ISO-9001 CERTIFIED BY DSCC
M.S.KENNEDY CORP.
HIGH CURRENT,
SUPER LOW DROPOUT
FIXED VOLTAGE REGULATORS
5020
SERIES
4707 Dey Road Liverpool, N.Y. 13088
(315) 701-6751
FEATURES:
MIL-PRF-38534 CERTIFIED
Extremely Low Dropout Voltage: 0.50V @ 20 Amps
Available in 3.3V, 5.0V and 12.0V versions
Output Voltages Are Internally Set to ±1%
TTL Level Enable Pin
Externally Programmable Current Limit
Low Quiescent Current
Available Fully Qualified to Mil-PRF-38534
Output Current to 20 Amps
Regulation Dropout Fault Pin
DESCRIPTION:
The MSK 5020 series voltage regulators are available in +3.3V, +5.0V or +12.0V fixed output configurations. All
three boast ultra low dropout specifications due to the utilization of a MOSFET output pass transistor with extremely
low Rds(on). Dropout voltages of 0.50V at 20 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 varies only ±2%
with temperature. A TTL input level can be used to enable/disable the device and a regulation dropout Fault pin
provides a means of monitoring the output level. The MSK 5020 series is packaged in a thermally efficient 12 pin
power dip.
EQUIVALENT SCHEMATIC
TYPICAL APPLICATIONS
PIN-OUT INFORMATION
1
2
3
4
5
6
High Efficiency, High Current Linear Regulators
Constant Voltage/Current Regulators
System Power Supplies
Switching Power Supply Post Regulators
1
Enable
NC
Ground
Filter Capacitor
Input
Fault
12
11
10
9
8
7
Output
Output
Sense
VSC
VSC
Case Connection
Rev. F
1/05
9
ABSOLUTE MAXIMUM RATINGS
VIN
VEN
IOUT
TJ
Input Voltage
Enable Voltage
Output Current
Junction Temperature
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TST
TLD
36V
-0.3V to 36V
20A within SOA
+175°C
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TC
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Storage Temperature Range -65°C to +150°C
Lead Temperature Range
300°C
(10 Seconds)
Case Operating Temperature
MSK5020 Series
-40°C to +85°C
MSK5020B/E Series
-55°C to +125°C
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ELECTRICAL SPECIFICATIONS
Output Voltage Tolerance
Dropout Voltage
Group A MSK 5020B/E SERIES
Test Conditions 1 3
Parameter
Subgroup
Min.
Typ.
Max.
Min.
Typ.
Max.
Units
1
-
±0.5
±1.0
-
±0.5
±1.0
%
2,3
-
±1.0
±2.0
-
-
-
%
IOUT= 0A
1
-
0.002
0.010
-
0.002
0.010
V
IOUT=0A; VIN=VOUT+1V
2
Load Regulation
Line Regulation
MSK 5020 SERIES
IOUT=20A
1
-
0.50
0.75
-
0.5
1.0
V
VIN=VOUT+1V
1
-
±0.5
±1.0
-
±0.5
±1.0
%
0A ≤ IOUT ≤ 10A
2,3
-
±0.5
±2.0
-
-
-
%
(VOUT +1V) ≤ VIN ≤ (VOUT+15V)
1
-
±0.5
±1.0
-
±0.5
±1.0
%
IOUT=0A
2,3
-
±0.5
±1.0
-
-
-
%
1
-
20
30
-
20
30
mA
2,3
-
20
30
-
-
-
mA
1
-
10
50
-
10
50
µA
VEN=5V; VIN=VOUT+1V; IOUT=0A
Quiescent Current
VEN=0V; VIN=VOUT+1V; IOUT=0A 2
Ripple Rejection 2
Thermal Resistance
2
2,3
-
10
50
-
-
-
µA
f=120Hz
-
-
45
-
-
45
-
dB
Junction to Case @ 125°C
-
-
0.8
1.0
-
0.8
1.1
°C/W
HIGH
1
2.4
1.2
-
2.4
1.2
-
V
LOW
1
-
1.2
0.8
-
1.2
0.8
V
HIGH
1
-
20
50
-
20
50
µA
LOW
1
-
10
25
-
10
25
µA
0.5
-
-
0.5
-
mS
Enable Input Voltage 2
Enable Input Current 2
Output Settling Time 2
8
To within 10mV (IOUT=0A)
-
-
Fault Output Voltage 2
9
IFAULT=1mA
HIGH
-
-
VIN
-
-
VIN
-
V
LOW
-
-
0.09
-
-
0.09
-
V
-
1
-
10
1
-
10
mA
Fault Output Sink Current Range 2
NOTES:
1 Output decoupled to ground using 33µF minimum capacitor and RSC=0Ω unless otherwise specified.
2 Guarateed by design but not tested. 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.
4 Industrial grade and "E" suffix devices shall be tested to subgroup 1 only unless otherwise specified.
5 Military grade devices ('B' suffix) shall be 100% tested to subgroups 1,2 and 3.
TA=TC=+25°C
6 Subgroup 1
Subgroup 2
TA=TC=+125°C
Subgroup 3
TC=TC=-55°C
7 After application of enable pulse.
8 Fault pin connected to VIN through a 5.1KΩ resistor for MSK5020-5.0.
9 Continuous operation at or above absolute maximum ratings may adversly effect the device performance
and/or life cycle.
