LT1086 Series
1.5A Low Dropout Positive
Regulators Adjustable and
Fixed 2.85V 3.3V, 3.6V, 5V 12V
,
,
FEATURES
s
s
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DESCRIPTION
The LT
®
1086 is designed to provide 1.5A with higher
efficiency than currently available devices. All internal
circuitry is designed to operate down to 1V input-to-
output differential and the dropout voltage is fully speci-
fied as a function of load current. Dropout is guaranteed at
a maximum of 1.5V at maximum output current, decreas-
ing at lower load currents. On-chip trimming adjusts the
reference/ouput voltage to 1%. Current limit is also
trimmed, minimizing the stress on both the regulator and
power source circuitry under overload conditions.
The LT1086 is pin compatible with older 3-terminal adjust-
able regulators. A 10µF output capacitor is required on
these new devices; however, this is usually included in
most regulator designs.
A 2.85V output version is offered for SCSI-2 active termi-
nation. For surface mount applications see the LT1117-
2.85 data sheet. For high current or lower dropout require-
ments see the LT1123-2.85 data sheet.
Unlike PNP regulators, where up to 10% of the output
current is wasted as quiescent current, the LT1086 quies-
cent current flows into the load, increasing efficiency.
, LTC and LT are registered trademarks of Linear Technology Corporation.
3-Terminal Adjustable or Fixed
2.85V, 3.3V, 3.6V, 5V, 12V
Output Current of 1.5A, (0.5A for LT1086H)
Operates Down to 1V Dropout
Guaranteed Dropout Voltage at Multiple Current Levels
Line Regulation: 0.015%
Load Regulation: 0.1%
100% Thermal Limit Functional Test
APPLICATIONS
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SCSI-2 Active Terminator
High Efficiency Linear Regulators
Post Regulators for Switching Supplies
Constant Current Regulators
Battery Chargers
Microprocessor Supply
TYPICAL APPLICATION
LT1086 Dropout Voltage
MINIMUM INPUT/OUTPUT DIFFERENTIAL (V)
5V to 3.3V Regulator
V
IN
≥
4.75V
2
INDICATES GUARANTEED TEST POINT
–55°C
≤
T
J
≤
150°C
0°C
≤
T
J
≤
125°C
IN
LT1086-3.3 OUT
GND
3.3V AT 1.5A
10µF*
TANTALUM
10µF
TANTALUM
1
T
J
= – 55°C
T
J
= 25°C
T
J
= 150°C
LT1086 • TA01
*MAY BE OMITTED IF INPUT SUPPLY IS WELL
BYPASSED WITHIN 2" OF THE LT1086
0
0
1
0.5
OUTPUT CURRENT (A)
1.5
LT1086 • TA02
U
U
U
1
LT1086 Series
ABSOLUTE
MAXIMUM
RATINGS
Power Dissipation............................... Internally Limited
Input Voltage (Note 1) ............................................. 30V
Operating Input Voltage
Adjustable Devices ........................................... 25V
2.85V Devices .................................................. 18V
3.3V, 3.6V, and 5V Devices ............................... 20V
12V Devices ...................................................... 25V
Operating Junction Temperature Range
“C” Grades
Control Section ............................... 0°C to 125°C
Power Transistor ............................. 0°C to 150°C
“I” Grades
Control Section .......................... – 40°C to 125°C
Power Transistor ........................ – 40°C to 150°C
“M” Grades
Control Section .......................... – 55°C to 150°C
Power Transistor ........................ – 55°C to 200°C
Storage Temperature Range ................. – 65°C to 150°C
Lead Temperature (Soldering, 10 sec).................. 300°C
Note 1:
Although the device’s maximum operating voltage is limited, (18V
for a 2.85V device, 20V for a 5V device, and 25V for adjustable and
12V devices) the devices are guaranteed to withstand transient input
voltages up to 30V. For input voltages greater than the maximum operating
input voltage some degradation of specifications will occur. For fixed
voltage devices operating at input/output voltage differentials greater than
15V, a minimum external load of 5mA is required to maintain regulation.
PRECONDITIONING
100% Thermal Shutdown Functional Test.
PACKAGE/ORDER INFORMATION
BOTTOM VIEW
ADJ
2
V
IN
1
3
V
OUT
(CASE)
ORDER
PART NUMBER
FRONT VIEW
3
TAB IS
OUTPUT
2
1
M PACKAGE
3-LEAD PLASTIC DD
V
IN
V
OUT
ADJ
(GND)*
LT1086CH
LT1086MH
H PACKAGE
3-LEAD TO-39 METAL CAN
θ
JA
= 30°C/W**
** WITH PACKAGE SOLDERED TO 0.5IN
2
COPPER AREA
OVER BACKSIDE GROUND PLANE OR INTERNAL POWER
PLANE.
