MIL-PRF-38534 CERTIFIED FACILITY
M.S.KENNEDY CORP.
FEATURES:
RAD HARD ULTRA LOW
DROPOUT ADJUSTABLE
POSITIVE LINEAR REGULATOR
5910RH
(315) 701-6751
4707 Dey Road Liverpool, N.Y. 13088
Total Dose Hardened to 100 Krads(Si) (Method 1019.7 Condition A)
Ultra Low Dropout for Reduced Power Consumption
External Shutdown/Reset Function
Latching Overload Protection
Adjustable Output Using Two External Resistors
Output Current Limit
Surface Mount Package Available with Lead Forming
Low Input Voltage for Maximum Efficiency
Up to 5A Output Current
Available as SMD 5962R05220
RAD Certified by DSCC
DESCRIPTION:
The MSK 5910RH is a rad hard 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 MSK 5910RH
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
TYPICAL APPLICATIONS
TYPICAL APPLICATIONS
Satellite System Power Supplies
Switching Power Supply Post Regulators
Constant Voltage/Current Regulators
Microprocessor Power Supplies
PIN-OUT INFORMATION
1
2
3
4
5
6
7
8
9
10
1
VINA
VINB
VINC
VIND
VINE
VBIAS
GND1
GND1
Latch
Shutdown
20
19
18
17
16
15
14
13
12
11
CASE=ISOLATED
VOUTE
VOUTD
VOUTC
VOUTB
VOUTA
NC
GND2
GND2
GND2
FB
8548-11 Rev. R 12/11
ABSOLUTE MAXIMUM RATINGS
+V
BIAS
+V
IN
I
OUT
T
C
8
Bias Supply Voltage
10.0V
Supply Voltage
10.0V
7
Output Current
5A
Case Operating Temperature Range
MSK5910K/H RH
-55°C to +125°C
MSK5910RH
-40°C to +85°C
10
T
ST
T
LD
P
D
T
C
Storage Temperature Range -65°C to +150°C
Lead Temperature Range
300°C
(10 Seconds)
Power Dissipation
See SOA Curve
Junction Temperature
150°C
ELECTRICAL SPECIFICATIONS
Parameter
Input Voltage Range
2
Input Bias Voltage
2
Test Conditions
1 9
10mA
≤
I
OUT
≤
1.0A
V
BIAS
≥
V
IN
I
OUT
=
1.0A R1=187Ω
Post Radiation
V
FB
=1.265V 10mA
≤
I
OUT
≤
1.0A
I
IN
+I
BIAS,
V
BIAS
=V
IN
=7.5V Not including I
OUT
V
BIAS
=7.5V
I
OUT
=10mA 2.9V
≤
V
IN
≤
7.5V
R1=187Ω
10mA
≤
I
OUT
≤
1.0A
R1=976
Delta FB=1% I
OUT
=1.0A
2.9V
≤
V
IN
≤
7.5V
R1=187Ω
V
IN
=7.5V
V
IN
=2.5V V
OUT
=1.5V
V
OUT
≤
0.2V (OFF)
V
OUT
=Nominal (ON)
Difference between voltage
threshold of V
SDI
(ON) and V
SDI
(OFF)
Group A
Subgroup
1,2,3
1,2,3
1
MSK5910K/H
Min.
2.0
2.9
1.225
1.225
1.215
0
-
-
-
-
-
-
-
-
-
-
1.5
3.2
3.0
1.0
1.0
-
-
20
20
30
10
-
-
Typ.
-
5.0
Max.
7.5
7.5
Min.
2.0
2.9
MSK5910
Typ.
-
5.0
1.265
-
-
-
14
2
0.01
-
0.06
-
0.11
-
8
-
-
3.6
-
1.3
-
0.02
-
-
-
80
30
-
7.3
Max.
7.5
7.5
1.328
-
-
5.0
20
4
Units
V
V
V
V
V
A
mA
mA
1.265 1.305 1.202
-
-
-
14
2
1.305
1.315
5.0
20
4
-
-
0
-
-
-
-
-
-
-
-
-
-
1.5
3.2
-
1.0
-
-
-
20
-
30
10
-
-
Feedback Voltage
2,3
1
1,2,3
1,2,3
1,2,3
1
2,3
1
2,3
1
2,3
Feedback Pin Current
2
Quiescent Current
Bias Current
Line Regulation
±0.01 ±0.50
-
±0.50
±0.06 ±0.80
-
0.11
0.14
8
9
-
3.6
-
1.3
1.3
0.02
0.03
-
-
80
30
-
7.3
±0.80
0.40
0.40
10
10
7.0
4.0
-
1.6
1.6
0.2
0.2
-
-
-
-
50
8.4
±0.60 %V
OUT
-
%V
OUT
Load Regulation
±1.0 %V
OUT
-
0.45
-
10
-
7.0
4.0
-
1.6
-
0.2
-
-
-
-
-
50
9.0
%V
OUT
V
V
mA
mA
V
A
A
V
V
V
V
dB
dB
degrees
dB
V
RMS
°C/W
Dropout Voltage
Minimum Output Current
2
1
2,3
-
1
2,3
Output Voltage Range
2
Output Current Limit
7
Shutdown Threshold
1
2,3
1
2,3
4
5,6
4,5,6
4,5,6
4,5,6
-
Shutdown Hysteresis
Ripple Rejection
2
Phase Margin
2
Gain Margin
2
Equivalent Noise Voltage
2
Thermal Resistance
2
f=1KHz to 10KHz
10mA
≤
I
OUT
≤
1.0A 1.0V=V
IN
-V
OUT
I
OUT
=450mA
I
OUT
=45OmA
Referred to Feedback Pin
Junction to Case @ 125°C Output Device
NOTES:
1
2
3
4
5
6
Unless otherwise specified, V
BIAS
=V
IN
=5.0V, R1=1.62K, V
SHUTDOWN
=0V and I
OUT
=10mA. I
OUT
is subtracted from I
Q
measurement. See typical application circuit.