2
PART
NUMBER
OUTPUT
VOLTAGE
MSK5020-3.3
+3.3V
MSK5020-5.0
+5.0V
MSK5020-12
+12.0V
Rev. F
1/05
APPLICATION NOTES
MINIMIZING OUTPUT RIPPLE:
The output voltage ripple of the MSK 5020 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 and is best determined by
experimentation. Transient load response can also be improved
by placing a 33uF or larger capacitor directly across the load.
FILTER CAPACITOR:
For all applications, the user must connect a 1.0uF capacitor
from pin 4 directly to ground. This capacitor is part of the
circuit which drives the gate of the internal MOSFETS. 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.
HEAT SINK SELECTION:
CASE CONNECTIONS:
The case of the MSK 5020 is connected to pin seven of the
package but isolated from the internal circuitry allowing direct
attachment of the heat sink to the case. It may be necessary
in some applications to ground the case to limit noise or eliminate oscillations on the output. Pin seven can be left as a no
connect if the designer chooses.
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 80mV/ft at a load current of
10 amps.
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
3 of the MSK 5020 and not to a ground plane inches away
from the hybrid.
ENABLE/DISABLE PIN:
To select a heat sink for the MSK 5020, 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
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).
EXAMPLE;
An MSK 5020-3.3 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 tempera
ture is 150°C. Rθjc = 1.0°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 - 1.0°C/W - 0.15°C/W
37W
In this example, a heat sink with a thermal resistance of no
more than 2.23°C/W must be used to maintain a junction temperature of no more than 150°C.
POWER DISSIPATION:
The MSK 5020 series of voltage regulators are equipped with a
TTL compatible ENABLE pin. A TTL high level on this pin activates 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 only 10µA of quiescent current. This pin
can be connected to VIN if the enable function is not desired.
The output pass transistors in the MSK 5020 are rated to dissipate nearly 200 watts. The limiting factor of this device is
effective dissipation of heat generated under such conditions.
For example, to dissipate 200 watts, calculations show that
the MSK 5020 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.
FAULT PIN CONNECTIONS
CURRENT LIMIT CONNECTIONS
Pin 6 of the MSK 5020 series is the Fault pin. When the output voltage drops 6% or more below its nominal value, the
voltage level on the Fault pin drops to a logic low (typically less
than 0.1 volts). This pin can be used to drive a light emitting
diode or other external circuitry as long as the current is limited
to less than 10.0mA (see typical connection diagram). The
Fault pin is an open collector output so the high state output
voltage will be equal to the pull up voltage since no current
flows under these conditions.
To implement current limiting, a sense resistor (Rsc) must be
placed from pin 5 to pins 8,9 and 10 as shown in the typical
connection diagram. When the voltage drop across the sense
resistor reaches 35mV, the internal control loop limits the output current only enough to maintain 35mV across the sense
resistor. The device is not disabled. The following formula
may be used to find the correct value of sense resistance:
RSC=35mV/ILIM
If current limit is not required simply connect the Vsc pins directly to the input voltage along with the sense pin. Refer to
the typical connection diagram for an illustration.
3
Rev. F 1/05
TYPICAL PERFORMANCE CURVES
4
Rev. F
1/05
TYPICAL CONNECTION DIAGRAM
The above connection diagram illustrates an MSK 5020-3.3 regulator. Q1 turns on the Fault L.E.D. when pin 6 of
the hybrid drops to a logic low. Current into pin 6 is limited to approximately 1mA by the 12KΩ resistor from pin 5
to pin 6. The optimum value of capacitance COUT may vary from one application to the next depending on the load
applied. 33µF is a good starting point. The ENABLE input is TTL compatible but can be tied to the input voltage when
shutdown is not needed. RSC should be selected for the desired current limit. See current limit connections application note.
5
Rev. F
1/05
MECHANICAL SPECIFICATIONS
WEIGHT= 22 GRAMS TYPICAL
ESD Triangle indicates Pin 1.
NOTE: ALL DIMENSIONS ARE ±0.010 INCHES UNLESS OTHERWISE LABELED.
ORDERING INFORMATION
MSK5020-3.3 B
SCREENING
BLANK= INDUSTRIAL; E=EXTENDED RELIABILITY
B=MIL-PRF-38534 CLASS H
OUTPUT VOLTAGE
3.3=+3.3V; 5.0=+5.0V; 12.0=+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.
6
Rev. F
1/05