MIL-PRF-38534 AND 38535 CERTIFIED FACILITY
RAD HARD 4.5A
SWITCHING REGULATOR
5052RH
FEATURES:
Manufactured using
Rad Hard RH1959MILDICE
Total Dose Hardened to 100 Krad(Si) (Method 1019.7 Condition A)
Adjustable Output Voltage Down to 1.21V
Input Voltage Range from 4.3V to 16V
500KHz or Externally Synchronizable Switching Frequency
Shutdown Pin
Short Circuit and Thermal Limit Protection
Contact MSK for MIL-PRF-38534 Qualification Status
DESCRIPTION:
The MSK5052RH is a radiation hardened adjustable output voltage switching regulator. A wide input and output voltage
range with 4.5A output current capability make these regulators suitable for many applications. Excellent efficiency and a
reduced output capacitance requirement minimize power dissipation and board space requirements. The switching frequency
can be controlled by an external signal through the SYNC pin or be set to a constant 500KHz. The regulator output can be
turned on and off remotely with logic levels via the shutdown pin for meeting power sequencing requirements. Short circuit
current limit and thermal shutdown features provide fault protection. The MSK5052RH is packaged in a hermetically sealed
40 pin flatpack with straight or gull wing leads and specifically designed for space/satellite applications.
EQUIVALENT SCHEMATIC
PIN-OUT INFORMATION
TYPICAL APPLICATIONS
POL Applications
Satellite System Power Supply
Microprocessor, FPGA Power Source
High Efficiency Low Voltage Subsystem
Power Supply 1-9
10-18
19-20
21
22
23
POWER GND
VIN
SIGNAL GND
FB
COMP
SHDN
24
25-26
27
28
29
30-40
SYNC
BOOST
NC
CASE
NC
VOUT
CASE=PIN 28 (NO INTERNAL CONNECTION)
1
8548-6 Rev. E 12/14
ABSOLUTE MAXIMUM RATINGS
VIN
IOUT
Input Voltage
Output Current 9
SYNC Pin Voltage
SHDN Pin Voltage
FB Pin Voltage
FB Pin Current
10
15V
4.5A
7.0 V
7.0V
3.5V
1mA
TST Storage Temperature Range 12
-65°C to +150°C
TLD Lead Temperature Range
(10 Seconds)
300°C
TJ Junction Temperature
150°C
TC Case Operating Temperature Range
MSK 5052K/HRH
-55°C to +125°C
MSK 5052RH
-40°C to +85°C
ESD Rating
3A
ELECTRICAL SPECIFICATIONS
NOTES:
1
2
3
4
5
6
7
8
9
10
11
12
Unless otherwise specified VIN=5.0V, VOUT=2.5V and IOUT=1.0A. See Figure 1 for typical application circuit.
Guaranteed by design but not tested. Typical parameters are representative of actual device performance but are for reference only.
Reference SYNC pin function in the Application Notes section herein.
Industrial grade devices shall be tested to subgroup 1 and 4 unless otherwise specified.
Military grade devices ("H" Suffix) shall be 100% tested to subgroups 1,2,3 and 4.
Subgroup 5 & 6 testing available on request.
Subgroup 1,4 TA=TC=+25°C
2,5 TA=TC=+125°C
3,6 TA=TC=-55°C
Verified during line regulation test.
The absolute maximum current of 4.5A applies for duty cycles of 0.75 or lower.
De-rate linearly from 4.5A at D=0.75 to 3.75A at D=93 (maximum duty cycle typical).
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 100 Krad(Si) TID, are identical unless otherwise specified.
Internal solder reflow temperature is 180°C, do not exceed.
2
8548-6 Rev. E 12/14
APPLICATION NOTES
PIN FUNCTIONS
VIN - VIN connects to the collector of the internal power
switch and provides power to the internal control circuitry and
internal regulator. Very high di/dt is seen at VIN during switch
on and off transitions. High frequency decoupling capacitors
are recommended to minimize voltage spikes. VIN should
be connected to a low impedence source for best operation.
COMP - The COMP pin is the output of the error amplifier and
the input of the peak current comparator. This pin is typically
used for frequency compensation but can also be used as a
current clamp or as an override to the internal error amplifier
control. The pin voltage is typically around 1V at light load
and 2V at heavy load. Driving the pin low will shut down
the regulator. Driving it high will increase the output current.
The current into the COMP pin must be limited to 4mA when
driving it high.