θ
JA
CAN VARY FROM 20°C/W TO > 40°C/W
DEPENDING ON MOUNTING TECHNIQUE.
θ
JA
= 150°C/W
BOTTOM VIEW
V
IN
2
CASE
IS OUTPUT
ORDER
PART NUMBER
FRONT VIEW
3
TAB IS
OUTPUT
2
1
T PACKAGE
3-LEAD PLASTIC TO-220
V
IN
V
OUT
ADJ
(GND)*
1
ADJ (GND)*
K PACKAGE
2-LEAD TO-3 METAL CAN
θ
JA
= 35°C/W
LT1086CK
LT1086CK-5
LT1086CK-12
LT1086IK
LT1086IK-5
LT1086IK-12
LT1086MK
LT1086MK-5
LT1086MK-12
θ
JA
= 50°C/W
*For fixed versions.
2
UU
U
U
U
W
W W
U
W
ORDER
PART NUMBER
LT1086CM
LT1086CM-3.3
LT1086CM-3.6
LT1086IM
LT1086IM-3.3
LT1086IM-3.6
ORDER
PART NUMBER
LT1086CT
LT1086CT-2.85
LT1086CT-3.3
LT1086IT
LT1086IT-5
LT1086IT-12
LT1086CT-3.6
LT1086CT-5
LT1086CT-12
LT1086 Series
ELECTRICAL CHARACTERISTICS
PARAMETER
Reference Voltage
(Note 2)
Output Voltage
(Note 2)
CONDITIONS
LT1086, LT1086H
LT1086-2.85
LT1086-3.3
LT1086-3.6
I
OUT
= 10mA, T
J
= 25°C, (V
IN
– V
OUT
) = 3V
10mA
≤
I
OUT
≤
1.5A, (0.5A for LT1086H), 1.5V
≤
(V
IN
– V
OUT
)
≤
15V
I
OUT
= 0mA, T
J
= 25°C, V
IN
= 5V
0V
≤
I
OUT
≤
1.5A, 4.35V
≤
V
IN
≤
18V
V
IN
= 5V, I
OUT
= 0mA, T
J
= 25°C
4.75V
≤
V
IN
≤
18V, 0V
≤
I
OUT
≤
1.5A
V
IN
= 5V, I
OUT
= 0mA, T
J
= 25°C
5V
≤
V
IN
≤
18V, 0
≤
I
OUT
≤
1.5A
4.75V
≤
V
IN
≤
18V, 0
≤
I
OUT
≤
1A, T
J
≥
0°C
V
IN
= 4.75V, I
OUT
= 1.5A, T
J
≥
0°C
I
OUT
= 0mA, T
J
= 25°C, V
IN
= 8V
0
≤
I
OUT
≤
1.5A, 6.5V
≤
V
IN
≤
20V
I
OUT
= 0mA, T
J
= 25°C, V
IN
= 15V
0
≤
I
OUT
≤
1.5A, 13.5V
≤
V
IN
≤
25V
I
LOAD
= 10mA, 1.5V
≤
(V
IN
– V
OUT
)
≤
15V, T
J
= 25°C
q
q
q
q
q
MIN
1.238
1.225
2.82
2.79
3.267
3.235
3.564
3.500
3.500
3.300
4.950
4.900
TYP
1.250
1.250
2.85
2.85
3.300
3.300
3.600
MAX
1.262
1.270
2.88
2.91
3.333
3.365
3.636
3.672
3.672
3.672
5.050
5.100
UNITS
V
V
V
V
V
V
V
V
V
V
V
V
V
V
%
%
mV
mV
mV
mV
mV
mV
mV
mV
mV
mV
%
%
mV
mV
mV
mV
mV
mV
mV
mV
mV
mV
mV
mV
V
V
LT1086-5
LT1086-12
Line Regulation
LT1086, LT1086H
LT1086-2.85
LT1086-3.3
LT1086-3.6
LT1086-5
LT1086-12
Load Regulation
LT1086, LT1086H
q
q
5.000
5.000
11.880 12.000 12.120
11.760 12.000 12.240
0.015
0.035
0.3
0.6
0.5
1.0
0.5
1.0
0.5
1.0
1.0
2.0
0.1
0.2
3
6
3
7
3
6
2
4
5
10
12
24
1.3
0.95
0.2
0.2
6
6
10
10
10
10
10
10
25
25
0.3
0.4
12
20
15
25
15
25
15
25
20
35
36
72
1.5
1.25
I
OUT
