MIL-PRF-38534 AND 38535 CERTIFIED FACILITY M.S.KENNEDY CORP. RAD HARD POSITIVE, 2.8A, LDO, SINGLE RESISTOR ADJ VOLTAGE REGULATOR 5984RH FEATURES: Manufactured using Space Qualified RH3083 Die MIL-PRF-38534 Class K Processing & Screening Total Dose Hardened to TBD Krads(Si) (Method 1019.7 Condition A) Low Dropout to 310mV (VIN - VOUT, with Seperate Control Supply) Output Adjustable to Zero Volts Internal Short Circuit Current Limit Output Voltage is Adjustable with 1 External Resistor Output Current Capability to 2.8A Internal Thermal Overload Protection Outputs may be Paralleled for Higher Current Contact MSK for MIL-PRF-38534 Qualification and Radiation Status DESCRIPTION: The MSK5984RH offers low dropout down to 310mV and an output voltage range down to zero volts while offering radiation tolerance for space applications. This, combined with the low θJC, allows increased output current while providing exceptional device efficiency. Output voltage is selected by the user through the use of 1 external resistor. Additionally, the regulator offers internal short circuit current and thermal limiting, which allows circuit protection and eliminates the need for external components and excessive derating. The MSK5984RH is hermetically sealed in a space efficient 3 pin package with straight, up and down pin configurations. EQUIVALENT SCHEMATIC PIN-OUT INFORMATION TYPICAL APPLICATIONS High Efficiency Linear Regulators Constant Voltage/Current Regulators Space System Power Supplies Switching Power Supply Post Regulators Very low Voltage Power Supplies 1 SET 2 CONTROL 3 VIN CASE=VOUT 1 PRELIMINARY Rev. C 9/14 10 ABSOLUTE MAXIMUM RATINGS VIN Input Voltage 7 No Overload or Short 7 Control Pin Voltage 7 Output Current Set Pin Current 8 Set Pin Voltage 7 ○ VCONTROL IOUT ISET VSET ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ +18V,-0.3V +23V,-0.3V +/-28V 3.0A +/-25mA +/-10V ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ PD TJ TST TLD ○ ○ ○ ○ Power Dissipation Junction Temperature Storage Temperature Range Lead Temperature Range (10 Seconds) Case Operating Temperature MSK5984RH MSK5984K/H RH ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ Internally Limited +150°C -65°C to +150°C ○ ○ ○ ○ ○ ○ ○ ○ ○ TC ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ 300°C -40°C to +85°C -55°C to +125°C ○ ○ ELECTRICAL SPECIFICATIONS NOTES: 1 Output is decoupled to ground using a 220μF tantalum low ESR capacitor in parallel with 3 pieces of 1.0μF and one 0.1μF ceramic capacitor unless otherwise specified. (See Figure 1) 2 Guaranteed by design but not tested. Typical parameters are representative of actual device performance but are for reference only. 3 Industrial grade devices shall be tested to subgroup 1 unless otherwise specified. 4 Class H and K devices shall be 100% tested to subgroups 1,2 and 3. 5 Subgroup 1 TA=TC=+25°C Subgroup 2 TA=TC=+125°C Subgroup 3 TA=TC=-55°C 6 Minimum load current verified while testing line regulation. 7 Voltage is measured with respect to VOUT. 8 Set pin is clamped to VOUT with diodes in series with 1KΩ resistors. Current will flow under transient conditions. 9 Reference current limit typical performance curve for output current capability versus voltage drop. 10 Continuous operation at or above absolute maximum ratings may adversely effect the device performance and/or life cycle. 11 Pre and Post irradiation limits at 25°C, up to TBD Krad(Si) TID, are identical unless otherwise specified. 2 PRELIMINARY Rev. C 9/14 APPLICATION NOTES OUTPUT VOLTAGE ADDITIONAL STABILITY A single resistor (RSET) from the SET pin to ground creates the reference voltage for the internal Error Amplifier. The MSK5984RH SET pin supplies a constant current of 50uA that develops the reference voltage. The output voltage is simply RSET x 50uA. Since the output is internally driven by a unitygain amplifier, an alternative to using RSET is to connect a high quality reference source to the SET pin. With a minimum load requirement of 1mA on the Output, the Output Voltage can be adjusted to near 0V. To bring the output voltage to 0V, the load must be connected to a slightly negative voltage supply to sink