FEATURES MHF SERIES 12 WATT DC/DC CONVERTERS 28 VOLT INPUT • –55° to +125°C operation • 16 to 40 VDC input (19 to 40 VDC for 15 volt outputs) • Fully Isolated • Optocoupler feedback • Fixed frequency 600 kHz typical • Forward converter topology • 50 V for up to 50 ms transient protection • Inhibit function • Indefinite short circuit protection • Up to 83% efficiency, 22 W/in3 MODELS VDC OUTPUT SINGLE 5 12 15 DUAL ±12 ±15 Size (max.): 1.460 x 1.130 x 0.330 inches (37.08 x 28.70 x 8.38 mm) See Section B8, case E1 for dimensions. Weight: 21 grams typical. Screening: Standard or ES. See section C2 for screening options. DESCRIPTION The MHF Series™ of DC/DC converters offer up to 12 watts of power from single or dual outputs in a single package over a the full military temperature range. Thick film hybrid manufacturing technology produces high levels of miniaturization, giving the MHF Series converters a low profile (0.330 inch), small board area (1.65 square inches), and high power density (22 watt/in3). The parts are packaged in hermetically sealed steel enclosures, making them ideal for use in military, aerospace, and high reliability industrial applications. DESIGN METHODOLOGY The MHF converters are switching regulators which use a quasisquare wave, single ended forward converter design with a nominal switching frequency of 600 kHz. Isolation between input and output circuits is provided with a transformer in the forward power loop and a temperature insensitive optical link in the feedback control loop. Output regulation is accomplished with constant frequency pulse width modulation. Both line and load regulation are typically within 10 mV. On dual output models, the positive output is independently regulated and the negative output is cross-regulated. Figures 7 and 8 illustrate what effects load changes have on the negative output. Indefinite short circuit protection and overload protection are provided by sensing output load current and restricting the output current to approximately 125% of full load output current. Since the output current is sensed in the secondary stage, the result is a predictable, constant output current control with no foldback characteristics. MHF converters are provided with internal filtering elements on both the input and output to help reduce the need for external components. For information about filtering to meet MILSTD-461’s CE03 test, contact your Interpoint representative. WIDE VOLTAGE RANGE The MHF Series is designed to provide full power operation over the input voltage range of 16 to 40 volts. The 15 volt models provide a 19 to 40 volt range. Operation below 16 volts (or 19 volts for the 15 volt models), including operation in MIL-STD-704E emergency power conditions, is possible with derated output power. Please refer to the low line drop-out graphs, Figures 9 and 10. MILITARY TEMPERATURE RANGE The MHF Series provides full power operation at case temperatures from –55°C up to +125°C. All 12 and 15 volt models in both single and dual output configurations provide full power operation at +125°C with derated power to 135°C. The +5 volt model provides full power at 110°C derated to 0% at 130°C. Depending on operating levels, air