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LT 3083 ET
Datasheet
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ANALOG DEVICES LT 3083 ET Datasheet

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LT3083
Adjustable 3A
Single Resistor Low
Dropout Regulator

FEATURES

n
Outputs May be Paralleled for Higher Current and
Heat Spreading
n
Output Current: 3A
n
Single Resistor Programs Output Voltage
n
50µA Set Pin Current: 1% Initial Accuracy
n
Output Adjustable to 0V
n
Low Output Noise: 40µV
n
Wide Input Voltage Range: 1.2V to 23V
(10Hz to 100kHz)
RMS
(DD-Pak and TO-220 Packages)
n
Low Dropout Voltage: 310mV
n
<1mV Load Regulation
n
<0.001%/V Line Regulation
n
Minimum Load Current: 1mA
n
Stable with Minimum 10µF Ceramic Capacitor
n
Current Limit with Foldback and Overtemperature
Protection
n
Available in 16-Lead TSSOP, 12-Lead 4mm × 4mm
DFN, 5-Lead TO-220 and 5-Lead Surface Mount DD-PAK Packages

APPLICATIONS

n
High Current All Surface Mount Supply
n
High Efficiency Linear Regulator
n
Post Regulator for Switching Supplies
n
Low Parts Count Variable Voltage Supply
n
Low Output Voltage Power Supplies

DESCRIPTION

The LT®3083 is a 3A low dropout linear regulator that can be paralleled to increase output current or spread heat on surface mounted boards. Architected as a precision current source and voltage follower, this new regulator finds use in many applications requiring high current, adjustability to zero, and no heat sink. The device also brings out the collector of the pass transistor to allow low dropout opera­tion—down to 310mV—when used with multiple supplies.
A key feature of the LT3083 is the capability to supply a wide output voltage range. By using a reference current through a single resistor, the output voltage is programmed to any level between zero and 23V (DD-PAK and TO-220 packages). The LT3083 is stable with 10µF of capacitance on the output, and the IC is stable with small ceramic ca­pacitors that do not require additional ESR as is common with other regulators.
Internal protection circuitry includes current limiting and thermal limiting. The LT3083 is offered in the 16-lead TSSOP (with an exposed pad for better thermal character­istics), 12-lead 4mm × 4mm DFN (also with an exposed pad), 5-lead TO-220, and 5-lead surface mount DD-PAK packages.
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners.

TYPICAL APPLICATION

1.5V to 0.9V at 3A Supply (Using 3.3V V
V
CONTROL
3.3V
V
1.5V
IN
4.7µF
10µF
V
CONTROL
LT3083
SET
R
SET
18.2k 1%
OUTIN
3083 TA01a
0.1µF
10µF
CONTROL
*
R
MIN
909Ω
)
V
= 0.9V
OUT
= 3A
I
MAX
*OPTIONAL FOR MINIMUM 1mA LOAD REQUIREMENT
Set Pin Current Distribution
N = 1052
49
49.5 50 50.5
SET PIN CURRENT DISTRIBUTION (µA)
3083 TA01b
51
3083fa
1
LT3083

ABSOLUTE MAXIMUM RATINGS

(Note 1) All Voltages Relative to V
CONTROL Pin Voltage .............................................±28V
IN Pin Voltage (T5, Q Packages)
No Overload or Short-Circuit
IN Pin Voltage (DF, FE Packages)
No Overload or Short-Circuit SET Pin Current (Note 7) SET Pin Voltage (Relative to OUT)
OUT
....................18V, –0.3V
.....................23V, –0.3V
.....................8V, –0.3V
.....................14V, –0.3V
.....................................±25mA
.......................... ±10V

