values between 0.8V and 1.2V please contact the National Semiconductor Sales Office.
Connection Diagrams
20131102
20131103
TO-263, Top View
TO-220, Top View
Pin Descriptions
TO220–5 and TO263–5 Packages
Pin #
1
2
3
4
5
TAB
Pin Symbol
EN
IN
GND
OUT
BIAS
TAB
The device Enable pin.
The unregulated input voltage pin
Ground
The regulated output voltage pin
The supply for the internal control and reference circuitry
The TAB is a thermal connection that is physically attached to the backside of
the die, and is used as a thermal heat-sink connection. See the Application
Information section for details
Pin Description
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2
LP38856
Absolute Maximum Ratings
(Note
1)
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
Storage Temperature Range
Lead Temperature
Soldering, 5 seconds
ESD Rating
Human Body Model (Note
2)
Power Dissipation (Note
3)
V
IN
Supply Voltage (Survival)
V
BIAS
Supply Voltage (Survival)
−65°C to +150°C
260°C
±2 kV
Internally Limited
−0.3V to +6.0V
−0.3V to +6.0V
V
EN
Voltage (Survival)
V
OUT
Voltage (Survival)
I
OUT
Current (Survival)
Junction Temperature
−0.3V to +6.0V
−0.3V to +6.0V
Internally Limited
−40°C to +150°C
(Note
1)
(V
OUT
+ V
DO
) to V
BIAS
3.0V to 5.5V
0.0V to V
BIAS
0 mA to 3.0A
−40°C to +125°C
Operating Ratings
V
IN
Supply Voltage
V
BIAS
Supply Voltage
V
EN
Enable Input Voltage
I
OUT
Junction Temperature Range
(Note
3)
Unless otherwise specified: V
IN
= V
OUT(NOM)
+ 1V, V
BIAS
= 3.0V, I
OUT
= 10 mA, C
IN
=
C
OUT
= 10 µF, C
BIAS
= 1µF, V
EN
= V
BIAS
. Limits in standard type are for T
J
= 25°C only; limits in
boldface type
apply over the
junction temperature (T
J
) range of -40°C to +125°C. Minimum and Maximum limits are guaranteed through test, design, or statistical
correlation. Typical values represent the most likely parametric norm at T
J
= 25°C, and are provided for reference purposes only.
Symbol
Parameter
Conditions
V
OUT(NOM)
+ 1V
≤
V
IN
≤
V
BIAS
,
3.0V
≤
V
BIAS
≤
5.5V,
10 mA
≤
I
OUT
≤
3.0A
MIN
-1.0
-3.0
TYP
0.0
MAX
+1.0
+3.0
%
-2.0
0
+2.0
Units
Electrical Characteristics
V
OUT
Output Voltage Tolerance
V
OUT(NOM)
+ 1V
≤
V
IN
≤
V
BIAS
,
3.0V
≤
V
BIAS
≤
5.5V,
0°C
≤
T
J
≤
125°C
10 mA
≤
I
OUT
≤
3.0A,
ΔV
OUT
/ΔV
IN
ΔV
OUT
/ΔV
BIAS
ΔV
OUT
/ΔI
OUT
V
DO
Line Regulation, V
IN
(Note
4)
Line Regulation, V
BIAS
(Note
4)
Output Voltage Load Regulation
(Note
5)
Dropout Voltage
V
IN
− V
OUT
(Note
6)
V
OUT(NOM)
+ 1V
≤
V
IN
≤
V
BIAS
3.0V
≤
V
BIAS
≤
5.5V
10 mA
≤
I
OUT
≤
3.0A
I
OUT
= 3.0A
LP38856-0.8
10 mA
≤
I
OUT
≤
3.0A
-
-
-
0.04
0.10
0.2
-
-
-
300
450
8.5
9.0
12
15
10
300
3.8
4.5
170
200
2.70
2.90
300
350
-
%/V
%/V
%/A
-
240
mV
-
-
-
-
-
2.20
2.00
60
50
-
7.0
11
1.0
3.0
100
2.45
150
6.2
I
GND(IN)
Ground Pin Current Drawn from
V
IN
Supply
LP38856-1.2
10 mA
≤
I
OUT
≤
3.0A
V
EN
≤
0.5V
mA
µA
mA
µA
V
mV
A
I
GND(BIAS)
Ground Pin Current Drawn from
V
BIAS
Supply
Under-Voltage Lock-Out
Threshold
Under-Voltage Lock-Out
Hysteresis
