Uses in the next generation distribution power source structure directcurrent main line converter and the power source moduletechnology

When faces for example the telecommunication rack or the serverengine room large-scale system integration, the distributional powersource structure appeared, thus has satisfied the challenge which thepower transmission faces. Two kind of topology have already occupiedthe superiority, but two all does not have completely to satisfydesigns the personnel for to pursue the high transfer efficiency, thefew total parts number and bill of material cost, on the small boardoccupies the position space, the design simple desire. In the newevolution, the middle main line structure (iba), has provided theanswer. This plan realization permission designs the power modulewhich the personnel uses simplifies to come rapidly to dispose onekind compact and the cost low solution.Carries on the evolution from the traditionOccupies the superiority in two kinds in the dpa topology, onerealization method is transforms the direct current input voltage thelevel which the majority part requests to the system in, for instancesaid 3.3v, this voltage directly uses in is the 3.3v part powersupply, as well as for produces other system voltages (pol)the converter power supply. But, directly transforms the 36-75v DCvoltage logical level power supply level for example 3.3v, rateis extremely low, moreover low voltage logic when 2.5v will changebadly. And, needs very many filters to protect the 3.3v load,simultaneously on successively the electricity fet request canincrease other rds (on) to lose.As the choice, may transform the direct current input voltage 12v theskeleton line voltage, is the pol converter array power supply, thenproduces respective system voltage again by pol which requests. Butthe majority may use the 12v output module is the entire brick typecharacteristic in fact. These are the efficiency relatively low, andhas provided the complete constant voltage 12v output, thus increasedthe unnecessary cost and complex, because the modern pol convertersolution can accept a width input voltage scope. This brick typemodule also has the high electric current, request secondaryfet has the relatively high voltage pressure resistance rated value,is 40v to 100v. Fet which these fet is lower than when the averageoutput voltage should use to have big rds (on) the value.However, two levels of transformations has the inherent merit. Theconstant voltage middle main line voltage does not have a betterefficiency and a lower cost. The assignment loses lowly, because whenuses 8v the middle main line voltage, when is opposite to 3.3v dpa,similarly assigns under the power level electric current is smaller.Also may realize in the pol converter function, thus eliminated inmany priorities electricity fet to lead passes the loss. And, whenuses in the 8v scope main line voltage, compares to 12v dpa, theswitch loses in downriver pol obtains the reduction, because theswitch loses with the input voltage concerns. When designs two levelof dpa, the always turnover efficiency is essential, moreover hasconsidered the entire power structure best optimization with this wayuse direct current main line converter.One kind of new module, took the direct current main line converter,presently may use carries on the first level to transform to the non-constant voltage 6-8v DC voltage. The passable simple changetransformer number of windings have compared to this main line voltagecarry on the change. Regarding is bigger than 200w the high efficiencysystem, it causes to design the non- constant voltage the 12v nominalmain line voltage more to have the significance, but regardingcompares the low power scope the system to say, the 6-8v main linevoltage has the significance. It used a work in fixed 50% occupiedempties the isolation converter to obtain simply compared to, from theactuation is secondary synchronized rectification. This has the highpower conversion efficiency, reduced has input and outputs the filterthe need, and improved the reliability. Regarding the second level,installs on the electric circuit board, has used pol which mustisolates. They only request the minority passive component, thereforewith establishes separately or the module method compares, reducedbetween the board sky and design complex.Direct current main line converter designIn order to obtain this kind of new topology the biggest merit,the direct current main line converter needs the new half bridge andthe entire bridge controller, as well as optimized power mosfettechnology.As the new form controller example, international rectifier company'sir2085s integrated 50% to occupy empties compared to the oscillator,with 100v, the 1a half bridge actuated ic to the sole so-8 seal in,has the frequency which outside might adjust and the dead time uses ineach kind of application request. Provided has enabled the end and theelectric current limit control end. Internal soft start characteristiclimit in start period surge current, through approximately in gatedriving signal at first 2,000 pulses period gradually increase occupythe spatial ratio 50%. The similar method may use in the entire bridgedirect current main line converter, uses new ir2086s, regardingreaches as high as 240w, under the similar profile factor, has theabout 96.4% efficiency under the full load current.Chart 1 had demonstrated the 48v direct current input schematicdiagram, it may use in 36 to arrive the 75v input voltage width scope,the 220w direct current main line converter electric circuit. Inprimary, the ir2085s controller and driver ic actuates two irf6644 lowelectric charge directfet seal power