 |
Electronic Components Datasheet Search |
|
|
Electronic Components Datasheet Search |
|
SMHF283R3S Datasheet(PDF) 1 Page - Interpoint Corporation Company |
|
||||||||||||||||||||||||||||||
SMHF283R3S Datasheet(HTML) 1 Page - Interpoint Corporation Company |
|
|
1 / 12 page  MODELS VDC OUTPUT 33 SINGLE 3.3 5 12 15 DUAL ±5 ±12 ±15 DC/DC CONVERTERS 28 VOLT INPUT SMHF SERIES SINGLE AND DUAL 15 WATT Size (max.): Non flanged 1.460 x 1.130 x 0.330 (37.08 x 28.70 x 8.38 mm) Flanged 2.005 x 1.130 x 0.330 (50.93 x 28.70 x 8.38 mm) See Figures 21 through 24 for dimensions. Weight: 30 grams maximum. Screening: Standard, Class H, or Class K (MIL-PRF-38534) Radiation hardness levels O, L, and R DESCRIPTION The SMHF Series™ of 28 V DC/DC converters offers a wide input voltage range of 16 to 40 volts and up to 15 watts of output power. The units are capable of withstanding short term transients up to 50 volts. The package is a hermetically sealed, seam-welded metal case. Flanged and non-flanged models are available. SCREENING AND REPORTS SMHF converters offer three screening options (Standard, Class H, or Class K) and three levels of radiation hardness (O, L, and R). See Tables 1, 2, and 3 for more information. Detailed reports on product performance are also available and are listed in Table 4. CONVERTER DESIGN The SMHF converters are switching regulators that use a quasi- square wave, single-ended forward converter design with a constant switching frequency of 550 kHz. Isolation between input and output circuits is provided with a transformer in the forward path and a temperature compensated opto-coupler in the feedback control loop. The opto-coupler is radiation hardened and is especially selected for space applications. For the SMHF dual output models, cross regulation is maintained by tightly coupled output magnetics. Up to 70% of the total output power is available from either output, providing the opposite output is simultaneously carrying 30% of the total output power. Predictable current limit is accomplished by directly monitoring the output load current and providing a constant current output above the overload point. HIGHER POWER DENSITY The SMHF Series offers a new standard of performance for small size and high power density. At just 0.33 inch high and a total foot- print of 1.7 in2, this low profile package offers a total power density of up to 30 watts per cubic inch. LOW NOISE,HIGH AUDIO REJECTION The SMHF converters’ feed-forward compensation system provides excellent dynamic response and noise rejection. Audio rejection is typically 50 dB. Typical output voltage response for a 50% to 100% step load transient is as low as 1.3% with a 150 msec recovery time. Input ripple current is typically 35 mA p-p with output ripple voltage typically 30 mV p-p . INHIBIT FUNCTION SMHF converters provide an inhibit terminal that can be used to disable internal switching, resulting in no output and very low quies- cent input current. The converter is inhibited when a TTL compatible low ( ≤0.8 – output disabled) is applied to the inhibit pin. The unit is enabled when the pin, which is internally connected to a pull-up resistor, is left unconnected or is connected to an open-collector gate. The open circuit output voltage associated with the inhibit pin is 8.5 to 12 VDC. In the inhibit mode, a maximum of 12 mA must be sunk from the inhibit pin at 28 VDC input. SYNCHRONIZATION A synchronization feature is included with the SMHF Series that allows the user to match the switching frequency of the converter to the frequency of the system clock. An external synchronization feature is included that allows the user to adjust the nominally 550kHz operating frequency to any frequency within the range of 500 kHz to 600 kHz. This is initiated by applying a TTL compatible input of the desired frequency to pin 5. SHORT CIRCUIT PROTECTION SMHF Series converters provide short circuit protection by restricting the output current to approximately 115% of the full load output current. The output current is sensed in the secondary stage to provide highly predictable and accurate current limiting, and to eliminate foldback characteristics. UNDERVOLTAGE LOCKOUT Undervoltage lockout prevents the units from operating below approximately 14 VDC input voltage to keep system current levels smooth, especially during initialization or re-start operations. FEATURES • Fully qualified to Class H or K • Radiation hardened • –55° to +125°C operation • 16 to 40 VDC input • Fully Isolated • Red hard optocoupler feedback • Fixed frequency, 550 kHz typical • Topology – Single Ended Forward • Transient protection 50 V/120 ms • Inhibit function • Sync function • Indefinite short circuit protection • Undervoltage lockout • Up to 84% efficiency |
English ▼
English
Chinese
German
Japanese
Russian
Korean
Spanish
French
Italian
Portuguese
Polish
Vietnamese
