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LT1083/LT1084/LT1085 Fixed 3A, 5A, 7.5A Low Dropout Positive Fixed Regulators
FEATURES

DESCRIPTIO
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
APPLICATIO S

High Efficiency Linear Regulators Post Regulators for Switching Supplies Constant Current Regulators Battery Chargers
DEVICE LT1083 LT1084 LT1085 OUTPUT CURRENT* 7.5 Amps 5.0 Amps 3.0 Amps
The LT(R)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 10F 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.
, LT, LTC and LTM are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners.
*For a 1.5A low dropout regulator see the LT1086 data sheet.
TYPICAL APPLICATIO
5V, 7.5A Regulator
INPUT/OUTPUT VOLTAGE DIFFERENTIAL (V)
2
Dropout Voltage vs Output Current
VIN 6.5V
LT1083-5
5V AT 7.5A
+
10F
+
22F* TANTALUM
LT1083/4/5 TA01
*REQUIRED FOR STABILITY
1
0
0
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IFULLLOAD/2 OUTPUT CURRENT (A) IFULLLOAD
1083/4/5 TA02
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LT1083/LT1084/LT1085 Fixed
ABSOLUTE
AXI U
RATI GS
PRECO DITIO I G
100% Thermal Limit Functional Test.
PACKAGE/ORDER I FOR ATIO
VIN 2 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
TAB IS OUTPUT FRONT VIEW
1 GND K PACKAGE 2-LEAD TO-3 METAL CAN
3 2 1 P PACKAGE 3-LEAD TO-3P PLASTIC
JA = 35C/W
OBSOLETE NOT RECOMMENDED FOR NEW DESIGNS
TAB IS OUTPUT FRONT VIEW
JA = 45C/W
3 2 1 T PACKAGE 3-LEAD PLASTIC TO-220
VIN VOUT GND
LT1084CT-3.3 LT1084CT-5 LT1084CT-12 LT1085CT-3.3 LT1085CT-3.6 LT1085CT-5 LT1085CT-12
FRONT VIEW 3 TAB IS OUTPUT 2 1 M PACKAGE 3-LEAD PLASTIC DD VIN VOUT GND
JA = 30C/W* *WITH PACKAGE SOLDERED TO 0.52IN2 COPPER AREA OVER BACKSIDE GROUND PLANE OR INTERNAL POWER PLANE. JA CAN VARY FROM 20C/W TO > 40C/W DEPENDING ON MOUNTING TECHNIQUE.
JA = 50C/W
Consult factory for parts specified with wider operating temperature ranges.
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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 .............................. 0C to 125C Power Transistor ............................ 0C to 150C "M" Grades Control Section .......................... -55C to 150C Power Transistor ........................ -55C to 200C
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(Note 1)
Storage Temperature Range ................ - 65C to 150C Lead Temperature (Soldering, 10 sec)................. 300C
*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.
ORDER PART NUMBER LT1083CP-5 LT1083CP-12 LT1084CP-5 LT1084CP-12
VIN VOUT GND
LT1085CM-3.3 LT1085CM-3.6 LT1085IM-3.6
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LT1083/LT1084/LT1085 Fixed
ELECTRICAL CHARACTERISTICS
PARAMETER Output Voltage CONDITIONS LT1084-3.3 LT1085-3.3 LT1085-3.6
The denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25C.
