3A L.D.O. VOLTAGE REGULATOR (Adjustable & Fixed)
FEATURES
●
Output Current of 3A
●
Fast Transient Response
●
0.04% Line Regulation
●
0.2% Load Regulation
●
Internal Thermal and Current Limiting
●
Adjustable or Fixed Output Voltage(1.5V, 1.8V, 2.5V, 3.3V, 5.0V)
●
Surface Mount Package TO-263 3LD & TO-252 3L
●
100% Thermal Limit Burn-in
●
Low Dropout Voltage 1.5V at 3A Output Current
●
Moisture Sensitivity Level 3
TO-263 PKG
LM1085
TO-252 PKG
APPLICATIONS
●
High Efficiency Linear Regulators / Power Supply
●
High Efficiency "Green" Computer Systems
●
Constant Current Regulators
●
Portable Instrumentation
●
SMPS Post-Regulator
●
Adjustable Power Supplies
●
Powering VGA & Sound Card
1. ADJ / GND
2. OUTPUT
3. INPUT
* Heatsink surface connected to Pin 2.
ORDERING INFORMATION
Device
LM1085R-X.X
LM1085RS-X.X
Package
TO-263 3LD
TO-252 3LD
(X.X=VOUT=1.5V, 1.8V, 2.5V, 3.3V, 5.0V, ADJ)
DESCRIPTION
The LM1085 series of positive adjustable and fixed regulators are designed to provide 3A with high efficient.
All internal circuitry is designed to operate down to 1.5V input to output differential.
On-chip trimming adjusts the reference voltage to 1%.
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
LM1085-3.3V
LM1085-ADJ
Note
(1) C1 needed if device is far away from filter capacitors.
(2) C2 minimum value required for stability
V
REF
=V
OUT
-V
ADJ
=1.25V(Typ.)
I
ADJ
=55㎂(Typ.)
V
OUT
= V
REF
x (1+RF2/RF1) + I
ADJ
x RF2
Nov. 2010-Rev. 1.4
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HTC
3A L.D.O. VOLTAGE REGULATOR (Adjustable & Fixed)
BLOCK DIAGRAM
LM1085
ABSOULTE MAXIMUM RATINGS
CHARACTERISTIC
Supply Voltage
Operating Temperature Range
Junction Temperarture
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
V
IN
T
A
T
J
Tstg
Tjc
Tja
Tsol
Imax
VALUE
12
-10 ~ 70
0 ~ 125
-65 ~ 150
3
60
300
3
UNIT
V
℃
℃
℃
C/W
C/W
℃
A
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HTC
3A L.D.O. VOLTAGE REGULATOR (Adjustable & Fixed)
LM1085
ELECTRICAL CHARACTERISTICS I
OUT
=100mA, T
A
=25°C, unless otherwise specified
PARAMETER
1.5V Version
Output Voltage
1.8V Version
Output Voltage
2.5V Version
Output Voltage
3.3V Version
Output Voltage
5.0V Version
Output Voltage
All Voltage Options
Reference Voltage (V
REF
)
V
IN
≤7V,
P≤P
MAX
1.5V≤(V
IN-
V
OUT
)≤5.75V, 10mA≤I
OUT
≤3A
Min. Load Current(Note 3)
Line Regulation (ΔV
REF
(V
IN
))
1.5V≤(V
IN-
V
OUT
)≤5.75V
2.75V≤V
IN
≤7V,
I
OUT
=10mA, T
J
=25℃
1.238
1.225
1.25
1.25
5
0.05
0.1
1.3
1.263
V
1.275
13
0.3
0.4
1.5
mA
%
%
V
0≤I
OUT
≤3A,
5.5V≤V
IN
4.900
5.0
5.100
V
0<I
OUT
<3A, 4.75V<V
IN
3.234
3.3
3.366
V
0<I
OUT
<3A, 3.5V<V
IN
2.450
2.5
2.550
V
0<I
OUT
<3A, 2.75V<V
IN
1.764
1.8
1.836
V
0<I
OUT
<3A, 2.75V<V
IN
1.470
1.5
1.530
V
TEST CONDITIONS
MIN
TYP
MAX
UNIT
Load Regulation (ΔV
REF
(V
OUT
)) 10mA≤I
OUT
≤3A,
(V
IN
-V
OUT
)=3V, T
J
=25℃
Dropout Voltage
Current Limit
I
OUT
(MAX)
Long Term Stability
Thermal Regulation
(ΔV
OUT
(Pwr))
Output Noise, RMS
Thermal Resistance
Junction to Ambient
T
A
=25℃, 30ms pulse
10Hz to 10Khz T
A
=25℃
Junction to Tab
0.003
ΔV
REF
=1% , I
OUT
=3A
V
IN
-V
OUT
=3V
3.2
1.4V≤(V
IN
-V
OUT
) Adjustable Only
T
A
=125℃, 1000Hrs
4.5
A
0.3
1
%
0.01
0.02
%/W
%/Vo
3
℃/W
60
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HTC
3A L.D.O. VOLTAGE REGULATOR (Adjustable & Fixed)
TYPICAL PERFORMANCE CHARACTERISTICS
LM1085
Figure 1. Dropout Voltage vs Output Current
Figure 2. Reference Voltage vs Temperature
Figure 3. Load Regulation vs. Output Current
Figure 4. Minimum Load Current
Figure 5. Adjust Pin Current vs Temperature
Figure 6. Ripple Rejection vs. Frequency
(Fixed Versions)
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HTC
3A L.D.O. VOLTAGE REGULATOR (Adjustable & Fixed)
LM1085
Figure 7. Ripple Rejection vs. Frequency (Adjustable Versions)
APPLICATIONS INFORMATION
LM1085-ADJ
ADJ
Figure 8. Resistor Divider Scheme for the Adjustable Version
LM1085-XX
Figure 9. Protection Diode Scheme for Fixed Output Regulators
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HTC
实时操作系统RTOS
