1/17
September 2003
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TYPICAL DROPOUT 1.2V
s
FAST TRANSIENT RESPONSE
s
THREE TERMINAL ADJUSTABLE OR FIXED
OUTPUT VOLTAGE 1.5V 1.8V, 2.5V, 2.85V,
3.3V, 5V, 8V, 9V, 12V.
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GUARANTEED OUTPUT CURRENT UP TO
5A
s
OUPUT TOLERANCE
1% AT 25C AND
2% IN FULL TEMPERATURE RANGE
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INTERNAL POWER AND THERMAL LIMIT
s
WIDE OPERATING TEMPERATURE RANGE
0C TO 125C
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PACKAGE AVAILABLE : TO-220, D
2
PAK,
D
2
PAK/A
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PINOUT COMPATIBILITY WITH STANDARD
ADJUSTABLE VREG
DESCRIPTION
The LD1585C is a LOW DROP Voltage Regulator
able to provide up to 5A of Output Current.
Dropout is guaranteed at a maximum of 1.4V at
the maximum output current, decreasing at lower
loads. The device has been improved to be
utilized in low voltage applications where transient
response and minimum input voltage are critical.
The most important feature of the device consist in
lower dropout voltage and very fast transient
response. 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 LD1585C quiescent current
flows into the load, so increase efficiency. Only a
10F 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 25C.
LD1585C
SERIES
5A LOW DROPOUT FAST RESPONSE
POSITIVE VOLTAGE REGULATOR ADJUSTABLE AND FIXED
SCHEMATIC DIAGRAM
TO-220
D
2
PAK
D
2
PAK/A
LD1585C SERIES
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ABSOLUTE MAXIMUM RATINGS
Absolute Maximum Ratings are those values beyond which damage to the device may occur. Functional operation under these condition is
not implied.
THERMAL DATA
APPLICATION CIRCUITS
Symbol
Parameter
Value
Unit
V
I
DC Input Voltage
30
V
I
O
Output Current
Internally Limited
mA
P
D
Power Dissipation
Internally Limited
mW
T
stg
Storage Temperature Range
-55 to +150
C
T
op
Operating Junction Temperature Range
0 to +125
C
Symbol
Parameter
TO-220
D
2
PAK
Unit
R
thj-case
Thermal Resistance Junction-case
3
3
C/W
R
thj-amb
Thermal Resistance Junction-ambient
50
62.5
C/W
R
2
V
O
= V
REF
(1 +
)
R
1
LD1585C SERIES
4/17
ELECTRICAL CHARACTERISTICS OF LD1585#15 (V
I
=4.5V, C
I
= C
O
=10
F, T
J
= 0 to 125C, unless
otherwise specified.)
NOTE 1: See short-circuit current curve for available output current at fixed dropout.
ELECTRICAL CHARACTERISTICS OF LD1585#18 (V
I
=4.8V, C
I
= C
O
=10
F, T
J
= 0 to 125C, unless
otherwise specified.)
NOTE 1: See short-circuit current curve for available output current at fixed dropout.
Symbol
Parameter
Test Conditions
Min.
Typ.
Max.
Unit
V
O
Output Voltage
I
O
= 0 mA
T
J
= 25C
1.485
1.5
1.515
V
I
O
= 0 to 5A V
I
= 3 to 25V (note 1)
1.47
1.5
1.53
V
V
O
Line Regulation
I
O
= 0 mA
V
I
= 3 to 15V
T
J
= 25C
0.005
0.2
%
I
O
= 0 mA
V
I
= 3 to 15V
0.005
0.2
%
V
O
Load Regulation
I
O
= 0 to 5A T
J
= 25C
0.05
0.3
%
I
O
= 0 to 5A
0.05
0.5
%
V
d
Dropout Voltage
I
O
=5 A
1.2
1.4
V
I
q
Quiescent Current
V
I
25V
5
10
mA
I
sc
Short Circuit Current
V
I
- V
O
= 5V
5.5
7
A
Termal Regulation
T
J
= 25C, 30ms pulse
0.004
0.02
%/W
SVR
Supply Voltage Rejection
f = 120 Hz,
C
O
= 25
F, I
O
= 5A
V
I
- V
O
= 3
1V
60
75
dB
eN
RMS Output Noise Voltage
(% of V
O
)
T
J
= 25C
f =10Hz to 10KHz
0.003
%
S
Temperature Stability
0.5
%
S
Long Term Stability
T
J
= 125C
1000Hrs
0.03
1
%
Symbol
Parameter
Test Conditions
Min.
Typ.
Max.
