MIL-PRF-38534 CERTIFIED FACILITY
M.S.KENNEDY CORP.
VERY HIGH CURRENT, LOW DROPOUT
SURFACE MOUNT
VOLTAGE REGULATORS
5250
SERIES
4707 Dey Road Liverpool, N.Y. 13088
(315) 701-6751
FEATURES:
Hermetic Surface Mount Package
Extremely Low Dropout Voltage: 370mV @ 5 Amps
Available in 1.5V, 1.7V, 1.9V, 2.5V, 3.3V, 5.0V and 12.0V
On Board Thermal Shut Down
Reverse Battery and Load Dump Protection
Low Ground Current: 70mA Typical at Full Load
1% Maximum Guaranteed Accuracy
Output Current to 5 Amps
Alternate Output Voltages Available
DESCRIPTION:
The MSK 5250 series voltage regulators are available in +1.5V, +1.7V, +1.9V, +2.5V, +3.3V, +5.0V, and
+12.0V output configurations. All boast ultra low dropout specifications due to the utilization of a super PNP output
pass transistor with monolithic technology. Dropout voltages of 370mV at 5 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 MSK 5250 series is packaged in a space efficient 3 pin power surface mount ceramic package.
EQUIVALENT SCHEMATIC
TYPICAL APPLICATIONS
PIN-OUT INFORMATION
1 VIN
2 VOUT
3 Ground
High Efficiency, High Current Linear Regulators
Constant Voltage/Current Regulators
System Power Supplies
Switching Power Supply Post Regulators
Battery Powered Equipment
LID=ISOLATED
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8548-44 Rev. G 4/12
10
ABSOLUTE MAXIMUM RATINGS
VINP
VIN
VEN
IOUT
Input Voltage (100mS 1%D.C.) -20V to +60V
Input Voltage
26V
Enable Voltage
-0.3V to 26V
Output Current
5.0A
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TST
TLD
Storage Temperature Range
Lead Temperature . . . . . . .
(10 Seconds Soldering)
Operating Temperature
MSK 5250 Series . . . . . . .
MSK 5250H Series . . . . . .
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TJ
. . -65°C to +150°C
. . . . . . . . . . 300°C
. . -40°C to +85°C
. -55°C to +125°C
ELECTRICAL SPECIFICATIONS
Parameter
Test Conditions 1 3
MSK 5250 SERIES
MSK 5250H SERIES
Group A
Typ.
Max. Units
Typ.
Max. Min.
Subgroup Min.
1
-
±0.5
±1.0
-
±0.5
±1.0
%
2, 3
-
±1.0
±2.0
-
-
-
%
ΔVOUT = -1%; IOUT = 250 mA
1
-
125
250
-
125
275
mV
ΔVOUT = -1%; IOUT = 5A
1
-
370
600
-
370
625
mV
VIN = VOUT+1.5V
1
-
±0.2
±1.0
-
±0.2
±1.2
%
10 mA ≤ IOUT ≤ 4.5A
2, 3
-
±0.3
±2.0
-
±0.3
-
%
(VOUT +1V) ≤ VIN ≤ 26V
1
-
±0.05
±0.5
-
±0.05
±0.6
%
IOUT = 10 mA
2, 3
-
±0.5
±1.0
-
±0.5
-
%
VOUT = 0V; VIN = VOUT +1V
-
-
7.5
10
-
7.5
10
A
VIN = VOUT +1V; IOUT = 2.5A
-
-
25
60
-
25
65
mA
VIN = VOUT +1V; IOUT = 5A
-
-
80
-
-
80
-
mA
CL = 20μF; 10 HZ ≤ f ≤ 100 KHZ
-
-
400
-
-
400
-
μV
Thermal Resistance 2
Junction to Case @ 125°C
-
-
1.7
2.0
-
1.7
2.2
°C/W
Thermal Shutdown 2
TJ
-
-
130
-
-
130
-
°C
Output Voltage Tolerance
Dropout Voltage
Load Regulation
2
8
Line Regulation
Output Current Limit 2 9
Ground Current
2
Output Noise 2
IOUT = 10mA; VIN = VOUT +1V
PART
NUMBER
NOTES:
OUTPUT
VOLTAGE
MSK5250-1.5
7
+1.5V
MSK5250-1.7
+1.7V
+1.9V
MSK5250-1.9
1 Output decoupled to ground using 47μF minimum capacitor unless otherwise specified.
2 This parameter is guaranteed by design but need not be tested.
+2.5V
MSK5250-2.5
Typical parameters are representative of actual device performance but are for reference only.
