1
LT1584/LT1585/LT1587
7A, 4.6A, 3A Low Dropout
Fast Response
Positive Regulators
Adjustable and Fixed
NOTE: MICROPROCESSOR APPLICATIONS WITH LOAD TRANSIENTS OF 3.8A REQUIRE
OUTPUT DECOUPLING CAPACITANCE > 1300
F ON FIXED VOLTAGE PARTS TO ACHIEVE
< 50mV OF DEVIATION FROM NOMINAL OUTPUT. CONSULT FACTORY FOR DETAILS
TYPICAL APPLICATIO
N
U
The LT
1584/LT1585/LT1587 are low dropout three-
terminal regulators with 7A, 4.6A and 3A output current
capability, respectively. Design has been optimized for low
voltage applications where transient response and mini-
mum input voltage are critical. Similar to the LT1083/4/5
family, it has lower dropout voltage and faster transient
response. These improvements make it ideal for low volt-
age microprocessor applications requiring a regulated
2.5V to 3.6V output with an input supply below 7V.
Current limit is trimmed to ensure specified output current
and controlled short-circuit current. On-chip thermal lim-
iting provides protection against any combination of over-
load that would create excessive junction temperatures.
The LT1585/LT1587 are available in both the through-hole
and surface mount versions of the industry standard 3-pin
TO-220 power package. The LT1584 is available in the
through-hole 3-pin TO-220 power package.
DESCRIPTIO
N
U
APPLICATIO
N
S
U
s
Fast Transient Response
s
Guaranteed Dropout Voltage at Multiple Currents
s
Load Regulation: 0.05% Typ
s
Trimmed Current Limit
s
On-Chip Thermal Limiting
s
Standard 3-Pin Power Package
FEATURES
s
Pentium
TM
Processor Supplies
s
PowerPC
TM
Supplies
s
Other 2.5V to 3.6V Microprocessor Supplies
s
Low Voltage Logic Supplies
s
Battery-Powered Circuitry
s
Post Regulator for Switching Supply
LT1585/7CM, LT1584/5/7CT
Adjustable
LT1585/7CM-3.3, LT1584/5/7CT-3.3
3.3V Fixed
LT1585CM-3.38, LT1584/5CT-3.38
3.38V Fixed
LT1585/7CM-3.45, LT1584/5/7CT-3.45
3.45V Fixed
LT1585/7CM-3.6, LT1584/5/7CT-3.6
3.6V Fixed
, LTC and LT are registered trademarks of Linear Technology Corporation.
Pentium is a trademark of Intel Corporation. PowerPC is a trademark of IBM Corporation.
3.3V, 7A, 4.6A, 3A Regulator
LT1584-3.3
LT1585-3.3
LT1587-3.3
V
IN
4.75V
1585 TA01
C1
10
F
* REQUIRED FOR STABILITY
LT1584: C2 = 22
F,
LT1585/LT1587: C2 = 10
F
3.3V
7A, 4.6A, 3A
+
C2*
SOLID
TANTALUM
+
OUTPUT CURRENT (A)
0
INPUT/OUTPUT DIFFERENTIAL (V)
1.5
1.4
1.3
1.2
1.1
1.0
0.9
0.8
0.7
0.6
0.5
1585 TA02
I
FULL LOAD
Dropout Voltage vs Output Current
2
LT1584/LT1585/LT1587
V
IN
............................................................................. 7V