mosfet, it is 100v n- trenchpower mosfet. The primary bias voltage obtains through a linearvoltage regulator, and uses in to start, then obtains under the stablestate by the transformer. Irf7380, is double 80v n- trench powermosfet, integrates in the so-8 seal, uses in to obtain this function.In is secondary, novel 30v n- trench irf6612 or irf6618 directfet sealpower mosfet uses in from in the actuation synchronized rectificationtopology. Applies regarding the 12v output said that, new 40v n-trench irf6613 may serve as synchronized rectification mosfet, thisunit in was smaller than 1/8 brick contour to achieve surpassed 96%efficiency, compared with the tradition, the efficiency probablyoutdid 3-5%, the volume reduced 50%, is power transformer which on thecomplete constant voltage, the board installed.When comparison direct current main line converter directfet seal andstandard so-8 product performance, here has some important results.So-8 product as a result of the reason limit power in 150w,in addition, the so-8 product frequently parallel uses. In order tomake the comparison, uses 100v when half bridge main line converterprimary comparison the so-8 product and the 100v directfet product,the directfet product (irf6644) has obtained the about 1% betterefficiency, or when 220w (27.5.a, 8v output), the efficiency is 95.7%,this consideration puts down work when this power level does has95-96%, is the important efficiency gain. This is only a part, becausethe directfet product also provides the important hot merit, isopposite to uses in the primary so-8 product to say, has approximatelythe 40oc lower knot temperature. This is to the system reliable hugelatent improvement, specially is ties the temperature when the matchrate the function. Primary uses directfet in the main line converter,now also considered the hot spot which secondary fet the temperaturebalance, eliminated watched when standard product primary produces. Italso indicated, when when primary compares the directfet product andthe parallel so-8 product, directfet still obtains the about 0.4%higher efficiency, confirmed the directfet product may replace theparallel standard component the fact.The directfet semiconductor seal technology eliminated the entirepassing condition resistance in fact to the mosfet seal influence, hasmaximized the circuit efficiency. The directfet seal technology alsoprovided has been extremely good to the pcb thermal resistance,probably was 1oc/w, but passed the component the crown (shell) theheat probably was 1.4 oc/w. Irf6612 or the irf6618 gate slavingvoltage through uses double 30v so-8 to seal mosfet the irf9956 clampto the 7.5v best value. The latent 220w direct current main lineconverter size may be 2.05 inch x 0.85 inch, this reduced about 25%,1/8 brick size survey compared to the field standard 1/8 brick is 2.30inch x 0.90 inch. Now provides some have the complete characteristicthe solution is 1/4 brick form factor, its standard size is 2.30 inchx 1.45 inches, if the use direct current main line converter designmethod, may provide 53% space to save.The turn-on frequency choice can affect the converter the efficiency,the size and the expense. Enhances the turn-on frequency to reduce theoutput voltage ripple, and may use smaller magnetic elements, becausethe magnetic-flux density reduced. The transformer may be smaller,has a lower loss. On the other hand, was higher primary and thesecondary switch loses reduced the entire circuit efficiency. Chart 1converter when the primary turn-on frequency is nearby 220khz achievesthe best performance. Is short between Gao Duan and the low end pulsewidth difference to 25ns, guards against the magnetic flux not to bebalanced, this in the bridge topology is the main nice question. Inhalf bridge electric circuit and the dead time is may adjust in GaoDuan and between the low end pulse frequency, suits variousapplication, the power level according to the exterior time baseelectric capacity, and the switch component.Second level of polIn pol, 12, double output synchronization falls presses theconverter only to request the output inductance, the output capacityand the input capacity, in addition some other passive components,cause iba to design easily to complete, and is opposite to may chooseestablished separately the solution to save 50% occupies the positionspace. The high ripple frequency also allows these parts to besmaller than the request other parts."The power constructs the block" in these in, international rectifierip1202 used ir the ipowirtm seal technology to integrate the pwmcontroller and the driver function, as well as was connected thecontrol and the synchronized mosfet switch, Xiao Teji the diode andthe input bypass electric capacity to the sole seal in, its size was9.25mm x 15.5mm x 2.6mm.Further economical occupies the position space, reduces the designtime is possible, because of these components might directly from thedirect current main line converter output voltage power supply,eliminate exterior bias circuit need. Outside it also can carry onsynchronization with other pol, may use more simply inputs the emifilter.All unifies in togetherIn order to test the new middle main line structure theperformance, used from as soon as started on the design module tocarry on the realization, thus optimized iba. Chart 1 direct currentmain line converter unified two ip1202 pol to obtain 3 outputsdemonstration units, if on chart 2 showed. Chart 3 had demonstratedhow iba is achieved 84.5% total electrical efficiencies, enable it tobecome to have the attraction the choice to satisfy the integration tohave the low pressure logic, the processor and the asic modern systemrequest.