Document
LT1083/LT1084/LT1085
7.5A, 5A, 3A Low Dropout Positive Adjustable Regulators
Features
nn 3-Terminal Adjustable 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 Fixed Versions Available nn Available in 3-Lead Plastic TO-220 and DD Packages
Applications
nn High Efficiency Linear Regulators nn Post Regulators for Switching Supplies nn Constant Current Regulators nn Battery Chargers
DEVICE
OUTPUT CURRENT*
LT1083
7.5A
LT1084
5.0A
LT1085
3.0A
*For a 1.5A low dropout regulator see the LT1086 data sheet.
Description
The LT®1083 series of positive adjustable regulators are designed to provide 7.5A, 5A and 3A 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 reference voltage to 1%. Current limit is also trimmed, minimizing the stress on both the regulator and power source circuitry under overload conditions.
The LT1083/LT1084/LT1085 devices are pin compatible with older 3-terminal regulators. A 10µF output capacitor is required on these new devices. However, this is 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.
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and UltraFast and ThinSOT are trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners.
Typical Application
5V, 7.5A Regulator
VIN ≥ 6.5V
+
IN 10µF
LT1083 OUT ADJ
*REQUIRED FOR STABILITY
121Ω
1% +
365Ω 1%
5V AT 7.5A
10µF* TANTALUM
1083/4/5 ADJ TA01
INPUT/OUTPUT VOLTAGE DIFFERENTIAL (V)
Dropout Voltage vs Output Current
2
1
0
0
IFULL LOAD
OUTPUT CURRENT
1083/4/5 ADJ TA02
For more information www.linear.com/LT1083
108345fh
1
LT1083/LT1084/LT1085
Absolute Maximum Ratings (Note 1)
Power Dissipation................................ Internally Limited
Input-to-Output Voltage Differential
C-Grades................................................................30V
I-Grades.................................................................30V
M-Grades (OBSOLETE).........................................35V
Operating Junction Temperature Range (Note 9)
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: (OBSOLETE)
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
Preconditioning
100% thermal shutdown functional test.
Pin Configuration
TAB IS
OUTPUT
FRONT VIEW
3 2 1
T PACKAGE 3-LEAD PLASTIC TO-220
θJA = 50°C/W
VIN VOUT ADJ
BOTTOM VIEW
VIN
CASE IS OUTPUT
2
1
ADJ
K PACKAGE 2-LEAD TO-3 METAL CAN
θJA = 35°C/W
OBSOLETE PACKAGE
TAB IS OUTPUT
FRONT VIEW
3 2 1
VIN VOUT ADJ
P PACKAGE 3-LEAD PLASTIC TO-3P
θJA = 35°C/W
OBSOLETE PACKAGE
TAB IS
OUTPUT
FRONT VIEW 3 2 1
VIN VOUT ADJ
M PACKAGE 3-LEAD PLASTIC DD
θJA = 30°C/W* *WITH PACKAGE SOLDERED TO 0.5IN2 COPPER AREA OVER BACKSIDE GROUND PLANE OR INTERNAL POWER PLANE. θJA CAN VARY FROM 20°C/W TO >40°C/W DEPENDING ON MOUNTING TECHNIQUE
108345fh
2
For more information www.linear.com/LT1083
LT1083/LT1084/LT1085
Order Information
LEAD FREE FINISH LT1083CP#PBF
TAPE AND REEL NA
LT1084CP#PBF
NA
LT1084CT#PBF LT1084IT#PBF LT1085CT#PBF LT1085IT#PBF LT1085CM#PBF LT1085IM#PBF LEAD BASED FINISH LT1083CP LT1084CP
NA NA NA NA LT1085CM#TRPBF LT1085IM#TRPBF TAPE AND REEL NA NA
LT1084CT LT1084IT LT1085CT LT1085IT LT1085CM LT1085IM
NA NA NA NA LT1085CM#TR LT1085IM#TR
PART MARKING LT1083CP
PACKAGE DESCRIPTION 3-Lead Plastic TO-3P
LT1084CP
3-Lead Plastic TO-3P
OBSOLETE PACKAGE
LT1084CT
3-Lead Plastic TO-220
LT1084IT
3-Lead Plastic TO-220
LT1085CT
3-Lead Plastic TO-220
LT1085IT
3-Lead Plastic TO-220
LT1085CM
3-Lead Plastic DD
LT1085IM
3-Lead Plastic DD
PART MARKING LT1083CP
PACKAGE DESCRIPTION 3-Lead Plastic TO-3P
LT1084CP
3-Lead Plastic TO-3P
OBSOLETE PACKAGE
LT1084CT
3-Lead Plastic TO-220
LT1084IT
3-Lead Plastic TO-220
LT1085CT
3-Lead Plastic TO-220
LT1085IT
3-Lead Plastic TO-220
LT1085CM
3-Lead Plastic DD
LT1085IM
3-Lead Plastic DD
TEMPERATURE RANGE Control: 0°C to 125°C Power: 0°C to 150°C Control: 0°C to 125°C Power: 0°C to 150°C
Control: 0°C to 125°C Pow.