MIL-PRF-38534 AND 38535 CERTIFIED FACILITY
RAD HARD ULTRA LOW
VOLTAGE ADJUSTABLE
POSITIVE LINEAR REGULATOR
5950RH
FEATURES:
•
•
•
•
•
•
•
•
•
•
•
Manufactured using
Space Qualified RH1009 and RH1573 Die
Total Dose Hardened to 100 Krads(Si) (Method 1019.7 Condition A)
Total Dose Test Reports to 450 Krads(Si) available on website.
Output Adjustable Down to Near Zero
External Shutdown/Reset Function
Latching Overload Protection
Adjustable Output Using External Resistors
Output Current Limit
Surface Mount Package Available with Lead Forming
Low Input Voltage for Maximum Efficiency
Up to 5A Output Current
DESCRIPTION:
The MSK5950RH is a radiation hardened adjustable linear regulator capable of delivering 5.0 amps of output current. The
typical dropout is only 0.11 volts at 1 amp. An external shutdown/reset function is ideal for power supply sequencing. This
device also has latching overload protection that requires no external current sense resistor. The MSK5950RH is radiation
hardened and specifically designed for many space/satellite applications. The device is packaged in a hermetically sealed
20 pin flatpack that can be lead formed for surface mount applications.
EQUIVALENT SCHEMATIC
PIN-OUT INFORMATION
TYPICAL APPLICATIONS
•
•
•
•
Satellite System Power Supplies
Switching Power Supply Post Regulators
Constant Voltage/Current Regulators
Microprocessor Power Supplies
1
2
3
4
5
6
7
8
9
10
-VINA
VINB
VINC
VIND
VINE
VBIAS
GND1
GND1
Latch
Shutdown
20
19
18
17
16
15
14
13
12
11
VOUTE
VOUTD
VOUTC
VOUTB
VOUTA
VREF
GND2
GND2
GND2
FB
CASE = ISOLATED
1
8548-18 Rev. M 9/17
ABSOLUTE MAXIMUM RATINGS
+VBIAS
+VIN
VSD
IVREF
IOUT
TC
8
Bias Supply Voltage...........................................10V
Supply Voltage...................................................10V
Shutdown Voltage..............................................10V
Reference Sink Current..................................20mA
7
Output Current ....................................................5A
Case Operating Temperature Range
MSK5950K/H RH...........................-55°C to +125°C
MSK5950RH....................................-40°C to +85°C
TST Storage Temperature Range..........-65°C to +150°C
TLD Lead Temperature Range
(10 Seconds)..................................................300°C
PD Power Dissipaton............................See SOA Curve
TJ Junction Temperature.....................................150°C
ESD Rating................................................Class 1C
ELECTRICAL SPECIFICATIONS
Input Voltage Range
2
10mA ≤ IOUT ≤ 1.0A
Group A
Subgroup
1, 2, 3
Bias Supply Voltage
2
VBIAS ≥ VIN
1, 2, 3
2.9
-
7.5
2.9
-
7.5
V
1
1.225
1.265
1.305
1.202
1.265
1.328
V
2, 3
1.225
-
1.305
-
-
-
V
1
1.225
1.272
1.305
1.202
1.272
1.328
V
1
2.495
2.500
2.505
2.485
2.500
2.515
V
2, 3
2.485
-
2.515
-
1
2.493
2.501
2.508
2.493
2.501
2.508
V
1
-