MIN IOUT = 0mA, TJ = 25C, VIN = 8V (K Package Only) 4.8V VIN 15V, 0 IOUT IFULLOAD (Notes 3, 4, 9) VIN = 5V, IOUT = 0mA, TJ = 25C (K Package Only) 4.8V VIN 15V, 0 IOUT IFULLOAD (Notes 3, 4, 9) VIN = 5V, IOUT = 0mA, TJ = 25C (K Package Only) 5V VIN 15V, 0 IOUT IFULLOAD (Note 9) 5V VIN 15V, 0 IOUT IFULLOAD, TJ 0C (Notes 3, 4, 9) 5V VIN 15V, 0 IOUT 2.5A (Notes 3, 4, 9) VIN = 4.75V, IOUT = 3A, TJ 0C VIN = 4.75V, IOUT = 2.5A, TJ 0C VIN = 4.75V, IOUT = 1.5A, TJ > 0C IOUT = 0mA, TJ = 25C, VIN = 8V (K Package Only) 0 IOUT IFULLOAD, 6.5V VIN 20V (Notes 4, 6, 7, 9)

TYP 3.300 3.300 3.300 3.300 3.600
MAX 3.330 3.365 3.330 3.365 3.636 3.672 3.672 3.672 3.672 3.672 3.672
UNITS V 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 V V V V A A A A A A A A
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3.270 3.235 3.270 3.235 3.564 3.500 3.528 3.528 3.350 3.450 3.528 4.950 4.900 11.880 11.760
LT1085-3.6
LT1083/4/5-5
5.000 5.000 12.000 12.000 0.5 1.0 0.5 1.0 0.5 1.0 0.5 1.0 1.0 2.0 3 7 3 7 3 7 5 10 12 24 1.3 1.3 1.3 1.3
5.050 5.100 12.120 12.240 6 6 6 6 6 6 10 10 25 25 15 20 15 20 15 20 20 35 36 72 1.5 1.5 1.5 1.5
LT1083/4/5-12 IOUT = 0mA, TJ = 25C, VIN = 15V (K Package Only) 0 IOUT IFULLOAD, 13.5V VIN 25V (Notes 4, 6, 7, 9) Line Regulation LT1084-3.3 LT1085-3.3 LT1085-3.6 LT1083/4/5-5 IOUT = 0mA, TJ = 25C, 4.8V VIN 15V 4.8V VIN 15V, IOUT = 0mA, TJ= 25C 4.8V VIN 15V, IOUT = 0mA, TJ= 25C IOUT = 0mA, TJ = 25C, 6.5V VIN 20V (Notes 2, 3)

LT1083/4/5-12 IOUT = 0mA, TJ = 25C, 13.5V VIN 25V (Notes 2, 3) Load Regulation LT1084-3.3 LT1085-3.3 LT1085-3.6 LT1083/4/5-5 VIN = 5V, 0 IOUT 5A, TJ = 25C VIN = 5V, 0 IOUT 3A, TJ = 25C VIN = 5.25V, 0 IOUT 3A, TJ = 25C VIN = 8V, 0 IOUT IFULLLOAD, TJ = 25C (Notes 2, 3, 4, 6)
LT1083/4/5-12 VIN = 15V, 0 IOUT IFULLLOAD, TJ = 25C (Notes 2, 3, 4, 6) Dropout Voltage LT1084/5-3.3 LT1085-3.6 LT1083/4/5-5 Current Limit LT1083-5 LT1083-12 LT1084-3.3 LT1084-5 LT1084-12 VOUT = 33mV, IOUT = IFULL LOAD (Notes 5, 6) VOUT = 36mV, IOUT = IFULL LOAD (Notes 5, 6) VOUT = 50mV, IOUT = IFULL LOAD (Notes 5, 6) VIN = 10V VIN = 17V VIN = 8V VIN = 10V VIN = 17V
LT1083/4/5-12 VOUT = 120mV, IOUT = IFULL LOAD (Notes 5, 6)
8.0 8.0 5.5 5.5 5.5 3.2 3.2 3.2
9.5 9.5 6.5 6.5 6.5 4.0 4.0 4.0
LT1085-3.3/3.6 VIN = 8V LT1085-5 VIN = 10V LT1085-12 VIN = 17V
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LT1083/LT1084/LT1085 Fixed
ELECTRICAL CHARACTERISTICS
PARAMETER Quiescient Current CONDITIONS LT1084-3.3 LT1085-3.3 LT1085-3.6 LT1083/4/5-5 LT1083/4/5-12 Thermal Regulation VIN = 18V VIN = 18V VIN = 18V VIN 20V VIN 25V
The denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25C.
