MIL-PRF-38534 AND 38535 CERTIFIED FACILITY RAD HARD 2.0A SWITCHING REGULATOR M.S.KENNEDY CORP. 5053RH 4707 Dey Road Liverpool, N.Y. 13088 (315) 701-6751 FEATURES: Manufactured using Space Qualified RH3480 Dice Total Dose Hardened 100 Krad (Method 1019.7 Condition A) Programmable Fixed Frequency or Synchronizable up to 2MHz 2.0A Integrated Switch Internal Slope Compensation Input Voltage Range from 3.6V to 36V Cycle by Cycle Current Limit Output Voltages Down to 0.79V External Compensation Power Good Indicator RUN/SS Pin for Power Sequencing and Rise Time Control DESCRIPTION: The MSK 5053RH is a radiation hardened 2MHz adjustable output voltage switching regulator. A wide input and output voltage range with a 2.0A output current capability make these regulators suitable for a wide variety of applications. The adjustable switching frequency allows the end user to select the frequency that maximizes the device performance in the given application. The switching frequency can be fixed at a chosen frequency with a single resistor or synchronized via the SYNC pin. The MSK 5053RH simplifies design of high efficiency radiation hardened switching regulators that use a minimum amount of board space. The MSK 5053RH is hermetically sealed in a 40 pin flatpack with straight or Gull wing leads and is specifically designed for space/satellite applications. EQUIVALENT SCHEMATIC TYPICAL APPLICATIONS PIN-OUT INFORMATION 1-9 10 11 12-20 21 22 23 POL Applications Satellite System Power Supply Step Down Switching Regulator Microprocessor, FPGA Power Source High Efficiency low Voltage Subsystems Power Supply 1 POWER GND CASE NC VIN SIGNAL GND RUN/SS SYNC 30-40 28-29 27 26 25 24 VOUT BD RT COMP FB PGOOD 8548-28 Rev. D 10/13 ABSOLUTE MAXIMUM RATINGS VIN Input Voltage RUN/SS Volatge Output Current BOOST Voltage BOOST Above SW Voltage FB, RT, VC Pin Voltage PG, BD, SYNC Pin Voltage ESD Rating ○ ○ ○ ○ ○ IOUT ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ 9 TST Storage Temperature Range -65°C to +150°C TLD Lead Temperature Range (10 Seconds) 300°C TJ Junction Temperature +150°C PD Power Dissipation 2.4 TC Case Operating Temperature Range MSK 5053K/H RH -55°C to +125°C MSK 5053RH -40°C to +85°C 36V 36V 2.0A 56V 30V 5.0V 30V Class 2 ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ 7 ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ELECTRICAL SPECIFICATIONS NOTES: Unless otherwise specified VIN=5V, VOUT=2.5V, VBD=VIN, IOUT=10mA, VPG=5V, RUN/SS=5V 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 subgroup 1 and 4 unless otherwise specified. Military grade devices ("H" and "K" Suffix) shall be 100% tested to subgroups 1,2,3 and 4. Subgroup 5 & 6 testing available on request. Subgroup 1,4 TC=+25°C 2,5 TC=+125°C 3,6 TC=-55°C 7 Continuous operation at or above absolute maximum ratings may adversely effect the device performance and/or life cycle. 8 Pre and Post irradiation limits, up to 100 Krad TID, are identical unless otherwise specified. 9 Internal solder reflow temperature is 180°C, do not exceed. 1 2 3 4 5 6 2 8548-28 Rev. D 10/13 APPLICATION NOTES PIN FUNCTIONS SYNC - The SYNC pin is the input for an external clock source to control the regulators switching frequency. The recommended clock source is a square-wave with 20% to 80% duty cycle. The clock source rise and fall times must be faster than 1uS. The Synchronization range is from 250KHz to 2MHz. The RT pin resistor must be set to a frequency which is 20% below the lowest synchronized frequency. Reference the PGOOD pin description. Tie the SYNC pin to ground when not used. VIN - The VIN pins connect to the collector of the internal power switch and provide power to the internal control circuitry and internal regulator. Very high di/dt is seen at these pins during switch on and off transitions. High frequency decoupling capacitors are recommended to minimize voltage spikes. The VIN pins should be connected to a low impedance source for best operation. VOUT - The VOUT pins are the power output of the regulator. Output capacitance must be connected between the VOUT pins and POWER ground to maintain stability and minimize output ripple voltage, see "Selecting the Output Capacitors". Provide a low impedance path between VOUT and the load to minimize voltage drops. PG - The PG pin is power good flag. It is an open collector output that transitions from low to high when the output rises to within 14% of it's programmed value. RT - The RT pin is used to program the oscillator frequency. A single resistor from RT to ground is all that is required to program the oscillator frequency. Use the table below to select the require resistor for the desired switching frequency. SIGNAL GND - The SIGNAL GND pin provides a return path for all internal control current and acts as the reference to the error amplifier. It is important that it is at the same voltage potential as the load return to ensure proper regulation. Keep current on the ground between the load and the MSK 5053RH to a minimum and use large copper traces to minimize voltage drops an regulation error. POWER GND- The POWER GND provides the high current load return path to the MSK 5053RH's internal catch diode. High speed switching transitions 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. BD- The BD pin connects to the anode of the internal boost diode and supplies current to the internal regulator. Connect BD to the VIN supply for typical applications. Slight efficiency improvements can be realized for applications with high input voltages and output voltages greater than or