OHD2805S OHD2812S OHD2815S LOW PROFILE DC/DC CONVERTER IN A HERMETIC METAL PACKAGE Low Profile Hermetic DC/DC Converter +5, +12, And +15 Volt In A Metal Package FEATURES * * * * * * * * * * * * * * * * Up To 20 Watts Output Power 5, 12, 15 Vdc Outputs MIL-STD-704D Compatible NAVMAT P-4855-1A Component Derating Ultra-Low Profile: 0.385" Height Constant Frequency PWM Design Seam Welded Case For Enhanced Reliability Low Voltage Lockout 16 to 40 Vdc Input Range -55 to +125C Full Power Operation Up to 81% Efficiency Industry Standard Pin-Outs Magnetic Feedback Short Circuit Current Limiting Protection Cascaded Dual Loop Control Scheme For Superior Load Transient Characteristics Available Hi-Rel Screened DESCRIPTION Omnirel's OHD2800S series of DC/DC Converters are rated up to 20 watts of output power over the full military temperature range. These converters are supplied in a fully hermetic, ultra-low profile package to produce a power density of up to 22 watts per cubic inch. MAXIMUM RATINGS (T = 25C, VIN = 28 Vdc unless otherwise specified) Operating Temperature Range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -55C to +125C (Tcase) Storage Temperature Range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -65C to +150C Isolation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . >100 M @ 500 Vdc Conversion Frequency: Free Run Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 400 KHz Conversion Frequency Sync. Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 425 KHz - 525 KHz 4 11 R0 2.1 - 1 2.1 OHD2805S OHD2812S OHD2815S ELECTRICAL CHARACTERISTICS Parameters Conditions OHD2805S OHD2812S OHD2815S Units Input Voltage Range No Load to Full Load -55C to +125C 16 to 40 16 to 40 16 to 40 Vdc Max. Input Current No Load 40 50 60 mA Max. Input Ripple Current Full Load DC to 2 MHz 25 25 25 mAp-p Output Voltage Full Load 5.0 (3%) 12.0 (2%) 15.0 (2%) Vdc Min. Output Power VIN = +16 Vdc to +40 Vdc -55C to +125C 15 20 20 W Min. Output Current VIN = +16 Vdc to +40 Vdc -55C to +125C 0 to 3.0 0 to 1.67 0 to 1.33 A Max. Output Ripple Voltage Full Load DC to 2 MHz 35 35 35 mVp-p Max. Load Regulation No Load to Full Load 15 15 15 mV Max. Line Regulation Full Load 10 10 10 mV Typ. Efficiency Full Load 79 81 81 % Typ. Transient No Load to Full Load Full Load to No Load 200 250 300 mV Typ. Recovery No Load to Full Load Full Load to No Load 65 65 65 s Step Load Response 2.1 BLOCK DIAGRAM 1 Input Filter Output Filter 5 2 PWM 9 Error Amp & Ref. 10 3 4 2.1 - 2 OHD2805S OHD2812S OHD2815S Topology Flexible Synchronization The OHD2800S series is a single ended forward converter operating at a nominal oscillator frequency of 400 KHz. These fixed frequency converters use a resonant transformer reset circuit which allows for a maximum duty cycle of 67% without increasing the voltage stress on the primary MOSFET or output rectifiers. Tight line and load regulation are achieved through wide bandwidth magnetic feedback circuit. This magnetic feedback circuit, in conjunction with bipolar control ICs, offers greater long term reliability and radiation tolerance when compared to converters using an optocoupler feedback circuit and/or CMOS control ICs. The OHD2800S series offers two different synchronization options. The standard OHD2800S can be synchronized to an external system clock for any rate between 425 KHz and 525 KHz. A second option allows the system designer to synchronize multiple "slave" converters to one "master" converter. The appropriate parts must be ordered to utilize this master/slave configuration. A suffix of "-MST" is added for the master part number and "-SLV" suffix for the slave part number. Example: Part No.: OHD2805S-MST Description: Master Synch. Config. High Reliability Design Omnirel's OHD2800S series of DC/DC converters are designed to achieve the high reliability demanded by military programs. The case is resistance seam welded for superior long term hermeticity. The converters use only ceramic input capacitors to provide high product reliability over the military temperature range of 55C to +125C. All semiconductor devices are of the highest level of performance and reliability. Omnirel's converters are designed in accordance with the NAVMAT P-4855-1A component derating guidelines when operating over the MILSTD-704D input voltage range. The converters meet the conducted emissions (CE03) noise limits of MIL-STD-461C when operated with Omnirel's OFC461 EMI filter module. Inhibit Feature The OHD2800S series of converters provide an active low (<0.8 V) inhibit pin that can be used to disable the converter, resulting in a zero output voltage and very low quiescent current. Low Voltage Lockout Omnirel's OHS2800S series of converters are designed to operate from an input voltage of 16 to 40 Vdc. The converter will not start until the input voltage reaches approximately 15 Vdc. Once operating, the unit will shut down when the input voltage drops below approximately 14 Vdc. 2.1 - 3 2.1 OHD2805S OHD2812S OHD2815S MECHANICAL OUTLINE 2.110 1.600 .400 8 PLCS. .255 1 2 .255 3 4 5 BOTTOM VIEW 1.110 .800 C/L PIN 8 BRAZED TO FRAME 10 .400 9 8 7 6 .155 DIA. .038 10 PLCS. .042 .010 .260 .390 MAX. SIDE VIEW 2.1 PIN CONNECTION Pin OHD2805S 1 + Input OHD2812S/OHD2815S + Input 2 Inhibit Input Inhibit Input 3 Output Adjust N/C 4 Output Common Output Common 5 + Output + Output 6 N/C N/C 7 N/C N/C 8 Case Ground Case Ground 9 Sync Sync 10 Input Common Input Common ORDERING INFORMATION OHD Model 28 XX Input Voltage Output Voltage 05 = 5 Vdc 12 = 12 Vdc 15 = 15 Vdc S X Outputs S = Single D = Dual Package Style F = Flange Option Blank For Standard Package - XXX Synchronization MST = Master SLV = Slave Blank For Standard Package 205 Crawford Street, Leominster, MA 01453 USA (508) 534-5776 FAX (508) 537-4246