Linear Technology LT1085MK-5, LT1085IM-3.6, LT1085CK-12, LT1084MK-5, LT1084CT-5 Datasheet

FEATURES

■

Three-Terminal 3.3V, 3.6V, 5V and 12V

■

Output Current of 3A, 5A or 7.5A

■

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

■

Adjustable Versions Available

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APPLICATIO S

■

High Efficiency Linear Regulators

■

Post Regulators for Switching Supplies

■

Constant Current Regulators

■

Battery Chargers

DEVICE OUTPUT CURRENT*

LT1083 7.5 Amps
LT1084 5.0 Amps
LT1085 3.0 Amps

*For a 1.5A low dropout regulator see the LT1086 data sheet.

LT1083/LT1084/LT1085 Fixed

3A, 5A, 7.5A Low Dropout

Positive Fixed Regulators

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DESCRIPTIO

The LT®1083 series of positive adjustable regulators are
designed to provide 3A, 5A and 7.5A 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 specified as a function of
load current. Dropout is guaranteed at a maximum of 1.5V
at maximum output current, decreasing at lower load
currents. On-chip trimming adjusts the output voltage to
1%. Current limit is also trimmed, minimizing the stress
on both the regulator and power source circuitry under
overload conditions.

The LT1083 series devices are pin compatible with older
three-terminal regulators. A 10µF output capacitor is
required on these new devices; however, this is usually
included in most regulator designs.

Unlike PNP regulators, where up to 10% of the output
current is wasted as quiescent current, the LT1083 quies­cent current flows into the load, increasing efficiency.

, LTC and LT are registered trademarks of Linear Technology Corporation.

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TYPICAL APPLICATIO

5V, 7.5A Regulator

VIN ≥ 6.5V 5V AT 7.5A

+

10µF

LT1083-5

*REQUIRED FOR STABILITY

+

22µF*
TANTALUM

LT1083/4/5 TA01

Dropout Voltage vs Output Current

2

1

INPUT/OUTPUT VOLTAGE DIFFERENTIAL (V)

0

0

I

/2

FULLLOAD

OUTPUT CURRENT (A)

I

FULLLOAD

1083/4/5 TA02

1

LT1083/LT1084/LT1085 Fixed

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ABSOLUTE AXI U RATI GS

(Note 1)

Power Dissipation.............................. Internally Limited

Input Voltage* ........................................................ 30V

Operating Input Voltage

3.3V, 3.6V Devices ........................................... 20V

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

“M” Grades

Control Section .......................... –55°C to 150°C

Power Transistor........................ –55°C to 200°C

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PACKAGE/ORDER I FOR ATIO

V

IN

GND

2-LEAD TO-3 METAL CAN

2

1

K PACKAGE

θJA = 35°C/W

CASE IS
OUTPUT

ORDER PART NUMBER

LT1083CK-5
LT1083CK-12
LT1083MK-5
LT1083MK-12
LT1084CK-5
LT1084CK-12

LT1084MK-5
LT1084MK-12
LT1085CK-5
LT1085CK-12
LT1085MK-5
LT1085MK-12

OBSOLETE NOT RECOMMENDED

Storage Temperature Range ................ –65°C to 150°C

Lead Temperature (Soldering, 10 sec)................. 300°C

*Although the devices maximum operating voltage is limited, (20V for a
3V, 5V device, and 25V for a 12V device) 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 input/output voltage differentials greater than
15V, a minimum external load of 5mA is required to maintain regulation.

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PRECO DITIO I G

100% Thermal Limit Functional Test.

ORDER PART NUMBER

TAB IS
OUTPUT

FRONT VIEW

3

2

1

P PACKAGE

3-LEAD TO-3P PLASTIC

θJA = 45°C/W

V

V

GND

IN

OUT

LT1083CP-5
LT1083CP-12
LT1084CP-5
LT1084CP-12

FOR NEW DESIGNS

TAB IS
OUTPUT

Consult factory for parts specified with wider operating temperature ranges.

FRONT VIEW

3

2

1

T PACKAGE

3-LEAD PLASTIC TO-220

= 50°C/W

θ

JA

V

IN

V

OUT

GND

LT1084CT-3.3
LT1084CT-5
LT1084CT-12
LT1085CT-3.3
LT1085CT-3.6
LT1085CT-5
LT1085CT-12

2

FRONT VIEW

3

TAB IS

OUTPUT

3-LEAD PLASTIC DD

*WITH PACKAGE SOLDERED TO 0.52IN
COPPER AREA OVER BACKSIDE GROUND
PLANE OR INTERNAL POWER PLANE. θ
VARY FROM 20°C/W TO > 40°C/W DEPENDING
ON MOUNTING TECHNIQUE.

