LT1085
LT1085G
LT1085IG
LT1085SMD
3 AMP POSITIVE
VOLTAGE REGULATOR
INPUT
SAFE AREA
PROTECT ION
CU RR EN T
LIMITING
AMPLIFIER
L IM I T
OU TPUT
SEN SE
T H E R M AL
O V ER L O AD
VOL T AGE
REGUL ATION
AMPLIFIER
VR E F
FEATURES
• Low Dropout Performance
• Fixed or Adjustable Voltages
• Fixed Output Voltages of 3.3V, 5V & 12V
• Adjustable Output Voltage Range From 1.2V
• Line Regulation 0.015% / V Typical.
• Load Regulation 0.01% Typical.
• Available in Hermetically Sealed TO–3, SMD1 and
TO–257 (isolated & non-isolated) Packages.
• Military Temperature Range (–55 to +150°C)
DEVICE(1)
LT1085K–XX
LT1085G–XX
LT1085IG–XX
LT1085SMD–XX
ADJUST
DESCRIPTION
The LT1085 voltage regulators are monolithic integrated circuits designed for use in applications
requiring a well regulated positive output voltage
with low input-output differential voltage.
PACKAGE
TO–3
TO–257
Isolated TO–257
SMD1
Note
1) –XX = Voltage Option: 3.3, 5 or 12
–XX = Left blank for Adjustable Option.
Features include full power usage of up to 3A load current, internal current limiting and thermal shutdown. Safe area
protection on the die is also included, providing protection of the series pass Darlington transistor under most conditions.
The hermetically sealed packages are utilised for high reliability and low thermal resistance, whilst the SMD1 package
is also designed for surface mount applications.
ABSOLUTE MAXIMUM RATINGS (Tcase = 25°C unless otherwise stated)
VIN
Input – Output Voltage Differential
PD
Power Dissipation
RθJC
Thermal Resistance Junction To Case
TO–3
TO–3
Control
Power
0.93°C / W
3.0°C / W
RθJC
Thermal Resistance Junction To Case
SMD1
SMD1
Control
Power
0.79°C / W
4.0°C / W
RθJC
Thermal Resistance Junction To Case
TO–257
TO–257
Control
Power
0.79°C / W
4.0°C / W
TJ
Operating Junction Temperature Range
Control
Power
–55 to 150°C
–55 to 200°C
TSTG
Storage Temperature Range
TLEAD
Lead Temperature (for 10 sec.)
35V
Internally limited *
–65 to 150°C
300°C
* These ratings are only applicable for power dissipations of 28 Watts over a limited range of VIN – VOUT.
Semelab Plc reserves the right to change test conditions, parameter limits and package dimensions without notice. Information furnished by Semelab is
believed to be both accurate and reliable at the time of going to press. However Semelab assumes no responsibility for any errors or omissions discovered in
its use. Semelab encourages customers to verify that datasheets are current before placing orders.
Semelab plc.
Telephone +44(0)1455 556565. Fax +44(0)1455 552612.
E-mail: sales@semelab.co.uk
Website: http://www.semelab.co.uk
Document Number 3452
Issue 4
