Page 1
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3A Fixed Low Dropout
Linear Regulator (LDO)
L1085-3.3
TO-252,263,220
JUL-05-2001
NIKO-SEM
GENERAL DESCRIPTION
The L1085 is a positive and low dropout
three-terminal voltage regulator with 3A output current capability. This device is designed for use in low voltage applications that
offers lower dropout voltage and faster transient response.
This device is fully protected against over
current faults, over temperature operation,
reversed input polarity, reversed lead insertion, transient voltage spike …etc.
On-Chips trimming the reference voltage to
1% and features the low dropout of maximum 1.50 volts.
The L1085 Series regulators are available
in the popular industry standard TO-263
TO-220 and TO-252 packages.
FEATURES
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Very easy to use, it requires only two
external resistors to set the output voltage
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Low dropout voltage:
1.3V typical at up to 3A
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Low ground current
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Fast transient response
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Current & thermal lim iting
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Line regulation: 0.5% typical
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Load regulation: 0.5% typical
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TO-263, TO-220 and TO-252 packages
APPLICATIONS
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High current microprocessor supplies
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Low voltage logic supply
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Powering VGA & sound card
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Portable instrumentation
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Constant current regulator
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Post regulator for switching power supply
TYPICAL APPLICATION
Vin>4.75V Vout=3.3V
OUT
GND
Cin
10uF
Cout
10uF
RL
L1085-3.3
IN
Basic Fixed Output Regulator Circuit
Page 2
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3A Fixed Low Dropout
Linear Regulator (LDO)
L1085-3.3
TO-252,263,220
JUL-05-2001
NIKO-SEM
ABSOLUTE MAXIMUM RATINGS
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Maximum Supply Voltage 7V
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Operating Junction
Temperature Range
0 to 125 °C
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Power Dissipation
Internally
Limited
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Storage Temperature
Range
-40 to 150 °C
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Thermal Resistance
Junction to Case,
θ
JC
5 °C/W
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Lead Temperature
(Soldering, 10 Seconds)
260 °C
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Thermal Resistance
Junction to Ambient,
θ
JA
TO-263
TO-252
TO-220
60 °C/W
70 °C/W
50 °C/W
ELECTRICAL CHARACTERISTI CS
(
Unless otherwise specified, TA = 25 °C.)
Parameter
Symbol
Test Conditions Typical Limits
Output Voltage
(Fixed Version)
Vo VIN = 5V, I
OUT
= 10mA
3.3V
3.234V
Min
3.367V
Max
Dropout Voltage VD
Δ
V
REF
= 1%, I
OUT
= 3A
1.3V 1.50V
Line Regulation REG
(LINE)
(V
OUT
+ 1.5V) ≤ V
IN
≤
7V, I
OUT
= 10mA
0.5% 2%
Load Regulation REG
(LOAD)
(V
IN -VOUT
) = 3V, 10mA ≤ I
OUT
≤ 3A
0.5% 2.5%
Minimum Load
Current
IO
1.5V ≤ (V
IN -VOUT
) ≤ 5.75V
10mA
GND Pin Current I
GND
55µA 100µA
Current Limit ICL VIN - V
OUT
= 2V 5.0A 4.0A (Min)
RMS Output Noise VN
0.003%
of V
OUT
Ripple Rejection
Ratio
R
A
f = 120Hz, C
ADJ
= 22µF for ADJ pin,
V
IN
= 5V, I
OUT
= 3A
72dB 60dB (Min)
DEVICE SELECTION GUIDE
Device
L1085D-3.3 L1085S-3.3 L1085S3-3.3 L1085T-3.3 L1085S5-3.3
Package
TO-252 TO-263 (2-Lead) TO-263 (3-Lead) TO-220 TO-263 (5-Lead)
Marking
L1085-33 L1085-33 L1085-33 L1085-33 L1085-33
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3A Fixed Low Dropout
Linear Regulator (LDO)
L1085-3.3
TO-252,263,220
JUL-05-2001
NIKO-SEM
PIN CONFIGURATIONS
Pin # Function
1 GND
2 Output
3 Input
Note: TAB is Output Pin
Pin # Function
2 GND
3 Output
5 Input
Note: TAB is Output Pin (For 5-pin)
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3A Fixed Low Dropout
Linear Regulator (LDO)
L1085-3.3
TO-252,263,220
JUL-05-2001
NIKO-SEM
TO-263 (D2PAK) MECHANICAL DATA
mm
mm
Dimension
Min. Typ. Max.
Dimension
Min. Typ. Max.
A 14.5 15 15.8 H 1.0 1.5 1.8
B 4.2 4.7 I 9.8 10.3
C 1.20 1.35 J 6.5
D 2.8 K 1.5
E 0.3 0.4 0.5 L 0.7 1.4
F -0.102 0.203 M 4.83 5.08 5.33
G 8.5 9 9.5 N
Page 5
5
3A Fixed Low Dropout
Linear Regulator (LDO)
L1085-3.3
TO-252,263,220
JUL-05-2001
NIKO-SEM
TO-263 (D2PAK) MECHANICAL DATA
mm
mm
Dimension
Min. Typ. Max.
Dimension
Min. Typ. Max.
A 14.5 15 15.8 H 1.0 1.5 1.8
B 4.2 4.7 I 9.8 10.3
C 1.20 1.35 J 6.5
D 2.8 K 1.5
E 0.3 0.4 0.5 L 0.7 1.4
F -0.102 0.203 M 4.83 5.08 5.33
G 8.5 9 9.5 N
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3A Fixed Low Dropout
Linear Regulator (LDO)
L1085-3.3
TO-252,263,220
JUL-05-2001
NIKO-SEM
TO-220 (3-Lead) MECHANICAL DATA
mm
mm
Dimension
Min. Typ. Max.
Dimension
Min. Typ. Max.
A 9.78 10.16 10.54 H 2.4 2.54 2.68
B 2.61 2.74 2.87 I 1.19 1.27 1.35
C 20 J 4.4 4.6 4.8
D 28.5 28.9 29.3 K 1.14 1.27 1.4
E 14.6 15.0 15.4 L 2.3 2.6 2.9
F 8.4 8.8 9.2 M 0.26 0.46 0.66
G 0.72 0.8 0.88 N
7°
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3A Fixed Low Dropout
Linear Regulator (LDO)
L1085-3.3
TO-252,263,220
JUL-05-2001
NIKO-SEM
TO-263 (D2PAK, 5-Lead) MECHANICAL DATA
mm
mm
Dimension
Min. Typ. Max.
Dimension
Min. Typ. Max.
A 14.5 15 15.8 H 1.0 1.5 1.8
B 4.2 4.7 I 9.8 10.3
C 1.20 1.35 J 6.5
D 2.8 K 1.5
E 0.3 0.4 0.5 L 0.7 0.85 1.0
F -0.102 0.203 M 1.57 1.7 1.83
G 8.5 9 9.5 N
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3A Fixed Low Dropout
Linear Regulator (LDO)
L1085-3.3
TO-252,263,220
JUL-05-2001
NIKO-SEM
TO-252 (DPAK) MECHANICAL DATA
mm
mm
Dimension
Min. Typ. Max.
Dimension
Min. Typ. Max.
A 9.35 10.1 H 0.8
B 2.2 2.4 I 6.4 6.6
C 0.48 0.6 J 5.2 5.4
D 0.89 1.5 K 0.6 1
E 0.45 0.6 L 0.64 0.9
F 0.03 0.23 M 4.4 4.6
G 6 6.2 N
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