2

1

M PACKAGE

θJA = 30°C/W*

V

V

GND

2

JA

IN

OUT

CAN

LT1085CM-3.3
LT1085CM-3.6
LT1085IM-3.6

LT1083/LT1084/LT1085 Fixed

ELECTRICAL CHARACTERISTICS

The ● denotes the specifications which apply over the full operating

temperature range, otherwise specifications are at TA = 25°C.

PARAMETER CONDITIONS MIN TYP MAX UNITS

Output Voltage LT1084-3.3 I

LT1085-3.3 VIN = 5V, I

LT1085-3.6 VIN = 5V, I

LT1085-3.6 5V ≤ VIN ≤ 15V, 0 ≤ I

LT1083/4/5-5 I

LT1083/4/5-12 I

Line Regulation LT1084-3.3 I

LT1085-3.3 4.8V ≤ VIN ≤ 15V, I

LT1085-3.6 4.8V ≤ VIN ≤ 15V, I

LT1083/4/5-5 I

LT1083/4/5-12 I

Load Regulation LT1084-3.3 VIN = 5V, 0 ≤ I

LT1085-3.3 VIN = 5V, 0 ≤ I

LT1085-3.6 VIN = 5.25V, 0 ≤ I

LT1083/4/5-5 VIN = 8V, 0 ≤ I

LT1083/4/5-12 VIN = 15V, 0 ≤ I

Dropout Voltage LT1084/5-3.3 ∆V

LT1085-3.6 ∆V
LT1083/4/5-5 ∆V
LT1083/4/5-12 ∆V

Current Limit LT1083-5 VIN = 10V ● 8.0 9.5 A

LT1083-12 VIN = 17V ● 8.0 9.5 A
LT1084-3.3 VIN = 8V ● 5.5 6.5 A
LT1084-5 VIN = 10V ● 5.5 6.5 A
LT1084-12 VIN = 17V ● 5.5 6.5 A
LT1085-3.3/3.6 VIN = 8V ● 3.2 4.0 A
LT1085-5 VIN = 10V ● 3.2 4.0 A
LT1085-12 VIN = 17V ● 3.2 4.0 A