FB - The FB (feedback) pin's primary function is to set the
output voltage to the desired level, see "Setting The Output
Voltage."The FB pin provides two additional functions. If the
voltage at the FB pin drops below 0.8V the switch current limit
is reduced. When the voltage at the FB pin drops below 0.7V
the switching frequency is reduced. The switching frequency
reduces to approximately 100KHz at VFB<=0.4V.
SYNC - The SYNC pin is used to synchronize the oscillator
to an external clock. It is logic compatible and can be driven
to any frequency between the free run frequency (500KHz
nominal) and 1MHz. At frequencies greater than 700KHz the
risk of sub harmonic oscillation increases for applications with
duty cycles greater than 50%. This is the result of the magnitude of the slope compensation ramp generated by the control
IC being limited at higher frequencies. The duty cycle of the
input signal must be between 10% and 90% to ensure proper
synchronization. Tie the SYNC pin to GND if it is not used.
SIGNAL GND - The SIGNAL GND provides a return path for
all internal control current and acts as a reference to the error
amplifier. It is important that it is at the same voltage potential
as the load return to ensure proper regulation. Tie the SIGNAL
GND to the POWER GND as close to the case as possible.
POWER GND- The power ground provides the high current
load return path to the MSK5052RH's internal catch diode.
High speed switching transition occur on the power ground
with every switching cycle. The load return current commutates between the input bus return and the POWER GND
pins. Place a minimum of 0.1uF to 1.0uF of high frequency
ceramic capacitance physically close to the POWER GND
and VIN pins to maximize performance.
SETTING THE OUTPUT VOLTAGE
The output voltage of the MSK5052RH is set with a simple
resistor divider network: see Figure 1 (Typical Application
Circuit). Select the resistor values to divide the desired output
down to equal VFB (1.21V nominal) at the FB pin. Use a 2.5K
or lower value resistor for R2 to keep output error due to FB
pin bias current less than 0.1%.
VOUT=VFB*(1+R1/R2)
SHDN - The SHDN (shutdown) pin has two shutdown functions. The first function disables switching when the voltage
on the pin drops below 2.38V (nominal). The second forces
a complete shutdown minimizing power consumption when
the voltage drops below 0.4V (nominal). Pull this pin high or
leave open for normal operation. The 2.38V threshold can be
used for UVLO functions by configuring a resistive divider to
VIN and GND that holds the pin voltage below 2.38V until
VIN rises to the minimum desired voltage.
R1=R2*((VOUT/VFB)-1)
Given VFB=1.21V Nominal
TYPICAL APPLICATION CIRCUIT
BOOST- The BOOST pin connects to an internal diode-capacitor network that supplies voltage to the power switch
driver circuit. This elevated voltage level ensures the power
switch saturates. A minimum of 3V is required for proper
operation. This can be power from the input power supply,
the regulator output , or a seperate supply if desired. Overall power dissipation increases slightly with higher BOOST
voltages. For a typical 5V input connect the BOOST pin to
the input source. For a 12V input to 3.3V output regulator,
efficiency may be improved by 1 to 2 percent by connecting
the BOOST pin to the regulator output.
VOUT - VOUT is the output of the regulator. External capacitance between the VOUT pin and GND is required to maintain
stability and minimize output ripple voltage, see "Selecting
The Output Capacitor." Provide a low impedance path between VOUT and the load to minimize voltage drops.
FIGURE 1
3
8548-6 Rev. E 12/14
APPLICATION NOTES CONT'D
SELECTING THE OUTPUT CAPACITOR
POWER DISSIPATION
The output capacitor filters the ripple current from the
internal inductor to an acceptable ripple voltage seen by
the load. The primary factor in determining voltage ripple
is the ESR of the output capacitor. The voltage ripple can
be approximated as follows:
Power dissipation in the MSK5052RH can be calculated as
follows:
PDISS =Switch loss + BOOST current loss + Quiescent current
loss
VP-P=IP-P*ESR
Where IP-P=VOUT*(VIN-VOUT)/(1.65*VIN)
=(RSW(IOUT)² (VOUT)+24nS(IOUT)(VIN)(F)) +
VIN
The typical ESR range for an MSK5052RH application is
between 0.05 and 0.20 ohm. Capacitors within these ESR
ranges typically have enough capacitance value to make
the capacitive term of the ripple equation insignificant. The
capacitive term of the output voltage ripple lags the ESR
term by 90° and can be calculated as follows:
((VBOOST)(VOUT)(IOUT/A)) +
VIN
(VIN(0.001)+VOUT(0.005)+(VOUT²)(0.002))
VIN
where,
RSW(Switch resistance)=0.07Ω typ 0.13Ω max
VP-P(CAP)=IP-P/(8*F*C)
Select
C=output capacitance in Farads
F=Switching Frequency in Hertz
24nS=Equivalent switch current/Voltage overlap time
F=Switch Frequency
Select a capacitor or combination of capacitors that can tolerate the worst-case ripple current with sufficient de-rating.
