MIL-PRF-38534 AND 38535 CERTIFIED FACILITY
M.S.KENNEDY CORP.
RAD HARD ULTRA LOW
DROPOUT ADJUSTABLE
POSITIVE LINEAR REGULATOR
5921RH
FEATURES:
Total Dose Hardened to 100 Krads(Si) (Method 1019.7 Condition A)
Ultra Low Dropout for Reduced Power Consumption
External Shutdown
Latching Overload Protection
Adjustable Output Using Two External Resistors
Output Current Limit
Available in 4 Lead Form Options: Straight, Up, Down and Gull Wing
Available as SMD 5962R05220
RAD Certified by DLA
DESCRIPTION:
The MSK5921RH is a radiation hardened adjustable linear regulator typically capable of delivering 5.0 amps of output
current. The typical dropout is only 0.30 volts with a 3.0A load. An external shutdown function is ideal for power supply
sequencing. This device also has latching overload protection that requires no external current sense resistor. The MSK5921RH
is radiation hardened and specifically designed for space/satellite applications. The device is packaged in a hermetically
sealed space efficient 5 pin SIP that is electrically isolated from the internal circuitry allowing for direct heat sinking.
EQUIVALENT SCHEMATIC
TYPICAL
APPLICATIONS
TYPICAL APPLICATIONS
PIN-OUT INFORMATION
Satellite System Power Supplies
Switching Power Supply Post Regulators
Constant Voltage/Current Regulators
Microprocessor Power Supplies
1
2
3
4
5
VIN
GND
VOUT
SHUTDOWN
ADJUST
CASE=ISOLATED
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8548-16 Rev. N 6/14
ABSOLUTE MAXIMUM RATINGS
+VIN
VSD
IOUT
TC
8
TST
TLD
Supply Voltage
+10V
Shutdown Voltage
10V
Output Current 7
5A
Case Operating Temperature Range
MSK5921K/H RH
-55°C to +125°C
MSK5921RH
-40°C to +85°C
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PD
TC
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Feedback Voltage
10mA ≤ IOUT ≤ 1.0A
Post Radiation
Quiescent Current
Line Regulation 9
Load Regulation 9
Output Voltage Range 2
7
Shutdown Threshold
Ripple Rejection 2
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300°C
See SOA Curve
150°C
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MSK5921K/H
MSK5921
Units
Subgroup
Min.
Typ.
Max.
Min.
Typ.
Max.
1
2.9
-
6.5
2.9
-
6.5
V
2,3
2.9
-
6.5
-
-
-
V
1
1.225
1.265
1.265
1.328
V
2,3
1.225
-
1.305
-
-
-
V
1
1.215
-
1.315
-
-
-
V
1,2,3
0
-
5.0
0
-
5.0
μA
1.305 1.202
VIN=6.5V
1
-
14
20
-
14
20
mA
Not Including IOUT
2,3
-
14
20
-
-
-
mA
IOUT=50mA
1
-
-
0.01
VOUT+0.4V ≤ VIN ≤ IOUT+1.3V
2,3
-
±2.5
-
-
±0.06 ±0.80
±0.01 ±0.50
-
±0.60 %VOUT
-
%VOUT
1
-
-
0.06
2,3
-
-
±2.5
-
-
-
%VOUT
1
-
0.22
0.40
-
0.22
0.45
V
2,3
-
0.26
0.40
-
-
-
V
2.9V ≤ VIN ≤ 6.5V
1
-
8
10
-
8
10
mA
R1=187Ω
2,3
-
9
10
-
-
-
mA
VIN=6.5V
-
1.5
-
6.0
1.5
-
6.0
V
VIN=3.5V VOUT=2.5V
1
3.0
4.0
5.0
3.0
4.0
5.0
A
Delta FB=1% IOUT=2.5A
Minimum Output Current 2
Output Current Limit
VFB=1.265V 10mA ≤ IOUT ≤ 3.0A
50mA ≤ IOUT ≤ 3.0A
Dropout Voltage 10
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Group A
IOUT=1A R1=187Ω
Feedback Pin Current 2
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-65°C to +150°C
12
Test Conditions 1 11
Input Voltage Range 2
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13
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ELECTRICAL SPECIFICATIONS
Parameter
Storage Temperature Range
Lead Temperature Range
(10 Seconds)
Power Dissipation
Junction Temperature
±1.0 %VOUT
2,3
3.0
4.0
5.0
-
-
-
A
VOUT ≤ 0.2V (OFF)
1
1.0
1.3
1.6
1.0
1.3
1.6
V
VOUT=Nominal (ON)
2,3
1.0
1.3
1.6
-
-
-
V
f=120Hz
4
65
-
-
65
-
-
dB
IOUT =50mA
5,6
65
-
-
-
-
-
dB
Phase Margin 2
4
30
70
-
30
70
-
degrees
Gain Margin 2
4
10
18
-
10
18
-
dB
Referred to Feedback Pin
4
-
-
50
-
-
50
μVRMS
Junction to Case @ 125°C Output Device
-
-
2.2
4.0
-
2.2
4.0
°C/W
Equivalent Noise Voltage 2
Thermal Resistance 2
NOTES:
1
2
3
4
5
6
7
8
9
10
11
12
13
Unless otherwise specified, VIN=5.0V, R1=1.62K, VSHUTDOWN=0V and IOUT=10mA. See Figure 2, typical application circuits.
