LT1584/LT1585/LT1587
7A, 4.6A, 3A Low Dropout
Fast Response
Positive Regulators
Adjustable and Fixed
FEATURES
s
s
s
s
s
s
DESCRIPTIO
Fast Transient Response
Guaranteed Dropout Voltage at Multiple Currents
Load Regulation: 0.05% Typical
Trimmed Current Limit
On-Chip Thermal Limiting
Standard 3-Pin Power Package
APPLICATIO S
s
s
s
s
s
s
Pentium
TM
Processor Supplies
PowerPC
TM
Supplies
Other 2.5V to 3.6V Microprocessor Supplies
Low Voltage Logic Supplies
Battery-Powered Circuitry
Post Regulator for Switching Supply
Adjustable
3.3V Fixed
3.38V Fixed
3.45V Fixed
3.6V Fixed
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.
, LTC and LT are registered trademarks of Linear Technology Corporation.
Pentium is a trademark of Intel Corporation. PowerPC is a trademark of IBM Corporation.
LT1585/7CM, LT1584/5/7CT
LT1585/7CM-3.3, LT1584/5/7CT-3.3
LT1585CM-3.38, LT1584/5CT-3.38
LT1585/7CM-3.45, LT1584/5/7CT-3.45
LT1585/7CM-3.6, LT1584/5/7CT-3.6
TYPICAL APPLICATIO
LT1584-3.3
LT1585-3.3
LT1587-3.3
C1
10µF
Dropout Voltage vs Output Current
1.5
1.4
3.3V, 7A, 4.6A, 3A Regulator
INPUT/OUTPUT DIFFERENTIAL (V)
V
IN
≥
4.75V
3.3V
7A, 4.6A, 3A
C2*
SOLID
TANTALUM
1.3
1.2
1.1
1.0
0.9
0.8
0.7
0.6
0.5
0
OUTPUT CURRENT (A)
1585 TA02
+
+
* REQUIRED FOR STABILITY
LT1584: C2 = 22µF,
LT1585/LT1587: C2 = 10µF
1585 TA01
NOTE: MICROPROCESSOR APPLICATIONS WITH LOAD TRANSIENTS OF 3.8A REQUIRE
OUTPUT DECOUPLING CAPACITANCE > 1300µF ON FIXED VOLTAGE PARTS TO ACHIEVE
< 50mV OF DEVIATION FROM NOMINAL OUTPUT. CONSULT FACTORY FOR DETAILS
U
I
FULL LOAD
158457a
U
U
1
LT1584/LT1585/LT1587
ABSOLUTE
(Note 1)
AXI U RATI GS
Storage Temperature Range ................. – 65°C to 150°C
Lead Temperature (Soldering, 10 sec).................. 300°C
PRECONDITIONI G
100% Thermal Limit Functional Test
PACKAGE/ORDER INFORMATION
ORDER PART
NUMBER
FRONT VIEW
3
TAB
IS
OUTPUT
2
1
M PACKAGE
3-LEAD PLASTIC DD
V
IN
V
OUT
ADJ
1
T PACKAGE
3-LEAD PLASTIC TO-220
ADJ
LT1585CM
LT1587CM
TAB
IS
OUTPUT
FRONT VIEW
3
2
V
IN
V
OUT
θ
JA
= 30°C/W*
θ
JA
= 50°C/W
FRONT VIEW
3
TAB
IS
OUTPUT
2
1
M PACKAGE
3-LEAD PLASTIC DD
V
IN
V
OUT
GND
LT1585CM-3.3
LT1585CM-3.38
LT1585CM-3.45
LT1585CM-3.6
LT1587CM-3.3
LT1587CM-3.45
LT1587CM-3.6
FRONT VIEW
3
TAB
IS
OUTPUT
2
1
T PACKAGE
3-LEAD PLASTIC TO-220
V
IN
V
OUT
GND
θ
JA
= 30°C/W*
θ
JA
= 50°C/W
* With package soldered to 0.5 square inch copper area over backside
ground plane or internal power plane.
θ
JA
can vary from 20°C/W to
> 40°C/W with other mounting techniques.
Consult LTC Marketing for parts specified with wider operating temperature ranges.
2
UU
U
V
IN
............................................................................. 7V
Operating Junction Temperature Range
C-Grade
Control Section ................................... 0°C to 125°C
Power Transistor ................................. 0°C to 150°C
I-Grade
Control Section ............................... –40°C to 125°C
Power Transistor ............................. –40°C to 150°C
U
U
W
W W
U
W
ORDER PART
NUMBER
LT1584CT
LT1585CT
LT1587CT
LT1584CT-3.3
LT1584IT-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
158457a
LT1584/LT1585/LT1587
The
q
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C.