MIN

TYP 5.0 5.0 5.0 5.0 5.0 0.002 0.003 0.004
MAX 10.0 10.0 10.0 10.0 10.0 0.010 0.015 0.020
UNITS mA mA mA mA mA %/W %/W %/W dB dB dB dB dB %
LT1083-5/12 TA = 25C, 30ms pulse LT1084-3.3/5/12 LT1085-3.3/3.6/5/12 f = 120Hz, COUT = 25F Tantalum, IOUT = IFULLLOAD (Note 4) LT1084-3.3 f = 120Hz, COUT = 25F Tantalum, IOUT = 5A, VIN = 6.3V LT1085-3.3 f = 120Hz, COUT = 25F Tantalum, VIN = 6.3V, IOUT = 3A LT1085-3.6 f = 120Hz, COUT = 25F Tantalum, VIN = 6.6V, IOUT = 3A LT1083/4/5-5 VIN = 8V (Note 6) LT1083/4/5-12 VIN = 15V (Note 6) TA = 125C, 1000 Hrs. TA = 25C, 10Hz = f 10kHz Control Circuitry/Power Transistor (See Applications Information) LT1083 K Package P Package LT1084 K Package P Package T Package K Package T Package DD Package

Ripple Rejection
60 60 60 60 54
72 72 72 68 60 0.5 0.03 0.003 0.6/1.6 0.5/1.6 0.75/2.3 0.65/2.3 0.65/2.7 0.9/3.0 0.7/3.0 0.7/3.0 1.0
Temperature Stability Long Term Stability RMS Output Noise (% of VOUT) Thermal Resistance Junctrion-to-Case
% % C/W C/W C/W C/W C/W C/W C/W C/W
LT1085
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: 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: IFULL LOAD is defined in the current limit curves. The IFULLLOAD curve is defined as the minimum value of current limit as a function of 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 IFULL LOAD is 5A for - 55C TJ - 40C and 7.5A for TJ - 40C. Note 7: 1.7V (VIN - VOUT) 25V for LT1084 at - 55C TJ - 40C. Note 8: Dropout voltage 1.7V maximum for LT1084 at - 55C TJ - 40C. Note 9: Full load current is not available at all input-output voltages. See Notes 3, 4, 6.
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LT1083/LT1084/LT1085 Fixed TYPICAL PERFOR A CE CHARACTERISTICS
LT1083 Dropout Voltage
MINIMUM INPUT/OUTPUT DIFFERENTIAL (V)
2 INDICATES GUARANTEED TEST POINT -40C TJ 150C 0C TJ 125C 12 10 8 6 4 2 0 0 1 2 345678 OUTPUT CURRENT (A) 9 10 0 20 30 15 25 5 10 INPUT/OUTPUT DIFFERENTIAL (V) 35 -55C 25C 150C
OUTPUT VOLTAGE DEVIATION (%)
SHORT-CIRCUIT CURRENT (A)
1
TJ = 150C TJ = 25C TJ = -55C
0
LT1083/4/5 FIXED G01
LT1084 Dropout Voltage
MINIMUN INPUT/OUTPUT DIFFERENTIAL (V) 2 INDICATES GUARANTEED TEST POINT -55C TJ 150C 0C TJ 125C
10 9
OUTPUT VOLTAGE DEVIATION (%)
SHORT-CIRCUIT CURRENT (A)
1 TJ = -55C TJ = 150C TJ = 25C
0 0 1 3 4 2 OUTPUT CURRENT (A) 5 6
LT1083/4/5 FIXEDG04
LT1085 Dropout Voltage
MINIMUM INPUT/OUTPUT DIFFERENTIAL (V)
2 INDICATES GUARANTEED TEST POINT
OUTPUT VOLTAGE DEVIATION (%)
0C TJ 125C
SHORT-CIRCUIT CURRENT (A)
-55C TJ 150C
1 TJ = 25C TJ = 150C
TJ = -55C
0 0 3 2 1 OUTPUT CURRENT (A) 4
LT1083/4/5 FIXED G07
UW
LT1083 Short-Circuit Current
0.10 0.05 0 -0.05 -0.10 -0.15
LT1083 Load Regulation
I = 7.5A
IFULL LOAD GUARANTEED
-0.20 -50 -25
0
25 50 75 100 125 150 TEMPERATURE (C)
LT1083/4/5 FIXED G03
LT1083/4/5 FIXED G02
LT1084 Short Circuit Current