Guaranteed by design but not tested. Typical parameters are representative of actual device performance but are for reference only.
Industrial grade devices shall be tested to subgroups 1 and 4 unless otherwise requested.
Military grade devices ("H" suffix) shall be 100% tested to subgroups 1,2,3 and 4.
Subgroup 5 and 6 testing available upon request.
Subgroup 1,4 TC=+25°C
Subgroup 2,5 TC=+125°C
Subgroup 3,6 TA=-55°C
Output current limit is dependent upon the values of VIN and VOUT. See Figure 1 and typical performance curves.
Continuous operation at or above absolute maximum ratings may adversely effect the device performance and/or life cycle.
VIN shall be as specified or VIN Min, whichever is greater.
Not applicable when VOUT<VIN Min - dropout voltage maximum.
Pre and post irradiation limits, up to 100Krad TID, are identical unless otherwise specified.
Reference DLA SMD 5962R05220 for electrical specifications for devices purchased as such.
Internal solder reflow temperature is 180°C, do not exceed.
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8548-16 Rev. N 6/14
APPLICATION NOTES
PIN FUNCTIONS
OUTPUT CAPACITOR SELECTION
Low ESR output capacitors are required to maintain regulation and stability. Four CWR29FB227 (AVX PN
TAZH227K010L) tantalum capacitors in parallel with ceramic decoupling capacitors (0.1μF typical) provides sufficient gain and phase margin for most applications. The
maximum ESR specification for the CWR29FB227 capacitor is 180mΩ at 100kHz and is sufficient for many applications. MSK has found through full WCCA that screening for a maximum ESR of 57mΩ ensures EOL stability
criteria to be met for many applications with the most
stringent requirements. The typical ESR of the
TAZH227K010L from AVX is 49mΩ . Analysis of the final
design is recommended to ensure stability requirements
are met.
VIN - This pin provides power to all internal circuitry
including bias, start-up, thermal limit and overcurrent
latch. Input voltage range is 2.9V to 6.5V.
GND - Internally connected to ground, this pin should be
connected externally by the user to the circuit ground.
SHUTDOWN - There are two functions to the SHUTDOWN pin. It may be used to disable the output voltage
or to reset a current latch condition. To activate the shutdown/reset functions the user must apply a voltage
greater than 1.6V to the SHUTDOWN pin. The voltage applied to the SHUTDOWN pin can be greater than the input
voltage. The output voltage will turn on when the SHUTDOWN pin is pulled below the threshold voltage. If the SHUTDOWN pin is not used, it should be connected to ground. It
should be noted that with the shutdown pin tied to ground,
a current latch condition can only be reset by cycling power
off, then on.
VOUT - This is the output pin for the device.
ADJUST - The ADJUST pin is the inverting input of the
internal error amplifier. The non-inverting input is connected to an internal 1.265V reference. This error amplifier controls the drive to the output transistor to force
the ADJUST pin to 1.265V. An external resistor divider
is connected to the output, ADJUST pin and ground to
set the output voltage.
OVERCURRENT LATCH
Overcurrent protection is provided by the MSK5921RH
series through the use of a timed latch off circuit. The
internal latch timeout is triggered by an overcurrent condition. To allow for start up surge currents, the timeout
is approximately 5.5mS at 25°C. If the overcurrent condition remains at the end of the timeout cycle, the regulator will latch off until the latch is reset. Reset the latch
by pulling the shutdown pin high or cycling VIN off then
back on. A thermal limit condition will trigger the latch
with no time out delay.
FIGURE 1
CURRENT LIMIT AND SOA
The MSK5921RH current limit function is directly affected
by the input and output voltages. Figure 1 illustrates the relationship between VIN and ICL for various output voltages. It
is very important for the user to consult the SOA curve when
using input voltages which result in current limit conditions
beyond 4.5 Amps. When using input voltages which result in
current limit above 4.5 Amps, the user must maintain output
current within the SOA curve to avoid damage to the device.
Note that 5 Amp maximum is due to current carrying capability of the internal wirebonds.
INPUT POWER SUPPLY BYPASSING
To maximize transient response and minimize power
supply transients it is recommended that a 100μF tantalum capacitor is connected between VIN and ground. A
0.1μF ceramic capacitor should also be used for high
frequency bypassing.
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8548-16 Rev. N 6/14
APPLICATION NOTES CONT.