the 1mA minimum load current from a 0V output. A capacitor placed in parallel with the SET pin resistor to ground, will improve the output transient response and filter noise in the system. To reduce output noise, typically 500-1000pF is required. Capacitors up to 1μF can be used, however consideration must be given to the effect the time constant created will have on the startup time. INPUT CAPACITANCE LOAD REGULATION The MSK5984RH specified load regulation is Kelvin Sensed, therefore the parasitic resistance of the system must be considered to design an acceptable load regulation. The overall load regulation includes the specified MSK5984RH load regulation plus the parasitic resistance multiplied by the load current as shown in Figure 3. RSO is the series resistance of all conductors between the MSK5984RH output and the load. It will directly increase output load regulation error by a voltage drop of ΔIO x RSO. RSS is the series resistance between the SET pin and the load. RSS will have little effect on load regulation if the SET pin trace is connected as close to the load as possible keeping the load return current on a separate trace as shown. RSR is the series resistance of all of the conductors between the load and the input power source return. RSR will not effect load regulation if the SET pin is connected with a Kelvin Sense type connection as shown in Figure 3, but it will increase the effective dropout voltage by a factor of IO x RSR. Keeping RSO and RSR as low as possible will ensure minimal voltage drops and wasted power. FIGURE 1 Pins 3 is the connection to the collector of the power device of the MSK 5984RH. Output load current is supplied through these pins. Minimum input capacitance for these devices is 10uF. Low ESR, ceramic input capacitors are acceptable for applications without long input leads. For applications with long input leads, the self inductance of the wires can cause instability. Care must be taken to minimize the inductance of the input wires. This can be accomplished through the use of series resistance or higher ESR input capacitors. A minimum of 10uF of low ESR tantalum bulk capacitance in parallel with low value ceramic decoupling capacitance is recommended. CONTROL PIN The control pin is the bias supply for the control circuitry of the MSK5984RH. Minimum input capacitance on the control pin is 2.2uF. Approximately 1.7% of the output current flows into this pin. For proper regulation, the control pin voltage must be 1.6V greater than the output voltage. (See Control Dropout Voltage Specification). FIGURE 3 OUTPUT CAPACITANCE PARALLELING DEVICES For stability purposes, the MSK5984RH requires a minimum output capacitor of 10μF with an ESR of 0.5Ω or less. Tantalum or ceramic capacitors are recommended. A larger capacitance value will improve transient response for increased load current changes. Consideration must also be given to temperature characteristics of the capacitors used. When currents greater than 2.8A are needed, the MSK5984RH's may be paralleled to multiply the current capacity. As shown in Figure 4, the VIN and SET pins must be tied together. The VOUT pins are connected to the load with consideration to the conductor resistance. The conductor resistance of each MSK5984RH VOUT connection to the load, must be equal to create equal load sharing. As little as 10mΩ ballast resistance typically ensures better than 80% equal sharing of load current at full load. Additional consideration must be given to the effect the additional VOUT conductor resistance has on load regulation; see paragraph titled "Load Regulation". LOW DROPOUT OPERATION Using separate VIN and CONTROL power supplies allows for lower dropout and improved efficiency. Figure 2 shows the MSK5984RH output transistor collector is connected to the VIN pin. The regulator control circuitry is powered by the CONTROL input. The dropout of the regulator is determined by the saturation voltage of the output transistor, typical 300mV at 2.8A ILOAD. The CONTROL supply must supply the base drive current for the output transistor. The CONTROL current minus the 50μA SET current is supplied to the load. See