Operating Junction Temperature Range
Control Section.................................... 0
C to 125
C
Power Transistor ................................. 0
C to 150
C
ABSOLUTE
M
AXI
M
U
M
RATINGS
W
W
W
U
Storage Temperature Range ................. 65
C to 150
C
Lead Temperature (Soldering, 10 sec) .................. 300
C
100% Thermal Limit Functional Test
PRECO
N
DITIO
N
I G
U
U
U
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
Reference Voltage LT1584
1.5V
(V
IN
V
OUT
)
3V, 10mA
I
OUT
7A
LT1585
1.5V
(V
IN
V
OUT
)
5.75V, 10mA
I
OUT
4.6A, T
J
25
C
1.5V
(V
IN
V
OUT
)
5.75V, 10mA
I
OUT
4A, T
J
< 25
C
LT1587
1.5V
(V
IN
V
OUT
)
5.75V, 10mA
I
OUT
3A
q
1.225 ( 2%)
1.250
1.275 (+ 2%)
V
Output Voltage
LT1584-3.3
4.75V
V
IN
6.3V, 0mA
I
OUT
7A
LT1585-3.3
4.75V
V
IN
7V, 0mA
I
OUT
4.6A, T
J
25
C
4.75V
V
IN
7V, 0mA
I
OUT
4A, T
J
< 25
C
LT1587-3.3
4.75V
V
IN
7V, 0mA
I
OUT
3A
q
3.235 ( 2%)
3.300
3.365 (+ 2%)
V
LT1584-3.38
4.75V
V
IN
6.38V, 0mA
I
OUT
7A
LT1585-3.38
4.75V
V
IN
7V, 0mA
I
OUT
4A
q
3.313 ( 2%)
3.380 3.465 (+ 2.5%)
V
LT1584-3.45
4.75V
V
IN
6.45V,
0mA
I
OUT
7A
LT1585-3.45
4.75V
V
IN
7V,
0mA
I
OUT
4A
LT1587-3.45
4.75V
V
IN
7V,
0mA
I
OUT
3A
q
3.381 ( 2%)
3.450
3.519 (+ 2%)
V
LT1584-3.6
4.75V
V
IN
7V,
0mA
I
OUT
6A
q
3.400 ( 5.5%)
3.600
3.672 (+ 2%)
V
LT1584-3.6
4.80V
V
IN
7V,
0mA
I
OUT
6A
q
3.450 ( 4%)
3.600
3.672 (+ 2%)
V
LT1584-3.6
4.80V
V
IN
6.6V,
0mA
I
OUT
7A
q
3.431 ( 4.7%)
3.600
3.672 (+ 2%)
V
LT1584-3.6
4.85V
V
IN
6.6V,
0mA
I
OUT
7A
q
3.481 ( 3.3%)
3.600
3.672 (+ 2%)
V
ELECTRICAL CHARACTERISTICS
ORDER PART
NUMBER
ORDER PART
NUMBER
T PACKAGE
3-LEAD PLASTIC TO-220
FRONT VIEW
3
2
1
V
IN
V
OUT
ADJ
JA
= 30
C/W*
JA
= 50
C/W
T PACKAGE
3-LEAD PLASTIC TO-220
FRONT VIEW
3
2
1
V
IN
V
OUT
GND
JA
= 30
C/W*
JA
= 50
C/W
LT1584CT-3.3
LT1585CT-3.3
LT1587CT-3.3
LT1584CT-3.38
LT1585CT-3.38
LT1584CT-3.45
LT1585CT-3.45
LT1587CT-3.45
LT1584CT-3.6
LT1585CT-3.6
LT1587CT-3.6
* With package soldered to 0.5 square inch copper area over backside
ground plane or internal power plane.
JA
can vary from 20
C/W to
> 40
C/ W with other mounting techniques.
Consult factory for Industrial and Military grade parts.
LT1585CM-3.3
LT1585CM-3.38
LT1585CM-3.45
LT1585CM-3.6
LT1587CM-3.3
LT1587CM-3.45
LT1587CM-3.6
LT1585CM
LT1587CM
LT1584CT
LT1585CT
LT1587CT
PACKAGE/ORDER I
N
FOR
M
ATIO
N
W
U
U
V
IN
V
OUT
ADJ
M PACKAGE
3-LEAD PLASTIC DD PAK
FRONT VIEW
3
2
1
V
IN
V
OUT
GND
M PACKAGE
3-LEAD PLASTIC DD PAK
FRONT VIEW
3
2
1
3
LT1584/LT1585/LT1587
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
Output Voltage