PIN CONFIGURATION

TOP VIEW
1
OUT
2
OUT
3
OUT OUT OUT
SET
12-LEAD (4mm × 4mm) PLASTIC DFN
= 125°C, θJA = 37°C/W, θJC = 8°C/W
T
JMAX
EXPOSED PAD (PIN 13) IS OUT, MUST BE SOLDERED TO PCB
4 5 6
13
OUT
DF PACKAGE
12 11 10
9 8 7
IN IN IN IN V
CONTROL
V
CONTROL
Output Short-Circuit Duration .......................... Indefinite
Operating Junction Temperature Range (Notes 2, 10)
E-, I-grades MP-grade
Storage Temperature Range
........................................ –40°C to 125°C
........................................... –55°C to 125°C
.................. –65°C to 150°C
Lead Temperature (Soldering, 10 sec)
T, Q, FE Packages Only
OUT
OUT
OUT
OUT
OUT
OUT
SET
OUT
16-LEAD PLASTIC TSSOP
= 125°C, θJA = 25°C/W, θJC = 8°C/W
T
JMAX
EXPOSED PAD (PIN 17) IS OUT, MUST BE SOLDERED TO PCB
..................................... 300°C
TOP VIEW
1
2
3
4
5
6
7
8
FE PACKAGE
17
OUT
OUT
16
IN
15
IN
14
IN
13
IN
12
V
11
CONTROL
V
10
CONTROL
OUT
9
FRONT VIEW
TAB IS
OUT
Q PACKAGE
5-LEAD PLASTIC DD-PAK
= 125°C, θJA = 15°C/W, θJC = 3°C/W
T
JMAX
5 4 3 2 1
IN V
CONTROL
OUT SET NC
TAB IS
OUT
T
JMAX
FRONT VIEW
5 4 3 2 1
T PACKAGE
5-LEAD PLASTIC TO-220
= 125°C, θJA = 40°C/W, θJC = 3°C/W
IN V
CONTROL
OUT SET NC

ORDER INFORMATION

LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE
LT3083EDF#PBF LT3083EDF#TRPBF 3083 12-Lead (4mm × 4mm) Plastic DFN –40°C to 125°C LT3083EFE#PBF LT3083EFE#TRPBF 3083FE 16-Lead Plastic TSSOP –40°C to 125°C LT3083EQ#PBF LT3083EQ#TRPBF LT3083Q 5-Lead Plastic DD-PAK –40°C to 125°C LT3083ET#PBF LT3083ET#TRPBF LT3083T 5-Lead Plastic TO-220 –40°C to 125°C LT3083IDF#PBF LT3083IDF#TRPBF 3083 12-Lead (4mm × 4mm) Plastic DFN –40°C to 125°C LT3083IFE#PBF LT3083IFE#TRPBF 3083FE 16-Lead Plastic TSSOP –40°C to 125°C
3083fa
2
LT3083
ORDER INFORMATION
LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE
LT3083IQ#PBF LT3083IQ#TRPBF LT3083Q 5-Lead Plastic DD-PAK –40°C to 125°C LT3083IT#PBF LT3083IT#TRPBF LT3083T 5-Lead Plastic TO-220 –40°C to 125°C LT3083MPDF#PBF LT3083MPDF#TRPBF 3083 12-Lead (4mm × 4mm) Plastic DFN –55°C to 125°C LT3083MPFE#PBF LT3083MPFE#TRPBF 3083FE 16-Lead Plastic TSSOP –55°C to 125°C LT3083MPQ#PBF LT3083MPQ#TRPBF LT3083Q 5-Lead Plastic DD-PAK –55°C to 125°C LT3083MPT#PBF LT3083MPT#TRPBF LT3083T 5-Lead Plastic TO-220 –55°C to 125°C
LEAD BASED FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE
LT3083EDF LT3083EDF#TR 3083 12-Lead (4mm × 4mm) Plastic DFN –40°C to 125°C LT3083EFE LT3083EFE#TR 3083FE 16-Lead Plastic TSSOP –40°C to 125°C LT3083EQ LT3083EQ#TR LT3083Q 5-Lead Plastic DD-PAK –40°C to 125°C LT3083ET LT3083ET#TR LT3083T 5-Lead Plastic TO-220 –40°C to 125°C LT3083IDF LT3083IDF#TR 3083 12-Lead (4mm × 4mm) Plastic DFN –40°C to 125°C LT3083IFE LT3083IFE#TR 3083FE 16-Lead Plastic TSSOP –40°C to 125°C LT3083IQ LT3083IQ#TR LT3083Q 5-Lead Plastic DD-PAK –40°C to 125°C LT3083IT LT3083IT#TR LT3083T 5-Lead Plastic TO-220 –40°C to 125°C LT3083MPDF LT3083MPDF#TR 3083 12-Lead (4mm × 4mm) Plastic DFN –55°C to 125°C LT3083MPFE LT3083MPFE#TR 3083FE 16-Lead Plastic TSSOP –55°C to 125°C LT3083MPQ LT3083MPQ#TR LT3083Q 5-Lead Plastic DD-PAK –55°C to 125°C LT3083MPT LT3083MPT#TR LT3083T 5-Lead Plastic TO-220 –55°C to 125°C Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container. For more information on lead free part marking, go to: http://www.linear.com/leadfree/
For more information on tape and reel specifications, go to: http://www.linear.com/tapeandreel/