-
±6
-
-
±6
mV
2, 3
-
-
±10
-
-
±10
mV
1
-
-
±12
-
-
±12
mV
VFB = 1.265V 10mA ≤ IOUT ≤ 1.0A
1, 2, 3
0
-
5.0
0
-
5.0
µA
IIN + IBIAS, VBIAS = VIN = 5.0V
Not including IOUT
1, 2, 3
-
8
15
-
8
15
mA
VBIAS = 5.0V
1, 2, 3
-
2
4
-
2
4
mA
IOUT = 10mA 2.9V ≤ VIN ≤ 7.5V
R1 = 187Ω
1
-
±0.01
±0.50
-
±0.01
±0.60
%VOUT
2, 3
-
-
±0.50
-
-
-
%VOUT
1
-
±0.06
±0.80
-
±0.06
±1.0
%VOUT
2, 3
-
-
±0.80
-
-
-
%VOUT
1
-
0.11
0.40
-
0.11
0.45
V
2, 3
-
0.14
0.40
-
-
-
V
1
-
8
10
-
8
10
mA
Parameter
Test Conditions
Feedback Voltage
IOUT = 1.0A
1
9
R1 = 187Ω
Post Radiation
VREF
IREF = 1mA
Post Radiation
VREF Load Reg
0.4mA ≤ IREF ≤ 10mA
Post Radiation
Feedback Pin Current
2
Quiescent Current
Bias Current
Line Regulation
10mA ≤ IOUT ≤ 1.0A
R1 = 976Ω
Load Regulation
Dropout Voltage
Delta FB = 1% IOUT = 1.0A
Minimum Output Current
2
2.9V ≤ VIN ≤ 7.5V
R1 = 187Ω
Output Voltage Range
2
VIN = 7.5V
Output Current Limit
7
VIN = 2.5V VOUT = 1.5V
Shutdown Threshold
VOUT ≤ 0.2V (OFF)
VOUT = Nominal (ON)
Shutdown Hysteresis
Difference between voltage threshold of
VSDI (ON) and VSDI (OFF)
Ripple Rejection
2
Phase Margin
Gain Margin
Thermal Resistance
2
Units
V
V
2, 3
-
9
10
-
-
-
mA
-
0
-
7.0
0
-
7.0
V
1
3.2
3.6
4.0
3.2
-
4.0
A
2, 3
3.0
-
-
-
-
-
A
1
1.0
1.3
1.6
1.0
1.3
1.6
V
2, 3
1.0
1.3
1.6
-
-
-
V
1
-
0.02
0.2
-
0.02
0.2
V
2, 3
-
0.03
0.2
-
-
-
V
-
-
20
-
-
dB
4
20
5, 6
20
-
-
-
-
-
dB
IOUT = 450mA
4, 5, 6
30
80
-
30
80
-
degrees
2
2
MSK5950 SERIES
Min.
Typ.
Max.
2.0
7.5
f = 1KHz to 10KHz
10mA ≤ IOUT≤ 1.0A 1.0V = VIN-VOUT
2
Equivalent Noise Voltage
MSK5950K/H SERIES
Min.
Typ.
Max.
2.0
7.5
IOUT = 450mA
4, 5, 6
10
30
-
10
30
-
dB
Referred to Feedback Pin
4, 5, 6
-
-
50
-
-
50
µVRMS
Junction to Case @ 125°C Output Device
-
-
7.3
8.4
-
7.3
9.0
°C/W
NOTES:
1
Unless otherwise specified, VBIAS = VIN = 5.0V, R1 = 1.62K, RREF = 249W (see figure 2), VSHUTDOWN = 0V and IOUT = 10mA.
2
Guaranteed by design but not tested. Typical parameters are representative of actual device performance but are for reference only. Not applicable to post
irradiation performance.
3
Industrial grade devices shall be tested to subgroups 1 and 4 unless otherwise requested.
4
Military grade devices ("H" suffix) shall be 100% tested to subgroups 1,2,3 and 4.
5
Subgroup 5 and 6 testing available upon request.4
6
Subgroup
1, 4
2, 5
3, 6
TA = +25°C
TA = +125°C
TA = -55°C
7
Output current limit is tested with a low duty cycle pulse to minimize junction heating and is dependent on the values of VIN, VOUT and case temperature. See
Typical Performance Curves.
8
Continuous operation at or above absolute maximum ratings may adversely effect the device performance and/or life cycle.
9
Pre and post irradiation limits @ 25°C, up to 100 Krad TID, are identical unless otherwise specified. Post irradiation performance is guaranteed by design with a 2X
radiation design margin.