Unit
V
O
Output Voltage
I
O
= 0 mA
T
J
= 25C
1.782
1.8
1.818
V
I
O
= 0 to 5A V
I
= 3.3 to 25V (note 1)
1.764
1.8
1.836
V
V
O
Line Regulation
I
O
= 0 mA
V
I
= 3.3 to 15V
T
J
= 25C
0.005
0.2
mV
I
O
= 0 mA
V
I
= 3.3 to 15V
0.005
0.2
V
O
Load Regulation
I
O
= 0 to 5A T
J
= 25C
0.05
0.3
mV
I
O
= 0 to 5A
0.05
0.5
V
d
Dropout Voltage
I
O
=5 A
1.2
1.4
V
I
q
Quiescent Current
V
I
25V
5
10
mA
I
sc
Short Circuit Current
V
I
- V
O
= 5.5V
5.5
7
A
Termal Regulation
T
J
= 25C, 30ms pulse
0.004
0.02
%/W
SVR
Supply Voltage Rejection
f = 120 Hz,
C
O
= 25
F, I
O
= 5A
V
I
- V
O
= 3
1V
60
75
dB
eN
RMS Output Noise Voltage
(% of V
O
)
T
J
= 25C
f =10Hz to 10KHz
0.003
%
S
Temperature Stability
0.5
%
S
Long Term Stability
T
J
= 125C
1000Hrs
0.03
1
%
LD1585C SERIES
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ELECTRICAL CHARACTERISTICS OF LD1585#25 (V
I
=5.5V, C
I
= C
O
=10
F, T
J
= 0 to 125C, unless
otherwise specified.)
NOTE 1: See short-circuit current curve for available output current at fixed dropout.
ELECTRICAL CHARACTERISTICS OF LD1585#285 (V
I
=5.85V, C
I
= C
O
=10
F, T
J
= 0 to 125C, unless
otherwise specified.)
NOTE 1: See short-circuit current curve for available output current at fixed dropout.
Symbol
Parameter
Test Conditions
Min.
Typ.
Max.
Unit
V
O
Output Voltage
I
O
= 0 mA
T
J
= 25C
2.475
2.5
2.525
V
I
O
= 0 to 5A V
I
= 4 to 25V (note 1)
2.45
2.5
2.55
V
V
O
Line Regulation
I
O
= 0 mA
V
I
= 4 to 16V
T
J
= 25C
0.005
0.2
mV
I
O
= 0 mA
V
I
= 4 to 16V
0.005
0.2
V
O
Load Regulation
I
O
= 0 to 5A T
J
= 25C
0.05
0.3
mV
I
O
= 0 to 5A
0.05
0.5
V
d
Dropout Voltage
I
O
=5 A
1.2
1.4
V
I
q
Quiescent Current
V
I
25V
5
10
mA
I
sc
Short Circuit Current
V
I
- V
O
= 5.5V
5.5
7
A
Termal Regulation
T
J
= 25C, 30ms pulse
0.004
0.02
%/W
SVR
Supply Voltage Rejection
f = 120 Hz,
C
O
= 25
F, I
O
= 5A
V
I
- V
O
= 3
1V
60
75
dB
eN
RMS Output Noise Voltage
(% of V
O
)
T
J
= 25C
f =10Hz to 10KHz
0.003
%
S
Temperature Stability
0.5
%
S
Long Term Stability
T
J
= 125C
1000Hrs
0.03
1
%
Symbol
Parameter
Test Conditions
Min.
Typ.
Max.
Unit
V
O
Output Voltage
I
O
= 0 mA
T
J
= 25C
2.821
2.85
2.879
V
I
O
= 0 to 5A V
I
= 4.5 to 30V (note 1)
2.793
2.85
2.907
V
V
O
Line Regulation
I
O
= 0 mA
V
I
= 4.5 to 18V
T
J
= 25C
0.005
0.2
mV
I
O
= 0 mA
V
I
= 4.5 to 18V
0.005
0.2
V
O
Load Regulation
I
O
= 0 to 5A T
J
= 25C
0.05
0.3
mV
I
O
= 0 to 5A
0.05
0.5
V
d
Dropout Voltage
I
O
=5 A
1.2
1.4
V
I
q
Quiescent Current
V
I
25V
5
10
mA
I
sc
Short Circuit Current
V
I
- V
O
= 5.5V
5.5
7
A
Termal Regulation
T
J
= 25C, 30ms pulse
0.004
0.02
%/W
SVR
Supply Voltage Rejection
f = 120 Hz,
C
O
= 25
F, I
O
= 5A
V
I
- V
O
= 3
1V
60
75
dB
eN
RMS Output Noise Voltage
(% of V
O
)
T
J
= 25C
f =10Hz to 10KHz
0.003
%
S
Temperature Stability
0.5
%
S
Long Term Stability
T
J
= 125C
1000Hrs
0.03
1
%
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