ISO-9001 CERTIFIED BY DSCC
M.S.KENNEDY CORP.
HIGH CURRENT,
SUPER LOW DROPOUT
ADJUSTABLE VOLTAGE REGULATOR
5012
4707 Dey Road Liverpool, N.Y. 13088
(315) 701-6751
MIL-PRF-38534 QUALIFIED
FEATURES:
Extremely Low Dropout Voltage 0.45V @ 10 Amps
Output Voltage Adjustable from +1.30V to +36V
Low External Component Count
Electrically Isolated Case
Low Quiescent Current
Output Current to 10 Amps
Available in Two Package Styles
Available with Three Lead Form Options
DESCRIPTION:
The MSK 5012 voltage regulator output is fully programmable through the use of two external resistors. Ultra low
dropout voltage specifications are realized due to the unique output configuration which uses an extremely low
Rds(on) MOSFET as a pass element. Dropout voltages of 0.45V at ten amps are typical in this configuration which
drives efficiency up and power dissipation down. Accuracy is guaranteed with a ±1% initial output voltage tolerance
that only varies ±2% with temperature. The MSK 5012 is packaged in a space efficient 5 pin SIP package that is
electrically isolated from the internal circuitry allowing direct heat sinking for efficient thermal dissipation.
EQUIVALENT SCHEMATIC
TYPICAL APPLICATIONS
High Efficiency, High Current Linear Regulators
Constant Voltage/Current Regulators
System Power Supplies
Switching Power Supply Post Regulators
1
Rev. H 10/02
ABSOLUTE MAXIMUM RATINGS
VIN
IOUT
TJ
Input Voltage
Output Current
Junction Temperature
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TST
TLD
36V
10A within SOA
+175°C
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TC
Storage Temperature Range -65°C to +150°C
Lead Temperature Range
300°C
(10 Seconds)
Case Operating Temperature
MSK5012
-40°C to +85°C
MSK5012B/E
-55°C to +125°C
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ELECTRICAL SPECIFICATIONS
Parameter
Output Voltage Range
R2=10KΩ
Ouput Voltage Tolerance 7
MSK 5012B/E
Group A
Test Conditions 3
IOUT=100mA; VIN=VOUT+3V
MSK 5012
Units
Subgroup
Min.
Typ.
Max.
Min.
Typ.
Max.
-
1.3
-
36
1.3
-
36
V
1
-
±0.3
±1.0
±0.3
±1.5
%
2,3
-
±1.0
±2.0
-
-
-
%
With Respect to VOUT
-
1.3
-
36
1.3
-
36
V
Dropout Voltage 2
IOUT= 0A
1
-
0.002
0.010
-
0.002
0.010
V
Dropout Voltage 2
IOUT=10A
1
-
0.4
0.75
-
0.5
1.0
V
VIN=VOUT+3V
1
-
±0.5
±1.0
-
±0.5
±1.5
%
100mA ≤ IOUT ≤ 9A
2,3
-
±0.5
±2.0
-
-
-
%
1
-
±0.3
±1.0
-
±0.3
±1.5
%
2,3
-
-
±1.0
-
-
-
%
Input Voltage 2
Load Regulation
(VOUT +1.5) ≤ VIN ≤ (VOUT+15), IOUT=100mA
Line Regulation
1
-
4.5
10
-
4.5
12
mA
2,3
-
-
10
-
-
-
mA
f=120Hz
-
-
45
-
-
45
-
dB
Junction to Case @ 125°C
-
-
0.7
0.8
-
0.7
0.8
°C/W
-
5
Quiescent Current
VIN=VOUT+3V; IOUT=0A
Ripple Rejection 2
Thermal Resistance 2
Output Settling Time
VAdjust Voltage
2
To within 10mV (IOUT=0A)
-
VIN = VOUT +3V
1
1.222 1.235
-
-
5
-
µS
1.248
1.21
1.24
1.26
V
NOTES:
1 Output decoupled to ground using 47µF minimum capacitor and R1=30KΩ; R2=10KΩ unless otherwise specified.
2 This parameter is guaranteed by design but need not be tested. Typical parameters are representative of actual device
performance at 25°C but are for reference only.