ELECTRICAL CHARACTERISTICS

The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C (Note 2).
PARAMETER CONDITIONS MIN TYP MAX UNITS
SET Pin Current I
– V
Output Offset Voltage (V V
= 1V, V
IN
CONTROL
= 2V, I
OUT
LOAD
) VOS
SET
= 1mA
Load Regulation (DF, FE Packages) ∆I ∆V
Load Regulation (T, Q Packages) ∆I ∆V
Line Regulation (DF, FE Packages) ∆I ∆V
Line Regulation (T, Q Packages) ∆I ∆V
Minimum Load Current (Notes 3, 9) V
SET
VIN = 1V, V V
≥ 1V, V
IN
CONTROL CONTROL
= 2V, I
= 1mA, TJ = 25°C
LOAD
≥ 2V, 5mA ≤ I
≤ 3A (Note 9)
LOAD
DF, FE Packages
T, Q Packages
∆I
SET
OS
SET
OS
SET
OS
SET
OS
= 1mA to 3A
LOAD
∆I
= 5mA to 3A (Note 8)
LOAD
∆I
= 1mA to 3A
LOAD
∆I
= 5mA to 3A (Note 8)
LOAD
∆VIN = 1V to 14V, ∆V ∆V
= 1V to 14V, ∆V
IN
∆VIN = 1V to 23V, ∆V ∆V
= 1V to 23V, ∆V
IN
= 1V, V
IN
V
IN
CONTROL
= 14V (DF/FE) or 23V (T/Q), V
CONTROL CONTROL
CONTROL CONTROL
= 2V
= 2V to 25V, I = 2V to 25V, I
= 2V to 25V, I = 2V to 25V, I
CONTROL
LOAD LOAD
LOAD LOAD
= 25V
= 1mA = 1mA
= 1mA = 1mA
49.5 4950 5050.5
l
–3 –4
l
–4 –6
l
l
l
–10
–0.4 –1
–10
–0.7 –4
0.1
0.002 0.01
0.1
0.002 0.01
l l
350 500
51
0 0
0 0
3 4
4 6
µA
mV mV
mV mV
nA
mV
nA
mV
nA/V
mV/V
nA/V
mV/V
µA
µA
1
mA
3083fa
3
LT3083
ELECTRICAL CHARACTERISTICS
The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C (Note 2).
PARAMETER CONDITIONS MIN TYP MAX UNITS
V
V
V
Dropout Voltage (Note 4) I
CONTROL
Dropout Voltage (Note 4) I
IN
Pin Current (Note 5) I
CONTROL
Current Limit V Error Amplifier RMS Output Noise (Note 6) I Reference Current RMS Output Noise (Note 6) 10Hz ≤ f ≤ 100kHz 1 nA Ripple Rejection
V
= 0.5V
RIPPLE
C
= 10µF
OUT
Thermal Regulation, I
, IL = 0.1A, C
P-P
SET
= 0.1µF,
SET
= 100mA
LOAD
I
= 1A
LOAD
I
= 3A
LOAD
= 100mA
LOAD
= 1A, Q, T Packages
I
LOAD
I
= 1A, DF, FE Packages
LOAD
= 3A, Q, T Packages
I
LOAD
I
= 3A, DF, FE Packages
LOAD
= 100mA
LOAD
I
= 1A
LOAD
I
= 3A
LOAD
= 5V, V
IN
= 500mA, 10Hz ≤ f ≤ 100kHz, C
LOAD
CONTROL
= 5V, V
f = 120Hz f = 10kHz f = 1MHz
SET
= 0V, V
OUT
OUT
= –0.1V
= 10µF, C
l l
l
l l
l l
l l l
l
= 0.1µF 40 µV
SET
1.2
1.22
1.25
1.55
1.6
10 25 mV
120 90190
160
310 240
5.5 18 40
510 420
10 35 80
mV mV
mV mV
mA mA mA
3 3.7 A
RMS
RMS
85 75 20
dB dB dB
10ms Pulse 0.003 %/W
V V V
Note 1: Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. Exposure to any Absolute Maximum Rating condition for extended periods may affect device reliability and lifetime.
Note 2: Unless otherwise specified, all voltages are with respect to V
OUT.
The LT3083 is tested and specified under pulse load conditions such that T
≅ TA. The LT3083E is 100% tested at TA = 25°C. Performance of the
J
LT3083E over the full –40°C to 125°C operating junction temperature range is assured by design, characterization, and correlation with statistical process controls. The LT3083I regulators are guaranteed over the full –40°C to 125°C operating junction temperature range. The LT3083MP is 100% tested and guaranteed over the –55°C to 125°C operating junction temperature range.
Note 3: Minimum load current is equivalent to the quiescent current of the part. Since all quiescent and drive current is delivered to the output of the part, the minimum load current is the minimum current required to maintain regulation.
Note 4: For the LT3083, dropout is caused by either minimum control voltage (V
) or minimum input voltage (VIN). Both parameters are
CONTROL
specified with respect to the output voltage. The specifications represent the minimum input-to-output differential voltage required to maintain regulation.
Note 5: The V
pin current is the drive current required for the
CONTROL
output transistor. This current will track output current with roughly a 1:60 ratio. The minimum value is equal to the quiescent current of the device.
Note 6: Output noise is lowered by adding a small capacitor across the voltage setting resistor. Adding this capacitor bypasses the voltage setting resistor shot noise and reference current noise; output noise is then equal to error amplifier noise (see the Applications Information section).
Note 7: The SET pin is clamped to the output with diodes through 1k resistors. These resistors and diodes will only carry current under transient overloads.
Note 8: Load regulation is Kelvin sensed at the package. Note 9: Current limit includes foldback protection circuitry. Current limit
decreases at higher input-to-output differential voltages. Note 10: This IC includes overtemperature protection that is intended
to protect the device during momentary overload conditions. Junction temperature will exceed the maximum operating junction temperature when overtemperature protection is active. Overtemperature protection (thermal limit) is typically active at junction temperatures of 165°C. Continuous operation above the specified maximum operating junction temperature may impair device reliability.
4
3083fa
LT3083

