Datasheet

ManualsBrandsLINEAR TECHNOLOGY ManualsVoltage RegulatorsLT 1085-12 CT Low-drop Precision Fixed Voltage Regulator, Positive

LT1083/LT1084/LT1085 Fixed

1083ffe

For more information www.linear.com/LT1083

Typical applicaTion

DescripTion

3A, 5A, 7.5A Low Dropout

Positive Fixed Regulators

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 cur

rent is wasted as quiescent current, the LT1083 quiescent

current flows into the load, increasing efficiency.

FeaTures

applicaTions

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

High Efﬁciency Linear Regulators

Post Regulators for Switching Supplies

Constant Current Regulators

Battery Chargers

DEVICE OUTPUT CURRENT*

LT1083

LT1084

LT1085

7.5 Amps

5.0 Amps

3.0 Amps

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

5V, 7.5A Regulator

≥ 6.5V 5V AT 7.5A

LT1083-5

LT1083/4/5 TA01

22µF*

TANTALUM

10µF

*REQUIRED FOR STABILITY

Dropout Voltage vs Output Current

OUTPUT CURRENT (A)

INPUT/OUTPUT VOLTAGE DIFFERENTIAL (V)

1083/4/5 TA02

FULLLOAD

L, LT , LT C , LT M , Linear Technology, the Linear logo and OPTI-LOOP are registered trademarks

and UltraFast is a trademark of Linear Technology Corporation. All other trademarks are the

property of their respective owners.

Summary of content (18 pages)