2
8548-18 Rev. M 9/17
APPLICATION NOTES
PIN FUNCTIONS
LATCH - The MSK5950RH LATCH pin is used for both current limit
and thermal limit. A capacitor between the LATCH pin and ground
sets a time out delay in the event of an over current or short circuit
condition. The capacitor is charged to approximately 1.6V from a
7.2µA (nominal) current source. Exceeding the thermal limit will
charge the latch capacitor from a larger current source for a near
instant shutdown. Once the latch capacitor is charged the device
latches off until the latch is reset. Momentarily pull the LATCH pin
low, toggle the shutdown pin high then low or cycle the power to
reset the latch. Toggling the shutdown pin or cycling the bias power
both disable the device during the reset operation (see SHUTDOWN
pin description). Pulling the LATCH pin low immediately enables the
device for as long as the LATCH pin is held low plus the time delay
to re-charge the latch capacitor whether or not the fault has been
corrected. Disable the latch feature by tying the LATCH pin low. With
the LATCH pin held low the thermal limit feature is disabled and the
current limit feature will force the output voltage to droop but remain
active if excessive current is drawn.
VIN A,B,C,D,E - These pins provide the input power connection to the
MSK5950RH. This is the supply that will be regulated to the output. All
five pins must be connected for proper operation.
VBIAS - This pin provides power to all internal circuitry including bias,
start-up, thermal limit and overcurrent latch. VBIAS voltage range is 2.9V
to 7.5V. VBIAS should be kept greater than or equal to VIN.
VREF - Internal general purpose 2.5V shunt regulator that will operate
over a wide current range while maintaining good stability. This reference
voltage is used along with the feedback voltage to configure the desired
output voltage. The reference will maintain good regulation as long as
0.4<ISHUNT<10mA. The shunt current is derived from a resistor tied to
VIN or VBIAS. The resistor must supply both the minimum shunt current
of 400µA (1mA recommended) and the current required by the output
voltage feedback divider network, between 2 and 2.5mA total is typically
sufficient. A constant current diode (CCR) may be used in place of the
resistor to minimize variations in ISHUNT due to line voltage variations.
SHUTDOWN - There are two functions to the SHUTDOWN pin. It may
be used to disable the output voltage or to reset the LATCH pin. To
activate the shutdown/reset functions the user must apply a voltage
greater than 1.3V 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.
Resistor calculation example:
VBIAS=3.3V±10%
VOUT=0.9V
First determine the required current by selecting R2 in the feed back
divider, typically between 1.0 and 1.2KΩ; see the output voltage selection
paragraph. Using standard value 0.1% tolerance resistors, the nominal
output will be 0.9V with R2=1.07K and R1=316Ω. The current in the
divider will be equal to (VREF-VFDBK)/R2 or 1.154mA nominal and 1.2mA
worst-case in this example.
FB - The FB 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 FB pin to 1.265V. An external resistor divider is connected to the
output, FB pin, VREF and VIN to set the output voltage.
The total current required is the sum of the worst-case divider current
plus the VREF shunt current. The minimum shunt current is 400µA but
1mA is recommended. Using the recommended 1mA the minimum
current required in RREF is 2.2mA.
POWER SUPPLY BYPASSING
To maximize transient response and minimize power supply
transients it is recommended that a 33µF minimum tantalum capacitor
is connected between VIN and ground. A 0.1µF ceramic capacitor
should also be used for high frequency bypassing.
The maximum resistor value to source the required current is equal to
(VBIAS min-VREF)/2.2mA or 218Ω for this example. The maximum
current in the reference must not exceed 10mA, the absolute maximum
allowable bias voltage is
10mA*RREF+VREF(min) or 4.67V for this application.
OUTPUT CAPACITOR SELECTION
The designer must also consider that the feedback divider will provide a
resistive connection from the source (VIN or VBIAS) to the output even
when the regulator is disabled. A minimum load resistor can be used to
draw the voltage down in the event this poses a problem. A 90Ω resistor
will sink 10mA during operation and pull the output well below 200mV
when the regulator is disabled in this application.