TYPICAL PERFORMANCE CHARACTERISTICS

SET Pin Current Set Pin Current Distribution
50.5
50.4
50.3
50.2
50.1
50.0
49.9
49.8
SET PIN CURRENT (µA)
49.7
49.6
49.5 –50
50
25–25 0 75 100 125
TEMPERATURE (°C)
150
3083 G01
Offset Voltage Distribution Offset Voltage (V
N = 1052
–2 –1 0 21
–3
V
DISTRIBUTION (mV)
OS
3
3083 G04
N = 1052
49
1.00
0.75
0.50
0.25
0
–0.25
OFFSET VOLTAGE (mV)
–0.50
–0.75
–1.00
49.5 50 50.5
SET PIN CURRENT DISTRIBUTION (µA)
I
= 5mA
LOAD
0
5
INPUT-TO-OUTPUT VOLTAGE (V)
– V
OUT
SET
10 15 20
TA = 25°C, unless otherwise noted.
Offset Voltage (V
1.0 I
= 5mA
LOAD
0.8
0.6
0.4
0.2
0
–0.2
–0.4
OFFSET VOLTAGE (mV)
–0.6
–0.8
3083 G02
–1.0
51
–50
25–25 0 75 100 125
TEMPERATURE (°C)
) Offset Voltage (V
0.25
3083 G05
–0.25
–0.50
–0.75
–1.00
OFFSET VOLTAGE (mV)
–1.25
–1.50
–1.75
25
0
0
0.5
TJ = 25°C
TJ = 125°C
1 1.5 2.52
LOAD CURRENT (A)
50
OUT
OUT
– V
– V
SET
SET
)
150
3083 G03
)
3
3083 G06
Load Regulation Minimum Load Current
0
CHANGE IN OFFSET VOLTAGE (V
–0.2
–0.4
CHANGE IN REFERENCE CURRENT
–0.6
–0.8
–1.0
–1.2
–1.4
∆I
= 5mA TO 3A
LOAD
= V
V
IN
CHANGE IN OFFSET VOLTAGE WITH LOAD (mV)
–1.6
–50
= V
CONTROL
OUT
50
25–25 0 75 100 125
TEMPERATURE (°C)
+ 2V
OUT
– V
SET
3083 G07
CHANGE IN REFERENCE CURRENT WITH LOAD (nA)
1.4 VIN = V
CONTROL
1.2
1.0
0.8
0.6
0.4
MINIMUM LOAD CURRENT (mA)
0.2
0
–50
V
IN,CONTROL
V
IN,CONTROL
TEMPERATURE (°C)
)
150
100
50
0
–50
–100
–150
–200
–250
–300
– V
= 23V
OUT
– V
= 1.5V
OUT
25–25 0 75 100 125
50
) (mV)
– V
MINIMUM VOLTAGE (V
150
3083 G08
Dropout Voltage, T/Q Packages (Minimum IN Voltage)
400
OUT
IN
100
350
300
250
200
150
TJ = 25°C
50
0
0
0.5
TJ = 125°C
1 1.5 2 2.5
LOAD CURRENT (A)
TJ = –50°C
3
3083 G09
3083fa
5
LT3083
TYPICAL PERFORMANCE CHARACTERISTICS
= 25°C, unless otherwise noted.
T
A
Dropout Voltage, FE/DF Packages
400
350
) (mV)
300
OUT
– V
250
IN
200
150
100
50
MINIMUM VOLTAGE (V
0
0
0.5
TJ = 25°C
LOAD CURRENT (A)
TJ = 125°C
TJ = –50°C
1 1.5 2 2.5
Dropout Voltage (Minimum V
CONTROL
1.6
1.4 TJ = –50°C
1.2
) (V)
1.0
OUT
PIN VOLTAGE
– V
0.8
CONTROL
0.6
CONTROL
(V
0.4
MINIMUM V
0.2
0
0
0.5
3
3083 G10
Pin Voltage)
TJ = 25°C
TJ = 125°C
1 1.5 2 2.5
LOAD CURRENT (A)
Dropout Voltage, T/Q Packages (Minimum IN Voltage)
500
450
) (mV)
400
OUT
350
– V
IN
300
250
