OM183SC OM185ST
OM184SC OM186ST
OM185SR
OM186SR
7.5A, 5A, 3A, 1.5A LOW DROPOUT POSITIVE
ADJUSTABLE REGULATORS
Three Terminal Adjustable Low Dropout
TO-257/TO-258 Positive Voltage Regulators
FEATURES
•
•
•
•
•
•
Operates Down to 1V Dropout, 1.5V @ Max. Current
.015% Line Regulation
.01% Load Regulation
1% Reference Voltage
Hermetic TO-257 and TO-258 Isolated Packages
Electrically Equivalent to LT1083, 84, 85 and 86
DESCRIPTION
These three terminal positive adjustable voltage regulators are designed to provide
7.5A, 5A, 3A, and 1.5A with higher efficiency than conventional voltage regulators. The
devices are designed to operate to 1 Volt input to output differential and the dropout
voltage is specified as a function of load current. All devices are pin compatible with
older three terminal regulators. Supplied in the easy-to-use hermetic metal TO-257
and TO-258 JEDEC packages also supplied in Omnirel’s new surface mount D
2
Pac..
These devices are ideally suited for Military applications where small size, hermeticity
and high reliability are required.
ABSOLUTE MAXIMUM RATINGS
@ 25°C
Input Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 V
Operating Junction Temperature Range . . . . . . . . . . . . . . . . . . . . - 55°C to + 150°C
Storage Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . - 65°C to + 150°C
Output Current - OM183SC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.5 A
OM184SC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 A
OM185ST/SR. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 A
OM186ST/SR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.5 A
3.3
Note:
OM183SC and OM184SC products are packaged in the TO-258 Package (7.5A & 5A).
OM185ST and OM186ST products are packaged in the TO-257 Package (3A & 1.5A).
0 03 R3
Supersedes 4 11 R2
3.3 - 1
OM183SC - OM186ST - OM186SR
ELECTRICAL CHARACTERISTICS
(T
C
= 25°C unless otherwise noted)
Parameter
Reference Voltage
Conditions
I
OUT
= 10 mA, T
j
= 25°C
(V
IN
- V
OUT
) = 3 V
10mA
≤
I
OUT
≤
I
FULL LOAD
1.5 V
≤
(V
IN
- V
OUT
)
≤
25 V (Note 3)
Line Regulation
I
LOAD
= 10 mA, 1.5 V
≤
(V
IN
- V
OUT
)
≤
15 V,
T
j
= 25°C
1.220
1.250
0.015
0.035
1.270
0.2
0.2
V
%
%
1.238
1.250
1.262
V
Min.
Typ.
Max.
Units
15 V
≤
(V
IN
- V
OUT
)
≤
35 V (Notes 1 & 2)
Load Regulation
(V
IN
- V
OUT
) = 3 V
10 mA
≤
I
OUT
≤
I
FULL LOAD
T
j
= 25°C
(Notes 1, 2, 3)
Dropout Voltage
Current Limit
OM183SC
(V
IN
- V
OUT
) = 5 V
(V
IN
- V
OUT
) = 25 V
OM184SC
(V
IN
- V
OUT
) = 5 V
(V
IN
- V
OUT
) = 25 V
OM185ST/SR
(V
IN
- V
OUT
) = 5 V
(V
IN
- V
OUT
) = 25 V
OM186ST/SR
(V
IN
- V
OUT
) = 5 V
(V
IN
- V
OUT
) = 25 V
Minimum Load Current
Thermal Regulation
OM183SC
OM184SC
OM185ST/SR
OM186ST/SR
Ripple Rejection
f = 120 Hz
C
ADJ
= 25 µF Tantalum
I
OUT
- I
FULL LOAD
(V
IN
- V
OUT
) = 3 V
Adjust Pin Current
Adjust Pin Current Change
T
J
= 25°C
10mA
≤
I
OUT
≤
I
FULL LOAD
1.5 V
≤
(V
IN
- V
OUT
)
≤
25 V
Temperature Stability
Long Term Stability
Thermal Resistance
TO-257AA/D
2
Pac
TO-258AA
-55°C
≤
T
J
≤
+150°C
T
A
= 125°C, 1000 Hrs.