PAGE 1
LT1083/LT1084/LT1085 Fixed 3A, 5A, 7.5A Low Dropout Positive Fixed Regulators Features Description Three-Terminal 3.3V, 3.6V, 5V and 12V nn Output Current of 3A, 5A or 7.5A nn Operates Down to 1V Dropout nn Guaranteed Dropout Voltage at Multiple Current Levels nn Line Regulation: 0.015% nn Load Regulation: 0.1% nn 100% Thermal Limit Functional Test nn Adjustable Versions Available Applications The LT®1083 series of positive adjustable regulators are designed to provide 3A, 5A and 7.
PAGE 2
LT1083/LT1084/LT1085 Fixed Absolute Maximum Ratings (Note 1) Power Dissipation............................... Internally Limited Input Voltage*........................................................... 30V Operating Input Voltage 3.3V, 3.6V Devices................................................ 20V 5V Devices............................................................ 20V 12V Devices..........................................................
PAGE 3
LT1083/LT1084/LT1085 Fixed Order Information LEAD FREE FINISH TAPE AND REEL PART MARKING PACKAGE DESCRIPTION TEMPERATURE RANGE LT1083CP-5#PBF NA LT1083CP-5 3-Lead Plastic TO-3P Control: 0°C to 125°C Power: 0°C to 150°C LT1083CP-12#PBF NA LT1083CP-12 3-Lead Plastic TO-3P Control: 0°C to 125°C Power: 0°C to 150°C LT1084CP-5#PBF NA LT1084CP-5 3-Lead Plastic TO-3P Control: 0°C to 125°C Power: 0°C to 150°C LT1084CP-12#PBF NA LT1084CP-12 3-Lead Plastic TO-3P Control: 0°C to 125°C Power: 0°
PAGE 4
LT1083/LT1084/LT1085 Fixed Order Information LEAD BASED FINISH TAPE AND REEL PART MARKING PACKAGE DESCRIPTION TEMPERATURE RANGE LT1084CK-5 NA LT1084CK-5 2-Lead TO-3 Metal Can Control: 0°C to 125°C Power: 0°C to 150°C LT1084CK-12 NA LT1084CK-12 2-Lead TO-3 Metal Can Control: 0°C to 125°C Power: 0°C to 150°C LT1084MK-5 NA LT1084MK-5 2-Lead TO-3 Metal Can Control: –55°C to 150°C Power: –55°C to 200°C LT1084MK-12 NA LT1084MK-12 2-Lead TO-3 Metal Can Control: –55°C to 150°C Power: –55°C t
PAGE 5
LT1083/LT1084/LT1085 Fixed Electrical Characteristics The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. PARAMETER CONDITIONS Output Voltage LT1084-3.3 LT1085-3.3 LT1085-3.6 Line Regulation UNITS IOUT = 0mA, TJ = 25°C, VIN = 8V (K Package Only) 4.8V ≤ VIN ≤ 15V, 0 ≤ IOUT ≤ IFULL_LOAD (Notes 3, 4, 9) l 3.270 3.235 3.300 3.300 3.330 3.365 V V VIN = 5V, IOUT = 0mA, TJ = 25°C (K Package Only) 4.
PAGE 6
LT1083/LT1084/LT1085 Fixed Electrical Characteristics The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. PARAMETER CONDITIONS TYP MAX UNITS Quiescent Current LT1084-3.3 VIN = 18V l MIN 5.0 10.0 mA LT1085-3.3 VIN = 18V l 5.0 10.0 mA LT1085-3.6 VIN = 18V l 5.0 10.0 mA LT1083/4/5-5 VIN ≤ 20V l 5.0 10.0 mA LT1083/4/5-12 VIN ≤ 25V l Thermal Regulation LT1083-5/12 TA = 25°C, 30ms pulse LT1084-3.
PAGE 7
LT1083/LT1084/LT1085 Fixed Typical Performance Characteristics LT1083 Short-Circuit Current –40°C ≤ TJ ≤ 150°C 0°C ≤ TJ ≤ 125°C TJ = 150°C TJ = 25°C TJ = –55°C 1 2 3 4 5 6 7 8 OUTPUT CURRENT (A) 9 10 8 6 – 55°C 4 2 0 10 150°C IFULL_LOAD GUARANTEED 0 20 30 15 25 5 10 INPUT/OUTPUT DIFFERENTIAL (V) SHORT-CIRCUIT CURRENT (A) MINIMUN INPUT/OUTPUT DIFFERENTIAL (V) 0°C ≤ TJ ≤ 125°C TJ = – 55°C 1 TJ = 25°C 7 150°C 25°C 6 –55°C 5 4 3 IFULL_LOAD GUARANTEED 2 3 4 2 OUTPUT CURRENT (A) 5 0 6
PAGE 8
LT1083/LT1084/LT1085 Fixed Typical Performance Characteristics LT1083/4/5-5 Ripple Rejection vs Current LT1083/4/5-5 Ripple Rejection VRIPPLE ≤ 3VP-P VRIPPLE ≤ 0.5VP-P 50 80 (VIN – VOUT) ≥ 3V 60 (VIN – VOUT) ≥ VDROPOUT 40 30 20 fR = 120Hz VRIPPLE ≤ 3VP-P 70 fR = 20kHz VRIPPLE ≤ 0.5VP-P 60 50 40 30 20 10 IOUT = IFULL_LOAD 0 10 100 1k 10k FREQUENCY (Hz) 2.0 90 RIPPLE REJECTION (dB) RIPPLE REJECTION (dB) 70 0 100k 0 0.8 0.2 0.6 0.
PAGE 9
LT1083/LT1084/LT1085 Fixed Block Diagram VIN + – THERMAL LIMIT VOUT GND LT1083/4/5 BD Applications Information The LT1083 family of three-terminal regulators are easy to use and have all the protection features that are expected in high performance voltage regulators. They are short circuit protected, have safe area protection as well as thermal shutdown to turn off the regulator should the temperature exceed about 165°C.
PAGE 10