PARAMETER
Reference Voltage LT1584
LT1585
LT1587
LT1584-3.3
LT1585-3.3
LT1587-3.3
LT1584-3.38
LT1585-3.38
LT1584-3.45
LT1585-3.45
LT1587-3.45
LT1584-3.6
LT1584-3.6
LT1584-3.6
LT1584-3.6
LT1585/7-3.6
LT1585/7-3.6
LT1585-3.6
LT1585-3.6
LT1584/5/7
LT1584/5/7-3.3
LT1584/5-3.38
LT1584/5/7-3.45
LT1584/5/7-3.6
LT1584/5/7
LT1584/5/7-3.3
LT1584/5-3.38
LT1584/5/7-3.45
LT1584/5/7-3.6
LT1585/7
LT1585/7-3.3
LT1585-3.38
LT1585/7-3.45
LT1585/7-3.6
LT1585
LT1585-3.3
LT1585-3.38
LT1585-3.45
LT1585-3.6
LT1584
LT1584-3.3
LT1584-3.38
LT1584-3.45
LT1584-3.6
LT1584IT-3.3
CONDITIONS
1.5V
≤
(V
IN
– V
OUT
)
≤
3V, 10mA
≤
I
OUT
≤
7A
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
1.5V
≤
(V
IN
– V
OUT
)
≤
5.75V, 10mA
≤
I
OUT
≤
3A
4.75V
≤
V
IN
≤
6.3V, 0mA
≤
I
OUT
≤
7A
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
4.75V
≤
V
IN
≤
7V, 0mA
≤
I
OUT
≤
3A
4.75V
≤
V
IN
≤
6.38V, 0mA
≤
I
OUT
≤
7A
4.75V
≤
V
IN
≤
7V, 0mA
≤
I
OUT
≤
4A
4.75V
≤
V
IN
≤
6.45V, 0mA
≤
I
OUT
≤
7A
4.75V
≤
V
IN
≤
7V, 0mA
≤
I
OUT
≤
4A
4.75V
≤
V
IN
≤
7V, 0mA
≤
I
OUT
≤
3A
4.75V
≤
V
IN
≤
7V, 0mA
≤
I
OUT
≤
6A
4.80V
≤
V
IN
≤
7V, 0mA
≤
I
OUT
≤
6A
4.80V
≤
V
IN
≤
6.6V, 0mA
≤
I
OUT
≤
7A
4.85V
≤
V
IN
≤
6.6V, 0mA
≤
I
OUT
≤
7A
4.75V
≤
V
IN
≤
7V
,
0mA
≤
I
OUT
≤
3A
4.80V
≤
V
IN
≤
7V
,
0mA
≤
I
OUT
≤
3A
4.80V
≤
V
IN
≤
7V
,
0mA
≤
I
OUT
≤
4A
4.85V
≤
V
IN
≤
7V
,
0mA
≤
I
OUT
≤
4A
2.75V
≤
V
IN
≤
7V, I
OUT
= 10mA
4.75V
≤
V
IN
≤
7V, I
OUT
= 0mA
4.75V
≤
V
IN
≤
7V, I
OUT
= 0mA
4.75V
≤
V
IN
≤
7V, I
OUT
= 0mA
4.75V
≤
V
IN
≤
7V, I
OUT
= 0mA
(V
N
– V
OUT
) = 3V, T
J
= 25°C, 10mA
≤
I
OUT
≤
I
FULL LOAD
V
IN
= 5V, T
J
= 25°C, 0mA
≤
I
OUT
≤
I
FULL LOAD
V
IN
= 5V, T
J
= 25°C, 0mA
≤
I
OUT
≤
I
FULL LOAD
V
IN
= 5V, T
J
= 25°C, 0mA
≤
I
OUT
≤
I
FULL LOAD
V
IN
= 5.25V, T
J
= 25°C, 0mA
≤
I
OUT
≤
I
FULL LOAD
∆V
REF
= 1%, I
OUT
= 3A
∆V
OUT
= 1%, I
OUT
= 3A
∆V
OUT
= 1%, I
OUT
= 3A
∆V
OUT
= 1%, I
OUT
= 3A
∆V
OUT
= 1%, I
OUT
= 3A
∆V
REF
= 1%, I
OUT
= 4.6A, T
J
≥
25°C
∆V
REF
= 1%, I
OUT
= 4A, T
J
< 25°C
∆V
OUT
= 1%, I
OUT
= 4.6A, T
J
≥
25°C
∆V
OUT
= 1%, I
OUT
= 4A, T
J
< 25°C
∆V
OUT
= 1%, I
OUT
= 4A
∆V
OUT
= 1%, I
OUT
= 4A
∆V
OUT
= 1%, I
OUT
= 4A
∆V
REF
= 1%, I
OUT
= 6A
∆V
OUT
= 1%, I
OUT
= 6A
∆V
OUT
= 1%, I
OUT
= 6A
∆V
OUT
= 1%, I
OUT
= 6A
∆V
OUT
= 1%, I
OUT
= 6A
T
J
≥
25°C
T
J
< 25°C