= 0mA, T
J
= 25°C, 4.35V
≤
V
IN
≤
18V
q
4.5V
≤
V
IN
≤
18V, I
OUT
= 0mA, T
J
= 25°C
q
4.75V
≤
V
IN
≤
18V, I
OUT
= 0mA, T
J
= 25°C
q
I
OUT
= 0mA, T
J
= 25°C, 6.5V
≤
V
IN
≤
20V
q
I
OUT
= 0mA, T
J
= 25°C, 13.5V
≤
V
IN
≤
25V
q
(V
IN
– V
OUT
) = 3V, 10mA
≤
I
OUT
≤
1.5A, (0.5A for LT1086H)
T
J
= 25°C (Notes 1, 2)
q
LT1086-2.85
LT1086-3.3
LT1086-3.6
V
IN
= 5V, 0
≤
I
OUT
≤
1.5A, T
J
= 25°C (Notes 1, 2)
q
V
IN
= 5V, 0
≤
I
OUT
≤
1.5A, T
J
= 25°C (Notes 1, 2)
q
V
IN
= 5.25V, 0
≤
I
OUT
≤
1.5A, T
J
= 25°C (Notes 1, 2)
q
V
IN
= 5V, 0
≤
I
OUT
≤
1A, T
J
= 25°C
q
LT1086-5
LT1086-12
Dropout Voltage
(V
IN
– V
OUT
)
V
IN
= 8V, 0
≤
I
OUT
≤
1.5A, T
J
= 25°C (Notes 1, 2)
q
V
IN
= 15V, 0
≤
I
OUT
≤
1.5A, T
J
= 25°C (Notes 1, 2)
q
LT1086/-2.85/-3.3/-3.6/-5/-12
LT1086H
∆V
OUT
,
∆V
REF
= 1%, I
OUT
= 1.5A (Note 3)
q
q
∆V
REF
= 1%, I
OUT
= 0.5A (Note 3)
3
LT1086 Series
ELECTRICAL CHARACTERISTICS
PARAMETER
Current Limit
CONDITIONS
LT1086/-2.85/-3.3/-3.6/-5/-12 (V
IN
– V
OUT
) = 5V
(V
IN
– V
OUT
) = 25V
LT1086H
Minimum Load Current
Quiescient Current
LT1086/LT1086H
LT1086-2.85
LT1086-3.3
LT1086-3.6
LT1086-5
LT1086-12
T
A
= 25°C, 30ms pulse
f = 120Hz, C
OUT
= 25µF Tantalum, I
OUT
= 1.5A, (I
OUT
= 0.5A for LT1086H)
LT1086, LT1086H
C
ADJ
= 25µF, (V
IN
– V
OUT
) = 3V
LT1086-2.85
V
IN
= 6V
LT1086-3.3
V
IN
= 6.3V
LT1086-3.6
V
IN
= 6.6V
LT1086-5
V
IN
= 8V
LT1083-12
V
IN
= 15V
LT1086, LT1086H
LT1086, LT1086H
T
J
= 25°C
q
q
q
q
q
q
q
q
q
q
q
q
q
q
q
q
q
MIN
1.50
0.05
0.50
0.02
TYP
2.00
0.15
0.700
0.075
5
5
5
5
5
5
0.008
MAX
UNITS
A
A
A
A
(V
IN
– V
OUT
) = 5V
(V
IN
– V
OUT
) = 25V
(V
IN
– V
OUT
) = 25V (Note 4)
V
IN
≤
18V
V
IN
≤
18V
V
IN
≤
18V
V
IN
≤
20V
V
IN
≤
25V
10
10
10
10
10
10
0.04
mA
mA
mA
mA
mA
mA
%/W
dB
dB
dB
dB
dB
dB
Thermal Regulation
Ripple Rejection
60
60
60
60
60
54
75
72
72
72
68
60
55
120
0.2
0.5
0.3
0.003
15/20
1.7/4.0
1.5/4.0
1.5/4.0
1
5
Adjust Pin Current
Adjust Pin Current
Change
Temperature Stability
Long Term Stability
RMS Output Noise
(% of V
OUT
)
Thermal Resistance
Junction-to-Case
µA
µA
µA
%
%
%
°C/W
°C/W
°C/W
°C/W
10mA
≤
I
OUT
≤
1.5A, (0.5A for LT1086H)
1.5V
≤
(V
IN
– V
OUT
)
≤
15V
q
q
T
A
= 125°C, 1000 Hrs.