0.10 0.05 0 -0.05 -0.10 -0.15
LT1084 Load Regulation
I = 5A
8 7 6 5 4 3 2 1 0 0 20 15 10 25 30 5 INPUT/OUTPUT DIFFERENTIAL (V) 35 IFULL LOAD GUARANTEED 150C 25C -55C
-0.20 -50 -25
0
25 50 75 100 125 150 TEMPERATURE (C)
LT1083/4/5 FIXED G06
LT1083/4/5 FIXED G05
LT1085 Short-Circuit Current
6 5 4 3 -55C 2 1 0 0 20 30 15 25 5 10 INPUT/OUTPUT DIFFERENTIAL (V) 35 IFULL LOAD GUARANTEED 25C 150C 0.10 0.05 0 -0.05 -0.10 -0.15
LT1085 Load Regulation
I = 3A
-0.20 -50 -25
0
25 50 75 100 125 150 TEMPERATURE (C)
LT1083/4/5 FIXED G09
LT1083/4/5 FIXED G08
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LT1083/LT1084/LT1085 Fixed TYPICAL PERFOR A CE CHARACTERISTICS
LT1083/4/5-5 Ripple Rejection
80 70 RIPPLE REJECTION (dB) 60 50 40 30 20 10 IOUT = IFULLLOAD 0 10 100 1k 10k FREQUENCY (Hz) 100k VRIPPLE 3VP-P VRIPPLE 0.5VP-P
RIPPLE REJECTION (dB)
(VIN - VOUT) 3V (VIN - VOUT) VDROPOUT
80 70 60 50 40 30 20 10 0 0 fR = 20kHz VRIPPLE 0.5VP-P
fR = 120Hz VRIPPLE 3VP-P
OUTPUT VOLTAGE CHANGE (%)
LT1083/4/5-12 Ripple Rejection
80 70 VRIPPLE 3VP-P VRIPPLE 0.5VP-P
RIPPLE REJECTION (dB)
RIPPLE REJECTION (dB)
60 50 40 30 20 10 IOUT = IFULLLOAD 0 10 100 1k 10k FREQUENCY (Hz) 100k (VIN - VOUT) 3V
60 50 40 30 20 10 0 0 0.8 0.2 0.6 0.4 OUTPUT CURRENT (0 TO IFULLLOAD) 1.0 fR = 20kHz VRIPPLE 0.5VP-P
POWER (W)
(VIN - VOUT) VDROPOUT
LT1084 Maximum Power Dissipation*
60 50 LT1084MK 40 50
POWER (W)
POWER (W)
30 LT1084CT 20 10 0 LT1084CK LT1084CP
50 60 70 80 90 100 110 120 130 140 150 CASE TEMPERATURE (C) * AS LIMITED BY MAXIMUM JUNCTION TEMPERATURE
LT1083/4/5 FIXED G16
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1083/4/5 FIXED G10
1083/4/5 FIXED G13
LT1083/4/5-5 Ripple Rejection vs Current
100 90
1.0 2.0
Temperature Stability
0
-1.0
0.8 0.2 0.6 0.4 OUTPUT CURRENT (0 TO IFULLLOAD)
1.0
-2.0 -50 -25
0
25 50 75 100 125 150 TEMPERATURE (C)
LT1183/4/5 FIXED G12
1083/4/5 FIXED G11
LT1083/4/5-12 Ripple Rejection vs Current
100 90 80 70 fR = 120Hz VRIPPLE 3VP-P
100 90 80 70 60 50 40 30 20 10 0
LT1083 Maximum Power Dissipation*
LT1083MK
LT1083CP
LT1083CK
1083/4/5 FIXED G14
50 60 70 80 90 100 110 120 130 140 150 CASE TEMPERATURE (C) * AS LIMITED BY MAXIMUM JUNCTION TEMPERATURE
LT1083/4/5 FIXED G15
LT1085 Maximum Power Dissipation*
40 LT1085MK
30
20 LT1085CT 10 LT1085CK 0 50 60 70 80 90 100 110 120 130 140 150 CASE TEMPERATURE (C) * AS LIMITED BY MAXIMUM JUNCTION TEMPERATURE
LT1083/4/5 FIXED G17
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LT1083/LT1084/LT1085 Fixed
BLOCK DIAGRA
APPLICATIO S I FOR ATIO