LT1585/7-3.6
4.75V
V
IN
7V
,
0mA
I
OUT
3A
q
3.474 ( 3.5%)
3.600
3.672 (+ 2%)
V
LT1585/7-3.6
4.80V
V
IN
7V
,
0mA
I
OUT
3A
q
3.528 ( 2%)
3.600
3.672 (+ 2%)
V
LT1585-3.6
4.80V
V
IN
7V
,
0mA
I
OUT
4A
q
3.450 ( 4%)
3.600
3.672 (+ 2%)
V
LT1585-3.6
4.85V
V
IN
7V
,
0mA
I
OUT
4A
q
3.492 ( 3%)
3.600
3.672 (+ 2%)
V
Line Regulation
LT1584/5/7
2.75V
V
IN
7V, I
OUT
= 10mA
(Notes 1, 2)
LT1584/5/7-3.3
4.75V
V
IN
7V, I
OUT
= 0mA
LT1584/5-3.38
4.75V
V
IN
7V, I
OUT
= 0mA
LT1584/5/7-3.45
4.75V
V
IN
7V, I
OUT
= 0mA
LT1584/5/7-3.6
4.75V
V
IN
7V, I
OUT
= 0mA
q
0.005
0.2
%
Load Regulation
LT1584/5/7
(V
N
V
OUT
) = 3V, T
J
= 25
C, 10mA
I
OUT
I
FULL LOAD
(Notes 1, 2, 3)
LT1584/5/7-3.3
V
IN
= 5V, T
J
= 25
C, 0mA
I
OUT
I
FULL LOAD
LT1584/5-3.38
V
IN
= 5V, T
J
= 25
C, 0mA
I
OUT
I
FULL LOAD
LT1584/5/7-3.45
V
IN
= 5V, T
J
= 25
C, 0mA
I
OUT
I
FULL LOAD
LT1584/5/7-3.6
V
IN
= 5.25V, T
J
= 25
C, 0mA
I
OUT
I
FULL LOAD
0.05
0.3
%
q
0.05
0.5
%
Dropout Voltage
LT1585/7
V
REF
= 1%, I
OUT
= 3A
LT1585/7-3.3
V
OUT
= 1%, I
OUT
= 3A
LT1585-3.38
V
OUT
= 1%, I
OUT
= 3A
LT1585/7-3.45
V
OUT
= 1%, I
OUT
= 3A
LT1585/7-3.6
V
OUT
= 1%, I
OUT
= 3A
q
1.150
1.300
V
LT1585
V
REF
= 1%, I
OUT
= 4.6A, T
J
25
C
V
REF
= 1%, I
OUT
= 4A, T
J
< 25
C
LT1585-3.3
V
OUT
= 1%, I
OUT
= 4.6A, T
J
25
C
V
OUT
= 1%, I
OUT
= 4A, T
J
< 25
C
LT1585-3.38
V
OUT
= 1%, I
OUT
= 4A
LT1585-3.45
V
OUT
= 1%, I
OUT
= 4A
LT1585-3.6
V
OUT
= 1%, I
OUT
= 4A
q
1.200
1.400
V
LT1584
V
REF
= 1%, I
OUT
= 6A
LT1584-3.3
V
OUT
= 1%, I
OUT
= 6A
LT1584-3.38
V
OUT
= 1%, I
OUT
= 6A
LT1584-3.45
V
OUT
= 1%, I
OUT
= 6A
LT1584-3.6
V
OUT
= 1%, I
OUT
= 6A
T
J
25
C
q
1.200
1.300
V
T
J
< 25
C
q
1.200
1.350
V
LT1584
V
REF
= 1%, I
OUT
= 7A
LT1584-3.3
V
OUT
= 1%, I
OUT
= 7A
LT1584-3.38
V
OUT
= 1%, I
OUT
= 7A
LT1584-3.45
V
OUT
= 1%, I
OUT
= 7A
LT1584-3.6
V
OUT
= 1%, I
OUT
= 7A
q
1.250
1.400
V
Current Limit
LT1584
(V
IN
V
OUT
) = 3V
(Note 3)
LT1584-3.3
(V
IN
V
OUT
) = 3V
LT1584-3.38
(V
IN
V
OUT
) = 3V
LT1584-3.45
(V
IN
V
OUT
) = 3V
LT1584-3.6
(V
IN
V
OUT
) = 3V
q
7.100
8.250
A
LT1585
(V
IN
V
OUT
)
= 5.5V
LT1585-3.3
(V
IN
V
OUT
)
= 5.5V
T
J
25
C
q
4.600
5.25
A
T
J
< 25
C
q
4.100
5.25
A
LT1585-3.38
(V
IN
V
OUT
)
= 5.5V
LT1585-3.45
(V
IN
V
OUT
)
= 5.5V
LT1585-3.6
(V
IN
V
OUT
)
= 5.5V
q
4.100
4.750
A
LT1587
(V
IN
V
OUT
) = 5.5V
LT1587-3.3
(V
IN
V
OUT
) = 5.5V
LT1587-3.45
(V
IN
V
OUT
) = 5.5V
LT1587-3.6
(V
IN
V
OUT
) = 5.5V
q
3.100
3.750
A
ELECTRICAL CHARACTERISTICS
4
LT1584/LT1585/LT1587
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
Adjust Pin Current
LT1584/5/7
q
55
120
A
Adjust Pin Current