the Typical Performance Characteristics curves for expected VIN dropout voltage, CONTROL pin dropout voltage and current requirements under various conditions. With separate supplies for VIN and CONTROL, power dissipation is reduced and efficiency improves. FIGURE 4 FIGURE 2 3 PRELIMINARY Rev. C 9/14 APPLICATION APPLICATION NOTES NOTES CONT'D CONT'D HEAT SINKING To determine if a heat sink is required for your application and if so, what type, refer to the thermal model and governing equation below. IMPROVING INITIAL ACCURACY AND REDUCING TEMPERATURE DRIFT Governing Equation: TJ = PD x (RθJC + RθCS + RθSA) + TA The initial output accuracy of the MSK5984RH due to SET pin current tolerance and set point resistor accuracy can be reduced to 0.2% using the MSK109RH radiation hardened precision reference. Minimal drift of the MSK109RH from temperature extremes and irradiation ensure very tight regulation. The circuit can be configured to use the 2.5V reference to directly set the output at 2.5V or with a slight variation it can provide any output within the operating range of the MSK5984RH down to 0V output. Select RS to maintain between 1mA and 10mA of current through the reference; see Figure 5 below. RS may be tied to VIN or another power source. The optional trim resistor can be used to further trim out initial output and system error. Reference the MSK109RH data sheet for application circuits that provide stable output voltages across the full operating range of the MSK5984RH including down to 0V output and the operating characteristics of the MSK109RH. 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 TC = Case Temperature TA = Ambient Temperature TS = Heat Sink Temperature EXAMPLE: This example demonstrates the thermal calculations for the regulator operating at 1.5A output current. Conditions for MSK5984RH: VCONTROL=VIN = +3.0V; IOUT = +1.5A VOUT=+1.0V 1.) Assume 45° heat spreading model. 2.) Find regulator power dissipation: PD = (VIN - VOUT)(IOUT) PD = (3-1)(1.50) = 3.0W 3.) For conservative design, set TJ = +125°C Max. 4.) For this example, worst case TA = +90°C. 5.) RθJC = 2.9°C/W from the Electrical Specification Table. 6.) RθCS= 0.15°C/W for most thermal greases. 7.) Rearrange governing equation to solve for RθSA: FIGURE 5 RθSA=(TJ - TA)/PD - (RθJC) - (RθCS) = (125°C - 90°C)/3.0W - 2.9°C/W - 0.15°C/W = 8.6°C/W ADDING SHUTDOWN In this case the result is 8.6°C/W. Therefore, a heat sink with a thermal resistance of no more than 8.6°C/W must be used in this application to maintain regulator circuit junction temperature under 125°C. The MSK5984RH can be easily shutdown by either reducing RSET to 0Ω or connecting a transistor from the SET pin to ground. By connecting two transistors, as shown in Figure 6, a low current voltage source is all that is required to take the SET pin to ground as well as pull the output voltage to ground. Q2 pulls the output voltage to ground when no load is present and only needs to sink 10mA. TOTAL DOSE RADIATION TEST PERFORMANCE Radiation performance curves for TID testing will be 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 MSK5984RH radiation test report. The complete radiation test report will be available in the RAD HARD PRODUCTS section on the MSK website. ADDITIONAL APPLICATION INFORMATION For additional applications information, please reference Linear Technology Corporation's® LT3083 and RH3083 data sheets. FIGURE 6 4 PRELIMINARY Rev. C 9/14 TYPICAL PERFORMANCE CURVES 5 PRELIMINARY Rev. C 9/14 TYPICAL PERFORMANCE CURVES CONT'D 6 PRELIMINARY Rev. C 9/14 MECHANICAL SPECIFICATIONS ESD TRIANGLE INDICATES PIN 1 WEIGHT=3.2 GRAMS TYPICAL ALL DIMENSIONS ARE SPECIFIED IN INCHES ORDERING INFORMATION MSK5984 K RH U LEAD CONFIGURATIONS S= STRAIGHT; U= BENT UP; D= BENT DOWN RADIATION HARDENED SCREENING BLANK= INDUSTRIAL K=MIL-PRF-38534 CLASS K GENERAL PART NUMBER The above example is an adjustable Class K regulator with leads bent up. 7 PRELIMINARY Rev. C 9/14 REVISION HISTORY M.S. Kennedy Corp. 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. Contact MSK for MIL-PRF-38534 Class H, Class K qualification and radiation status. 8 PRELIMINARY Rev. C 9/14