3A LOW DROPOUT VOLTAGE REGULATOR (Adjustable & Fixed)
FEATURES
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Low Dropout Voltage 500mV at 3A Output Current
Fast Transient Response
0.015% Line Regulation
0.1% Load Regulation
Internal Thermal and Current Limiting
Adjustable or Fixed Output Voltage
(1.5, 2.5, 2.85, 3.0, 3.3, 5.0V)
Surface Mount Package SOT-223 & TO-263 (D2 Package)
100% Thermal Limit Burn-in
LM1085
SOT-223 PKG (FRONT VIEW)
1
2
3
PIN FUNCTION
1. Adj/Gnd
2. Vout
3. Vin
TO-263 (D2 PKG, FRONT VIEW)
APPLICATIONS
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Battery Charger
Adjustable Power Supplies
Constant Current Regulators
Portable Instrumentation
High Efficiency Linear Power Supplies
High Efficiency "Green" Computer Systems
SMPS Post-Regulator
Power PC Supplies
Powering VGA & Sound Card
PIN FUNCTION
1. Adj/Gnd
2. Vout
3. Vin
1
2
3
ORDERING INFORMATION
Device & Marking
LM1085S-XX
LM1085T-XX
Package
SOT 223
TO263 (D2)
DESCRIPTION
(XX=Vout=1.5V, 2.5V, 2.85V, 3.0V, 3.3V, 5.0V
Adjustable= AD)
The LM1085 is a low dropout three terminal regulator with 3A output current capability.
The output voltage is adjustable with the use of a resistor divider. Dropout is guaranteed at a maximum
of 500 mV at maximum output current.
It's low dropout voltage and fast transient response make it ideal for low voltage microprocessor
applications. Internal current and thermal limiting provides protection against any overload condition
that would create excessive junction temperature.
TEST & TYPICAL APPLICATION CIRCUIT
V
IN
5V
+
C1
10㎌
RF2
205Ω
1%
3
2
LM1085
1
ADJ
V
REF
RF1
124Ω
1%
V
OUT
3.33V
V
REF
=V
OUT
-V
ADJ
=1.25V(Typ.)
V
OUT
=V
REF
x(1+RF2/RF1)+I
ADJ
xRF2
I
ADJ
=55㎂(Typ.)
C2
10㎌
(1) C1 Needed if device is far away
from filter capacitors.
(2) C2 Required for stability
Adjustable Voltage Regulator
HTC
1
3A LOW DROPOUT VOLTAGE REGULATOR(ADJ)
ABSOULTE MAXIMUM RATINS
CHARACTERISTIC
Supply Voltage
Operating Junction Temperature Range
Storage Temperature Range
Thermal Resistance Junction to Case TO-263
Thermal Resistance Junction to Ambient TO-263
Lead Temperature (Soldering) 10 sec.
Maximum Output Current
SYMBOL
Vin
Topr
Tstg
Tjc
Tja
Tsol
Imax
OUT
=100㎃,
LM1085
VALUE
7
0~125
-65~150
3
60
300
3
UNIT
V
℃
℃
C/W
C/W
℃
A
ELECTRICAL CHARACTERISTICS I
PARAMETER
1.5V Version
Output Voltage
2.5V Version
Output Voltage
2.85V Version
Output Voltage
3.0V Version
Output Voltage
3.3V Version
Output Voltage
5.0V Version
Output Voltage
All Voltage Options
Reference Voltage (V
REF
)
Min. Load Current(Note 3)
Line Regulation (ΔV
REF
(V
IN
))
Load Regulation (ΔV
REF
(V
OUT
))
Dropout Voltage
Current Limit
I
OUT
(MAX)
Long Term Stability
Thermal Regulation
(ΔV
OUT
(Pwr))
Output Noise, RMS
Thermal Resistance
T
A
=25℃, unless otherwise specified
MIN
TYP
MAX
UNIT
TEST CONDITIONS
0<I
OUT
<3A, 2.75V<V
IN
<10V
1.485
1.5
1.515
V
0<I
OUT
<3A, 3.5V<V
IN
<10V
2.475
2.5
2.525
V
0<I
OUT
<3A, 4.35V<V
IN
<10V
2.821
2.85
2.878
V
0<I
OUT
<3A, 4.5V<V
IN
<10V
2.97
3
3.03
V
0<I
OUT
<3A, 4.75V<V
IN
<10V
3.267
3.3
3.333
V
0≤I
OUT
≤3A, 5.5V≤V
IN
<10V
4.95
5
5.05
V
V
IN
≤7V,P≤P
MAX
1.5V≤(V
IN- OUT
)≤5.75V, 10㎃≤I
OUT
≤3A
V
1.5V≤(V
IN- OUT
)≤5.75V
V
2.75V≤V
IN
≤7V, I
OUT
=10㎃, T
J
=25℃
10㎃≤I
OUT
≤3A,(V
IN
-V
OUT
)=3V,T
J
=25℃
ΔV
REF
=1% , Iout=3A
Vin-Vout=3V
1.4V≤(V
IN
-V
OUT
) Adjustable Only
T
A
=125℃, 1000Hrs
T
A
=25℃, 30㎳ pulse
10Hz to 10Khz T
A
=25℃
Junction to Tab
Junction to Ambient
1.238
1.225
1.25
1.25
5
0.005
0.05
1.1
1.263
1.27
10
0.2
0.3
1.2
V
mA
%
%
V
A
3.2
4.0
0.3
0.01
1
0.02
%
%/W
%/Vo
0.003
3
60
℃/W
HTC
2
Analog electronics
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