Junction-to-Case
60
(V
IN
- V
OUT
) = 25 V
T
A
= 25°C, 30 ms pulse
Guaranteed by design
∆V
REF
= 1%, I
OUT
= I
FULL LOAD
0.05
0.5
%
0.5
.8
1.3
0.8
1.0
1.5
%
%
V
8.0
0.4
5.5
0.3
3.2
0.2
1.5
0.75
5
10
A
A
A
A
A
A
A
A
mA
0.002
0.003
0.004
0.010
0.01
0.15
0.02
0.05
%/W
%/W
%/W
%/W
75
55
dB
µA
3.3
0.2
0.5
0.3
5
µA
%
1
%
4.2
2.75
°C/W
°C/W
Note 1:
Load and line regulation 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 (OM183/60W, OM184/45W, OM185/30W,
OM186/15W). 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.
Note 3:
I
FULL LOAD
curve is defined as the minimum value of current limit as a function of input to output voltage. Note that power
dissipation is only achievable over a limited range of input to output voltage.
Note 4:
Dropout voltage is specified over the full output current range of the device.
3.3 - 2
OM183SC - OM186ST - OM186SR
TYPICAL PERFORMANCE CHARACTERISTICS
Minimum Input/Output Differential (V)
OM183SC Dropout Voltage
2
Short Circuit Current (A)
12
10
8
6
T
J
= -55°C
T
J
= 25°C
T
J
= 150°C
OM183SC Short Circuit Current
0.10
Output Voltage Deviation (%)
0.05
0
-0.05
-0.10
-0.15
OM183SC Load Regulation
I = 7.5A
1
T
J
= 25°C
4
2
0
0
5
I
FULL LOAD
0
0 1 2 3 4 5 6 7 8 9 10
Output Current (A)
10
15
20
25
30
35
Input/Output Differential (V)
OM184SC Short Circuit Current
10
9
8
6
6
5
4
3
2
1
0
T
J
= -55°C
-0.20
-50 -25 0 25 50 75 100 125 150
Temperature (°C)
OM184SC Load Regulation
0.10
Output Voltage Deviation (%)
I = 5A
Minimum Input/Output Differential (V)
OM184SC Dropout Voltage
2
Short Circuit Current (A)
T
J
= 150°C
T
J
= 25°C
0.05
0
-0.05
-0.10
-0.15
-0.20
-50 -25 0 25 50 75 100 125 150
Temperature (°C)
OM185ST Load Regulation
0.10
1
T
J
= 25°C
I
FULL LOAD
0
0
1
2
3
4
5
6
0
5
10
15
20
25
30
35
Output Current (A)
OM185ST Dropout Voltage
2
Short Circuit Current (A)
6
5
4
3
2
1
Input/Output Differential (V)
OM185ST Short Circuit Current
Output Voltage Deviation (%)
Minimum Input/Output Differential (V)
I = 3A
T
J
= 150°C
T
J
= 25°C
0.05
0
-0.05
-0.10
-0.15
-0.20
-50 -25 0 25 50 75 100 125 150
Temperature (°C)
OM186ST Load Regulation
1
T
J
= 25°C
T
J
= -55°C
I
FULL LOAD
0
0
0
1
2
3
4
0
5
10
15
20
25
30
35
Output Current (A)
OM186ST Dropout Voltage
Input/Output Differential (V)
OM186ST Short Circuit Current
3.0
Short Circuit Current (A)
2.5
2.0
1.5
1
.5
I
FULL LOAD
T
J
= -55°C
3.3
Minimum Input/Output Differential (V)
2
0.10
Output Voltage Deviation (%)
I = 3A
T
J
= 150°C
T
J
= 25°C
0.05
0
-0.05
-0.10
-0.15
-0.20
-50 -25 0 25 50 75 100 125 150
Temperature (°C)
1
T
J
= 25°C
0
0
1
Output Current (A)
2
0
0
5 10 15 20 25 30
Input/Output Differential (V)
35
3.3 - 3
OM183SC - OM186ST - OM186SR
APPLICATION NOTES
Stability
The OM183-186 Series requires the use of an output
capacitor as part of the device frequency compensation.
