•
LND1083/84/85
DATA
SHEET
GENERAL DESCRIPTION
• Three terminal Adjustable
• Output Current of 3A, 5A or 7.5A
• Operates Down to 1V dropout
• Guaranteed Dropout Voltage at
Multiple Current Levels
• 0.015% Line regulation
• 0.01% Load Regulation
• 100% Thermal Limit Burn-In
FEATURES
The LND1083/LND1084/LND1085 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. 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 LND1083/LND1084/LND1085 devices are
pin compatible with older 3 terminal regulators.
A 10µF output capacitor is required on these
new devices: however, this is usually included
in most regulator designs.
APPLICATIONS
• High Efficiency Linear Regulators
• Post Regulators for Switching
Supplies
• Constant Current Regulators
• Battery Chargers
7.5 A, 5 A, 3 A Low Dropout Positive Adjustable Regulators
TYPICAL APPLICATION DATA
5V, 5A Regulator
• Linear Dimensions, Inc. • 445 East Ohio Street, Chicago IL 60611 USA • tel 312.321.1810 • fax 312.321.1830 • www.lineardimensions.com •
SYMBOL PARAMETER MAXIMUM UNITS
PDPower Dissipation Internally Limited W
VIN
Input to Output Voltage Differential «M»
grades
«C»grades
35
30
V
TJ
Operating Junction Temperature Range
«M»grades
Control section
Power Transistor
«C»Grades
Control Section
Power Transistor
-55 to 150
-55 to 200
0 to 125
0 to 150
ºC
TSTG Storage Temperature -65 to 150 ºC
TLEAD Lead Temperature(soldering,10 sec) 300 ºC
DEVICE OUTPUT CURRENT
LND1083 7.5A
LND1084 5.0A
LND1085 3.0A
ABSOULUTE MAXIMUM RATING
LND1083/84/85
DEVICE SELECTION GUIDE
Package Information
T Package TO–220 Plastic K PackageTO-3 Metal Can P Package TO–3P Plastic
Front View Bottom View Front View
• Linear Dimensions, Inc. • 445 East Ohio Street, Chicago IL 60611 USA • tel 312.321.1810 • fax 312.321.1830 • www.lineardimensions.com •
(See Note 1)
Parameter Test conditions Min Typ Max Units
Reference Voltage
IOut=10mA, Tj=25ºC
(Vin-Vout)=3V(K Package Only)
10mA<=Iout <=I full load
1.5V <=(Vin-Vout) <= 25V(Note 3) *
1.238
1.225
1.250
1.250
1.262
1.270
V
Line Regulation
Iload=10mA, 1.5<=(Vin-Vout) <=15V,
TJ =25ºC
M grade
15V<=(Vin-Vout) <=35V
C grade
15V <=(Vin-Vout) <=30V(Notes1,2)
*
*
*
0.015
0.035
0.05
0.05
0.2
0.2
0.5
0.5
%
Load Regulation
(Vin-Vout)=3V
10mA <=Iout <=Ifullload.
Tj=25ºC(notes 1,2,3,5) *0.1
0.2
0.3
0.4
%
Dropout Voltage ∆Vref=1%,Iout =Ifullload (See Notes 4,5) *1.31.5V
Current Limit
LND1083
LND1084
LND1085
(Vin-Vout)=5V
(Vin-Vout)=25V
(Vin-Vout)=5V
(Vin-Vout)=25V
(Vin-Vout)=5V
(Vin-Vout)=25V
*
*
*
*
*
*
8.0
0.4
5.5
0.3
3.2
0.2
9.5
1.0
6.5
0.6
4.0
0.5
A
Minimum Load Current (Vin-Vout)=25V * 5 10 mA
Thermal regulation
LND1083
LND1083
LND1085
TA =25ºC, 30ms pulse 0.002
0.003
0.004
0.01
0.015
0.02
%/W
Ripple Rejection
f=120Hz,
Cadj=25µF Cout=25µF tantalum,
Iout=I fullload , (Vin-Vout)=3V(Note5)
*6075 dB
Adjust Pin Current Tj=25ºC * 55 120
Adjust Pin Current
Change
10mA ≤Iout ≤ Ifullload ,
1.5 V ≤ (Vin-Vout)=25V(Note 5) *0.25
µA
Temperature Stability * 0.5
Long Term Stability TA=125º C,1000Hrs 0.3 1
RMS output Noise(%
of Vout)
TA=25º C
10Hz ≤f ≤10kHz 0.003
%
ELECTRICAL CHARACTERISTICS
LND1083/84/85
• Linear Dimensions, Inc. • 445 East Ohio Street, Chicago IL 60611 USA • tel 312.321.1810 • fax 312.321.1830 • www.lineardimensions.com •
LND1083/84/85
The * denotes the specifications which apply over the full operating temperature range.
