Page 1
NIKO-SEM
3A Adjustable Low Dropout
Linear Regulator (LDO)
GENERAL DESCRIPTION
FEATURES
L1085
TO-252,263,220
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 1.45 volts.
The L1085 Series regulators are available
in the popular industry standard TO-220
TO-263 and TO-252 packages.
TYPICAL APPLICATION
Very easy to use, it requires only two
z
external resistors to set the output voltage
Low dropout voltage:
z
1.3V typical at up to 3A
Low ground current
z
Fast transient response
z
Current & thermal lim iting
z
Line regulation: 0.5% typical
z
Load regulation: 0.5% typical
z
TO-220, TO-263 and TO-252 packages
z
APPLICATIONS
High current microprocessor supplies
z
Low voltage logic supply
z
Powering VGA & sound card
z
Portable instrumentation
z
Constant current regulator
z
z
zz
Post regulator for switching power supply
z
Vin
Cin
10uF
L1085
IN
+
ADJ
Iadj
OUT
Vref
R1
R2
+
Vout
Cout
10uF
Vo = Vref (1+R2/R1) + I adj x R2
1. Cin needed if dev ice is far f r om f r om f ilt er capacitor s.
2. Cout required for st abil ity.
- Basic Adjustable Regulator Circuit -
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MAY-31-2001
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NIKO-SEM
3A Adjustable Low Dropout
Linear Regulator (LDO)
ABSOLUTE MAXIMUM RATINGS
L1085
TO-252,263,220
Maximum Supply Voltage 7V
z
Power Dissipation
z
Thermal Resistance
z
Junction to Case,
Thermal Resistance
z
θ
JC
Junction to Ambient,
TO-263
TO-252
TO-220
θ
JA
Internally
Limited
5 °C/W
60 °C/W
70 °C/W
50 °C/W
ELECTRICAL CHARACTERISTICS
Parameter
Symbol
Reference Voltage V
Dropout Voltage VD
Line Regulation REG
Load Regulation REG
Minimum Load
Current
Adjust Pin Current I
Current Limit ICL VIN - V
RMS Output Noise VN
Ripple Rejection
Ratio
VIN = 5V, I
REF
Δ
(V
(LINE)
(V
(LOAD)
IO
ADJ
1.5V ≤ (V
0.003%
f = 120Hz, C
R
A
V
V
= 1%, I
REF
+ 1.5V) ≤ V
OUT
IN -VOUT
OUT
= 5V, I
IN
Test Conditions Typical Limits
OUT
) = 3V, 10mA ≤ I
IN -VOUT
= 2V 5.0A 4.0A (Min)
OUT
Operating Junction
z
Temperature Range
Storage Temperature
z
Range
Lead Temperature
z
(Soldering, 10 Seconds)
(
Unless otherwise specified, TA = 25 °C.)
= 10mA
= 3A
OUT
≤
IN
) ≤ 5.75V
7V, I
= 10mA
OUT
≤ 3A
OUT
1.25V
1.3V 1.45V
0.5% 2%
0.5% 2.5%
10mA
55µA 100µA
= 22µF for ADJ pin,
ADJ
= 3A
of V
72dB 60dB (Min)
OUT
0 to 125 °C
-40 to 150 °C
260 °C
1.23V
1.27V
Min
Max
DEVICE SELECTION GUIDE
Device
Package
Marking
L1085D L1085S L1085S3 L1085T
TO-252 TO-263 (2-Lead) TO-263 (3-Lead) TO-220
L1085D L1085S L1085S3 L1085T
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MAY-31-2001
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NIKO-SEM
3A Adjustable Low Dropout
PIN CONFIGURATIONS
Linear Regulator (LDO)
L1085
TO-252,263,220
Pin # Function
1 Adjust
2 Output
3 Input
Note: TAB is Output Pin
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MAY-31-2001
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NIKO-SEM
Dimension
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
3A Adjustable Low Dropout
Linear Regulator (LDO)
TO-263 (D2PAK) MECHANICAL DATA
mm
Min. Typ. Max.
Dimension
L1085
TO-252,263,220
mm
Min. Typ. Max.
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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NIKO-SEM
Dimension
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
3A Adjustable Low Dropout
Linear Regulator (LDO)
TO-263 (D2PAK) MECHANICAL DATA
mm
Min. Typ. Max.
Dimension
L1085
TO-252,263,220
mm
Min. Typ. Max.
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NIKO-SEM
Dimension
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
3A Adjustable Low Dropout
Linear Regulator (LDO)
TO-220 (3-Lead) MECHANICAL DATA
mm
Min. Typ. Max.
Dimension
L1085
TO-252,263,220
mm
Min. Typ. Max.
7°
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MAY-31-2001
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NIKO-SEM
3A Adjustable Low Dropout
Linear Regulator (LDO)
TO-252 (DPAK) MECHANICAL DATA
L1085
TO-252,263,220
Dimension
mm
mm
Dimension
Min. Typ. Max.
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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MAY-31-2001
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