T
A
= 25°C, 10Hz =
≤
f
≤
10kHz
H Package: Control Circuitry/Power Transistor
K Package: Control Circuitry/Power Transistor
M Package: Control Circuitry/Power Transistor
T Package: Control Circuitry/Power Transistor
The
q
denotes the specifications which apply over the full operating
temperature range.
Note 1:
See thermal regulation specifications for changes in output voltage
due to heating effects. Line and load regulation are measured at a constant
junction temperature by low duty cycle pulse testing. Load regulation is
measured at the output lead
≈1/8"
from the package.
Note 2:
Line and load regulation are guaranteed up to the maximum power
dissipation of 15W (3W for the LT1086H). Power dissipation is determined
by the input/output differential and the output current. Guaranteed
maximum power dissipation will not be available over the full input/output
range. See Short-Circuit Current curve for available output current.
Note 3:
Dropout voltage is specified over the full output current range of
the device. Test points and limits are shown on the Dropout Voltage curve.
Note 4:
Minimum load current is defined as the minimum output current
required to maintain regulation. At 25V input/output differential the device
is guaranteed to regulate if the output current is greater than 10mA.
4
LT1086 Series
TYPICAL PERFORMANCE CHARACTERISTICS
LT1086 Short-Circuit Current
2.5
OUTPUT VOLTAGE DEVIATION (%)
SHORT-CIRCUIT CURRENT (A)
2.0
T
J
= 150°C
T
J
= 25°C
T
J
= –55°C
0.05
0
–0.05
–0.10
–0.15
–0.20
–50 –25
MINIMUM OPERATING CURRENT (mA)
1.5
1.0
0.5
GUARANTEED
OUTPUT CURRENT
0
25
10
15
20
5
INPUT/OUTPUT DIFFERENTIAL (V)
30
0
Temperature Stability
2
OUTPUT VOLTAGE CHANGE (%)
ADJUST PIN CURRENT (µA)
1
60
50
40
30
20
10
POWER (W)
0
–1
–2
–50 –25
0
25 50 75 100 125 150
TEMPERATURE (°C)
LT1086 • TPC04
LT1086 Ripple Rejection
100
90
80
V
RIPPLE
≤
3V
P-P
V
RIPPLE
≤
0.5V
P-P
RIPPLE REJECTION (dB)
RIPPLE REJECTION (dB)
70
60
50
40
30
20
10
0
10
100
70
60
50
40
30
20
10
V
OUT
= 5V
C
ADJ
= 25µF
C
OUT
= 25µF
0
0.25
f
R
= 20kHz
V
RIPPLE
≤
0.5V
P-P
RIPPLE REJECTION (dB)
(V
IN
– V
OUT
)
≥
3V
(V
IN
– V
OUT
)
≥
V
DROPOUT
C
ADJ
= 200µF AT FREQUENCIES < 60Hz
C
ADJ
= 25µF AT FREQUENCIES > 60Hz
I
OUT
= 1.5A
1k
10k
FREQUENCY (Hz)
100k
LT1086 • TPC07
U W
LT1086 • TPC01
LT1086 Load Regulation
0.10
∆I
= 1.5A
Minimum Operating Current
(Adjustable Device)
10
9
8
7
6
5
4
3
2
1
0
0
20
15
10
25
30
5
INPUT/OUTPUT DIFFERENTIAL (V)
35
T
J
= 150°C
T
J
= 25°C
T
J
= –55°C
0
25 50 75 100 125 150
TEMPERATURE (°C)
LT1086 • TPC02
LT1086 • TPC03
Adjust Pin Current
100
90
80
70
15
20
LT1086 Maximum Power
Dissipation*
LT1086MK
LT1086CT
10
LT1086CK
5
0
–50 –25
0
25 50 75 100 125 150
TEMPERATURE (°C)
LT1086 • TPC05
50 60 70 80 90 100 110 120 130 140 150
CASE TEMPERATURE (°C)
*AS LIMITED BY MAXIMUM JUNCTION TEMPERATURE
LT1086 • TPC06
0
LT1086 Ripple Rejection
vs Current
100
90
80
f
R
= 120Hz
V
RIPPLE
≤
3V
P-P
80
70
60
50
40
30
20
10
0
LT1086-5 Ripple Rejection
V
RIPPLE
≤
3V
P-P
V
RIPPLE
≤
0.5V
P-P
(V
IN
– V
OUT
)
≥
3V
(V
IN
– V
OUT
)
≥
V
DROPOUT
I
OUT
= 1.5A
10
100
1k
10k
FREQUENCY (Hz)
100k
LT1086 • TPC09
0
1.25
0.75
1.0
0.5
OUTPUT CURRENT (A)
1.5
LT1086 • TPC08
5
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