General Description
The
LR1084 is a series of low dropout positive voltage
regulators with a maximum dropout of 1.5V at 5A of
load current.
The series features on-chip thermal limiting which pro-
vides protection against any combination of overload
and ambient temperatures that would create excessive
junction temperatures. It also includes a trimmed band-
gap reference and a current limiting circuit.
The
LR1084 is available in 1.5V, 1.8V, 2.5V, 2.85V,
3.3V and 5.0Vversions. The fixed versions integrate
the adjust resistors. It is also available in an adjustable
version which can set the output voltage with two
external resistors.
The
LR1084 series is available in standard packages of
TO-263-2L, TO-263-3L, TO-220 and TO-252.
Features
Low Dropout Voltage: 1.3V Typically at 5A
Current Limiting and Thermal Protection
Output Current: 5A
Current Limit: 6.5A
Operating Junction Temperature Range: 0 to
125
o
C
Line Regulation: 0.015% (Typical)
Load Regulation: 0.2% (Typical)
Applications
High Efficiency Linear Regulators
Battery Chargers
Post Regulation for Switching Supply
Microprocessor Supply
Desktop PCs, RISC and Embedded Processors'
Supply
TO-252
TO-220
TO-263-3L
TO-263-2L
LESHAN RADIO COMPANY, LTD.
LR1084-1/12
Figure 1. Package Types of
LR
1084
Figure 2. Pin Configuration of
LR
1084 (Top View)
Pin Configuration
T Package
(TO-220)
S Package
(TO-263-3L)
INPUT
OUTPUT
ADJ/GND
1
2
3
1
2
3
ADJ/GND
OUTPUT
D Package
(TO-252)
1
2
3
ADJ/GND
OUTPUT
INPUT
INPUT
S Package
(TO-263-2L)
ADJ/GND
INPUT
1
2
3
OUTPUT (TAB)
LESHAN RADIO COMPANY, LTD.
LR1084-2/12
Ordering Information
Package
Temperature Range
Part Number
Marking ID
Packing Type
TO-252
0 to 125
o
C
LR1084D-ADJ
LR1084D-ADJ
Tube/Tape/Reel
LR1084D-1.5
LR1084D-1.5
LR1084D-1.8
LR1084D-1.8
LR1084D-2.5
LR1084D-2.5
LR1084D-2.85
LR1084D-2.85
LR1084D-3.3
LR1084D-3.3
LR1084D-5.0
LR1084D-5.0
TO-220
0 to 125
o
C
LR1084T-ADJ
LR1084T-ADJ
Tube
LR1084T-1.5
LR1084T-1.5
LR1084T-1.8
LR1084T-1.8
LR1084T-2.5
LR1084T-2.5
LR1084T-2.85
LR1084T-2.85
LR1084T-3.3
LR1084T-3.3
LR1084T-5.0
LR1084T-5.0
TO-263-3L
0 to 125
o
C
LR1084S-ADJ
LR1084S-ADJ
Tube/Tape/Reel
LR1084S-1.5
LR1084S-1.5
LR1084S-1.8
LR1084S-1.8
LR1084S-2.5
LR1084S-2.5
LR1084S-2.85
LR1084S-2.85
LR1084S-3.3
LR1084S-3.3
LR1084S-5.0
LR1084S-5.0
TO-263-2L
0 to 125
o
C
LR1084S2-ADJ
LR1084S2-ADJ
Tube/Tape/Reel
LR1084S2-1.5
LR1084S2-1.5
LR1084S2-1.8
LR1084S2-1.8
LR1084S2-2.5
LR1084S2-2.5
LR1084S2-2.85
LR1084S2-2.85
LR1084S2-3.3
LR1084S2-3.3
LR1084S2-5.0
LR1084S2-5.0
LR1084 X - Y
Circuit Type
Package
S: TO-263-3L
T: TO-220
D: TO-252
S2: TO-263-2L
ADJ: Adjustable Output
1.5: Fixed Output 1.5V
1.8: Fixed Output 1.8V
2.5: Fixed Output 2.5V
2.85: Fixed Output 2.85V
3.3: Fixed Output 3.3V
5.0: Fixed Output 5.0V
Some of our products are available in Lead Free packages; If buyers need Lead Free product, please add -E1 after
the part number in your order. For example,
LR358M is a standard tin-lead product, LR358M-E1 means a Lead
Free product.
LESHAN RADIO COMPANY, LTD.
LR1084-3/12
Note 1: Stresses greater than those listed under "Absolute Maximum Ratings" may cause permanent damage to the
device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond
those indicated under"Recommended Operating Conditions" is not implied. Exposure to "Absolute Maximum
Ratings" for extended periods may affect device reliability.