flow, and ambient temperature; heat sinking may be required. INHIBIT FEATURE An inhibit terminal is provided that can be used to disable internal switching, resulting in a very low quiescent input current. An open collector TTL compatible low (≤0.8V) is required to control the inhibit function. This level may be supplied by an open collector gate since the inhibit pin is provided with an internal pull-up resistor. B2-77 MHF SERIES 12 WATT DC/DC CONVERTERS INHIBIT ABSOLUTE MAXIMUM RATINGS TYPICAL CHARACTERISTICS Inhibit TTL Open Collector • Logic low (output disabled) Logic low 0.8 V max Inhibit pin current 4 mA max • Referenced to input common • Logic high (output enabled) Open collector Input Voltage • 16 to 40 VDC (19 to 40 VDC 15 volt output) Output Power • 12 watts (10 watts MHF2805S) Lead Soldering Temperature (10 sec per lead) • 300°C Storage Temperature Range (Case) • –55°C to +135°C Output Voltage Temperature Coefficient • 150 ppm/°C, typical Input to Output Capacitance • 50 pF, typical Current Limit • 125% of full load, typical Isolation • 100 megohm minimum at 500 V Conversion Frequency • 600 kHz typical Inhibit Pin Voltage (unit enabled) • 8 to 11 V RECOMMENDED OPERATING CONDITIONS Input Voltage Range • 16 to 40 VDC continuous • 19 to 40 VDC 15 volt outputs continuous • 50 V for 50 msec transient Case Operating Temperature (Tc) • –55°C to +125°C full power • –55°C to +110°C full power for MHF2805S • –55°C to +135°C absolute • –55°C to +130°C absolute for MHF2805S Derating Output Power/Current • Linearly from 100% at 125°C to 0% at 135°C • Linearly from 100% at 110°C to 0% at 130°C for MHF2805S Electrical Characteristics: 25°C Tc, 28 VDC Vin, 100% load, unless otherwise specified. SINGLE OUTPUT MODELS PARAMETER MHF2805S MHF2812S MHF2815S MIN TYP MAX MIN TYP MAX MIN TYP MAX UNITS OUTPUT VOLTAGE 4.95 5.0 5.05 11.88 12 12.12 14.85 15 15.15 VDC OUTPUT CURRENT — — 2.0 — — 1.0 — — 0.8 A — — 10 — — 12 — — 12 W OUTPUT POWER OUTPUT RIPPLE CONDITIONS MIN. TO MAX. VIN 10 kHz to 2 MHz — 40 60 — 30 60 — 25 50 mV p-p LINE REGULATION MIN. TO MAX. VIN — 10 50 — 10 50 — 10 50 mV LOAD REGULATION NO LOAD TO FULL — 10 50 — 10 50 — 10 50 mV CONTINUOUS 16 28 40 16 28 40 19 28 40 VDC TRANSIENT 50 ms — — 50 — — 50 — — 50 V NO LOAD — 20 30 — 20 30 — 20 30 FULL LOAD — — 483 — — 557 — — 535 INHIBITED — 2 3 — 2 3 — 2 3 INPUT VOLTAGE INPUT CURRENT mA INPUT RIPPLE CURRENT 10 kHz TO 2 MHz EFFICIENCY LOAD FAULT1 START-UP — 135 180 — 150 200 — 150 220 mA p-p 74 77 — 77 81 — 80 83 — % POWER DISSIPATION OVERLOAD — — 5 — — 5 — — 5 SHORT CIRCUIT — – 3.5 — — 2.8 — — 2 DELAY — 180 300 — 80 200 — 150 250 Notes 1. Indefinite short circuit protection not guaranteed above 125°C case temperature (110°C case for MHF2805S). B2-78 W ms MHF SERIES 12 WATT DC/DC CONVERTERS Electrical Characteristics: 25°C Tc, 28 VDC Vin, 100% load, unless otherwise specified. DUAL OUTPUT MODELS PARAMETER OUTPUT VOLTAGE OUTPUT RIPPLE VOLTAGE MIN MHF2815D TYP MAX MIN +VOUT 11.88 12.0 12.12 14.85 15.0 15.15 – VOUT 11.82 12.0 12.18 14.77 15.0 15.23 OUTPUT CURRENT1, 2 OUTPUT POWER2 MHF2812D TYP MAX CONDITION UNITS VDC — 0.5 1.0 — 0.4 0.8 +VOUT — — 10.8 — — 10.8 A – VOUT — — 10.8 — — 10.8 TOTAL — — 12 — — 12 10 