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 165C. These regulators offer lower dropout voltage and more precise reference tolerance. Further, the reference stability with temperature is improved over older types of regulators. The only circuit difference between using the LT1083 family and older regulators is that they require an output capacitor for stability. Stability The circuit design used in the LT1083 family requires the use of an output capacitor as part of the device frequency compensation. For all operating conditions, the addition of 150F aluminum electrolytic or a 22F solid tantalum on the output will ensure stability. Normally capacitors much smaller than this can be used with the LT1083. Many different types of capacitors with widely varying charac-
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THERMAL LIMIT
VIN
+ -
VOUT
GND
LT1083/4/5 BD
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teristics are available. These capacitors differ in capacitor tolerance (sometimes ranging up to 100%), equivalent series resistance, and capacitance temperature coefficient. The 150F or 22F values given will ensure stability. Normally, capacitor values on the order of 100F are used in the output of many regulators to ensure good transient response with heavy load current changes. Output capacitance can be increased without limit and larger values of output capacitance further improve stability and transient response of the LT1083 regulators. Another possible stability problem that can occur in monolithic IC regulators is current limit oscillations. These can occur because in current limit the safe area protection exhibits a negative impedance. The safe area protection decreases the current limit as the input-tooutput voltage increases.That is the equivalent of having a negitive resistance since increasing voltage causes current to decrease. Negitive 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
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LT1083/LT1084/LT1085 Fixed
APPLICATIO S I FOR ATIO
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. Depending on the value of series resistance, the overall circuitry may end up unstable. Since this is a system problem, it is not necessarily easy to solve; however it does not cause any problems with the IC regulator and can usually be ignored. Protection Diodes In normal operation the LT1083 family does not need any protection diodes, The internal diode between the input and the output pins of the LT1083 family can handle microsecond surge currents of 50A to 100A. Even with large output capacitances it is very difficult to get those values of surge current in normal operation. Only with high value output capacitors, such as 1000F to 5000F and with the input pin instantaneously shorted to ground, can damage occur. A crowbar circuit at the input of the LT1083 can generate those kinds of currents and a diode from output-to-input is then recommended. Normal power supply cycling or even plugging and unplugging in the system will not generate currents large enough to do any damage.