Recommended Operating Conditions
Parameter
Symbol
Min
Max
Unit
Operating Junction Temperature Range
T
J
150
o
C
Storage Temperature Range
T
S
-65
150
o
C
Lead Temperature (Soldering, 10 sec.)
T
LEAD
300
o
C
ESD (Human Body Model)
ESD
2000
V
Parameter
Symbol
Min
Max
Unit
Input Voltage
V
IN
12
V
Operating Junction Temperature Range
T
J
0
125
o
C
Absolute Maximum Ratings (Note 1)
LESHAN RADIO COMPANY, LTD.
LR1084-4/12
Electrical Characteristics
Typicals and limits appearing in normal type apply for T
J
= 25
o
C
. Limits appearing in Boldface type apply over
Parameter
Symbol
Conditions
Min
Typ
Max
Unit
Reference Voltage
V
REF
LR1084-ADJ,
I
OUT
= 10mA, V
IN
-V
OUT
= 3V,
10mA I
OUT
5A, 1.5V V
IN
- V
OUT
5V
1.238
1.225
1.250
1.250
1.262
1.270
V
Output Voltage
V
OUT
V
LR1084-2.5,
I
OUT
= 0mA, V
IN
= 5.5V,
10mA I
OUT
5A, 4.1V V
IN
7V
2.475
2.45
2.5
2.5
2.525
2.55
LR1084-2.85,
I
OUT
= 0mA, V
IN
= 6V,
10mA I
OUT
5A, 4.5V V
IN
8V
2.822
2.793
2.85
2.85
2.879
2.907
LR1084-3.3,
I
OUT
= 0mA, V
IN
= 6.3V,
10mA I
OUT
5A, 4.9V V
IN
8V
3.267
3.234
3.3
3.3
3.333
3.366
LR1084-5.0,
I
OUT
= 0mA, V
IN
= 8V,
10mA I
OUT
5A, 6.6V V
IN
10V
4.95
4.9
5
5
5.05
5.1
Line Regulation
V
OUT
LR1084-ADJ,
I
OUT
= 10mA, 2.85V V
IN
10V
0.015
0.035
0.2
0.2
%
LR1084-1.5,
I
OUT
= 10mA, 3.1V V
IN
10V
0.5
1
6
6
mV
LR1084-1.8,
I
OUT
= 10mA, 3.4V V
IN
10V
0.5
1
6
6
mV
LR1084-2.5,
I
OUT
= 10mA, 4.1V V
IN
10V
0.5
1
6
6
mV
LR1084-2.85,
I
OUT
= 10mA, 4.5V V
IN
10V
0.5
1
6
6
mV
LR1084-3.3,
I
OUT
= 10mA, 4.9V V
IN
10V
0.5
1
6
6
mV
LR1084-5.0,
I
OUT
= 10mA, 6.6V V
IN
10V
0.5
1
10
10
mV
the entire operating junvtion temperature range.
I
OUT
= 0mA, V
IN
= 4.5V,
10mA I
OUT
5A, 3.1V V
IN
6V
1.485
1.47
1.5
1.5
1.515
1.53
LR1084-1.8,
I
OUT
= 0mA, V
IN
= 4.8V,
10mA I
OUT
5A, 3.4V V
IN
6V
1.782
1.764
1.8
1.8
1.818
1.836
LR1084-1.5,
LESHAN RADIO COMPANY, LTD.
LR1084-5/12
Electrical Characteristics (Continued)
Parameter
Symbol
Conditions
Min
Typ
Max
Unit
Load Regulation
V
OUT
LR1084-ADJ, 0mA I
OUT
5A,
V
IN
- V
OUT
= 3V
0.1
0.2
0.3
0.4
%
LR1084-1.5, 0mA I
OUT
5A,
V
IN
- V
OUT
= 3V
3
7
15
20
mV
LR1084-1.8, 0mA I
OUT
5A,
V
IN
- V
OUT
= 3V
3
7
15
20
mV
LR1084-2.5, 0mA I
OUT
5A,
V
IN
- V
OUT
= 3V
3
7
15
20
mV
LR1084-2.85, 0mA I
OUT
5A,
V
IN
- V
OUT
= 3V
3
7
15
20
mV
LR1084-3.3, 0mA I
OUT
5A,
V
IN
- V
OUT
= 3V
3
7
15
20
mV
LR1084-5.0, 0mA I
OUT
5A,
V
IN
- V
OUT
= 3V
5
10
20
35
mV
Dropout Voltage
I
O
= 5A, V
REF
, V
OUT
= 1%
1.3
1.5
V
Current Limit
I
LIMIT
V
IN
- V
OUT
= 3V,
5.5
6.5
A
Minimum
Load Current
V
IN
= 10V (
LR1084-ADJ)
3
10
mA
Quiescent Current
V
IN
= 10V (
LR1084)
5
10
mA
Ripple Rejection
f
RIPPLE
= 120Hz, C
OUT
= 25 F Tantalum,
I
OUT
= 5A, V
IN
- V
OUT
= 3V
60
72
dB
Adjust Pin Current
V
IN
= 4.25V, I
OUT
= 10mA
55
120
A
Adjust Pin Current
Change
10mA I
OUT
5A,
1.5V (V
IN
-V
OUT
) 4.5V
0.2
5
A
Temperature
Stability
I
OUT
= 10mA, V
IN
- V
OUT
= 1.5
0.5
%
Long Term Stability
T
A
= 125
o
C, 1000Hrs
0.5
%
RMS Noise
(% of V
OUT
)
10Hz f
10kHz
0.003
%
Thermal Resistance
Junction -to-Case
Q
JC
TO-263
TO-220
TO-252
3
3
0
C / W
Typicals and limits appearing in normal type apply for T
J
= 25
o
C
. Limits appearing in Boldface type apply over
the entire operating junvtion temperature range.