For all operating conditions, the addition of 150µF alu-
minum electrolytic or a 22µF solid tantalum on the output
will ensure stability. Normally, capacitors much smaller
than this can be used. Many different types of capacitors
with widely varying characteristics are available. These
capacitors differ in capacitor tolerance (sometimes ranging
up to ±100%), equivalent series resistance, and capaci-
tance
temperature
coefficient.
The 150µF or 22µF values given will ensure stability.
When the adjustment terminal is bypassed to improve the
ripple rejection, the requirement for an output capacitor
increases. The values of 22µF tantalum or 150µF alu-
minum cover all cases of bypassing the adjustment termi-
nal. Without bypassing the adjustment terminal, smaller
capacitors can be used with equally good results and the
table below shows approximately what size capacitors are
needed to ensure stability.
Recommended Capacitor Values
Input
10µF
10µF
Output
10µF Tantalum, 50µF Aluminum
22µF Tantalum, 150µF Aluminum
Adjustment
None
20µF
Normally, capacitor values on the order of 100µF are used
in the output of many regulators to ensure good transient
response with heavy load current changes. Output capac-
itance can be increased without limit and larger values of
output capacitor further improve stability and transient
response of the OM183SC regulators.
Output Voltage — Adjustable Regulators
The OM183-OM186 devices develop a 1.25V reference
voltage between the output and the adjust terminal (see
below). By placing a resistor, R1, between these two ter-
minals, a constant current is caused to flow through R1
and down through R2 to set the overall output voltage.
Normally this current is the specified minimum load current
of 10mA. Because I
ADJ
is very small and constant when
compared with the current through R1, it represents a
small error and can usually be ignored.
V
IN
IN OM183SC OUT
ADJ
I
ADJ
50 µA
R2
V
OUT
= V
REF
1+ R1 + I
ADJ
R2
V
OUT
V
REF
R1
(
)
R2
Basic Adjustable Regulator
MECHANICAL SPECIFICATIONS
P/N OM183SC and OM184SC JEDEC TO-258AA
.165
.155
.695
.685
.270
.240
.045
.035
.835
.815
.707
.697
.550
.530
1
.092 MAX.
.750
.500
.065
.055
.140 TYP.
.005
2
3
Pin 1 - Adjust
Pin 2 - V
OUT
Pin 3 - V
IN
.200 TYP.
P/N OM185ST and OM186ST JEDEC TO-257AA
.420
.410
.200
.190
.045
.035
.665
.645
.537
.527
.430
.410
.038 MAX.
3.3
.150
.140
.750
.500
.005
Pin 1 - Adjust
Pin 2 - V
OUT
Pin 3 - V
IN
1
2
3
.035
.025
.100 TYP.
.120 TYP.
205 Crawford Street, Leominster, MA 01453 USA (508) 534-5776 FAX (508) 537-4246
OM183SC - OM186ST - OM186SR
MECHANICAL OUTLINE
SOLDERING FOOTPRINT
1 2 3
Pin 1:
Pin 2:
Pin 3:
Case
Adjust
Vout
Vin
N/C
TYPICAL SOLDERING PROFILE
Figure 1 shows a typical soldering profile for the D2 and D3 Packages when soldering a to a printed circuit board. The
profile will vary from system to system and solders to solders. Factors that can affect the profile include the type of sol-
dering system used, density and type of components on the board or substrate material being used. This profile shows
temperature versus time. The two profiles described are based on a high density and a low density board. The type sol-
der used was 62/36/2 Tin Lead Silver with a melting point between 177-189ºC. An convection/infrared soldering reflow
system was used. The circuit and solder joints heat up first due to their mass followed by the components which typi-
cally run 30 degrees cooler than the solder joints.
TYPICAL HEATING PROFILE
PART NUMBER DESIGNATOR
OM
183
S
R
M
Omnirel
Device
Type
Isolated
Package
Package
Style
Hi-Rel Screening
Level
205 Crawford Street, Leominster, MA 01453 USA (508) 534-5776 FAX (508) 537-4246
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