200
150
100
50
MINIMUM IN VOLTAGE (V
0
–50
3083 G13
I
LOAD
3
= 3A
I
LOAD
I
= 500mA
LOAD
25–25 0 75 100 125
50
TEMPERATURE (°C)
= 1.5A
I
= 100mA
LOAD
150
3083 G11
Dropout Voltage (Minimum V
CONTROL
1.6
1.4
1.2
) (V)
1.0
OUT
PIN VOLTAGE
– V
0.8
CONTROL
0.6
CONTROL
(V
0.4
MINIMUM V
0.2
0
–50
Pin Voltage)
25–25 0 75 100 125
TEMPERATURE (°C)
Dropout Voltage, FE/DF Packages (Minimum IN Voltage)
500
450
) (mV)
400
OUT
350
– V
IN
300
250
200
150
100
50
MINIMUM IN VOLTAGE (V
0
–50
I
= 3A
LOAD
50
I
= 3A
LOAD
I
= 1.5A
LOAD
I
= 500mA
LOAD
I
LOAD
25–25 0 75 100 125
50
TEMPERATURE (°C)
150
3083 G14
= 100mA
150
3083 G12
6
Current Limit
5.0
4.5
4.0
3.5
3.0
2.5
2.0
CURRENT LIMIT (A)
1.5
1.0 VIN = V
0
–50
CONTROL
= 0V
V
OUT
0.5
= 7V
50
25–25 0 75 100 125
TEMPERATURE (°C)
3083 G15
150
Current Limit
4.0
3.5
3.0
2.5
2.0
1.5
CURRENT LIMIT (A)
1.0
0.5
0
0
IN-TO-OUT DIFFERENTIAL (V
5 10 15
– V
IN
TJ = 25°C
) (V)
OUT
3083 G16
20
3083fa
TYPICAL PERFORMANCE CHARACTERISTICS
Load Transient Response Load Transient Response
150
VIN = 2V
= 3V
V
100
CONTROL
= 1V
V
OUT
= 0.1µF
C
SET
50
0
DEVIATION (mV)
–50
–100
1.0
0.5
LOAD CURRENT (A) OUTPUT VOLTAGE
0
0
C
= 22µF CERAMIC
OUT
C
= 10µF CERAMIC
OUT
∆I
= 100mA TO 1A
LOAD
80
6020 40 140 160100 120 180
TIME (µs)
3083 G17
200
Line Transient Response Turn-On Response Turn-On Response
7
6
5
CONTROL
4
VOLTAGE (V)
IN/ V
3
10
0
–10
DEVIATION (mV)
OUTPUT VOLTAGE
–20
0
V
= 1V
OUT
= 10mA
I
LOAD
= 10µF CERAMIC
C
OUT
= 0.1µF
C
SET
80
6020 40 140 160100 120 180
TIME (µs)
200
3083 G19
6
5
4
3
CONTROL
2
VOLTAGE (V)
IN/ V
1
0
1.0
0.5
0
OUTPUT
VOLTAGE (V)
–0.5
0
155 10 35 4025 30 45
250
150
–50
DEVIATION (mV)
–150
LOAD CURRENT (A) OUTPUT VOLTAGE
R
= 20k
SET
= 0
C
SET
R
LOAD
= 10µF CERAMIC
C
OUT
20
TIME (µs)
50
4
2
0
0
= 0.33Ω
= 25°C, unless otherwise noted.
T
A
VIN = 2V
= 3V
V
CONTROL
= 1V
V
OUT
= 0.1µF
C
SET
C
= 22µF CERAMIC
OUT
∆I
= 500mA TO 3A
LOAD
80 200
6020 40 140 160100 120 180
TIME (µs)
4
3
2
CONTROL
1
VOLTAGE (V)
IN/ V
0
1.0
0.5
0
OUTPUT
VOLTAGE (V)
–0.5
50
3083 G20
0
LT3083
3083 G18
R
= 20k
SET
= 0.1µF
C
SET
= 1Ω
R
LOAD
= 10µF CERAMIC
C
OUT
62 4 14 1610 12 18
8
TIME (ms)
20
3083 G21
V
CONTROL
80
70
60
50
40
I
PIN CURRENT (mA)
30
20
CONTROL
V
10
LOAD
I
= 1.5A
LOAD
0
0
2
4 6 8 10 12 14 16
