feature

Dimensions: 61.0 mm x 116.8 mm x 13.5 mm (2.40 in. x 4.60 in. x 0.53 in)

Wide input voltage range

Efficient: 79% typical

Parallel operation with load sharing

Output voltage setting value adjustment (fine adjustment)

Thermal Protection

Synchronize

good power signal

Output current monitor

Output overvoltage and overcurrent protection

constant frequency

Shell ground pin

Input and output isolation

Remote perception

Remote on/off

Short circuit protection

Output overvoltage clamp

ISO9001 certified manufacturing facility

UL*60950 Listed, CSA 8482 ; 22.2 No. 60950-00 Listed, VDE 0805 (IEC60950, 3rd Edition) Licensed CE Marked to 73/23/EEC and 93/68/EEC

application

Redundant and/or distributed power architecture Telecom data processing options available for long-running heat sinks

illustrate

250 f1-ic/" title="FW250F1 Product Specifications, Documentation and Sourcing Information" target="_blank">FW250F1 and FW 300 F1 Power Modules are dc-dc converters that operate over the input voltage range of 36 to 75 volts DC power and provides a precisely regulated DC output. The output is fully isolated from the input, allowing multiple polarity configurations and ground connections. The modules have maximum power ratings from 250 W to 300 W at typical full load efficiency of 79% .For redundant or enhanced power supply applications, two or more modules can be paralleled with forced load sharing.The package is mounted on a printed circuit board and can accommodate heat sink applications for high temperature.UL is Underwriters Laboratories Inc. is a registered trademark. ~CSA is a registered trademark of the Canadian Standards Association. This product is intended for integration into end-use equipment. All procedures required for CE marking of end equipment shall be tracked. (The CE marking is placed on selected products. )

Absolute Maximum Ratings

Stresses in excess of the Absolute Maximum Ratings can cause permanent damage to the device. These are only absolute pressure ratings. at these or any other conditions exceeding those given in the operating section of the data sheet. Exposure to extended cycles at Absolute Maximum Ratings can adversely affect device reliability.

Electrical Specifications

Specifications apply to all operating input voltages, resistive loads and temperature conditions unless otherwise noted.

Table 1. Input Specifications

Integrate Considerations

NOTE: This power module does not have an internal fuse. Input line fuses must always be used. Power modules in this package can be used in a variety of applications, from simple stand-alone operation to integrated parts of complex power architectures. For maximum flexibility, internal fuses are not included; however, for maximum safety and system protection, input line fuses are always used. This safety mechanism requires a normal blow, and the DC fuse has a maximum rating of 20 A (see Safety Considerations section). The same can be used with a lower rated fuse based on the information provided by this data sheet on surge energy and maximum DC input current. See the fuse manufacturer's data for more information.

Electrical Specifications (continued)

Table 2. Output Specifications

These are manufacturing test limits. In some cases, results may vary. }Consult your sales representative or factory.

Functional Specifications

Specifications apply to all operating input voltages, resistive loads and temperature conditions unless otherwise noted. See the feature description for details.

These are manufacturing test limits. In some cases, results may vary

Characteristic curve (continued)

Note: Test loads with 4000µF aluminum and 1.0µF ceramic capacitors.

Fig. Typical FW300F1 startup transient at room temperature, 48 V input, fully loaded

Note: measure the input reflected ripple current with an analog source

The inductance (LTEST) of the 12µH capacitor CS cancels out possible battery impedance. Measure the current as shown above.

Fig. Input Reflected Ripple Test Set

Note: All measurements are made at the module terminals. when? Mating, placing Kelvin connections on module terminals to avoid measurement errors due to socket contact resistance

Safety Precautions

For safety agency approved systems where power modules are used, the power modules must be installed at the spacing, spacing required by end-use safety agency standards, i, e., UL1950, CSA C22.2 No. 950-95 and VDE 0805 (IEC60950, 3rd edition). If the input source is non-SELV (ELV or hazardous voltage greater than 60 VDC and less than or equal to 75 Vdc), considering that the module output meets the safety extra low voltage requirements (SELV), all of the following must be true: The input source should be Voltage isolation, including AC power; and one VI pin and one VO pin to ground or both input and output pins left floating; and the module's input pins not accessible to operators; and throughout the system, as required by safety agencies The combined module of the supply source and the main body verifies that under a single fault, no voltage appears at the output terminal of the dangerous module. NOTE: Do not connect one of the module output pins to ungrounded. This can cause non-SELV voltages to appear between the output pins and ground. Power modules have extra low voltage (ELV) outputs when all inputs are ELV. The inputs to these units will provide a maximum of 20 normally blown fuses in the ungrounded leads.