Note 1: See thermal regulation specifications for changes in output voltage due to heating effects. Load
and line regulations are measured at a constant junction temperature by low duty cycle pulse testing.
Note 2: Line and load regulation are guaranteed up to the maximum power dissipation (60W for the
LND1083, 45W for the LND1084 (K, P) 30W for the LND1084 (T) and 30W for the LND1085). Power
dissipation will not be available over the full input/output voltage range.
Note 3:Ifillload is defined in the current limit curves. Ifillload curve is defined as the minimum value of current
limit as a function of input to output voltage.
Note 4: Dropout voltage is specified over the full output current range of the device.
Note 5: For LND1083 IfillLoad is 5Afor -55ºC ≤Tj ≤ -40ºand 7.5A for Tj >-40ºC
BLOCK DIAGRAM
• Linear Dimensions, Inc. • 445 East Ohio Street, Chicago IL 60611 USA • tel 312.321.1810 • fax 312.321.1830 • www.lineardimensions.com •
LND1083/84/85
APPLICATIONS INFORMATION
The LND1083 family of three-terminal
adjustable regulators is easy to use and has all
the protection features that are expected in
high performance voltage regulators.
Stability
The circuit design used in the LND1083 series
requires the use of an output capacitor as part
of the device frequency compensation. The
addition of 150 µF aluminum electrolytic or a
22 µF solid tantalum on the output will ensure
stability for all operating conditions.
Output Voltage
The LND1083 develops a 1.25V reference
voltage between the Output pin and the Adjust
pin (Figure 1). Placing a resistor between
these two terminals causes a constant current
to flow through R1 and down though R2 to set
the output voltage. In general R1 is chosen so
that this current is the specified minimum load
current of 10mA. The current out of the Adjust
pin is small as compared to the current from
R1and can be ignored.
Microsecond surge currents of 50A to 100A
can be handled by the internal diode
between the Output pin and the Input pin of
the device. In normal operations it is difficult
to get those values of surge currents even
with the use of large output capacitance.
Only with high value output capacitors, such
as 1000 to 5000µF and with the Input pin
instantaneously shorted to ground, can
damage occur. A diode from output to input
is recommended (Figure 2).
Protection Diodes
In normal operation LND1083 family does not
need any protection diodes between the
adjustment pin and the output and from the
out to the input to prevent die overstresses.
Internal resistors are limiting the internal
current paths on the ADJ pin. Therefore
even with bypass capacitors on the adjust pin
no protection diode is needed to ensure
device safety under short-circuit conditions.
Thermal Considerations
The LND1083 series have internal power and
thermal-limiting circuitry designed to protect
the device under overload conditions.
However, maximum junction temperature
ratings should not be exceeded under
continuous normal load conditions. Careful
consideration must be given to all sources of
thermal resistance from junction to ambient,
including junction-to-case, case to-heat sink
interface and heat sink resistance itself.
• Linear Dimensions, Inc. • 445 East Ohio Street, Chicago IL 60611 USA • tel 312.321.1810 • fax 312.321.1830 • www.lineardimensions.com •
Figure 1 Output Voltage Figure 2. Protection Diodes.