LESHAN RADIO COMPANY, LTD.
LR1084-6/12
Typical Performance Characteristics
Figure
3
. Dropout Voltage vs. Output Current
Figure
4
. Output Voltage vs. Temperature
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
0.80
0.85
0.90
0.95
1.00
1.05
1.10
1.15
1.20
1.25
1.30
1.35
1.40
1.45
1.50
Dr
op
o
u
t
V
o
lt
ag
e(
V
)
Output Current(A)
0
25
50
75
100
125
-1.0
-0.8
-0.6
-0.4
-0.2
0.0
L
ine regu
lat
ion(mV
)
T
J
(
o
C)
0
25
50
75
100
125
2.47
2.48
2.49
2.50
2.51
2.52
2.53
O
u
t
p
ut
V
o
lt
ag
e(
V
)
T
J
(
o
C)
Figure
5
. Line Regulation vs. Temperature
0
1
2
3
4
5
20
25
30
35
40
45
50
55
60
65
70
75
80
ADJUST PIN CURRENT VS. OUTPUT CURRENT
Ia
d
j
(
u
A
)
Io(A)
Figure
6
. Adjust Pin Current vs. Output Current
LESHAN RADIO COMPANY, LTD.
LR1084-7/12
Figure
7
. Dropout Voltage vs. Temperature
Figure
8
. Short Circuit Current vs. Dropout Voltage
Typical Performance Characteristics (Continued)
0
25
50
75
100
125
1.20
1.25
1.30
1.35
1.40
D
r
op
ou
t
V
o
lt
a
g
e(
V
)
T
J
(
o
C)
0
2
4
6
8
10
12
0
1
2
3
4
5
6
7
8
Short Circuit Current vs Dropout Voltage
S
h
or
t
C
i
rcu
it Cu
rre
n
t
(
A
)
Dropout Voltage(V)
Figure
9
. Load Transient Response
Figure 1
0
. Line Transient Response
LESHAN RADIO COMPANY, LTD.
LR1084-8/12
Typical Applications
LESHAN RADIO COMPANY, LTD.
LR1084-9/12
IN
LR1084-XX
OUT
3
1
2
22UF
10UF
V
OUT
V
IN
Fig 11. Fixed Output Regulator
IN
LR1084-ADJ
OUT
ADJ
3
1
2
22UF
10UF
V
OUT
=1.25V
V
IN
R1
120
22UF
IN
LR1084-ADJ
OUT
ADJ
3
1
2
10UF
V
OUT
V
IN
R2
R1
120
V
REF
22UF
10UF
IN
LR1084-ADJ
OUT
ADJ
3
1
2
10UF
V
OUT
V
IN
R2
R1
120
V
REF
FIG 12 . Adjustable Output 1.25 Voltage Application Circuit
FIG 13 . Adjustable Output Voltage Application Circuit
FIG 14 . Adjustable Output Voltage Application with improved Ripple Rejection
Adjustable Output Voltage V
OUT
=V
REF
*(1+R2/R1)+I
ADJ
*R2 Or V
OUT
=V
REF
(1+R2/R1) , V
REF
=1.25V
Mechanical Dimensions
TO-263
TO-263-3L
Unit: mm
LESHAN RADIO COMPANY, LTD.
LR1084-10/12
Mechanical Dimensions (Continued)
Unit: mm
TO-263-2L
LESHAN RADIO COMPANY, LTD.
LR1084-11/12
Mechanical Dimensions (Continued)
Unit: mm
LESHAN RADIO COMPANY, LTD.
LR1084-12/12
TO-220
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