MIL-PRF-38534 & 38535 CERTIFIED FACILITY
M.S.KENNEDY CORP.
RAD HARD ULTRA LOW
DROPOUT POSITIVE ADJUSTABLE
LINEAR REGULATOR
5826RH
(315) 701-6751
4707 Dey Road Liverpool, N.Y. 13088
FEATURES:
Manufactured using
Space Qualified RH1573 Die
Replaces IR OMR9605 and IRUH50PA23A
Total Dose Hardened to 300 Krads(Si) (Method 1019.7 Condition A)
Ultra Low Dropout for Reduced Power Consumption
External Shutdown Function
Latching Overload Protection
Optimized for 5.0V Input
1.265V to (VIN-0.4V) Output Voltage Range
Output Current Limit
Available in 2 Lead Form Options: Straight and Gullwing
Available to DSCC SMD 5962F09210
ELDRS Tested to 100 Krads(Si) (Method 1019.7 Condition D)
Neutron Tested to 1.0x10¹² n/cm² (Method 1017.2)
DESCRIPTION:
The MSK 5826RH is a rad hard adjustable output linear regulator capable of delivering 3.0 amps of output current.
Typical dropout is only 0.30 volts with a 3 amp load. An external shutdown function is ideal for power supply
sequencing. This device also has internal latching overload protection. The MSK 5826RH is radiation hard and specifi-
cally designed for space/satellite applications. The device is packaged in a hermetically sealed space efficient 8 pin
flatpack that is electrically isolated from the internal circuitry allowing for direct heat sinking.
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
GND
8
GND
7
SHUTDOWN
6
ADJUST
5
CASE=ISOLATED
VIN
VIN
VOUT
VOUT
8548-57 Rev. G 7/12
1
ABSOLUTE MAXIMUM RATINGS
VIN
I
OUT
T
C
9
Supply Voltage
+7V
Output Current
7
3.5A
Case Operating Temperature Range
MSK5826K/H RH
-55°C to +125°C
MSK5826RH
-40°C to +85°C
T
ST
T
LD
P
D
T
C
Storage Temperature Range -65°C to +150°C
300°C
Lead Temperature Range
(10 Seconds)
See SOA Curve
Power Dissipation
150°C
Junction Temperature
ELECTRICAL SPECIFICATIONS
NOTES:
1
2
3
4
5
6
7
8
9
10
11
Unless otherwise specified, V
IN
=5.0V, V
SHUTDOWN
=0V and I
OUT
=50mA. See figure 2 for typical test 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" and "K" suffix) shall be 100% tested to subgroups 1,2,3 and 4.
Dropout limited by minimum value of VIN.
Subgroup 1,4 T
C
=+25°C
Subgroup 2
T
C
=+125°C
Subgroup 3
T
A
=-55°C
Output current limit is dependent upon the values of V
IN
and V
OUT
. See application notes "Over Current Latch" and "Current Limit and SOA".
Refer to typical performance curves.
Continuous operation at or above absolute maximum ratings may adversely effect the device performance and/or life cycle.
Pre and post irradiation limits at 25°C, up to 300Krad TID, are identical unless otherwise specified.
Reference DSCC SMD 5962F09210 for electrical specification for devices purchased as such.
2
8548-57 Rev. G 7/12
APPLICATION NOTES
PIN FUNCTIONS
VIN -
These pins provide power to all internal circuitry
including bias, start-up, thermal limit and overcurrent latch.
Input voltage range is 2.9V to 6.5V but the MSK 5826RH
is optimized for 5.0V input. See MSK 5824RH for 3.3V
input version.
GND -
Internally connected to ground, these pins 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 output voltage will turn
on when the SHUTDOWN pin is pulled below the thresh-
old 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 -
These are the output pins for the device.
ADJUST -
This pin is used to set the output voltage. Con-
nect a resistor between the adjust pin (4) and the output
pins (5 and 6) to fix the output voltage at the desired
value. Use the following equations to determine the nomi-
nal value of the adjust resistor (RADJ).