T
J
< 25°C
MIN
TYP
MAX
UNITS
ELECTRICAL CHARACTERISTICS
q
1.225 (– 2%)
1.250
1.275 (+ 2%)
V
Output Voltage
q
q
3.235 (– 2%)
3.313 (– 2%)
3.300
3.365 (+ 2%)
V
V
3.380 3.465 (+ 2.5%)
q
q
q
q
q
q
q
q
q
3.381 (– 2%)
3.400 (– 5.5%)
3.450 (– 4%)
3.431 (– 4.7%)
3.481 (– 3.3%)
3.474 (– 3.5%)
3.528 (– 2%)
3.450 (– 4%)
3.492 (– 3%)
3.450
3.600
3.600
3.600
3.600
3.600
3.600
3.600
3.600
3.519 (+ 2%)
3.672 (+ 2%)
3.672 (+ 2%)
3.672 (+ 2%)
3.672 (+ 2%)
3.672 (+ 2%)
3.672 (+ 2%)
3.672 (+ 2%)
3.672 (+ 2%)
V
V
V
V
V
V
V
V
V
Line Regulation
(Notes 2, 3)
q
0.005
0.2
%
Load Regulation
(Notes 2, 3, 4)
q
0.05
0.05
0.3
0.5
%
%
Dropout Voltage
q
1.150
1.300
V
q
1.200
1.400
V
q
q
q
1.200
1.200
1.200
1.300
1.350
1.450
V
V
V
158457a
3
LT1584/LT1585/LT1587
The
q
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C.
PARAMETER
Dropout Voltage
LT1584
LT1584-3.3
LT1584-3.38
LT1584-3.45
LT1584-3.6
LT1584IT-3.3
LT1584
LT1584-3.3
LT1584-3.38
LT1584-3.45
LT1584-3.6
LT1585
LT1585-3.3
CONDITIONS
∆V
REF
= 1%, I
OUT
= 7A
∆V
OUT
= 1%, I
OUT
= 7A
∆V
OUT
= 1%, I
OUT
= 7A
∆V
OUT
= 1%, I
OUT
= 7A
∆V
OUT
= 1%, I
OUT
= 7A
T
J
< 25°C
(V
IN
– V
OUT
) = 3V
(V
IN
– V
OUT
) = 3V
(V
IN
– V
OUT
) = 3V
(V
IN
– V
OUT
) = 3V
(V
IN
– V
OUT
) = 3V
(V
IN
– V
OUT
) = 5.5V
(V
IN
– V
OUT
) = 5.5V
T
J
≥
25°C
T
J
< 25°C
(V
IN
– V
OUT
) = 5.5V
(V
IN
– V
OUT
) = 5.5V
(V
IN
– V
OUT
) = 5.5V
(V
IN
– V
OUT
) = 5.5V
(V
IN
– V
OUT
) = 5.5V
(V
IN
– V
OUT
) = 5.5V
(V
IN
– V
OUT
) = 5.5V
1.5V
≤
(V
IN
– V
OUT
)
≤
3V, 10mA
≤
I
OUT
≤
I
FULL LOAD
1.5V
≤
(V
IN
– V
OUT
)
≤
5.75V, 10mA
≤
I
OUT
≤
I
FULL LOAD
1.5V
≤
(V
IN
– V
OUT
)
≤
5.75V
V
IN
= 5V
V
IN
= 5V
V
IN
= 5V
V
IN
= 5V
V
IN
= 5V
f = 120Hz, C
OUT
= 25µF Tant., (V
IN
– V
OUT
) = 2.5V, I
OUT
= 7A
f = 120Hz, C
OUT
= 25µF Tant., V
IN
= 5.8V, I
OUT
= 7A
f = 120Hz, C
OUT
= 25µF Tant., V
IN
= 5.88V, I
OUT
= 7A
f = 120Hz, C
OUT
= 25µF Tant., V
IN
= 5.95V, I
OUT
= 7A
f = 120Hz, C
OUT
= 25µF Tant., V
IN
= 6.1V, I
OUT
= 7A
f = 120Hz, C
OUT
= 25µF Tant., (V
IN
– V
OUT
) = 3V,
I
OUT
= 4.6A, T
J
≥
25°C
f = 120Hz, C
OUT
= 25µF Tant., (V
IN
– V
OUT
) = 3V,
I
OUT
= 4A, T
J
< 25°C
f = 120Hz, C
OUT
= 25µF Tant., V
IN
= 6.3V,
I
OUT
= 4.6A, T
J
≥
25°C
f = 120Hz, C
OUT
= 25µF Tant., V
IN
= 6.3V,
I
OUT
= 4A, T
J
< 25°C
f = 120Hz, C