3 All output parameters are tested using a low duty cycle pulse to maintain TJ = TC.
+3.3V
MSK5250-3.3
4 Industrial grade devices shall be tested to subgroup 1 unless otherwise specified.
+5.0V
MSK5250-5.0
5 Military grade devices ('H' suffix) shall be 100% tested to subgroups 1,2,3.
6 Subgroup 1 TC = +25°C
+12.0V
MSK5250-12
Subgroup 2 TJ = +125°C
Subgroup 3 TA = -55°C
7 Please consult the factory if alternate output voltages are required.
8 Due to current limit, maximum output current may not be available at all values of VIN-VOUT and temperatures.
See typical performance curves for clarification.
9 The output current limit function provides protection from transient overloads but it may exceed the maximum continuousrating.
Continuous operation in current limit may damage the device.
10 Continuous operation at or above absolute maximum ratings may adversely effect the device performance and/or life cycle.
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8548-44 Rev. G 4/12
APPLICATION NOTES
REGULATOR PROTECTION:
PACKAGE CONNECTIONS:
The MSK 5250 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.
The MSK 5250 series are highly thermally conductive
devices and the thermal path from the package heat sink
to the internal junctions is very short. Standard surface
mount soldering techniques should be used when mounting the device. Some applications may require additional
heat sinking of the device.
OUTPUT CAPACITOR:
HEAT SINK SELECTION:
The output voltage ripple of the MSK 5250 series voltage regulators 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 20μF is recommended for optimum performance. Transient load response can also be
improved by placing a capacitor directly across the load.
The capacitor should not be an ultra-low ESR type. Tantalum capacitors are best for fast load transients but
aluminum electrolytics will work fine in most applications.
To select a heat sink for the MSK 5250, the following
formula for convective heat flow may be used.
Governing Equation:
Tj = Pd x (Rθjc + Rθcs + Rθsa) + Ta
WHERE:
Tj = Junction Temperature
Pd = Total Power Dissipation
Rθjc = Junction to Case Thermal Resistance
Rθcs = Case to Heat Sink Thermal Resistance
Rθsa = Heat Sink to Ambient Thermal Resistance
Ta = Ambient Temperature
First, the power dissipation must be calculated as follows:
LOAD CONNECTIONS:
In voltage regulator applications where very large load
currents 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.
Power Dissipation = (Vin - Vout) x Iout
Next, the user must select a maximum junction temperature. The absolute maximum allowable junction temperature is 125°C. The equation may now be rearranged to
solve for the required heat sink to ambient thermal resistance (Rθsa).
MINIMIZING POWER DISSIPATION:
Many applications can not take full advantage of the
extremely low dropout specifications of the regulator due
to large input to output voltage differences. The simple
circuit below illustrates a method to reduce the input
voltage at the regulator to just over the dropout specification to keep the internal power dissipation minimized:
EXAMPLE:
An MSK 5250-3.3 is configured for Vin=+5V and
Vout=+3.3V. Iout is a continuous 1A DC level. The
ambient temperature is +25°C. The maximum desired
junction temperature is 125°C.
Rθjc = 1.7°C/W and Rθcs = 0.5°C/W typically.
Power Dissipation = (5V - 3.3V) x (1A)
= 1.7 Watts
Solve for Rθsa:
Rθsa = 125°C - 25°C - 1.7°C/W - 0.5°C/W
1.7W
[
]
= 56.62°C/W
In this example, a heat sink with a thermal resistance of
no more than 56°C/W must be used to maintain a junction temperature of no more than 125°C.
For a given continuous maximum load of 1 amp, R1 can
be selected to drop the voltage seen at the regulator to
4V. This allows for the output tolerance and dropout
specifications. Input voltage variations (5V) also should
be included in the calculations. The resistor should be
sized according to the power levels required for the application.
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8548-44 Rev. G 4/12
TYPICAL PERFORMANCE CURVES
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8548-44 Rev. G 4/12
MECHANICAL SPECIFICATIONS
WEIGHT=2.2GRAMS TYPICAL
NOTE: ALL DIMENSIONS ARE ±0.010 INCHES UNLESS OTHERWISE LABELED.
ORDERING INFORMATION
MSK5250-3.3 H
SCREENING
BLANK= INDUSTRIAL; H= MIL-PRF-38534 CLASS H
OUTPUT VOLTAGE
1.5=+1.5V; 1.7=+1.7V; 1.9=+1.9V; 2.5=+2.5V;
3.3=+3.3V; 5.0=+5.0V; 12=+12.0V
GENERAL PART NUMBER
The above example is a +3.3V, Military regulator.
M.S. Kennedy Corp.
4707 Dey Road, Liverpool, New York 13088
Phone (315) 701-6751
FAX (315) 701-6752
www.mskennedy.com
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.
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8548-44 Rev. G 4/12