equal to 3.3V by connecting the BD pin to the output. FB - The FB (feedback) pin's primary function is to set the output voltage. Use a resistive divider from VOUT to GND to set the voltage at the feedback pin to 0.79V when the output voltage is at the desired level. Switching Frequency Resistor Value 200KHz 300KHz 187KΩ 121KΩ 400KHz 500KHz 600KHz 700KHz 88.7KΩ 68.1KΩ 800KHz 40.2KΩ 900KHz 1.0MHz 1.2MHz 34KΩ 29.4KΩ 23.7KΩ 1.4MHz 19.1KΩ 1.6MHz 16.2KΩ 1.8MHz 2.0MHz 13.3KΩ 11.5KΩ 56.2KΩ 46.4KΩ SETTING THE OUTPUT VOLTAGE The output voltage of the MSK 5053RH 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 VREF (0.790V nominal) at the FB pin. COMP - The COMP pin is the output of the error amplifier and the input of the peak current comparator. This pin is used for frequency compensation. Tie an RC network between the VC pin and ground to adjust the frequency response of the loop. VOUT=VREF*(1+R1/R2) R1=R2*(VOUT/VREF-1) RUN/SS - The RUN/SS pin has two shutdown functions. The first function disables the regulator when the voltage on the pin is pulled low. Tie to 2.5V or greater for normal operation. The second function is softstart. Use an RC network to control the rise time of the RUN/SS pin to limit the rise time of the current supplied to the load. The resistor must be chosen such that the RUN/SS pin will rise above and remain above 2.5V under all operating conditions and while sourcing the RUN/SS pin worst case sink current. 3 8548-28 Rev. D 10/13 APPLICATION NOTES CONT'D SELECTING THE SWITCHING FREQUENCY COMPENSATING THE LOOP The MSK 5053RH can be set to operate over a frequency range of 400KHz to 2.0MHz but 800KHz to 1MHz works well for most applications. The output ripple voltage and efficiency will vary with frequency and input voltage. Higher frequency increases switching losses but reduces output current ripple and core losses while lower frequency reduces switching losses and increases output current ripple and core losses. Higher voltages tend to increase output current ripple so higher frequencies may be preferred to reduce the ripple in applications in higher voltage applications. Care must be taken when increasing the frequency to ensure that the required switch on time is greater than the control circuit's minimum on time for low noise systems, the same is true for the minimum off time. The output will still regulate if the minimum on or off time is violated but the output ripple will increase. The typical minimum off time is 60nS. Reference the minimum on time curve in the typical performance curves section for typical minimum on time information. The current mode power stage from the VC node to the SW node can be modeled as a transconductance of gm=3.5A/V. The DC output gain will be 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 of 400u-mho with an output impedance of about 3M-ohm. Typically a single RC network from VC to ground works well for applications with mostly ceramic capacitance. An additional capacitor from VC to ground may be needed to cancel the ESR zero in applications with mostly tantalum bulk capacitance. LOW RIPPLE BURST MODE The MSK 5053RH can be operated in low ripple burst mode to maximize efficiency at very light loads. In low ripple burst mode the control circuitry delivers single bursts of current to maintain regulation followed by periods of no switching or sleep periods. The quiescent current draw is minimized during the sleep periods increasing overall efficiency. Tie the SYNC pin to ground to enable low ripple burst mode at light loads. Low ripple burst mode is not available when using the SYNC feature. If the MSK 5053RH is being synchronized to an external clock source the control circuitry will skip pulses at light loads to improve efficiency. SELECTING THE OUTPUT CAPACITOR The output capacitor filters the ripple current from the 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: TOTAL DOSE RADIATION TEST PERFORMANCE VP-P=IP-P*ESR 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 5053RH radiation test report. The complete test report is available in the RAD HARD PRODUCTS section of the MSK website. The typical ESR range for an MSK 5053RH 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: ADDITIONAL APPLICATION INFORMATION For additional applications information, please reference Linear Technology's® LT3480 data sheet. VP-P(CAP)=IP-P/(8*F*C) Where C=Output capacitance in Farads TYPICAL APPLICATION CIRCUIT Select a capacitor or combination of capacitors that can tolerate the worst-case ripple current with sufficient derating. 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. Additional ceramic capacitance may be required at switching frequencies above 1MHz where some tantalum capacitors begin to act inductive. 4 8548-28 Rev. D 10/13 TYPICAL PERFORMANCE CURVES 5 8548-28 Rev. D 10/13 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. 6 8548-28 Rev. D 10/13 MECHANICAL SPECIFICATIONS ESD TRIANGLE INDICATES PIN 1 WEIGHT=12.2 GRAMS TYPICAL ORDERING INFORMATION PART NUMBER SCREENING LEVEL MSK5053RH INDUSTRIAL MSK5053HRH MIL-PRF-38534 CLASS H MSK5053KRH MIL-PRF-38534 CLASS K 7 LEADS STRAIGHT 8548-28 Rev. D 10/13 MECHANICAL SPECIFICATIONS ESD TRIANGLE INDICATES PIN 1 WEIGHT=12.2 GRAMS TYPICAL ORDERING INFORMATION PART NUMBER SCREENING LEVEL MSK5053RHG INDUSTRIAL MSK5053HRHG MIL-PRF-38534 CLASS H MSK5053KRHG MIL-PRF-38534 CLASS K LEADS GULL WING M.S. Kennedy Corp. 4707 Dey Road, Liverpool, New York 13088 Phone (315) 701-6751 FAX (315) 701-6752 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. 8 8548-28 Rev. D 10/13