Output Short-Circuit Current
10 mA
≤
I
OUT
≤
3.0A
V
EN
≤
0.5V
V
BIAS
rising until device is
functional
V
BIAS
falling from UVLO threshold
until device is non-functional
V
IN
= V
OUT(NOM)
+ 1V,
V
BIAS
= 3.0V, V
OUT
= 0.0V
UVLO
UVLO
(HYS)
I
SC
3
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LP38856
Symbol
ENABLE Pin
Parameter
Conditions
V
EN
= V
BIAS
MIN
-
-19
-13
1.00
0.90
50
30
-
-
TYP
0.01
-30
1.25
100
20
15
MAX
-
-40
-51
1.50
1.55
150
200
-
-
Units
I
EN
ENABLE pin Current
V
EN
= 0.0V, V
BIAS
= 5.5V
V
EN
rising until Output = ON
V
EN
falling from V
EN(ON)
until
Output = OFF
R
LOAD
× C
OUT
<< t
OFF
R
LOAD
× C
OUT
<< t
ON
V
IN
= V
OUT
+1V,
f = 120 Hz
V
IN
= V
OUT
+ 1V,
f = 1 kHz
V
BIAS
= V
OUT
+ 3V,
f = 120 Hz
V
BIAS
= V
OUT
+ 3V,
f = 1 kHz
f = 120 Hz
BW = 10 Hz − 100 kHz
BW = 300 Hz − 300 kHz
µA
V
EN(ON)
V
EN(HYS)
t
OFF
t
ON
Enable Voltage Threshold
Enable Voltage Hysteresis
Turn-OFF Delay Time
Turn-ON Delay Time
V
mV
µs
AC Parameters
PSRR
(V
IN
)
Ripple Rejection for V
IN
Input
Voltage
-
-
-
-
-
-
-
80
65
58
58
1
150
90
-
dB
-
-
dB
-
-
-
-
µV/
√
Hz
µV (rms)
PSRR
(V
BIAS
)
Ripple Rejection for V
BIAS
Voltage
Output Noise Density
e
n
Output Noise Voltage
Thermal Parameters
T
SD
T
SD(HYS)
θ
JA
θ
JC
Thermal Shutdown Junction
Temperature
Thermal Shutdown Hysteresis
Thermal Resistance, Junction to
Ambient(Note
3)
Thermal Resistance, Junction to
Case(Note
3)
TO220-5
TO263-5
TO220-5
TO263-5
-
-
-
-
-
-
160
10
60
60
3
3
-
-
-
-
-
-
°C/W
°C
Note 1:
Absolute maximum ratings indicate limits beyond which damage to the component may occur. Operating ratings indicate conditions for which the device
is intended to be functional, but do not guarantee specific performance limits. For guaranteed specifications, see Electrical Characteristics. Specifications do not
apply when operating the device outside of its rated operating conditions.
Note 2:
The Human Body Model (HBM) is a 100 pF capacitor discharged through a 1.5k resistor into each pin. Test method is per JESD22-A114. The HBM rating
for device pin 1 (EN) is ±1.5 kV.
Note 3:
Device power dissipation must be de-rated based on device power dissipation (T
D
), ambient temperature (T
A
), and package junction to ambient thermal
resistance (θ
JA
). Additional heat-sinking may be required to ensure that the device junction temperature (T
J
) does not exceed the maximum operating rating. See
the Application Information section for details.
Note 4:
Output voltage line regulation is defined as the change in output voltage from nominal value resulting from a change in input voltage.
Note 5:
Output voltage load regulation is defined as the change in output voltage from nominal value as the load current increases from no load to full load.
Note 6:
Dropout voltage is defined the as input to output voltage differential (V
IN
- V
OUT
) where the input voltage is low enough to cause the output voltage to
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