MIL-PRF-38534 AND 38535 CERTIFIED FACILITY
5953RH
HARD
DUAL
RADRAD
HARD
DUAL
POSITIVE
POSITIVE
LDOLDO
VOLTAGE
REGULATOR
ADJADJ
VOLTAGE
REGULATOR
FEATURES:
Manufactured using
Space Qualified RH3080 Die
Total Dose Hardened to 300 Krads(Si) (Method 1019.7 Condition A)
Low Dropout Voltage
Wide Input Voltage Range
Dual Output Adjustable to Zero Volts
Output Current to 1.0A Each Output
Outputs May Easily be Paralleled for Increased Output Current
Internal Thermal Overload and Current Limit Protection
Contact MSK for MIL-PRF-38534 Qualification Status
DESCRIPTION:
The MSK5953RH is a radiation hardened, low dropout, dual linear regulator. Each regulator is capable of up to 1.0A output current and can easily be paralleled for increased current capability and increased heat spreading. The output voltage
is selected through the use of a single resistor and may be adjusted as low as 0V. The MSK5953RH regulators also have
internal current limit and thermal protection. These features combined with low Øjc, make the MSK5953RH regulator an
excellent choice for many space applications. The MSK5953RH is packaged in a hermetically sealed 12 pin flatpack that is
lead formed for surface mount applications.
EQUIVALENT SCHEMATIC
TYPICAL
APPLICATIONS
TYPICAL APPLICATIONS
PIN-OUT INFORMATION
Post Regulator for Switching Supplies
Low Output Voltage Power Supplies
High Efficiency Linear Regulator
Satellite System Power Supply
FPGA and Microprocessor Power Supply
Coincident Output Tracking
1
2
3
4
5
6
CTL A
VIN A
VIN A
VIN B
VIN B
CTL B
12
11
10
9
8
7
SET A
VOUT A
VOUT A
VOUT B
VOUT B
SET B
CASE=ISOLATED
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ABSOLUTE MAXIMUM RATINGS
VIN
VCTL
PD
IOUT
TJ
10
Input Voltage 7
+40V,-0.3V
Control Voltage 7
+40,-0.3V
Power Dissipation
Internally Limited
Output Current (Each Output) 8
1.0A
Junction Temperature
+150°C
TST
TLD
TC
Storage Temperature Range 12
Lead Temperature Range
(10 Seconds)
Case Operating Temperature
MSK5953RH
MSK5953K/H
ESD Rating
-65°C to +150°C
300°C
-40°C to +85°C
-55°C to +125°C
Class 2
ELECTRICAL SPECIFICATIONS
NOTES:
1 Output is decoupled to ground using a 220µF tantalum low ESR capacitor in parallel with a 0.1µF ceramic capacitor unless otherwise specified.
(See Figure 1).
2 Guaranteed by design but not tested. Typical parameters are representative of actual device
performance but are for reference only.
3 Industrial grade devices shall be tested to subgroup 1 unless otherwise specified.
4 Military grade ("H"suffix) and space grade ("K"suffix) devices shall be 100% tested to subgroups 1,2 and 3.
5 Subgroup 1 TA=TC=+25°C
Subgroup 2 TA=TC=+125°C
Subgroup 3 TA=TC=-55°C
6 Minimum load current verified while testing line regulation.
7 Voltage is measured with respect to VOUT.
8 The output current limit is dependant on the input to output voltage differential (VIN-VOUT). At VIN-VOUT>26V the available output current may be
reduced to zero amps. Refer to the current limit curve for typical current limit characteristics.
9 All limits and specifications apply to each individual regulator.
10 Continuous operation at or above absolute maximum ratings may adversely effect the device performance and/or life cycle.
11 Pre and Post irradiation limits at 25°C, up to 300 Krads(Si) TID, are identical unless otherwise specified.
12 Internal solder reflow temperature is 180°C, do not exceed.
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APPLICATION NOTES
OUTPUT VOLTAGE
LOAD REGULATION
A single resistor (RSET) from the SET pins to ground creates the reference voltage for the internal Error Amplifier. The
MSK5953RH SET pins each supply a constant current of 10uA
that develops the reference voltage. The output voltage is simply
Rset x 10uA. In the event that both outputs will be the same value,
both SET pins may be tied together and a single resistor used for
output voltage selection, according to the formula VOUT=RSET x
20µA. Since the output is internally driven by a unity-gain amplifier,
an alternative to using Rset is to connect a high quality reference
source to the SET pin. With a minimum load requirement of 1mA on
the Output, the Output Voltage can be adjusted to near 0V. To bring
the output voltage to 0V, the load must be connected to a slightly
negative voltage supply to sink the 1mA minimum load current from
a 0V output.
The MSK5953RH specified load regulation is Kelvin Sensed,
therefore the parasitic resistance of the system must be considered
to design an acceptable load regulation. The overall load regulation
includes the specified MSK5953RH load regulation plus the parasitic
resistance multiplied by the load current as shown in Figure 2. RSO
is the series resistance of all conductors between the MSK5953RH
output and the load. It will directly increase output load regulation
error by a voltage drop of ∆Io x RSO. Rss is the series resistance
between the set pin and the load. RSS will have little effect on load
regulation if the set pin trace is connected as close to the load as possible keeping the load return current on a separate trace as shown.
RSR is the series resistance of all of the conductors between the load
and the input power source return. RSR will not effect load regulation
if the set pin is connected with a Kelvin Sense type connection as
shown in Figure 2, but it will increase the effective dropout voltage
by a factor of IO x RSR. Keeping RSO and RSR as low as possible will
ensure minimal voltage drops and wasted power.