IN-TO-OUT DIFFERENTIAL (V
Pin Current V
70
60
50
40
= 3A
DEVICE IN CURRENT LIMIT
– V
) (V)
IN
OUT
3083 G22
18
30
PIN CURRENT (mA)
20
CONTROL
V
10
0
CONTROL
V
CONTROL
– V
V
IN
TJ = 25°C
0
Pin Current
– V
= 2V
OUT
= 1V
OUT
1 1.5 2 2.5
0.5 LOAD CURRENT (A)
TJ = –50°C
TJ = 125°C
3083 G23
600
500
400
300
200
OUTPUT VOLTAGE (mV)
100
3
Residual Output Voltage with Less Than Minimum Load
V
= 20V
IN
V
= 10V
IN
V
= 5V
IN
ADD 1N4148 FOR
SET PIN = 0V
V
IN
0
0
500 1000 1500
(Ω)
R
SET
R
TEST
< 1k
V
OUT
R
TEST
3083 G24
2000
3083fa
7
LT3083
TYPICAL PERFORMANCE CHARACTERISTICS
Ripple Rejection, Dual Supply,
Ripple Rejection, Single Supply
100
90
80
70
60
I
I
LOAD
C
= 10µF CERAMIC
OUT
= 0.1µF CERAMIC
C
SET
RIPPLE = 50mV V
– V
IN
0
10
100
LOAD
= 0.5A
CONTROL
50
40
30
RIPPLE REJECTION (dB)
20
10
I
= 0.1A
LOAD
= 1.5A
P-P
= V
OUT(NOMINAL)
1k 10k 100k 1M
FREQUENCY (Hz)
Ripple Rejection (120Hz)
80
79
78
77
76
75
74
73
RIPPLE REJECTOIN (dB)
VIN = V
72
71
70
CONTROL
RIPPLE = 500mV
= 0.5A
I
LOAD
= 0.1µF, C
C
SET
–50
+ 2V
10M
3083 G25
= V
OUT(NOMINAL)
, ƒ = 120Hz
P-P
= 10µF
OUT
25–25 0 75 100 125
50
TEMPERATURE (°C)
V
CONTROL
120
105
90
75
60
I
LOAD
45
RIPPLE REJECTION (dB)
30
C C
15
V V
0
10
+ 2V
3083 G28
Pin
I
LOAD
= 1.5A
= 10µF CERAMIC
OUT
= 0.1µF
SET
= V
IN
OUT(NOMINAL)
= V
CONTROL
100
150
= 0.1A
+ 1V
OUT(NOMINAL)
1k 10k 100k 1M
FREQUENCY (Hz)
+ 2V
Noise Spectral Density
1000
100
ERROR AMPLIFIER NOISE
SPECTRAL DENSITY (nV/√Hz)
10
10
TA = 25°C, unless otherwise noted.
Ripple Rejection, Dual Supply, IN Pin
120
I
LOAD
I
LOAD
= 1.5A
+ 1V
OUT(NOMINAL)
1k 10k 100k 1M
FREQUENCY (Hz)
100
10
1
100k
3083 G29
10M
3083 G26
100
105
90
75
60
45
RIPPLE REJECTION (dB)
30
C C
15
V V
0
10
1k 10k
FREQUENCY (Hz)
I
LOAD
= 10µF CERAMIC
OUT
= 0.1µF
SET
= V
IN
OUT(NOMINAL)
= V
CONTROL
100
= 0.1A
= 0.5A
+ 2V
10M
3083 G27
SPECTRAL DENSITY (pA/√Hz)
REFERENCE CURRENT NOISE
8
V
OUT
100µV/DIV
Output Voltage Noise Error Amplifier Gain and Phase
21 18
PHASE
15 12
9 6 3 0
GAIN (dB)
GAIN
–3
V C I
LOAD
OUT SET
= 1V, R
= 0.1µF, C
= 3A
TIME 1ms/DIV
= 20k
SET
= 10µF
OUT
3083 G30
–6 –9
–12
–15
I
= 0.5A
LOAD
= 1.5A
I
LOAD
= 3A
I
LOAD
10
100
1k 10k 100k
FREQUENCY (Hz)
3083 G31
1M
36 0 –36 –72 –108 –144 –180 –216
–252
–288
–324 –360 –396
3083fa
LT3083