OUT
= 25µF Tant., V
IN
= 6.38V, I
OUT
= 4A
f = 120Hz, C
OUT
= 25µF Tant., V
IN
= 6.45V, I
OUT
= 4A
f = 120Hz, C
OUT
= 25µF Tant., V
IN
= 6.6V, I
OUT
= 4A
f = 120Hz, C
OUT
= 25µF Tant., (V
IN
– V
OUT
) = 3V, I
OUT
= 3A
f = 120Hz, C
OUT
= 25µF Tant., V
IN
= 6.3V, I
OUT
= 3A
f = 120Hz, C
OUT
= 25µF Tant., V
IN
= 6.45V, I
OUT
= 3A
f = 120Hz, C
OUT
= 25µF Tant., V
IN
= 6.6V, I
OUT
= 3A
MIN
TYP
MAX
UNITS
ELECTRICAL CHARACTERISTICS
q
q
1.250
1.250
1.400
1.500
V
V
Current Limit
(Note 4)
q
7.100
8.250
A
q
q
4.600
4.100
5.25
5.25
A
A
LT1585-3.38
LT1585-3.45
LT1585-3.6
LT1587
LT1587-3.3
LT1587-3.45
LT1587-3.6
Adjust Pin Current LT1584/5/7
Adjust Pin Current LT1584
Change (Note 4)
LT1585/7
Minimum
Load Current
LT1584/5/7
q
4.100
4.750
A
q
q
q
q
3.100
3.750
55
0.2
2
120
5
10
A
µA
µA
mA
Quiescent Current LT1584/5/7-3.3
LT1584/5-3.38
LT1584/5/7-3.45
LT1584/5/7-3.6
LT1584IT-3.3
Ripple Rejection
LT1584
LT1584-3.3
LT1584-3.38
LT1584-3.45
LT1584-3.6
LT1585
q
q
8
8
13
15
mA
mA
LT1585-3.3
LT1585-3.38
LT1585-3.45
LT1585-3.6
LT1587
LT1587-3.3
LT1587-3.45
LT1587-3.6
q
60
72
dB
158457a
4
LT1584/LT1585/LT1587
The
q
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C.
PARAMETER
Thermal Regulation
LT1584/5/7
LT1584/5/7-3.3
LT1584/5-3.38
LT1584/5/7-3.45
LT1584/5/7-3.6
CONDITIONS
T
A
= 25°C, 30ms pulse
T
A
= 25°C, 30ms pulse
T
A
= 25°C, 30ms pulse
T
A
= 25°C, 30ms pulse
T
A
= 25°C, 30ms pulse
q
ELECTRICAL CHARACTERISTICS
MIN
TYP
MAX
UNITS
0.004
0.5
0.03
0.003
0.02
1.0
%/W
%
%
%
Temperature Stability
Long-Term Stability
RMS Output Noise
(% of V
OUT
)
Thermal Resistance
Junction to Case
LT1584
LT1585
LT1585
LT1587
LT1587
T
A
= 125°C, 1000 Hrs.
T
A
= 25°C, 10Hz
≤
f
≤
10kHz
T Package: Control Circuitry/Power Transistor
T Package: Control Circuitry/Power Transistor
M Package: Control Circuitry/Power Transistor
T Package: Control Circuitry/Power Transistor
M Package: Control Circuitry/Power Transistor
0.65/2.7
0.7/3.0
0.7/3.0
0.7/3.0
0.7/3.0
°C/W
°C/W
°C/W
°C/W
°C/W
Note 1:
Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.
Note 2:
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 3:
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.
Note 4:
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.
158457a
5