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 on the MSK5820RH-1.5 that
screening for a maximum ESR of 57mΩ ensures EOL stability criteria
to be met for many applications with the most stringent requirements.
Analysis of the final design is recommended to ensure stability
requirements are met.
VREF can be used as a precision 2.5V reference for other parts of
the circuit as long as circuit loading, shunt current and parasitics are
carefully considered.
GND1 - SIGNAL GROUND - Internally connected to the reference
ground, these pins should be connected externally by the user to the
circuit ground and the GND2 pins.
THERMAL LIMITING
VOUT A,B,C,D,E - These are the output pins for the device. All five pins
must be connected for proper operation.
The MSK5950RH 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 MSK5950RH. See LATCH pin description for instructions to reset
the latch or disable the latch feature.
GND2 - POWER GROUND - Internally connected to the pass element
drive circuitry, these pins should be connected externally by the user
to the circuit ground and the GND1 pins.
3
8548-18 Rev. M 9/17
APPLICATION NOTES CONT'D
Governing Equation:
START UP OPTIONS
The MSK5950RH starts up and begins regulating immediately
when VBIAS and VIN are applied simultaneously. Applying VBIAS
before VIN starts the MSK5950RH up in a disabled or latched state.
When starting in a latched state the device output can be enabled
either by pulling the latch pin low to drain the latch capacitor or
pulsing the shutdown pin high. The shutdown pulse duration is
partially dependent upon the size of the latch capacitor and should
be characterized for each application; 30uS is typically adequate
for a 1uF latch capacitor at 25°C. A momentary high pulse on the
shutdown pin can be achieved using the RC circuit below if VIN
rises rapidly. The resistor and capacitor must be selected based on
the required pulse duration, the rise characteristic of VIN and the
shutdown pin threshold (see shutdown pin threshold and current
curves).
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
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).
The shutdown pin can be held high and pulled low after VIN
comes up or the latch pin held low and released after VIN comes
up to ensure automatic startup when applying VBIAS before VIN.
Either of the basic circuits below can be adapted to a variety of
applications for automatic start up when VBIAS rises before VIN.
Example:
An MSK5950RH is connected for VIN=+3.3V and VOUT=+1.2V.
IOUT is a continuous 1A DC level. The ambient temperature is
+25°C. The maximum desired junction temperature is +125°C.
RθJC=8.4°C/W and RθCS=0.15°C/W for most thermal
greases
Power Dissipation = (3.3V-1.2V) x (1A)
= 2.1Watts
Solve for RθSA:
125°C - 25°C
2.1W
= 39°C/W
RθSA =
-8.4°C/W - 0.15°C/W
In this example, a heat sink with a thermal resistance of
no more than 39°C/W must be used to maintain a junction
temperature of no more than 125°C.
START UP CURRENT
The MSK5950RH 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 MSK's RH1573 Based Rad Hard LDO Regulators"
application note in the application notes section of the MSK Web
site for more information.
OVERCURRENT LATCH-OFF/LATCH PIN CAPACITOR
SELECTION
As previously mentioned, the LATCH pin provides over current/
output short circuit protection with a timed latch-off circuit. Reference
the LATCH pin description note. The latch off time out is determined
with an external capacitor connected from the LATCH pin to ground.
The time-out period is equal to the time it takes to charge this
external capacitor from 0V to 1.6V. The latch charging current is
provided by an internal current source. This current is a function of
bias voltage and temperature (see latch charging current curve).
For instance, at 25°C, the latch charging current is 7.2µA at
VBIAS = 3V and 8µA at VBIAS = 7V.
In the latch-off mode, some additional current will be drawn from
the bias supply. This additional latching current is also a function of
bias voltage and temperature (see typical performance curves).
The MSK5950RH current limit function is directly affected by the
input and output voltages. Custom current limit is available; contact
the factory 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 MSK. These
curves show performance trends throughout the TID test process
and are located in the MSK5950RH 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
HEAT SINK SELECTION
To select a heat sink for the MSK5950RH, the following formula
for convective heat flow may be used.