When using multiple capacitors in parallel to achieve ESR
and/or total capacitance, sharing of ripple current between
capacitors will be approximately equal if all of the capacitors
are the same type and preferably from the same lot. Low
ESR tantalum capacitors are recommended over aluminum
electrolytic. The zero created by the ESR of the capacitor
is necessary for loop stabilty. A small amount of ceramic
capacitance close to the load to decouple high frequency
is acceptable but it should not cancel the ESR zero.
A=Current Gain~50 typ 32 min
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 are located in the MSK5052RH radiation test report. The
complete radiation test report is available in the RAD HARD
PRODUCTS section on the MSK website.
COMPENSATING THE LOOP
The current mode power stage from COMP node to VOUT
can be modeled as a transconductance of gm=5.3A/V.
The DC output gain will be the product of the transconductance times the load resistance. As frequency increases
the output capacitance rolls off the gain until the ESR
zero is reached. The error amplifier can be modeled as a
transconductance amplifier with gm=2000uMho and gain
of 400 with finite output impedence. Typically a resistor
and capacitor in series to ground are all that is needed to
compensate the loop, but more complex compensation
schemes are readily achieved.
4
8548-6 Rev. E 12/14
TYPICAL PERFORMANCE CURVES
5
8548-6 Rev. E 12/14
TYPICAL PERFORMANCE CURVES CONT'D
6
8548-6 Rev. E 12/14
TYPICAL PERFORMANCE CURVES CONT'D
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.
200
60
150
60
150
40
100
40
100
20
50
20
50
0
0
0
0
-50
-20
VIN = 5.0V
VOUT = 3.3V
IOUT = 1.0A
COMPENSATION =0.01uF || 1000pF + 7.5KΩ
-60
-80
1
10
100
-50
GAIN (dB)
-20
-100
-40
-150
-60
-200
-80
1000
VIN = 5.0V
VOUT = 2.5V
IOUT = 1.0A
COMPENSATION =0.01uF || 1000pF + 7.5KΩ
-100
-150
-200
1
10
100
FREQUENCY (kHz)
1000
FREQUENCY (kHz)
GAIN AND PHASE vs. FREQUENCY
80
200
60
150
40
100
20
50
0
0
-50
-20
VIN = 5.0V
VOUT = 1.5V
IOUT = 1.0A
COMPENSATION =0.01uF || 1000pF + 7.5KΩ
-40
-60
PHASE (deg)
-40
PHASE (deg)
80
PHASE (deg)
GAIN AND PHASE vs. FREQUENCY
200
GAIN (dB)
GAIN (dB)
GAIN AND PHASE vs. FREQUENCY
80
-100
-150
-200
-80
1
10
100
1000
FREQUENCY (kHz)
7
8548-6 Rev. E 12/14
MECHANICAL SPECIFICATIONS
ESD TRIANGLE INDICATES PIN 1
WEIGHT=12.5 GRAMS TYPICAL
ALL DIMENSIONS ARE SPECIFIED IN INCHES
ORDERING INFORMATION
PART NUMBER
SCREENING LEVEL
MSK5052RH
INDUSTRIAL
MSK5052HRH
MIL-PRF-38534 CLASS H
MSK5052KRH
MIL-PRF-38534 CLASS K
8
LEADS
STRAIGHT
8548-6 Rev. E 12/14
MECHANICAL SPECIFICATIONS
ESD TRIANGLE INDICATES PIN 1
WEIGHT=12.5 GRAMS TYPICAL
ALL DIMENSIONS ARE SPECIFIED IN INCHES
ORDERING INFORMATION
PART NUMBER
SCREENING LEVEL
MSK5052RHG
INDUSTRIAL
MSK5052HRHG
MIL-PRF-38534 CLASS H
MSK5052KRHG
MIL-PRF-38534 CLASS K
9
LEADS
GULL
WING
8548-6 Rev. E 12/14
REVISION HISTORY
MSK
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.
Contact MSK for MIL-PRF-38534 Class H and Class K qualification status.
10
8548-6 Rev. E 12/14