D1 1N4002 (OPTIONAL)
VIN
IN
LT1083 ADJ
OUT
VOUT
+
COUT 150F
1083/4/5 AI01
Overload Recovery Like any of the IC power regulators, the LT1083 has safe area protection. The safe area protection decreases the current limit as input-to-output voltage increases and keeps the power transistor inside a safe operating region for all values of input-to-output voltage. The LT1083 protection is designed to provide some output current at all values of input-to-output voltage up to the device breakdown. When power is first turned on, as the input voltage rises, the output follows the input, allowing the regulator to start
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up into very heavy loads. During the start-up, as the input voltage is rising, the input-to-output voltage differential remains small allowing the regulator to supply large output currents. With high input voltage a problem can occur wherein removal of an output short will not allow the output voltage to recover. Older regulators such as the 7800 series, also exhibited this phenomenon so it is not unique to the LT1083. The problem occurs with a heavy output load when the input voltage is high and the output voltage is low, such as immediately after a removal of a short. The load line for such a load may intersect the output current curve at two points. If this happens there are two stable output operating points for the regulator. With this double intersection the power supply may need to be cycled down to zero and brought up again to make the output recover. Ripple Rejection In applications that require improved ripple rejection the LT1083 series adjustable regulators should be used. With LT1083 series adjustable regulators the addition of a bypass capacitor from the adjust pin to ground will reduce output ripple by the ratio of VOUT/1.25V. See LT1083 series adjustable regulator data sheet. 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. Thermal Considerations The LT1083 series of regulators have internal power and thermal limiting circuitry designed to protect the device under overload conditions. For continuous normal load conditions however, maximum junction temperature ratings must not be exceeded. It is important to give careful consideration to all sources of thermal resistance from junction to ambient. This includes junction-to-case,
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LT1083/LT1084/LT1085 Fixed
APPLICATIO S I FOR ATIO
case- to-heat sink interface, and heat sink resistance itself. New thermal resistance specifications have been developed to more accurately reflect device temperature and ensure safe operating temperatures. The data section for these new regulators provides a separate thermal resistance and maximum junction temperature for both the Control Section and the Power Section. Previous regulators, with a single junction-to-case thermal resistance specification, used an average of the two values provided here and therefore could allow excessive junction temperatures under certain conditions of ambient temperature and heat sink resistance. To avoid this possibility, calculations should be made for both sections to ensure that both thermal limits are met. Junction-to-case thermal resistance is specified from the IC junction to the bottom of the case directly below the die. This is the lowest resistance path for heat flow. Proper mounting is required to ensure the best possible thermal flow from this area of the package to the heat sink. Thermal compound at the case-to-heat sink interface is strongly recommended. If the case of the device must be electronically isolated, a thermally conductive spacer can be used as long as its added contribution to thermal resistance is considered. Note that the case of all devices in this series is electronically connected to the ouput.
TYPICAL APPLICATIO S
High Efficiency Regulator
1mH IN LT1083-5 OUT GND 470 1N914 OUTPUT
28V INPUT 10k
+
10,000F MR1122 28V
1k
1M
4N28
+
LT1011
10k
-
1N914
10k
28V
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For example, using a LT1083-5CP (TO-3P, Commercial) and assuming: VIN(max continuous) = 9V, VOUT = 5V, IOUT = 6A, TA = 75C, HEAT SINK = 1C/W, CASE-TO-HEAT SINK = 0.2C/W for P package with thermal compound. Power dissipation under these conditions is equal to: PD = (VIN - VOUT) (IOUT) = 24W Junction temperature will be equal to: TJ = TA + PD (HEAT SINK + CASE-TO-HEAT SINK + JC) For the Control Section: TJ = 75C + 24W (1C/W + 0.2C/W + 0.5C/W) = 118C 118C < 125C = TJMAX (Control Section Commercial Range) For the Power Transistor: TJ = 75C + 24W (1C/W + 0.2C/W + 1.6C/W) = 142C 142C < 150C = TJMAX (Power Transistor Commercial Range) In both cases the junction temperature is below the maximum rating for the respective sections, ensuring reliable operation.
Paralleling Regulators
2 FEET #18 WIRE* VIN IN LT1083-5 OUT GND VOUT = 5V IOUT = 0A TO 15A 0.015 IN LT1083-5 OUT GND *THE #18 WIRE ACTS AS BALLAST RESISTANCE INSURING CURRENT SHARING BETWEEN BOTH DEVICES
LT1083/4/5 TA04
LT1083/4/5 TA03
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LT1083/LT1084/LT1085 Fixed
TYPICAL APPLICATIO S
7.5A Regulator
T1 TRIAD F-269U C30B L 1MH IN 20 110VAC 20 3 T2 4 2 LT1004-1.2 C30B 1N4003 1N4003 1F 560 1N914 16k* 15V 16k* 1N4003 LT1083-12 OUT GND 12V 0A TO 7.5A
82k
10k 1N4148
* 1% FILM RESISTOR L-DALE TO-5 TYPE T2-STANCOR 11Z-2003
REGULATOR WITH SCR PREREGULATOR TO LOWER POWER DISSIPATION. ABOUT 1.7V DIFFERENTIAL IS MAINTAINED ACROSS THE LT1083 INDEPENDENT OF LOAD CURRENT.