TYPICAL APPLICATIONS CIRCUIT
THERMAL LIMITING
The MSK5921RH control circuitry has a thermal shutdown
temperature of approximately 150°C. This thermal shutdown can be used as a protection feature, but for continuous operation, the junction temperature of the pass transistor must be maintained below 150°C. Proper heat sink
selection is essential to maintain these conditions. Exceeding the thermal limit activates the latch feature of the
MSK5921RH. Toggle the shutdown pin high then low or
cycle power to reset the latch. See SHUTDOWN pin description and overcurrent latch description for more information.
HEAT SINK SELECTION
To select a heat sink for the MSK5921RH, the following
formula for convective heat flow may be used.
Governing Equation:
TJ = PD X (RθJC + RθCS + RθSA) + TA
Where
TJ
PD
RθJC
RθCS
RθSA
TA
=
=
=
=
=
=
Junction Temperature
Total Power Dissipation
Junction to Case Thermal Resistance
Case to Heat Sink Thermal Resistance
Heat Sink to Ambient Thermal Resistance
Ambient Temperature
OUTPUT VOLTAGE SELECTION
As noted in the above typical applications circuit, the
formula for output voltage selection is
VOUT=1.265 1+ R1
R2
A good starting point for this output voltage selection is
to set R2=1K. By rearranging the formula it is simple to
calculate the final R1 value.
R1=R2
Power Dissipation=(VIN-VOUT) x IOUT
Next, the user must select a maximum junction temperature. The absolute maximum allowable junction temperature is 150°C. The equation may now be rearranged
to solve for the required heat sink to ambient thermal
resistance (RθSA).
Example:
An MSK5921RH is connected for VIN=+3.3V and
VOUT=+2.5V. IOUT is a continuous 3A DC level. The ambient temperature is +25°C. The maximum desired junction temperature is +125°C.
RθJC=4.0°C/W and RθCS=0.15°C/W for most thermal
greases
Power Dissipation=(3.3V-2.5V) x (3A)
=2.4Watts
Solve for RθSA:
RθSA= 125°C - 25°C -4.0°C/W - 0.15°C/W
2.4W
= 36.5°C/W
In this example, a heat sink with a thermal resistance
of no more than 36.5°C/W must be used to maintain a
junction temperature of no more than 125°C.
VOUT -1
1.265
START UP CURRENT
The MSK5921RH sinks increased current during startup
to bring up the output voltage. Reference the "Saturated
Drive Current vs. Input Voltage" graph in the typical performance curves of this data sheet and the "Understanding Startup Surge Current With MS Kennedy's RH1573
Based Rad Hard LDO Regulators" application note in the
application notes section of the MS Kennedy Web site
for more information.
http://www.mskennedy.com/
TOTAL DOSE RADIATION TEST
PERFORMANCE
Radiation performance curves for TID testing have been
generated for all radiation testing performed by MS
Kennedy. These curves show performance trends
throughout the TID test process and can be located in
the MSK5921RH radiation test report. The complete radiation test report is available in the RAD HARD PRODUCTS
section on the MSK website.
http://www.mskennedy.com/store.asp?pid=9951&catid=19680
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8548-16 Rev. N 6/14
TYPICAL PERFORMANCE CURVES
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8548-16 Rev. N 6/14
TYPICAL PERFORMANCE CURVES
GAIN AND PHASE RESPONSE
The gain and phase response curves are for the MSK typical application circuit and are representative of typical device
performance, but are for reference only. The performance should be analyzed for each application to insure individual
program requirements are met. External factors such as temperature, input and output voltages, capacitors, etc. all
can be major contributors. Please consult factory for additional details.
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8548-16 Rev. N 6/14
MECHANICAL SPECIFICATIONS
ESD TRIANGLE INDICATES PIN 1
WEIGHT=7.7 GRAMS TYPICAL
ALL DIMENSIONS ARE SPECIFIED IN INCHES
ORDERING INFORMATION
MSK5921 K RH GW
LEAD CONFIGURATIONS
GW= GULL WING
RADIATION HARDENED
SCREENING
BLANK= INDUSTRIAL; H=MIL-PRF-38534 CLASS H;
K=MIL-PRF-38534 CLASS K
GENERAL PART NUMBER
The above example is an adjustable Class K regulator with gull wing leads.
NOTE: See DLA SMD 5962R05220 for DLA part number options.
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8548-16 Rev. N 6/14
MECHANICAL SPECIFICATIONS
ESD TRIANGLE INDICATES PIN 1
WEIGHT=7.7 GRAMS TYPICAL
ALL DIMENSIONS ARE SPECIFIED IN INCHES
ORDERING INFORMATION
MSK5921 K RH U
LEAD CONFIGURATIONS
S= STRAIGHT; U= BENT UP; D= BENT DOWN
RADIATION HARDENED
SCREENING
BLANK= INDUSTRIAL; H=MIL-PRF-38534 CLASS H;
K= MIL-PRF-38534 CLASS K
GENERAL PART NUMBER
The above example is an adjustable Class K regulator with leads bent up.
NOTE: See DLA SMD 5962R05220 for DLA part number options.
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8548-16 Rev. N 6/14
REVISION HISTORY
M.S. Kennedy Corp.
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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8548-16 Rev. N 6/14