Feature description

Over Current Protection To provide protection in the event of a fault (output overload), the unit is equipped with an internal current limit circuit capable of withstanding an infinite current limit. The unit switches from voltage control to current control at the beginning of the current limit. If the output voltage is pulled low during a severe fault, the current limiting circuit can exhibit a folding or wake characteristic (decrease or increase in output current). once the output current is brought back to the specified range. Remote On/Off To turn the power module on and off, the user must provide a switch to control the on/off between the voltage terminal and the VI (–) terminal (Von/off). The switch can be an open collector or equivalent (see Figure 17). The logic low voltage is V on/off = 0 V to 1.2 V, during which the module is turned on. The maximum ion/off at logic low is 1 mA. The switch should remain logic low while sinking 1mA. At logic high, the maximum VON/OFF produced by the power module is 15 V, the maximum allowed value. The leakage current of the switch is 50µA at Von/off=15V. If not using the remote on/off function, short the on/off connection to VI (–).

Characterization (continued) Synchronization

Any module can be synchronized with any other module or use the sync input or sync to an external clock pin. These modules are not designed to be used in a master/slave configuration; that is, if one module fails, the other modules will continue to function. SYNC IN PIN This pin can be connected to an external clock or directly to another FW250x or FW300x module. If an external clock signal is applied to the sync input pin, the signal must be a 500 kHz (±50 kHz) square wave with an amplitude of 4vp-p. Operating frequency bands outside of this will adversely affect the performance of the module and must be avoided. If the sync input is connected to the sync output of another module, the connection should be direct. The VI(–) pins of the module must be shorted together as much as possible. Unused sync input pins should be tied to VI (–). If the sync input pin is not used, the module will start from its own internal clock. Sync Output Pin This pin contains a reference VI's clock signal (–) pin. The frequency of this signal is equal to the frequency of the module's internal clock or the frequency determined by the external clock applied to the sync input pins. When synchronizing multiple modules, the modules can be connected in a daisy-chain fashion where the sync output pin of one module is connected to the sync input terminal of another module. Each module chain will synchronize with the frequency of the first module in the chain. To avoid loading effects, make sure that the sync pins of either module are connected to the sync input pins of only one module. Any number of modules can be synchronized in a daisy-chain fashion.

Over temperature shutdown

To provide protection in the event of a fault, the unit is equipped with an overtemperature shutdown circuit. Unless the unit is operating at maximum temperature. Recovery from an overtemperature shutdown is done by cycling off the DC input power at the at least 1.0s or switching the main reference on/off signal for at least 1.0s. Forced load sharing (parallel operation) For redundant operation or additional power requirements, power modules can be configured for parallel operation with forced load sharing (see figure). For typical redundant configurations, a Schottky diode or equivalent should be used to prevent short circuits. Because of remote sensing, the forward voltage through the Schottky diode does not affect the voltage applied to the load. Schottky diodes are not required for additional energy requirements where multiple cells are used to develop combined power beyond the rated maximum power. Good layout techniques should be followed to prevent noise immunity. To achieve forced load sharing, the following connections must be made: Parallel pins of all units must be connected together. The paths of these connections should be as direct as possible. All remote sense pins should be connected to the power bus at the same point, i.e. connect all the sense points on the (+) side of the power bus to the same point and all sense points (–) fixed to the power bus at the same point. Proximity and directness are necessary for good noise immunity

Characterization (Continued) Mandatory Load Sharing (Parallel Operation) (Continued) When the parallel function is not used, please keep the parallel pins open.

Power Good Signal The PWR Good pin provides an open drain signal (Reference indicates the operating status of the module. A low impedance PWR good (<100Ω) between sense (–) indicates the module is operating. High impedance PWR good (>1 MΩ) between and sense (–) indicates that the module is off or malfunctioning. The PWR good pin can be pulled to an external voltage through a resistor to aid in sensing. This external voltage level must not exceed 40 V and goes into PWR good pins in the low impedance state should be limited to 1 mA maximum.

Introduction to thermal factors: The power module works in various temperature environments; however, it should be sufficiently cooled to ensure reliable operation of the unit. A heat sink within the device is thermally coupled to the housing. Heat is removed from the environment by conduction, convection, and radiation to the surroundings. Correct cooling can be verified by measuring the case temperature. The peak temperature occurs at the location shown in the figure.

The temperature at this location should not exceed 100°C to limit the maximum temperature to a very low value for very high reliability. The output module power should not exceed the power rating for the modules listed in the ordering information table. For more information on these modules, see Thermal Management for the FC- and FW Series 250 W-300 W Board Mount Power Modules Technical Note (TN96-009EPS).