PACKAGE DESCRIPTIO
K Package 2-Lead TO-3 Metal Can
(LTC DWG # 05-08-1310)
.320 - .350 (8.13 - 8.89) .760 - .775 (19.30 - 19.69)
.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) .151 - .161 (3.86 - 4.09) DIA, 2PLCS .167 - .177 (4.24 - 4.49) R .067 - .077 (1.70 - 1.96) .490 - .510 (12.45 - 12.95) R
.425 - .435 (10.80 - 11.05)
OBSOLETE PACKAGE
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+ C1
50,000F
+
100F
1
15k
8 2
+ -
-15V 4 7
200k
11k*
LT1011 3 1 15V -15V 4 7 8
0.1F NC 100pF 2N3904 3 8 1 10k
- +
1
LT1011 2 6
+ -
4 -15V
3
LM301A 2 11k*
LT1083/4/5 TA05
15k 15V
7 15V
1F
T Package 3-Lead Plastic TO-220
(LTC DWG # 05-08-1420)
.390 - .415 (9.906 - 10.541) .147 - .155 (3.734 - 3.937) DIA .230 - .270 (5.842 - 6.858) .460 - .500 (11.684 - 12.700) .570 - .620 (14.478 - 15.748) .330 - .370 (8.382 - 9.398) .165 - .180 (4.191 - 4.572)
.045 - .055 (1.143 - 1.397)
.980 - 1.070 (24.892 - 27.178)
.520 - .570 (13.208 - 14.478)
.218 - .252 (5.537 - 6.401) .013 - .023 (0.330 - 0.584)
.100 (2.540) BSC
.028 - .038 (0.711 - 0.965)
.050 (1.270) TYP
.095 - .115 (2.413 - 2.921)
T3 (TO-220) 0801
K2 (TO-3) 0801
LT1083/LT1084/LT1085 Fixed
PACKAGE DESCRIPTIO
.256 (6.502)
.060 (1.524)
.060 (1.524)
.183 (4.648)
.075 (1.905) .300 (7.620) BOTTOM VIEW OF DD PAK HATCHED AREA IS SOLDER PLATED COPPER HEAT SINK .420 +.012 .143 -.020 +0.305 3.632 -0.508 .100 (2.54) BSC .013 - .023 (0.330 - 0.584)
.090 .100 .070
RECOMMENDED SOLDER PAD LAYOUT
.560 (14.224) .325 (8.255) .275 (6.985)
.580 (14.732) .700 (17.780)
.098 (2.489) .124 (3.149)
BOTTOM VIEW OF TO-3P HATCHED AREA IS SOLDER PLATED COPPER HEAT SINK
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.
