LT1085–220M–05
LT1085–05–220M
LT1085–12–220M
MILITARY VERSION
TO–220 Isolated Metal Package
10.41
10.67
4.70
5.00
0.70
0.90
3.56
Dia.
3.81
10.41
10.92
LOW DROPOUT
3 AMP POSITIVE
VOLTAGE REGULATOR
FEATURES
•
•
•
•
•
•
•
Low Dropout Performance
Fixed or Adjustable Voltages
Fixed Output Voltages of 5V & 12V
Output Current 3A
Line Regulation 0.015% / V Typical.
Load Regulation 0.1% Typical.
Military Temperature Range (–55 to +150°C)
16.38
16.89
13.39
13.64
1 2 3
12.70
19.05
0.89
1.14
2.54
BSC
2.65
2.75
BLOCK DIAGRAM
V
IN
Pinouts
Pin
1
2
3
Fixed
Adjustable
GROUND
ADJUST
OUTPUT
OUTPUT
INPUT
INPUT
Case is ISOLATED
THERMAL
LIMIT
Ordering Information
LT1085–220M
LT1085–05–220M
LT1085–12–220M
Positive Adjustable Regulator
Fixed +5V Regulator
Fixed +12V Regulator
V
ADJ
V
OUT
ABSOLUTE MAXIMUM RATINGS
(T
case
= 25°C unless otherwise stated)
V
IN
V
I-O
P
D
V
IN
Input Voltage
Input–Output Differential Voltage
Power Dissipation
Operating Input Voltage
Adjustable
5 Volt
12 Volt
Control
Power
5V, 12V
Adjustable
30V
35V
Internally limited
25V
20V
25V
–55 to 150°C
–55 to 200°C
–65 to 150°C
300°C
T
J
T
STG
T
LEAD
Operating Junction Temperature Range
Storage Temperature Range
Lead Temperature (for 10 sec.)
* Although the devices’ maximum operating voltage is limited (20V for the 5V device, and 25V for the 12V and adjustable devices) 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 5V and 12V devices operating at input-output voltage differentials >15V, a minimum external load of 5mA is required to
maintain regulation.
Semelab plc.
Telephone +44(0)1455 556565. Fax +44(0)1455 552612.
E-mail:
sales@semelab.co.uk
Website:
http://www.semelab.co.uk
Prelim. 10/95
LT1085–220M–05
LT1085–05–220M
LT1085–12–220M
MILITARY VERSION
DESCRIPTION
The LT1085 is designed to provide 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 output voltage to 1%. Current limit is also trimmed, minimising the stress on both
the regulator and power source circuitry under overload conditions.
The LT1085 is pin compatible with older 3 terminal adjustable regulators. A 10
m
F 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 LT1085 quiescent
current flows into the load, increasing efficiency.
ELECTRICAL CHARACTERISTICS
Parameter
(T
J
= 25°C unless otherwise stated)
Min.
I
O
= 0 to 3A
I
O
= 0 to 3A
I
O
= 10mA to 3A
4.90
Output
Voltage Test Conditions
5
V
IN
= 6.5 to 20V
T
J
= –55 to 150°C
V
IN
= 13.5V to 25V
T
J
= –55 to 150°C
V
IN
– V
OUT
= 1.5 to 15V
T
J
= –55 to 150°C
V
IN
= 6.5 to 20V
I
O
= 0
V
IN
= 13.5 to 25V
I
O
= 0
V
IN
– V
OUT
= 1.5 to 15V
I
LOAD
= 10mA
V
IN
= 8V
I
O
= 0 to 3A
V
IN
= 15V
I
O
= 0 to 3A
V
IN
– V
OUT
= 3V
I
O
= 10mA to 3A
T
J
= –55 to 150°C
T
J
= –55 to 150°C
T
J
= –55 to 150°C
T
J
= –55 to 150°C
T
J
= –55 to 150°C
T
J
= –55 to 150°C
T
J
= –55 to 150°C
T
J
= –55 to 150°C
T
J
= –55 to 150°C
Typ. Max.
5
5.10
Unit
V
O
Output Voltage
12
11.76
12
12.24
V
V
REF
Reference Voltage
ADJ.
1.225
1.25
0.5
1
1
2
0.015
0.035
5
10
12
24
0.1
0.2
1.3
1.270
10
10
25
25
0.2
0.2
20
35
36
72
0.3
0.4
1.5
%
mV
%
mV
5
REG
(LINE)
Line Regulation
12
ADJ.
5
REG
(LOAD)
Load Regulation
12
See notes 1,2
ADJ.
5
D
V
OUT
= 50mV
I
OUT
= 3A
V
D
Dropout Voltage
12
D
V
OUT
= 120mV
I
OUT
= 3A
1.3
1.5
V
See note 3
ADJ.
D
V
REF
= 1%
I
OUT
= 3A
1.3
1.5
Semelab plc.
Telephone +44(0)1455 556565. Fax +44(0)1455 552612.
E-mail:
sales@semelab.co.uk
Website:
http://www.semelab.co.uk
Prelim. 10/95
LT1085–220M–05
LT1085–05–220M
LT1085–12–220M
MILITARY VERSION
ELECTRICAL CHARACTERISTICS
Parameter
I
CL
I
Q
Current Limit
Quiescent Current
Minimum Load Current
REG
(THERM)
4
(T
J
= –55 to +150°C unless otherwise stated)
Min.
T
J
= –55 to 150°C
T
J
= –55 to 150°C
T
J
= –55 to 150°C
T
J
= –55 to 150°C
T
J
= –55 to 150°C
T
A
= 25°C
V
IN
= 8V
V
IN
= 15V
V
IN
– V
OUT
= 3V
C
ADJ
= 25
m
F
T
J
= –55 to 150°C
60
54
60
3.2
0.2
Output
Voltage Test Conditions
V
IN
– V
OUT
= 5V
V
IN
– V
OUT
= 25V
5
12
ADJ.
Typ. Max.
4
0.5
5
5
5
0.004
68
60
75
55
120
0.2
0.5
5
10
10
10
0.02
Unit
A
£
20V
V
IN
£
25V
V
IN
V
IN
– V
OUT
= 25V
T
P
= 30ms
T
J
= –55 to 150°C
C
OUT
= 25
m
F Tantalum
f = 120Hz
I
O
= 3A
mA
Thermal Regulation
5
12
ADJ.
%/W
R
A
Ripple Rejection
dB
I
PIN
Adjust Pin Current
Adjust Pin Current Change
Temperature Stability
Long Term Stability
RMS Output Noise
Thermal Resistance
Junction – Case
ADJ.
m
A
m
A
%
D
I
PIN
T
S
V
N
R
q
JC
ADJ.
V
IN
– V
OUT
= 1.5 to 15V
I
O
= 10mA to 3A
T
J
= –55 to 150°C
T
A
= 125°C
f = 10Hz to 10kHz
T = 1000 Hrs
T
A
= 25°C
Control Circuitry
Power Transistor
T
J
= –55 to 150°C
0.3
0.003
TBA
TBA
1
%
%
°C/W
Notes:
1. 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. Load regulation is measured at the output
lead
»
1/8
” from the package.
2. Line and load regulation are guaranteed up to the maximum power dissipation of 30W. 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 voltage range.
3. Dropout voltage is specified over the full output current range of the device.
Semelab plc.
Telephone +44(0)1455 556565. Fax +44(0)1455 552612.
E-mail:
sales@semelab.co.uk
Website:
http://www.semelab.co.uk
Prelim. 10/95