kHz TO 2 MHz — 30 60 — 30 60 mV p-p +VOUT — 5 50 — 5 50 mV mV W LINE REGULATION MIN. TO MAX. VIN LOAD REGULATION NO LOAD TO FULL CROSS REGULATION INPUT VOLTAGE NO LOAD TO FULL INPUT CURRENT +VOUT — 5 50 — 10 50 20% TO 80% LOAD3 — 5 10 — 4 8 50% LOAD4 — 4 5 — 3 5 % CONTINUOUS 16 28 40 19 28 40 VDC TRANSIENT 50 ms — — 50 — — 50 V NO LOAD FULL LOAD INHIBITED — — — 25 — 1.9 35 550 3 — — — 25 — 1.9 35 536 3 mA — 175 240 — 175 240 mA p-p 78 81 — 80 83 — % INPUT RIPPLE CURRENT 10 kHz TO 2 MHz EFFICIENCY LOAD FAULT5 START-UP POWER DISSIPATION SHORT CIRCUIT — — 2.8 — — 2 OVERLOAD — — 5 — — 5 DELAY — 150 250 — 150 250 Notes 1. Applies to both outputs. 2. Maximum combined output power is 12 watts. A maximum of 90% is available from either output. 3. 20% to 80% load on the positive output and 80% to 20% on the negative output. See Figure 8. W ms 4. 50% load on the positive output and 50% to 20% load on the negative output. 50% load on the negative output and 50% to 20% load on the positive output. See Figure 7. 5. Indefinite short circuit protection not guaranteed above 125°C case temperature. PIN OUT Pin 1 2 3 4 5 6 7 8 Single Output Inhibit No connection Output Common Positive Output No connection Case Ground Input Common Positive Input Dual Output Inhibit Positive Output Output Common Negative Output No connection Case Ground Input Common Positive Input Squared corner and dot on top of cover indicate pin one. MODEL NUMBER KEY MHF 28 12 D / ES Base Model 1 2 3 4 5 Number of Outputs (S = single, D = dual) BOTTOM VIEW MHF 8 7 Input Voltage Output Voltage Screening (Standard screening has no designator in this position.) 6 See Section B8, case E1, for dimensions. FIGURE 1: PIN OUT B2-79 MHF SERIES 12 WATT DC/DC CONVERTERS Typical Performance Curves: 25°C Tc , 28 VDC Vin, 100% load, unless otherwise specified. 90 90 90 16V 80 40V 70 28V 60 50 80 40V 70 28V 60 2 4 6 8 10 12 50 14 2 4 6 8 10 12 50 14 2 4 6 8 10 12 Output Power (Watts) Output Power (Watts) MHF2805S Efficiency MHF2812S Efficiency MHF2815S Efficiency 19V 80 Efficiency (%) 40V 70 28V 40V 70 28V 60 60 50 4 6 8 10 12 14 2 4 6 8 10 12 Output Power (Watts) Output Power (Watts) MHF2812D Efficiency MHF2815D Efficiency 14 Negative Output Voltage Change (%) 90 80 14 FIGURE 4 FIGURE 3 16V Efficiency (%) 28V Output Power (Watts) 90 2 40V 70 60 FIGURE 2 50 Efficiency (%) Efficiency (%) Efficiency (%) 19V 16V 80 10 8 6 Cond. A 2812D 4 2 0 2815D 2 –4 2812D –6 Cond. B –8 –10 0 10 2 30 40 50 Output Load (%) Condition A: 50% Load Pos. Vout, 50% to 20% Neg. Vout Condition B: 50% Load Neg. Vout, 50% to 20% Pos. Vout MHF Negative Output Voltage Cross Regulation FIGURE 6 19 15 18 10 17 5 0 2815D –5 2812D –10 –15 –20 19 18 2815S 16 15 2812S 14 13 2805S 12 0 20 40 60 80 100 Output Load (%) Positive Output 20% to 80% Load Negative Output 80% to 20% Load MHF Dual Negative Output Voltage Cross Regulation FIGURE 8 B2-80 FIGURE 7 Input Voltage (Volts) 20 Input Voltage (Volts) Negative Output Voltage Change (%) FIGURE 5 11 17 2815D 16 15 14 13 2812D 12 2 4 6 8 10 12 14 11 2 4 6 8 10 12 14 Output Power (Watts) 50 mV Drop Output Power (Watts) 50 mV Drop MHF Single Low Line Dropout MHF Dual Low Line Dropout FIGURE 9 218211-001-DTS Rev A DQ# 1011 All technical information is believed to be accurate, but no responsibility is assumed for errors or omissions. Interpoint reserves the right to make changes in products or specifications without notice. MHF Series is a trademark of Interpoint. Copyright © 1992 - 1999 Interpoint. All rights reserved. FIGURE 10 CASES CASE E Squared corner and dot on top of case indicate pin one. CASE E BOTTOM VIEW See Figures 16 – 18 for pin configurations. 