U
M Package 3-Lead Plastic DD Pak
(LTC DWG # 05-08-1460)
.060 (1.524) TYP .390 - .415 (9.906 - 10.541) 15 .165 - .180 (4.191 - 4.572) .045 - .055 (1.143 - 1.397) .330 - .370 (8.382 - 9.398)
.059 (1.499)
(
+.008 .004 -.004 +0.203 0.102 -0.102
)
.095 - .115 (2.413 - 2.921) .050 .012 (1.270 0.305)
(
)
.050 (1.270)
.420 .080 .276
.350 .205 .565
.325 .565
.320 NOTE: 1. DIMENSIONS IN INCH/(MILLIMETER) 2. DRAWING NOT TO SCALE .100 .070 .090
M (DD3) 0204
RECOMMENDED SOLDER PAD LAYOUT FOR THICKER SOLDER PASTE APPLICATIONS
P Package 3-Lead Plastic TO-3P (Similar to TO-247)
(LTC DWG # 05-08-1450)
.620 - .64O (15.75 - 16.26) .187 - .207 (4.75 - 5.26) MOUNTING HOLE 18 - 22 .115 - .145 (2.92 - 3.68) DIA .060 - .080 (1.52 - 2.03)
.830 - .870 (21.08 - 22.10) .580 - .6OO (14.73 - 15.24)
.170 - .2OO (4.32 - 5.08) EJECTOR PIN MARKS .105 - .125 (2.67 - 3.18) DIA
3 - 7 .170 (4.32) MAX .780 - .800 (19.81 - 20.32)
.042 - .052 (1.07 - 1.32) .074 - .084 (1.88 - 2.13)
.215 (5.46) BSC .113 - .123 (2.87 - 3.12)
.087 - .102 (2.21 - 2.59) .020 - .040 (0.51 - 1.02)
P3 0801
1083ffd
11
LT1083/LT1084/LT1085 Fixed
TYPICAL APPLICATIO S
Adjusting Output Voltage Regulator with Reference
VIN > 12V
LT1085-5
+
10F
+
10F* 1k
LT1083/4/5 TA06
*OPTIONAL IMPROVES RIPPLE REJECTION
Low Dropout Negative Supply
VIN
IN
+
10,000F
FLOATING INPUT
RELATED PARTS
PART NUMBER LT1129 LT1175 LT1374 LT1529 LT1573 LT1575 LT1580 LT1581 LT1584/85/87 LT1735 LT1761 Series LT1762 Series LT1763 Series LT1764 LT1962 LT1963 DESCRIPTION 700mA Micropower Low Dropout Regulator 500mA Negative Low Dropout Micropower Regulator 4.5A, 500kHz Step-Down Converter 3A Low Dropout Regulator with 50A IQ UltraFastTM Transient Response Low Dropout Regulator UltraFast Transient Response Low Dropout Regulator 7A, Very Low Dropout Regulator 10A, Very Low Dropout Regulator 7A/4.6A/3A Fast Response LDOs Synchronous Step-Down Converter 150mA, Low Noise, LDO Micropower Regulators 500mA, Low Noise LDO Micropower Regulators 3A Low Noise Fast Transient Response LDO 300mA, Low Noise LDO Micropower Regulator 1.5A, Low Noise, Fast Transient Response LDO COMMENTS 50A Quiescent Current 45A IQ, 0.26V Dropout Voltage, SOT-223 Package 4.5A, 0.07 Internal Switch, SO-8 Package 500mV Dropout Voltage Drives External PNP Drives External N-Channel MOSFET 0.54V Dropout at 7A, Fixed 2.5VOUT and Adjustable 0.63V Dropout at 10A, Fixed 2.5VOUT and Adjustable Fast Transient Response for Microprocessor Applications High Efficiency, OPTI-LOOPTM Compensation 25A Quiescent Current, 20VRMS Noise, MSOP Package 30A Quiescent Current, 20VRMS Noise, SO-8 Package 40VRMS Noise, 5-Lead DD Package 20VRMS Noise, MSOP Package 40VRMS Noise, SOT-223 Package
1083ffd
100mA, Low Noise, Low Dropout Micropower Regulators in SOT-23 20A Quiescent Current, 20VRMS Noise, SOT-23 Package
UltraFast and OPTI-LOOP are trademarks of Linear Technology Corporation.
12
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900 FAX: (408) 434-0507
U
5V to 10V
VIN > 11.5V
LT1085-5
10V
+
100F
+
10F 5VOUT LT1029
LT1083/4/5 TA07
+
100F
Battery Backed Up Regulated Supply
VIN
LT1084-12 OUT GND
LT1084-5
5.2V LINE 5.0V BATTERY
+
10F 50
+
100F VOUT = -12V
SELECT FOR CHARGE RATE LT1084-5
LT1083/4/5 TA08
6.5V
+
10F
+
100F
LT1083/4/5 TA09
LT 1007 REV D * PRINTED IN USA
www.linear.com
(c) LINEAR TECHNOLOGY CORPORATION 1994

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