LP2985LV
Electrical Characteristics
(Continued)
Limits in standard typeface are for T
J
= 25˚C. and limits in
boldface type
apply over the full operating temperature range. Un-
less otherwise specified: V
IN
= V
O
(NOM) + 1V, I
L
= 1 mA, C
IN
= 1 µF, C
OUT
= 4.7 µF, V
ON/OFF
= 2V.
LP2985AI-X.X
Symbol
Parameter
Ripple Rejection
Conditions
f = 1 kHz, C
BYPASS
= 10 nF
C
OUT
= 10 µF
45
dB
Typ
Min
Max
LP2985I-X.X
Min
Max
Units
I
O
(SC)
I
O
(PK)
Short Circuit Current
Peak Output Current
R
L
= 0 (Steady State)
V
OUT
≥
V
o
(NOM) −5%
400
350
mA
mA
Note 1:
“Absolute Maximum Ratings” indicate limits beyond which damage to the component may occur. Electrical specifications do not apply when operating the
device outside of its rated operating conditions.
Note 2:
The ESD rating of pins 3 and 4 for the SOT-23 package, or pins 5 and 2 for the micro SMD package, is 1 kV.
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
J-A
,
and the ambient temperature, T
A
. The maximum allowable power dissipation at any ambient temperture is calculated using:
Where the value of
θ
J-A
for the SOT-23 package is 220˚C/W in a typical PC board mounting. Exceeding the maximum allowable dissipation will cause excessive 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 LP2985LV output must be diode-clamped to ground.
Note 5:
The output PNP structure contains a diode between the V
IN
to V
OUT
terminals that is normally reverse-biased. Reversing the polarity from V
IN
to V
OUT
will
turn on this diode, and possibly damage the device (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:
The ON/OFF input must be properly driven to prevent possible misoperation. For details, refer to Application Hints.
Note 8:
The LP2985LV has foldback current limiting which allows a high peak current when V
OUT
>
0.5V, and then reduces the maximum output current as V
OUT
is forced to ground (see Typical Performance Characteristics curves).
Note 9:
V
IN
must be the greater of 2.2V or V
OUT(nom)
+ Dropout Voltage to maintain output regulation. Dropout Voltage is defined as the input to output differential
at which the output voltage drops 2% below ther value measured with a 1V differential.
Note 10:
Exposing the micro SMD device to direct sunlight will cause misoperation. See Application Hints for additional information.
5
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