1.130 max (28.70) Materials Header Cold Rolled Steel/Nickel/Gold Cover Kovar/Nickel (SMHF Series Cold Rolled Steel/Nickel/Gold) Pins #52 alloy/Gold compression glass seal Case dimensions in inches (mm) Tolerance ±0.005 (0.13) for three decimal places ±0.01 (0.3) for two decimal places unless otherwise specified 1.460 max (37.08) CAUTION Heat from reflow or wave soldering may damage the device. Solder pins individually with heat application not exceeding 300°C for 10 seconds per pin. FIGURE 15: CASE E MAXIMUM DIMENSIONS BOTTOM VIEW CASE E1 MHF+ Series Single and Dual: Screening – Standard, ES, or 883 MHF Series and LIM5050 Module: Screening – Standard or ES SMHF Series Single and Dual and SLIM5050 Module: Screening – Space Standard, H, or K HR120 Series: No screening options Seam Seal Projection Weld Squared corner and dot on top of case indicate pin one. 0.960 (24.38) 1 2 3 4 5 0.030 dia. (0.76) 0.205 (5.21) 0.000 0.25 (6.35) 0.000 0.330 max (8.38) 0.25 (6.35) 0.000 0.330 max (8.38) 7 6 0.505 (12.83) 0.705 (17.91) 0.905 (22.99) 1.105 (28.07) 8 0.160 (4.06) 0.000 FIGURE 16: CASE E1 Note: Although every effort has been made to render the case drawings at actual size, variations in the printing process may cause some distortion. Please refer to the numerical dimensions for accuracy. B8-10 QA SCREENING 125°C PRODUCTS 125°C PRODUCTS TEST (125°C Products) STANDARD /ES /883 (Class H)* PRE-CAP INSPECTION Method 2017, 2032 yes yes yes TEMPERATURE CYCLE (10 times) Method 1010, Cond. C, -65°C to 150°C Method 1010, Cond. B, -55°C to 125°C no no no yes yes no CONSTANT ACCELERATION Method 2001, 3000 g Method 2001, 500 g no no no yes yes no BURN-IN Method 1015, 160 hours at 125°C 96 hours at 125°C case (typical) no no no yes yes no FINAL ELECTRICAL TEST MIL-PRF-38534, Group A Subgroups 1 through 6: -55°C, +25°C, +125°C Subgroups 1 and 4: +25°C case no yes no yes yes no HERMETICITY TESTING Fine Leak, Method 1014, Cond. A Gross Leak, Method 1014, Cond. C Gross Leak, Dip (1 x 10-3) no no yes yes yes no yes yes no FINAL VISUAL INSPECTION Method 2009 yes yes yes Test methods are referenced to MIL-STD-883 as determined by MIL-PRF-38534. *883 products are built with element evaluated components and are 100% tested and guaranteed over the full military temperature range of –55°C to +125°C. Applies to the following products MOR Series MHD Series MFLHP Series MHV Series MFL Series MHF+ Series MHP Series MHF Series** MTR Series MGA Series MQO Series** MSA Series MGH Series MCH Series FM-704A EMI Filter FMD**/FME EMI Filter FMC EMI Filter FMH EMI Filter FMGA EMI Filter FMSA EMI Filter HUM Modules** LCM Modules** LIM Modules **MFLHP Series, MQO Series, MHF Series, FMD EMI Filters, Hum Modules, and LCM Modules do not offer ‘883” screening. C2-10