1
4707 Dey Road Liverpool, N.Y. 13088
M.S.KENNEDY CORP.
(315) 701-6571
FEATURES:
SERIES
HIGH CURRENT,
LOW DROPOUT
VOLTAGE REGULATORS
Electrically Isolated Top Tab or Z Tab SIP
Extremely Low Dropout Voltage: 350mV @ 3 Amps
Available in +1.5V,+1.7V,+1.8V,+1.9V,+2.5V,+3.3V,+5.0V and
+12.0V
TTL Level Enable Pin: Zero Current Shutdown Mode
Reverse Battery and Load Dump Protection
Low Ground Current: 42mA Typical at Full Load
1% Maximum Guaranteed Accuracy
Output Current to 3 Amps
Contact MSK for MIL-PRF-38534 Qualification Status
MIL-PRF-38534 CERTIFIED
DESCRIPTION:
The MSK 5131 series voltage regulators are available in +1.5V,+1.7V,+1.8V,+1.9V,+2.5V,+3.3V,+5.0V and
+12.0V configurations. All boast ultra low dropout specifications due to the utilization of a super PNP output pass
transistor with monolithic technology. Dropout voltages of 350mV at 3 amps are typical in this configuration, which
drives efficiency up and power dissipation down. Accuracy is guaranteed with a 1% maximum output voltage
tolerance. The series also offers a TTL/CMOS compatible on/off enable function. The MSK 5131 series is packaged
in a space efficient 5 pin power SIP available in two styles with three lead bend options.
EQUIVALENT SCHEMATIC
TYPICAL APPLICATIONS
PIN-OUT INFORMATION
High Efficiency, High Current Linear Regulators
Constant Voltage/Current Regulators
System Power Supplies
Switching Power Supply Post Regulators
Battery Powered Equipment
Enable
Vin
Ground
Vout
N/C
1
2
3
4
5
5131
Rev. B 2/06
Output Current Limit
Output Noise
Shutdown Output Current
Thermal Resistance
Thermal Shutdown
Max.
1.0
2.0
175
600
1.0
2.0
0.5
1.0
5.0
45
-
-
-
0.8
600
2
500
2.4
-
Output Voltage Tolerance
Dropout Voltage
Load Regulation
Line Regulation
Ground Current
Enable Input Voltage
Enable Input Current
Storage Temperature Range
Lead Temperature
(10 Seconds Soldering)
Operating Temperature
MSK 5131 Series
MSK 5131H/E Series
%
%
mV
mV
%
%
%
%
A
mA
mA
V
V
V
A
A
A
C/W
C
V
OUT
=-1%; I
OUT
=
100mA
V
OUT
=-1%; I
OUT
=3A
V
IN
=V
OUT
+1.5V
10mA
I
OUT
2.5A
(V
OUT
+1V)
V
IN
26V
I
OUT
=10mA
V
OUT
=0V; V
IN
=V
OUT
+1V
V
IN
=V
OUT
+1V; I
OUT
=1.5A
V
IN
=V
OUT
+1V; I
OUT
=3A
C
L
=20F; 10Hz
f
100KHz
V
ENABLE
0.8V
Junction to Case @ 125C
T
J
Input Voltage (100mS 1%D.C.)
Input Voltage
Enable Voltage
Output Current
V
INP
V
IN
V
EN
I
OUT
Parameter
T
ST
T
LD
T
J
ELECTRICAL SPECIFICATIONS
ABSOLUTE MAXIMUM RATINGS
-65C to +150C
300C
-40C to +85C
-55C to +125C
1
Test Conditions
1
2
3
4
5
6
7
8
9
NOTES:
Output decoupled to ground using 27F minimum capacitance unless otherwise specified.
This parameter is guaranteed by design but need not be tested.
Typical parameters are representative of actual device performance but are for reference only.
All output parameters are tested using a low duty cycle pulse to maintain T
J
= T
C
.
Industrial grade and "E" suffix devices shall be tested to subgroup 1 unless otherwise specified.
Military grade devices ('H' suffix) shall be 100% tested to subgroups 1,2 and 3.
Subgroup 1
Subgroup 2
Subgroup 3
Please consult the factory if alternate output voltages are required.
Due to current limit, maximum output current may not be available at all values of V
IN
-V
OUT
and
temperatures. See typical performance curves for clarification.
Continuous operation at or above absolute maximum ratings may adversely effect the device
performance and/or life cycle.
T
C
=+25C
T
J
=+125C
T
A
=-55C
HIGH/ON
LOW/OFF
HIGH/ON
LOW/OFF
MSK 5131H/E SERIES
Min.
-
-
-
-
-
-
-
-
-
-
-
-
2.4
-
-
-
-
-
-
Typ.
0.5
1.0
80
350
0.2
0.3
0.05
0.5
4.5
20
42
400
1.2
1.2
20
-
10
2.1
135
Typ.
0.5
-
80
350
0.2
0.3
0.05
0.5
4.5
20
42
400
1.2
1.2
20
-
10
2.1
135
MSK 5131 SERIES
Min.
-
-
-
-
-
-
-
-
-
-
-
-
2.4
-
-
-
-
-
-
Max.