LT1083/LT1084/LT1085 Fixed applications information resistance since increasing voltage causes current to decrease. Negative resistance during current limit is not unique to the LT1083 series and has been present on all power IC regulators. The value of negative resistance is a function of how fast the current limit is folded back as input-to-output voltage increases. This negative resistance can react with capacitors or inductors on the input to cause oscillations during current limiting.
PAGE 11
LT1083/LT1084/LT1085 Fixed applications information Load Regulation Because the LT1083 is a three-terminal device, it is not possible to provide true remote load sensing. Load regulation will not be limited by the resistance of the wire connecting the regulator to the load. The data sheet specification for the load regulation is measured at the bottom of the package. Negative side sensing is a true Kelvin connection, with the ground pin of the device returned to the negative side of the load.
PAGE 12
LT1083/LT1084/LT1085 Fixed Typical Applications High Efficiency Regulator Paralleling Regulators 1mH 28V INPUT 10,000µF 10k IN + OUTPUT LT1083-5 OUT VIN IN 2 FEET #18 WIRE* LT1083-5 OUT GND GND 470Ω MR1122 VOUT = 5V IOUT = 0A TO 15A 0.015Ω 1N914 28V IN LT1083-5 OUT *THE #18 WIRE ACTS AS BALLAST RESISTANCE INSURING CURRENT SHARING BETWEEN BOTH DEVICES GND 1k 1M 4N28 LT1083/4/5 TA04 10k + LT1011 LT1083/4/5 TA03 10k – 28V 1N914 7.
PAGE 13
LT1083/LT1084/LT1085 Fixed Package Description Please refer to http://www.linear.com/designtools/packaging/ for the most recent package drawings. K Package 2-Lead TO-3 Metal Can (LTC DWG # 05-08-1310) .760 – .775 (19.30 – 19.69) .320 – .350 (8.13 – 8.89) .060 – .135 (1.524 – 3.429) .420 – .480 (10.67 – 12.19) .038 – .043 (0.965 – 1.09) 1.177 – 1.197 (29.90 – 30.40) .655 – .675 (16.64 – 17.15) .210 – .220 (5.33 – 5.59) .425 – .435 (10.80 – 11.05) .151 – .161 (3.86 – 4.09) DIA, 2PLCS .167 – .177 (4.
PAGE 14
LT1083/LT1084/LT1085 Fixed Package Description Please refer to http://www.linear.com/designtools/packaging/ for the most recent package drawings. T Package 3-Lead Plastic TO-220 T Package (LTC DWG # 05-08-1420) 3-Lead Plastic TO-220 (Reference LTC DWG # 05-08-1420) .147 – .155 (3.734 – 3.937) DIA .390 – .415 (9.906 – 10.541) .165 – .180 (4.191 – 4.572) .045 – .055 (1.143 – 1.397) .230 – .270 (5.842 – 6.858) .460 – .500 (11.684 – 12.700) .570 – .620 (14.478 – 15.748) .330 – .370 (8.382 – 9.398) .
PAGE 15
LT1083/LT1084/LT1085 Fixed Package Description Please refer to http://www.linear.com/designtools/packaging/ for the most recent package drawings. M Package M Package 3-Lead Plastic DD Pak 3-Lead DD Pak (LTC DWG Plastic # 05-08-1460 Rev F) (Reference LTC DWG # 05-08-1460 Rev F) .256 (6.502) .060 (1.524) TYP .060 (1.524) .390 – .415 (9.906 – 10.541) .165 – .180 (4.191 – 4.572) .045 – .055 (1.143 – 1.397) 15° .060 (1.524) .183 (4.648) .330 – .370 (8.382 – 9.398) +.008 .004 –.004 +0.203 0.102 –0.
PAGE 16
LT1083/LT1084/LT1085 Fixed Package Description Please refer to http://www.linear.com/designtools/packaging/ for the most recent package drawings. P Package P Package 3-Lead Plastic TO-3P (Similar to TO-247) 3-Lead Plastic (Similar (LTC DWG #TO-3P 05-08-1450 RevtoA)TO-247)) (Reference LTC DWG # 05-08-1450 Rev A) .515 – .580 (13.08 – 14.73) .305 – .370 (7.75 – 9.40) .560 – .620 (14.22 – 15.75) .187 – .207 (4.75 – 5.26) .620 – .640 (15.75 – 16.26) .265 – .293 (6.73 – 7.44) MOUNTING HOLE 18° – 22° .
PAGE 17
LT1083/LT1084/LT1085 Fixed Revision History (Revision history begins at Rev E) REV DATE DESCRIPTION E 06/15 Obsolete TO-3P package. PAGE NUMBER 2, 16 1083ffe Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However, no responsibility is assumed for its use. Linear Technology Corporation makes no representation that the interconnection of its circuits as described herein will not infringe on existing patent rights. For more information www.linear.
PAGE 18
LT1083/LT1084/LT1085 Fixed Typical Application Adjusting Output Voltage VIN > 12V LT1085-5 + + 10µF + Regulator with Reference VIN > 11.5V 5V to 10V 100µF LT1085-5 + + 10µF 10V 100µF 5VOUT LT1029 1k 10µF* LT1083/4/5 TA07 LT1083/4/5 TA06 *OPTIONAL IMPROVES RIPPLE REJECTION Low Dropout Negative Supply Battery Backed Up Regulated Supply VIN IN VIN + LT1084-12 OUT GND + + 10,000µF 10µF 50Ω SELECT FOR CHARGE RATE 100µF LT1083/4/5 TA08 FLOATING INPUT 5.2V LINE 5.