(Each Regulator)
FIGURE 2
FIGURE 1
INCREASED CURRENT CAPACITY
OUTPUT CAPACITANCE
When currents greater than 1.0 A are needed, the MSK5953
RH's outputs may be paralleled to double the current capacity. As
shown in Figure 3, the VIN and SET pins must be tied together. The
VOUT pins are connected to the load with consideration to the conductor resistance. The conductor resistance of each MSK5953RH
VOUT connection to the load, must be equal to create equal load
sharing. As little as 10mΩ ballast resistance typically ensures better than 80% equal sharing of load current at full load. Additional
consideration must be given to the effect the additional VOUT
conductor resistance has on load regulation; see paragraph titled
"Load Regulation".
For stability purposes, the MSK5953RH requires a minimum
output capacitor of 10µF with an ESR of 0.5Ω or less. Tantalum or
ceramic capacitors are recommended. A larger capacitance value
and lower ESR will improve transient response for increased load
current changes. Consideration must also be given to temperature
characteristics of the capacitors used.
ADDITIONAL STABILITY
Capacitors placed in parallel with the SET pin resistors to ground,
will improve the output transient response and filter noise in the
system. To reduce output noise, typically less than 100pF is all
that will be required. Capacitors up to 1µF can be used, however
consideration must be given to the effect the time constant created
will have on the startup time.
FIGURE 3
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APPLICATION
NOTES
CONT'D
APPLICATION
NOTES
CONT'D
IMPROVING INITIAL ACCURACY AND
REDUCING TEMPERATURE DRIFT
COINCIDENT TRACKING
The initial output accuracy of the MSK5953RH due to set
pin current tolerance and set point resistor accuracy can be
reduced to 0.2% using the MSK109RH radiation hardened precision reference. Minimal drift of the MSK109RH from temperature extremes and irradiation ensure very tight regulation. The
circuit can be configured to use the 2.5V reference to directly
set the output at 2.5V or with a slight variation it can provide
any output within the operating range of the MSK5953RH down
to 0V output. Select RS to maintain between 1mA and 10mA of
current through the reference; see Figure 4 below. RS may be
tied to VIN or another power source. The optional trim resistor
can be used to further trim out initial output and system error.
Reference the MSK109RH data sheet for application circuits
that provide stable output voltages across the full operating
range of the MSK5953RH including down to 0V output and
the operating characteristics of the MSK109RH.
For applications that require multiple output voltages and
tight control over voltage differentials, the coincident tracking shown in Figure 6 may be used. In this configuration
regulator B is configured for an output voltage of 0.8V with
reference to output A. Output B will never exceed output A
by more than 0.8V but will be 3.3V with respect to ground
when output A is at the specified 2.5V. Although a very small
portion of the overall current, it should be noted that load
connected to regulator A must sink the 10µA set pin current
of regulator B.
FIGURE 6
FIGURE 4
ADDING SHUTDOWN
The MSK5953RH can be easily shutdown by either reducing RSET to 0Ω or connecting a transistor from the set pin to
ground. By connecting two transistors, as shown in Figure 5,
a low current voltage source is all that is required to take the
set pin to ground as well as pull the output voltage to ground.
Q2 pulls the output voltage to ground when no load is present
and only needs to sink 10mA. Use a low leakage switching
diode between VOUT and SET to avoid overstress during
shutdown transitions.
FIGURE 5
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APPLICATION
NOTES
CONT'D
APPLICATION
NOTES
CONT'D
TOTAL DOSE RADIATION TEST
PERFORMANCE
HEAT SINKING
To determine if a heat sink is required for your application
and if so, what type, refer to the thermal model and governing
equation below.
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 MSK5953RH radiation
test report. The complete radiation test report is available in
the RAD HARD PRODUCTS section on the MSK website. 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
TC = Case Temperature
TA = Ambient Temperature
TS = Heat Sink Temperature
ADDITIONAL APPLICATION INFORMATION
For additional applications information, please reference
Linear Technology Corporation's® LT3080 and RH3080 data
sheets.
EXAMPLE:
This example demonstrates the thermal calculations for the
package with the regulator operating at one-half of its maximum rated output current.
Conditions for MSK5953RH:
VIN = +3.0V; IOUT= +0.50A VOUT=+1.0V
1.) Assume 45° heat spreading model.
2.) Find regulator power dissipation:
PD= (VIN - VOUT)(IOUT)
PD =(3-1)(0.50)
=1.0W
3.) For conservative design, set TJ = +125°C Max.
4.) For this example, worst case TA = +90°C.
5.) RθJC =10.5°C/W from the Electrical Specification Table.
6.) RθCS= 0.15°C/W for most thermal greases.
7.) Rearrange governing equation to solve for RθSA:
RθSA =((TJ - TA)/PD) - (RθJC) - (RθCS)
=(125°C - 90°C)/1.0W - 10.5°C/W - 0.15°C/W
=24.4°C/W
In this case the result is 24.4°C/W. Therefore, a heat sink
with a thermal resistance of no more than 24.4°C/W must be
used in this application to maintain regulator circuit junction
temperature under 125°C.
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TYPICAL PERFORMANCE CURVES
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TYPICAL PERFORMANCE CURVES CONT'D
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MECHANICAL SPECIFICATIONS
ESD TRIANGLE INDICATES PIN 1
WEIGHT=3.5 GRAMS TYPICAL
ALL DIMENSIONS ARE SPECIFIED IN INCHES
ORDERING INFORMATION
Part
Number
Screening Level
MSK5953RH
INDUSTRIAL
MSK5953HRH
MIL-PRF-38534 CLASS H
MSK5953KRH
MIL-PRF-38534 CLASS K
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8548-112 Rev. H 8/15
REVISION HISTORY
MSK
www.anaren.com/msk
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.
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8548-112 Rev. H 8/15