3 All output parameters are tested using a low duty cycle pulse to maintain TJ = TC.
4 Industrial grade and "E" suffix devices shall be tested to subgroup 1 unless otherwise specified.
5 Military grade devices ('B' suffix) shall be 100% tested to subgroups 1,2 and 3.
6 Subgroup 1
TA=TC=+25°C
Subgroup 2
TA=TC=+125°C
Subgroup 3
TA=TC=-55°C
7 Does not include tolerance effects from external resistors.
2
Rev. H 10/02
APPLICATION NOTES
MINIMIZING OUTPUT RIPPLE:
FILTER CAPACITOR:
The output voltage ripple of the MSK 5012 voltage regulator
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 and is best determined by
experimentation. Transient load response can also be improved
by placing a capacitor directly across the load. Typically a
10µF capacitor is a good starting point.
For all applications, the user must connect a 1.0uF capacitor
from pin 5 directly to ground. This capacitor is part of the
circuit which drives the gate of the internal MOSFET. Approximately three times the voltage seen on the input will appear
across this capacitor. Careful attention must be paid to capacitor voltage rating since voltages larger than the power supply
are present.
CASE CONNECTIONS:
HEAT SINK SELECTION:
The case of the MSK 5012 is electrically isolated from the
internal circuitry so that a direct connection can be made to
the heat sink for most efficient heat dissipation. However, it
may be necessary in some applications to connect the case to
ground. Grounding the case will help eliminate oscillations and
produce a clean, noise free output.
To select a heat sink for the MSK 5012, the following formula
for convective heat flow must 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
LOAD REGULATION:
For best results, the ground pin should be connected directly to
the load (see next note). This effectively reduces the ground
loop effect and eliminates excessive voltage drop in the sense
leg. It is also important to keep the output connection between the regulator and the load as short as possible since this
directly affects the load regulation. For example, if 20 gauge
wire were used which has a resistance of about .008 ohms per
foot, this would result in a drop of 8mV/ft at a load current of
1 amp.
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 175°C.
The equation may now be rearranged to solve for the required
heat sink to ambient thermal resistance (Rθsa).
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. The same holds true for the connection
from the low end of the load to ground. For best load regulation, the low end of the load must be connected directly to pin
2 of the MSK 5012 and not to a ground plane inches away
from the hybrid.
EXAMPLE:
An MSK 5012 is configured for Vin = +7V and Vout = +3.3V.
Iout is a continuous 10A DC level. The ambient temperature is
+25°C. The maximum desired junction temperature is 150°C.
Rθjc = 0.8°C/W and Rθcs = 0.15°C/W typically.
Power Dissipation = (7V - 3.3V) x (10A)
= 37 Watts
Solve for Rθsa:
Rθsa = 150°C - 25°C - 0.8°C/W - 0.15°C/W
37W
In this example, a heat sink with a thermal resistance of no
more than 2.43°C/W must be used to maintain a junction temperature of no more than 150°C. The Thermalloy Corporation
makes a heat sink with a thermal resistance of 2.2°C/W that
would work well for this application.
(See Thermalloy part number 7023)
OUTPUT VOLTAGE ADJUSTMENT
The output voltage of the MSK 5012 can be adjusted from
+1.3 volts to +36 volts. Refer to the following formula for
resistor divider selection. R2 should be 10KΩ for all applications.
POWER DISSIPATION:
R1 = R2 ((VOUT / 1.235) -1)
The output pass transistor in the MSK 5012 is rated to dissipate nearly 100 watts. The limiting factor of this device is
effective dissipation of heat generated under such conditions.
For example, to dissipate 100 watts, calculations show that
the MSK 5012 would have to be bolted to the underbelly of a
submarine submerged in the Arctic Ocean! Careful consideration must be paid to heat dissipation and junction temperature
when applying this device.
Figure one below illustrates proper resistor divider connection.
3
Rev. H 10/02
TYPICAL PERFORMANCE CURVES
4
Rev. H 10/02
MECHANICAL SPECIFICATIONS
TOP TAB
Z- TAB
NOTE: ALL DIMENSIONS ARE ±0.010 INCHES UNLESS OTHERWISE LABELED.
ESD Triangle indicates Pin 1.
ORDERING INFORMATION
MSK5012 B T U
LEAD CONFIGURATIONS
S= STRAIGHT; U= BENT UP; D= BENT DOWN
PACKAGE STYLE
T= TOP TAB; Z= Z PACK
SCREENING
BLANK= INDUSTRIAL; E=EXTENDED RELIABILITY
B=MIL-PRF-38535 CLASS H
GENERAL PART NUMBER
The above example is a Military grade regulator using the top tab package with
leads bent up.
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.
5
Rev. H 10/02