= 0mA, TJ = 25°C, VIN = 8V (K Package Only) 3.270 3.300 3.330 V

OUT

4.8V ≤ VIN ≤ 15V, 0 ≤ I

= 0mA, TJ = 25°C (K Package Only) 3.270 3.300 3.330 V

4.8V ≤ V

5V ≤ V

OUT

≤ 15V, 0 ≤ I

IN

= 0mA, TJ = 25°C (K Package Only) 3.564 3.600 3.636 V

OUT

≤ 15V, 0 ≤ I

IN

5V ≤ VIN ≤ 15V, 0 ≤ I

VIN = 4.75V, I
V

= 4.75V, I

IN

VIN = 4.75V, I

= 0mA, TJ = 25°C, VIN = 8V (K Package Only) 4.950 5.000 5.050 V

OUT

0 ≤ I

≤ I

OUT

= 0mA, TJ = 25°C, VIN = 15V (K Package Only) 11.880 12.000 12.120 V

OUT

0 ≤ I

≤ I

OUT

= 0mA, TJ = 25°C, 4.8V ≤ VIN ≤ 15V 0.5 6 mV

OUT

= 0mA, TJ = 25°C, 6.5V ≤ VIN ≤ 20V (Notes 2, 3) 0.5 10 mV

OUT

= 0mA, TJ = 25°C, 13.5V ≤ VIN ≤ 25V (Notes 2, 3) 1.0 25 mV

OUT

= 33mV, I

OUT

= 36mV, I

OUT

= 50mV, I

OUT

= 120mV, I

OUT

= 3A, TJ ≥ 0°C 3.350 3.672 V

OUT

= 2.5A, TJ ≥ 0°C 3.450 3.672 V

OUT

= 1.5A, TJ > 0°C 3.528 3.672 V

OUT

FULLOAD

FULLOAD

OUT

OUT

OUT

OUT

OUT

OUT
OUT
OUT

≤ I

OUT

≤ I

OUT

≤ I

OUT

FULLOAD

≤ I

OUT

FULLOAD

≤ 2.5A (Notes 3, 4, 9) ● 3.528 3.672 V

OUT

(Notes 3, 4, 9) ● 3.235 3.300 3.365 V

FULLOAD

(Notes 3, 4, 9) ● 3.235 3.300 3.365 V

FULLOAD

(Note 9) ● 3.500 3.672 V
, TJ ≥ 0°C (Notes 3, 4, 9) 3.528 3.672 V

, 6.5V ≤ VIN ≤ 20V (Notes 4, 6, 7, 9) 4.900 5.000 5.100 V

, 13.5V ≤ VIN ≤ 25V (Notes 4, 6, 7, 9) 11.760 12.000 12.240 V

● 1.0 6 mV

= 0mA, TJ= 25°C 0.5 6 mV

OUT

= 0mA, TJ= 25°C 0.5 6 mV

OUT

● 1.0 6 mV

● 1.0 6 mV

● 1.0 10 mV

● 2.0 25 mV

≤ 5A, TJ = 25°C315mV

● 720 mV

≤ 3A, TJ = 25°C315mV

● 720 mV

≤ 3A, TJ = 25°C315mV

● 720 mV

≤ I

FULLLOAD, TJ

≤ I

FULLLOAD, TJ

= I

FULL LOAD

= I

FULL LOAD

= I

FULL LOAD

= I

OUT

= 25°C (Notes 2, 3, 4, 6) 5 20 mV

● 10 35 mV

= 25°C (Notes 2, 3, 4, 6) 12 36 mV

● 24 72 mV

(Notes 5, 6) ● 1.3 1.5 V
(Notes 5, 6) ● 1.3 1.5 V
(Notes 5, 6) ● 1.3 1.5 V

FULL LOAD

(Notes 5, 6) ● 1.3 1.5 V

3

LT1083/LT1084/LT1085 Fixed

ELECTRICAL CHARACTERISTICS

The ● denotes the specifications which apply over the full operating

temperature range, otherwise specifications are at TA = 25°C.

PARAMETER CONDITIONS MIN TYP MAX UNITS

Quiescient Current LT1084-3.3 VIN = 18V ● 5.0 10.0 mA

LT1085-3.3 VIN = 18V ● 5.0 10.0 mA
LT1085-3.6 VIN = 18V ● 5.0 10.0 mA
LT1083/4/5-5 VIN ≤ 20V ● 5.0 10.0 mA
LT1083/4/5-12 VIN ≤ 25V ● 5.0 10.0 mA

Thermal Regulation LT1083-5/12 TA = 25°C, 30ms pulse 0.002 0.010 %/W

LT1084-3.3/5/12 0.003 0.015 %/W
LT1085-3.3/3.6/5/12 0.004 0.020 %/W

Ripple Rejection f = 120Hz, C

LT1084-3.3 f = 120Hz, C
LT1085-3.3 f = 120Hz, C
LT1085-3.6 f = 120Hz, C
LT1083/4/5-5 VIN = 8V (Note 6) ● 60 68 dB
LT1083/4/5-12 V

Temperature Stability ● 0.5 %
Long Term Stability TA = 125°C, 1000 Hrs. 0.03 1.0 %
RMS Output Noise TA = 25°C,

(% of V
Thermal Resistance Control Circuitry/Power Transistor (See Applications Information)

Junctrion-to-Case LT1083 K Package 0.6/1.6 °C/W

) 10Hz = ≤ f ≤ 10kHz 0.003 %

OUT

LT1084 K Package 0.75/2.3 °C/W

LT1085 K Package 0.9/3.0 °C/W

= 25µF Tantalum, I

OUT

= 15V (Note 6) ● 54 60 dB

IN

P Package 0.5/1.6 °C/W

P Package 0.65/2.3 °C/W
T Package 0.65/2.7 °C/W

T Package 0.7/3.0 °C/W
DD Package 0.7/3.0 °C/W

= I

OUT

FULLLOAD

= 25µF Tantalum, I

OUT

= 25µF Tantalum, VIN = 6.3V, I

OUT

= 25µF Tantalum, VIN = 6.6V, I

OUT

(Note 4)

OUT

= 5A, VIN = 6.3V ● 60 72 dB

= 3A ● 60 72 dB

OUT

= 3A ● 60 72 dB

OUT

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 (60W for the LT1083, 45W for the LT1084 (K, P), 30W for the
LT1084 (T) and 30W for the LT1085). 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.

Note 4: I

FULL LOAD

curve is defined as the minimum value of current limit as a function of

is defined in the current limit curves. The I

FULLLOAD

input to output voltage. Note that the 60W power dissipation for the
LT1083 (45W for the LT1084 (K, P), 30W for the LT1084 (T), 30W for the
LT1085) is only achievable over a limited range of input to output voltage.

Note 5: 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 6: For LT1083 I
T

≥ –40°C.

J

Note 7: 1.7V ≤ (V
Note 8: Dropout voltage 1.7V maximum for LT1084 at

–55°C ≤ T
Note 9: Full load current is not available at all input-output voltages.

See Notes 3, 4, 6.

≤ –40°C.

J

FULL LOAD

– V

IN

is 5A for –55°C ≤ TJ ≤ –40°C and 7.5A for

) ≤ 25V for LT1084 at –55°C ≤ TJ ≤ –40°C.

OUT

4