PIN FUNCTIONS

(DF/FE/Q/T Packages)
OUT (Pins 1-5,13/Pins 1-6,8,9,16,17/ Pin 3, Tab/ Pin 3, Tab): Output. The exposed pad of the DF package (Pin 13)
and the FE package (Pin 17) and the Tab of the DD-PAK and TO-220 packages is an electrical connection to OUT. Connect the exposed pad of the DF and FE packages and the Tab of the DD-PAK package directly to OUT on the PCB and the respective OUT pins for each package. There must be a minimum load current of 1mA or the output may not regulate.
SET (Pin 6/Pin 7/Pin 2/Pin 2): Set Point. This pin is the non-inverting input to the error amplifier and the regula­tion set point. A fixed current of 50μA flows out of this pin through a single external resistor, which programs the output voltage of the device. Output voltage range is zero to the V
IN(MAX)
– V
DROPOUT
. Transient performance can be improved by adding a small capacitor from the SET pin to ground.
V
CONTROL
(Pins 7,8/Pins 10,11/ Pin 4/Pin 4): Bias Sup-
ply. This is the supply pin for the control circuitry of the device. Minimum input capacitance is 2.2µF (see Input Capacitance and Stability in the Applications Information section). The current flow into this pin is about 1.7% of the output current. For the device to regulate, this voltage must be more than 1.2V to 1.4V greater than the output voltage (see dropout specifications in the Electrical Char­acteristics section).
IN (Pins 9-12/ Pins 12-15/Pin 5/Pin 5): Power Input. This is the collector to the power device of the LT3083. The output load current is supplied through this pin. Minimum IN capacitance is 10µF (see Input Capacitance and Stabil­ity in Applications Information section). For the device to regulate, the voltage at this pin must be more than 0.1V to 0.5V greater than the output voltage (see dropout specifications in the Electrical Characteristics section).
NC (NA/ NA/Pin 1/Pin 1): No Connection. No Connect pins have no connection to internal circuitry and may be tied to V
IN
, V
CONTROL
, V
, GND, or floated.
OUT

BLOCK DIAGRAM

V
CONTROL
IN
50µA
+
–
3083 BD
OUTSET
3083fa
9
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