1.0
-
200
625
1.2
-
0.6
-
5.0
45
-
-
-
0.8
600
2
500
2.5
-
Units
2
2
2
2
3
Group A
Subgroup
1
2,3
1
1
1
2,3
1
2,3
-
-
-
-
1
1
1
1
-
-
-
2
I
OUT
=10mA; V
IN
=V
OUT
+1V
2
-20V to +60V
26V
-0.3V to 26V
3.5A
2
2
2
2
Rev. B 2/06
8
9
APPLICATION NOTES
HEAT SINK SELECTION:
To select a heat sink for the MSK 5131, the following formula
for convective heat flow may be used.
Governing Equation:
Tj = Pd x (R
jc + R
cs + R
sa) + Ta
WHERE:
Tj = Junction Temperature
Pd = Total Power Dissipation
R
jc = Junction to Case Thermal Resistance
R
cs = Case to Heat Sink Thermal Resistance
R
sa = Heat Sink to Ambient Thermal Resistance
Ta = Ambient Temperature
REGULATOR PROTECTION:
The MSK 5131 series is fully protected against reversed input
polarity, overcurrent faults, overtemperature conditions (Pd) and
transient voltage spikes of up to 60V. If the regulator is used
in dual supply systems where the load is returned to a negative
supply, the output voltage must be diode clamped to ground.
First, the power dissipation must be calculated as follows:
Power Dissipation = (Vin - Vout) x Iout
Next, the user must select a maximum junction temperature.
The absolute maximum allowable junction temperature is 125C.
The equation may now be rearranged to solve for the required
heat sink to ambient thermal resistance (R
sa).
EXAMPLE:
An MSK 5131-3.3 is configured for Vin=+5V and
Vout=+3.3V. Iout is a continuous 1A DC level. The ambient
temperature is +25C. The maximum desired junction tem-
perature is 125C.
R
jc = 2.4C/W and R
cs = 0.15C/W for most thermal greases
Power Dissipation =
(5V - 3.3V) x (1A)
=
1.7 Watts
Solve for R
sa:
R
sa = 125C - 25C - 2.4C/W - 0.15C/W
In this example, a heat sink with a thermal resistance of no
more than 56C/W must be used to maintain a junction tem-
perature of no more than 125C.
DEVICE/CASE CONNECTION:
The MSK 5131 series are highly thermally conductive devices
and the thermal path from the package heat sink to the internal
junctions is very short. Since the case is electrically isolated
from the internal circuitry, the package can be directly con-
nected to a heat sink.
ENABLE PIN:
The MSK 5131 series of voltage regulators are equipped with a
TTL compatible ENABLE pin. A TTL high level on this pin acti-
vates the internal bias circuit and powers up the device. A TTL
low level on this pin places the controller in shutdown mode
and the device draws approximately 10A of quiescent cur-
rent. If the enable function is not used, simply connect the
enable pin to the input.
LOAD CONNECTIONS:
In voltage regulator applications where very large load cur-
rents are present, the load connection is very important. The
path connecting the output of the regulator to the load must be
extremely low impedance to avoid affecting the load regulation
specifications. Any impedance in this path will form a voltage
divider with the load.
OUTPUT CAPACITOR:
The output voltage ripple of the MSK 5131 series voltage regu-
lators can be minimized by placing a filter capacitor from the
output to ground. The optimum value for this capacitor may
vary from one application to the next, but a minimum of 10F
is recommended for optimum performance. This capacitor need
not be an expensive low ESR type: aluminum electrolytics are
adequate. In fact, extremely low ESR capacitors may contrib-
ute to instability. Tantalum capacitors are recommended for
systems where fast load transient response is important. Tran-
sient load response can also be improved by placing a capaci-
tor directly across the load.
1.7W
3
Rev. B 2/06
= 56.27C/W
TYPICAL PERFORMANCE CURVES
4
Rev. B 2/06
The information contained herein is believed to be accurate at the time of printing. MSK reserves the right to make
changes to its products or specifications without notice, however, and assumes no liability for the use of its products.
Please visit our website for the most recent revision of this datasheet.
Contact MSK for MIL-PRF-38534 qualification status.
MECHANICAL SPECIFICATIONS
M.S. Kennedy Corp.
4707 Dey Road, Liverpool, New York 13088
Phone (315) 701-6751
FAX (315) 701-6752
www.mskennedy.com
5
Rev. B 2/06
ORDERING INFORMATION
LEAD CONFIGURATIONS
S= STRAIGHT; U= BENT UP; D= BENT DOWN
PACKAGE STYLE
T= TOP TAB; Z= Z PACK
SCREENING
BLANK= INDUSTRIAL; E=EXTENDED RELIABILITY
H=MIL-PRF 38534 CLASS H
OUTPUT VOLTAGE
1.5=+1.5V; 1.7=+1.7V; 1.8=+1.8V; 1.9=+1.9V;
2.5=+2.5V; 3.3=+3.3V; 5.0=+5.0V; 12=+12.0V
GENERAL PART NUMBER
MSK5131-3.3 H T U
The above example is a +3.3V, Military regulator using the top tab package with leads bent up.
NOTE: ALL DIMENSIONS ARE 0.010 INCHES UNLESS OTHERWISE LABELED.
ESD Triangle indicates Pin 1.
WEIGHT = 7.5 GRAMS TYPICAL.
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