LT1584
1.5V
(V
IN
V
OUT
)
3V, 10mA
I
OUT
I
FULL LOAD
Change (Note 3)
LT1585/7
1.5V
(V
IN
V
OUT
)
5.75V, 10mA
I
OUT
I
FULL LOAD
q
0.2
5
A
Minimum
LT1584/5/7
1.5V
(V
IN
V
OUT
)
5.75V
q
2
10
mA
Load Current
Quiescent Current
LT1584/5/7-3.3
V
IN
= 5V
LT1584/5-3.38
V
IN
= 5V
LT1584/5/7-3.45 V
IN
= 5V
LT1584/5/7-3.6
V
IN
= 5V
q
8
13
mA
Ripple Rejection
LT1584
f = 120Hz, C
OUT
= 25
F Tant., (V
IN
V
OUT
) = 2.5V, I
OUT
= 7A
LT1584-3.3
f = 120Hz, C
OUT
= 25
F Tant., V
IN
= 5.8V, I
OUT
= 7A
LT1584-3.38
f = 120Hz, C
OUT
= 25
F Tant., V
IN
= 5.88V, I
OUT
= 7A
LT1584-3.45
f = 120Hz, C
OUT
= 25
F Tant., V
IN
= 5.95V, I
OUT
= 7A
LT1584-3.6
f = 120Hz, C
OUT
= 25
F Tant., V
IN
= 6.1V, I
OUT
= 7A
LT1585
f = 120Hz, C
OUT
= 25
F Tant., (V
IN
V
OUT
) = 3V,
I
OUT
= 4.6A, T
J
25
C
f = 120Hz, C
OUT
= 25
F Tant., (V
IN
V
OUT
) = 3V,
I
OUT
= 4A, T
J
< 25
C
LT1585-3.3
f = 120Hz, C
OUT
= 25
F Tant., V
IN
= 6.3V,
I
OUT
= 4.6A, T
J
25
C
f = 120Hz, C
OUT
= 25
F Tant., V
IN
= 6.3V,
I
OUT
= 4A, T
J
< 25
C
LT1585-3.38
f = 120Hz, C
OUT
= 25
F Tant., V
IN
= 6.38V, I
OUT
= 4A
LT1585-3.45
f = 120Hz, C
OUT
= 25
F Tant., V
IN
= 6.45V, I
OUT
= 4A
LT1585-3.6
f = 120Hz, C
OUT
= 25
F Tant., V
IN
= 6.6V, I
OUT
= 4A
LT1587
f = 120Hz, C
OUT
= 25
F Tant., (V
IN
V
OUT
) = 3V, I
OUT
= 3A
LT1587-3.3
f = 120Hz, C
OUT
= 25
F Tant., V
IN
= 6.3V, I
OUT
= 3A
LT1587-3.45
f = 120Hz, C
OUT
= 25
F Tant., V
IN
= 6.45V, I
OUT
= 3A
LT1587-3.6
f = 120Hz, C
OUT
= 25
F Tant., V
IN
= 6.6V, I
OUT
= 3A
q
60
72
dB
Thermal Regulation
LT1584/5/7
T
A
= 25
C, 30ms pulse
LT1584/5/7-3.3
T
A
= 25
C, 30ms pulse
LT1584/5-3.38
T
A
= 25
C, 30ms pulse
LT1584/5/7-3.45 T
A
= 25
C, 30ms pulse
LT1584/5/7-3.6
T
A
= 25
C, 30ms pulse
0.004
0.02
%/W
Temperature Stability
q
0.5
%
Long-Term Stability
T
A
= 125
C, 1000 Hrs.
0.03
1.0
%
RMS Output Noise
T
A
= 25
C, 10Hz
f
10kHz
0.003
%
(% of V
OUT
)
Thermal Resistance
LT1584
T Package: Control Circuitry/Power Transistor
0.65/2.7
C/W
Junction to Case
LT1585
T Package: Control Circuitry/Power Transistor
0.7/3.0
C/W
LT1585
M Package: Control Circuitry/Power Transistor
0.7/3.0
C/W
LT1587
T Package: Control Circuitry/Power Transistor
0.7/3.0
C/W
LT1587
M Package: Control Circuitry/Power Transistor
0.7/3.0
C/W
ELECTRICAL CHARACTERISTICS
Note 3: I
FULL LOAD
is defined as the maximum value of output load current
as a function of input-to-output voltage. I
FULL LOAD
is equal to 7A for the
LT1584, 4.6A at T
J
25
C and 4A at T
J
< 25
C for the LT1585/LT1585-3.3
and 3A for the LT1587. The remaining LT1585 fixed voltage versions are
4A.
