LD1084
SERIES
5A LOW DROP POSITIVE VOLTAGE
REGULATOR ADJUSTABLE AND FIXED
I
I
I
I
I
I
I
I
TYPICAL DROPOUT 1.3V (AT 5A)
THREE TERMINAL ADJUSTABLE OR FIXED
OUTPUT VOLTAGE 1.5, 1.8V, 2.5V, 2.85V,
3.3V, 3.6V, 5V, 8V, 9V, 12V.
GUARANTEED OUTPUT CURRENT UP TO
5A
OUPUT TOLERANCE
±1%
AT 25°C AND
±2%
IN FULL TEMPERATURE RANGE
INTERNAL POWER AND THERMAL LIMIT
WIDE OPERATING TEMPERATURE RANGE
-40°C TO 125°C
PACKAGE AVAILABLE: TO-220, D
2
PAK,
D
2
PAK/A
PINOUT COMPATIBILITY WITH STANDARD
ADJUSTABLE VREG
D
2
PAK
TO-220
D
2
PAK/A
DESCRIPTION
The LD1084 is a LOW DROP Voltage Regulator
able to provide up to 5A of Output Current.
Dropout is guaranteed at a maximum of 1.5V at
the maximum output current, decreasing at lower
loads. The LD1084 is pin to pin compatible with
the older 3-terminal adjustable regulators, but has
better performances in term of drop and output
tolerance.
A 2.85V output version is suitable for SCSI-2
active termination. Unlike PNP regulators, where
a part of the output current is wasted as quiescent
current, the LD1084 quiescent current flows into
the load, so increase efficiency. Only a 10µF
minimum capacitor is need for stability.
The device is supplied in TO-220, D
2
PAK and
D
2
PAK/A. On chip trimming allows the regulator to
reach a very tight output voltage tolerance, within
±1% at 25°C.
Figure 1: Schematic Diagram
February 2005
Rev. 4
1/20
LD1084 SERIES
Table 2: Absolute Maximum Ratings
Symbol
V
I
I
O
P
D
T
stg
T
op
DC Input Voltage
Output Current
Power Dissipation
Storage Temperature Range
Operating Junction Temperature Range
Parameter
Value
30
Internally Limited
Internally Limited
-55 to +150
-40 to +125
Unit
V
mA
mW
°C
°C
Absolute Maximum Ratings are those values beyond which damage to the device may occur. Functional operation under these condition is
not implied.
Table 3: Thermal Data
Symbol
R
thj-case
R
thj-amb
Parameter
Thermal Resistance Junction-case
Thermal Resistance Junction-ambient
TO-220
3
50
D
2
PAK
3
62.5
Unit
°C/W
°C/W
Table 4: Electrical Characteristics Of LD1084#15
(V
I
=4.5V, C
I
= C
O
=10µF, T
A
= -40 to 125°C, unless
otherwise specified.)
Symbol
V
O
∆V
O
∆V
O
V
d
I
q
I
sc
Parameter
Output Voltage
Line Regulation
Load Regulation
Dropout Voltage
Quiescent Current
Short Circuit Current
Thermal Regulation
SVR
eN
S
S
Supply Voltage Rejection
RMS Output Noise Voltage
(% of V
O
)
Temperature Stability
Long Term Stability
Test Conditions
I
O
= 0 mA T
J
= 25°C
I
O
= 0 to 5AV
I
= 3.1 to 30V (note 1)
I
O
= 0 mA V
I
= 3.1 to 18V
I
O
= 0 mA V
I
= 3.1 to 15V
I
O
= 0 to 5AT
J
= 25°C
I
O
= 0 to 5A
I
O
=5 A
V
I
≤
30V
V
I
- V
O
= 5V
V
I
- V
O
= 25V
T
A
= 25°C, 30ms pulse
f = 120 Hz, C
O
= 25
µF,
V
I
= 6.8
±
3V
T
A
= 25°C f =10Hz to 10KHz
I
O
= 5A
60
5.5
0.5
T
J
= 25°C
Min.
1.485
1.47
Typ.
1.5
1.5
0.5
0.1
3
7
1.3
5
6.5
0.7
0.003
75
0.003
0.5
0.5
0.015
Max.
1.515
1.53
6
6
15
20
1.5
10
Unit
V
V
mV
mV
mV
mV
V
mA
A
A
%/W
dB
%
%
%
T
A
= 125°C 1000Hrs
NOTE 1: See short-circuit current curve for available output current at fixed dropout.
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