1.6
0.15
−1
15
mA
µV
µA
LP2981I-XX
(Note 6)
Min
−1.25
−2.0
−3.5
Max
1.25
2.0
3.5
0.014
0.032
3
5
10
15
100
150
250
375
95
125
110
170
300
550
800
1500
0.8
2
V
µA
mV
%/V
%V
NOM
Units
www.national.com
4
LP2981
Electrical Characteristics
Note 2:
The ESD rating of pins 3 and 4 is 1 kV.
(Continued)
Note 1:
Absolute maximum ratings indicate limits beyond which damage to the component may occur. Electrical specifications do not apply when operating the de-
vice outside of its rated operating conditions.
Note 3:
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
. The maximum allowable power dissipation at any ambient temperature is calculated using:
The value of
θ
JA
for the SOT-23 package is 220˚C/W and the micro SMD package is 320˚C/W. Exceeding the maximum allowable power dissipation will cause ex-
cessive die temperature, and the regulator will go into thermal shutdown.
Note 4:
If used in a dual-supply system where the regulator load is returned to a negative supply, the LP2981 output must be diode-clamped to ground.
Note 5:
The output PNP structure contains a diode between the V
IN
and V
OUT
terminals that is normally reverse-biased. Reversing the polarity from V
IN
to V
OUT
will turn on this diode (see Application Hints).
Note 6:
Limits are 100% production tested at 25˚C. Limits over the operating temperature range are guaranteed through correlation using Statistical Quality Control
(SQC) methods. The limits are used to calculate National’s Average Outgoing Quality Level (AOQL).
Note 7:
Dropout voltage is defined as the input to output differential at which the output voltage drops 100 mV below the value measured with a 1V differential.
Note 8:
The ON/OFF inputs must be properly driven to prevent misoperation. For details, refer to Application Hints.
Note 9:
See Typical Performance Characteristics curves.
Basic Application Circuit
DS012506-4
*
ON/OFF input must be actively terminated. Tie to V
IN
if this function is not to be used.
**
Minimum Output Capacitance is shown to insure stability over full load current range. More capacitance provides superior dynamic performance and
additional stability margin (see Application Hints).