The LT1585 and LT1587 have constant current limit with changes in
input-to-output voltage. The LT1584 has variable current limit which
decreases about 4A as input-to-output voltage increases from 3V to 7V.
The
q
denotes specifications which apply over the specified operating
temperature range.
Note 1: See thermal regulation specifications for changes in output voltage
due to heating effects. Load and line regulation are measured at a constant
junction temperature by low duty cycle pulse testing.
Note 2: Line and load regulation are guaranteed up to the maximum power
dissipation (25W for the LT1584 in T package, 26.5W for the LT1585 in T
package, 18W for the LT1587 in T package). Power dissipation is
determined by input/output differential and the output current. Guaranteed
maximum output power will not be available over the full input/output
voltage range.
5
LT1584/LT1585/LT1587
TYPICAL PERFOR
M
A
N
CE CHARACTERISTICS
U
W
LT1584 Dropout Voltage
vs Output Current
TEMPERATURE (
C)
0.20
OUTPUT VOLTAGE DEVIATION (%)
0.10
0
0.10
0.15
0.05
0.05
25
25
75
125
LT1584 TPC03
175
50
75
0
50
100
150
I = 7A
LT1584 Load Regulation
vs Temperature
INPUT/OUTPUT DIFFERENTIAL (V)
0
0
SHORT-CIRCUIT CURRENT (A)
4
10
2
4
5
LT1584 TPC02
2
8
6
1
3
6
7
T = 125
C
T = 25
C
T = 5
C
MINIMUM
LT1584 Short-Circuit Current
vs Input/Output Differential
LT1585 Dropout Voltage
vs Output Current
LT1585 Load Regulation
vs Temperature
LT1585 Short-Circuit Current
vs Temperature
TEMPERATURE (
C)
75
SHORT-CIRCUIT CURRENT (A)
5.0
5.5
125
LT1584 TPC05
4.5
4.0
25
25 50
175
6.0
75
50
0
150
100
TEMPERATURE (
C)
0.20
OUTPUT VOLTAGE DEVIATION (%)
0.10
0
0.10
0.15
0.05
0.05
25
25
75
125
LT1584 TPC03
175
50
75
0
50
100
150
I = 4.6A
LT1587 Dropout Voltage
vs Output Current
LT1587 Load Regulation
vs Temperature
LT1587 Short-Circuit Current
vs Temperature
TEMPERATURE (
C)
75
SHORT-CIRCUIT CURRENT (A)
4.0
4.5
125
LT1584 TPC05
3.5
3.0
25
25 50
175
5.0
75
50
0
150
100
TEMPERATURE (
C)
0.20
OUTPUT VOLTAGE DEVIATION (%)
0.10
0
0.10
0.15
0.05
0.05
25
25
75
125
LT1584 TPC09
175
50
75
0
50
100
150
I = 3A
OUTPUT CURRENT (A)
0
0.5
DROPOUT VOLTAGE (V)
0.6
0.8
0.9
1.0
1.5
1.2
2
4
5
LTC1584 TPC01
0.7
1.3
1.4
1.1
1
3
6
7
T = 5
C
T = 125
C
T = 25
C
GUARANTEED
TEST POINTS
OUTPUT CURRENT (A)
0
DROPOUT VOLTAGE (V)
1.1
1.3
1.5
4
LT1585 TPC04
0.9
0.7
1.0
1.2
1.4
0.8
0.6
0.5
1
2
3
5
T = 5
C
T = 125
C
T = 25
C
GUARANTEED
TEST POINTS
OUTPUT CURRENT (A)
0
0.5
DROPOUT VOLTAGE (V)
0.7
0.8
0.9
1.0
1.1
1.2
0.5
1.0
1.5
2.0
LT1584 TPC07
2.5
1.3
1.4
1.5
0.6
3.0
T = 5
C
T = 125
C
T = 25
C
GUARANTEED
TEST POINTS
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