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 T
C
=+25°C
Subgroup 2,5 T
C
=+125°C
Subgroup 3,6 T
A
=-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 V
IN
, V
OUT
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 at 25°C, up to 100Krad TID, are identical unless otherwise specified.
Reference DSCC SMD 5962R05220 for electrical specifications for devices purchased as such.
2
8548-11 Rev. I 12/11
APPLICATION NOTES
PIN FUNCTIONS
VIN A,B,C,D,E -
These pins provide the input power connection to
the MSK 5910RH. 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.
GND1 -
Internally connected to input ground, these pins should be
connected externally by the user to the circuit ground and the GND2
pins.
LATCH -
The MSK 5910RH 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
7.2 A (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.
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 output volt-
age 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.
FB -
The FB pin is the inverting input of the internal error amplifier.
The non-inverting input is connected to an internal 1.265V refer-
ence. 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 and ground to set the output voltage.
GND2 -
Internally connected to output ground, these pins should be
connected externally by the user to the circuit ground and the GND1
pins.
VOUT A,B,C,D,E -
These are the output pins for the device. All five
pins must be connected for proper operation.
START UP OPTIONS
The MSK 5910RH starts up and begins regulating immediately
when VBIAS and VIN are applied simultaneously. Applying VBIAS
before VIN starts the MSK 5910RH 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 par-
tially 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 shut-
down 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 shut-
down pin threshold (see shutdown pin threshold and current curves).
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 applica-
tions for automatic start up when VBIAS rises before VIN.
OUTPUT CAPACITOR SELECTION
Low ESR output capacitors are required to maintain regulation
and stability. Four CWR29FB227 (AVX PN TAZH227K010L) tanta-
lum capacitors in parallel with ceramic decoupling capacitors (0.1 F
typical) provides sufficient gain and phase margin for most applica-
tions. The maximum ESR specification for the CWR29FB227 ca-
pacitor is 180mΩ at 100kHz and is sufficient for many applications.
MSK has found through full WCCA on the MSK 5820RH-1.5 that
screening for a maximum ESR of 57mΩ ensures EOL stability crite-
ria to be met for many applications with the most stringent require-
ments. Analysis of the final design is recommended to ensure stabil-
ity requirements are met.
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. Refer-
ence the LATCH pin description note. The latch off time out is de-
termined 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 7.2 A at
VBIAS=3V and 8 A 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 MSK 5910RH current limit function is directly affected by the
input and output voltages. Custom current limit is available; contact
the factory for more information.
POWER SUPPLY BYPASSING
To maximize transient response and minimize power supply tran-
sients it is recommended that a 33 F minimum tantalum capacitor
is connected between VIN and ground. A 0.1 F ceramic capacitor
should also be used for high frequency bypassing.
3
8548-11 Rev. I 12/11
APPLICATION NOTES CONT.
THERMAL LIMITING
The MSK 5910RH control circuitry has a thermal shut-
down temperature of approximately 150°C. This ther-
mal 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 condi-
tions. Exceeding the thermal limit activates the latch fea-
ture of the MSK 5910RH. See LATCH pin description for
instructions to reset the latch or disable the latch fea-
ture.
TYPICAL APPLICATIONS CIRCUIT
HEAT SINK SELECTION
To select a heat sink for the MSK 5910RH, the follow-
ing formula for convective heat flow may be used.
V
OUT
=1.265(1+R1/R2)
Governing Equation:
T
J
=
P
D
X (R
θJC
+ R
θCS
+ R
θSA
) + T
A
Where
T
J
P
D
R
θJC
R
θCS
R
θSA
T
A
=
=
=
=
=
=
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
V
OUT
=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
V
OUT
-1
1.265
Power Dissipation=(V
IN
-V
OUT
) x I
OUT
Next, the user must select a maximum junction tem-
perature. The absolute maximum allowable junction tem-
perature is 150°C. The equation may now be rearranged
to solve for the required heat sink to ambient thermal
resistance (R
θSA
).
START UP CURRENT
The MSK 5910RH sinks increased current during startup
to bring up the output voltage. Reference the "Saturated
Drive Current vs. Input Voltage" graph in the typical per-
formance curves of this data sheet and the "Understand-
ing 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/
Example:
An MSK 5910RH is connected for V
IN
=+5V and
V
OUT
=+3.3V. I
OUT
is a continuous 1A DC level. The
ambient temperature is +25°C. The maximum desired
junction temperature is +125°C.
R
θJC
=8.5°C/W and R
θCS
=0.15°C/W for most thermal
greases
Power Dissipation=(5V-3.3V) x (1A)
=1.7Watts
Solve for R
θSA:
R
θSA
= 125°C - 25°C -8.4°C/W - 0.15°C/W
1.7W
= 50.3°C/W
In this example, a heat sink with a thermal resistance
of no more than 50°C/W must be used to maintain a
junction temperature of no more than 125°C.
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 MSK 5910RH radiation test report. The complete
radiation test report is available in the RAD HARD PROD-
UCTS section on the MSK website.
http://www.mskennedy.com/store.asp?pid=9951&catid=19680
4
8548-11 Rev. I 12/11
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