4
8548-18 Rev. M 9/17
APPLICATION NOTES CONT'D
TYPICAL APPLICATIONS CIRCUIT
For output voltages above the feedback voltage the unit should be
configured as shown in Figure 2.
FIGURE 1
OUTPUT VOLTAGE SELECTION
The MSK5950RH output voltage can be adjusted from 0 to 5V.
Three different resistor network schemes are used depending on
the required output voltage level.
FIGURE 2
For output voltages below the minimum feedback voltage tolerance
of 1.225V, R3 as shown in Figure 1 can be omitted. Output voltage
can be calculated as follows:
VOUT=1.265(1+R1/R2)
Given:
VFB=1.265V
VREF=2.5V
As noted in the above typical applications circuit, the formula for
output voltage selection is:
VOUT=1.265(1+(R1/R2))
VOUT=VFB-((VREF-VFB)/R2)R1
A good starting point for this output voltage selection is set to R2=1K.
By rearranging the formula it is simple to calculate the final R1 value.
For convenience Table 1 below provides standard 0.1% tolerance
resistor values required to achieve several output voltages based
on nominal feedback voltage, R3 is ommitted.
R1=R2((VOUT/1.265)-1)
Table 3 below lists some of the most probable resistor combinations
based on industry standard usage, R3 is ommitted.
VREFcan be used as a precision 2.5V reference as long as circuit
loading and shunt current are carefully considered. If VREF is not
used the pin should be pulled to ground.
For output voltages close to the feedback voltage tolerance of
1.225V-1.305V, a three resistor network may be used to improve
adjustment capabilities and trim out initial feedback voltage tolerances. Reference Figure 1.
VOUT= (R2R3VFB+R1R3(VFB-VREF)+R1R2VFB)/(R2R3)
5
8548-18 Rev. M 9/17
TYPICAL PERFORMANCE CURVES
6
8548-18 Rev. M 9/17
MECHANICAL SPECIFICATIONS
ESD TRIANGLE INDICATES PIN 1
WEIGHT=3.5 GRAMS TYPICAL
ALL DIMENSIONS ARE SPECIFIED IN INCHES
ORDERING INFORMATION
PART NUMBER
SCREENING LEVEL
MSK5950RH
INDUSTRIAL
MSK5950HRH
MIL-PRF-38534 CLASS H
MSK5950KRH
MIL-PRF-38534 CLASS K
7
LEADS
STRAIGHT
8548-18 Rev. M 9/17
MECHANICAL SPECIFICATIONS CONT'D
ESD TRIANGLE INDICATES PIN 1
WEIGHT=3.3 GRAMS TYPICAL
ALL DIMENSIONS ARE SPECIFIED IN INCHES
ORDERING INFORMATION
PART NUMBER
SCREENING LEVEL
MSK5950RHG
INDUSTRIAL
MSK5950HRHG
MIL-PRF-38534 CLASS H
MSK5950KRHG
MIL-PRF-38534 CLASS K
8
LEADS
GULL WING
8548-18 Rev. M 9/17
REVISION HISTORY
REV
STATUS
DATE
DESCRIPTION
H
Released
01/14
Update IQ specifications and test methods to match MSK5810 and test VREF seperately.
Clarify figure 2 by adding note 3.
Delete incomplete performance curves on original sheet 7.
I
Released
04/14
Update bias supply voltage, feedback voltage and output voltage range specifications.
J
Released
06/14
Add maximum rating for shutdown input.
K
Released
04/16
L
Released
07/17
M
Released
09/17
Remove note 10 on page 2.
Change standard TID hardness to 100 Krads(Si).
Add Post RAD VREF Load REG Limit
Update parameters to better correlate to manufacturer's pre and post RAD specs.
ANAREN, MSK Products
www.anaren.com/msk
The information contained herein is believed to be accurate at the time of printing. Anaren, MSK products 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 Anaren, MSK Products for MIL-PRF-38534 Class H, Class K status.
9
8548-18 Rev. M 9/17