VOUT=VREF x (1 + RADJ/1KΩ)
RADJ=(VOUT/VREF - 1) x 1KΩ
OUTPUT CAPACITOR SELECTION
The MSK 5826RH contains three internal 4.7 F tanta-
lum output capacitors, type CWR19HB475KCBB. The
capacitors are rated for 15V maximum applied voltage
and have been surge tested in accordance with condition
B of MIL-PRF-55365. The system designer must ensure
proper de-rating in accordance with their system require-
ments. Low ESR output capacitors are required to main-
tain regulation and stability. Four CWR29FB227 (AVX PN
TAZH227K010L) tantalum capacitors in parallel with ce-
ramic decoupling capacitors (0.1 F typical) provides suf-
ficient gain and phase margin for most applications. The
maximum ESR specification for the CWR29FB227 capaci-
tor is 180mΩ at 100kHz and is sufficient for many appli-
cations. MSK has found through full WCCA that screen-
ing 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.
OVERCURRENT LATCH
Overcurrent protection is provided by the MSK 5826RH
series through the use of a timed latch off circuit. The
internal latch timeout is triggered by an overcurrent con-
dition. To allow for start up surge currents, the timeout is
approximately 22mS at 25°C. If the overcurrent condi-
tion remains at the end of the timeout cycle, the regulator
will latch off until the latch is reset. To reset the latch,
toggle the shutdown pin high then low or cycle VIN off
then back on. At elevated temperatures or input voltages
the device may simply limit the output current without
activating the latch feature. A thermal limit condition will
trigger the latch with no time out delay.
FIGURE 1
CURRENT LIMIT AND SOA
The MSK 5826RH current limit function is directly af-
fected by the input and output voltages. Figure 1 illus-
trates the relationship between VIN and ICL for various
output voltages. It is very important for the user to con-
sult the SOA curve when using input voltages which re-
sult in current limit conditions beyond 3.5 Amps. When
using input voltages which result in current limit above
3.5 Amps, the user must maintain output current within
the SOA curve to avoid damage to the device. The cur-
rent limit is adjusted internally for an input voltage of 5V.
INPUT POWER SUPPLY BYPASSING
The MSK 5826RH contains an internal 4.7 F tantalum
input capacitor, type CWR19HB475KCBB. The capacitor
is rated for 15V maximum applied voltage and has been
surge tested in accordance with condition B of MIL-PRF-
55365. The system designer must ensure proper de-rat-
ing in accordance with their system requirements. To
maximize transient response and minimize power supply
transients it is recommended that two 47 F tantalum
capacitors are connected between VIN and ground. A
0.1 F ceramic capacitor should also be used for high fre-
quency bypassing. See typical application circuit.
3
8548-57 Rev. G 7/12
APPLICATION NOTES CONT.
THERMAL LIMITING
The MSK 5826RH 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 5826RH. Toggle the shutdown pin high
then low or cycle power to reset the latch. See shut-
down pin description and overcurrent latch description
for more information.
TYPICAL APPLICATIONS CIRCUIT
HEAT SINK SELECTION
To select a heat sink for the MSK 5826RH, the follow-
ing formula for convective heat flow may be used.
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
FIGURE 2
START UP CURRENT
The MSK 5826RH 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/
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
).
Example:
An MSK 5826RH is connected for V
IN
=+5.0V and
V
OUT
=+3.3V. I
OUT
is a continuous 3A DC level. The am-
bient temperature is +25°C. The maximum desired junc-
tion temperature is +125°C.
R
θJC
=6.5°C/W and R
θCS
=0.15°C/W for most thermal
greases
Power Dissipation=(5.0V-3.3V) x (3A)
=5.1 Watts
Solve for R
θSA:
R
θSA
=
125°C - 25°C
- 6.5°C/W - 0.15°C/W
5.1W
TOTAL DOSE RADIATION TEST
PERFORMANCE
Radiation performance curves for TID, Neutron and
ELDRS testing have been generated for all radiation test-
ing performed by MS Kennedy. These curves show per-
formance trends throughout the TID test process and
are located in the MSK 5826RH 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
= 12.9°C/W
In this example, a heat sink with a thermal resistance
of no more than 12.9°C/W must be used to maintain a
junction temperature of no more than 125°C.
4
8548-57 Rev. G 7/12
TYPICAL PERFORMANCE CURVES
5
8548-57 Rev. G 7/12
