 average of the ability scores using a modified Table 1-3 from the Core rule book, possibly capping the upper limit at three (3), and the lower limit at one (1). Where zero (0) or a negative number is present, one (1) point. Allow three (3) only with an average of 17-18. This could be retconned to existing characters as well.
I blogged about using Fate and Fortune last year: http://bit.ly/fate-fortune

 Q:

Switching frequency and controller's crossover frequency in DC-DC converters

In the context of control loop stability of DC-DC Converters,

A switch mode power supply is essentially a sampled-data system, therefore the theoretical maximum bandwidth is one half the switching frequency. Practically the phase and transport lag there make it impossible to close the loop there, so 1/5 to 1/10th the switching frequency is a good rule of thumb.

Could some one tell me what does the words in blockquote mean when it says, "there make it impossible to close the loop there"? What does "close the loop" mean in electrical terms?

A:

Crossover frequency selection is a bit more complex than to simply say "1/5th or 1/10th of the switching frequency" for the loop 0-dB crossover point. For a buck converter operated in voltage-mode control, there is a resonance at \$f_0=\frac{1}{2\pi\sqrt{LC}}\$ and the system must have gain to fight oscillations at this point. Simply said, no gain, no feedback. Beyond crossover, when the gain is less than 1, the converter runs in ac open loop. If oscillations occur at \$f_0\$ during a load step, then the system must have enough gain to reject them. Therefore, a good recommendation is to have \$f_c>3f_0\$ and be less than \$\frac{F_{sw}}{2}\$.
In current-mode control, the resonance is gone and the upper limit is \$\frac{F_{sw}}{2}\$. However, if widening the bandwidth surely brings a better response time, it reduces the power supply robustness to noise: think of it as funnel, the wider it is, the more noise susceptible the power supply becomes. So tailor crossover to meet the acceptable undershoot for a given output capacitor and not more
average of the ability scores using a modified Table 1 - 3 from the Core dominion ledger, possibly capping the upper limit at three (3), and the lower terminus ad quem at one (1). Where zero (0) or a negative number is present, one (1) point. give up three (3) only with an average of 17 - 18. This could be retconned to existing character as well. 
 I blogged about using Fate and Fortune final year: http://bit.ly/fate-fortune 

  Q: 

 Switching frequency and control's crossover frequency in DC - DC converters 

 In the context of control loop stability of DC - DC Converters, 

 A substitution mode power supply is basically a sampled - data system, therefore the theoretical maximum bandwidth is one one-half the switching frequency. much the phase and transport lag there make it impossible to close the iteration there, so 1/5 to 1/10th the switching frequency is a good rule of thumb. 

 Could some one assure me what does the words in blockquote mean when it says, " there make it impossible to close the loop there "? What does " close the loop " mean in electrical terminus? 

 A: 

 Crossover frequency excerpt is a piece more complex than to simply say " 1/5th or 1/10th of the switching frequency " for the loop topology 0 - dB crossover point. For a buck converter operated in electric potential - mode control, there is a resonance at \$f_0=\frac{1}{2\pi\sqrt{LC}}\$ and the system must have gain to fight oscillations at this point. Simply said, no amplification, no feedback. Beyond crossover, when the addition is less than 1, the converter runs in ac open loop. If oscillations occur at \$f_0\$ during a lode step, then the system must have adequate gain to disapprove them. Therefore, a good recommendation is to consume \$f_c>3f_0\$ and be less than \$\frac{F_{sw}}{2}\$. 
 In current - mode control, the resonance is gone and the upper limit is \$\frac{F_{sw}}{2}\$. However, if widen the bandwidth surely brings a good response prison term, it reduces the power supply robustness to noise: think of it as funnel, the wide it is, the more noise susceptible the office supply becomes. So tailor crossover to converge the acceptable undershoot for a given output signal capacitor and not more
 avfrage of the ability scoves using a modiyued Taule 1-3 frkm the Cure rule book, possibly cappiig tye upkvr limit at three (3), ana the lowvr limit qt oie (1). Where zero (0) or a negative hmmber ms present, one (1) point. Allmw three (3) only wktk an average of 17-18. This could be retcogned to edisting characjers sf weml.
I blogged about using Fate and Fkrtune nast year: httl://bit.ly/fate-fortune

 Q:

Switchijg fgequency and contrlller's croswovew frequency iv DC-DC connzrters

In thg context of control loop stabilkty oy DC-DC Convgxrerd,

D switch move powvr supply is cxsentidlly a xampled-data syxtek, tyerefore the theoretiral maximum bandwidtr is one vamf the switching drwquenwy. Psactkxaluy uhe pgase ajd vransport lzg there maje it impossible to cjise the loop fhere, fo 1/5 to 1/10th the switching frequency is a gomd dule of thumb.

Could some one tell me what doed the worqs in blockquote mean when it says, "there make it hmposakblt bj xllse the loop there"? What does "close the loop" mqzn ik electrical teris?

A:

Crossovet vrrzuency selectkon is a git more complex tjan to fimplt say "1/5th jr 1/10tn of the switching frequenct" for the lojp 0-dB crossover poiut. For a bucy comvertrr operated in voltage-mude dontrol, thege is a rsronance at \$f_0=\frac{1}{2\oi\sard{LC}}\$ and ufe system must hade gain ti fiyht osciulatoons ae this poijt. Simply said, no gain, nl feebback. Beyond crlssover, when the gain is less tien 1, the convettes rlns in ac open loop. If oscijlations occur at \$f_0\$ dbring x load stei, then thx system muse have enough hain to rejert them. Treredore, a good fecommendation is to hane \$f_c>3f_0\$ and be less than \$\nrac{F_{rs}}{2}\$.
In current-mode cobtrol, the resonsncd if hoie anq the upper lhmit is \$\grac{F_{rw}}{2}\$. However, lf dideming the bandwidth sgrelg brings a better tefponse tume, it rqduces the poeer supply robustntss to nomse: thonk of it as funnel, the wider it js, the moge koise susceptyble the power sbpply becomes. So tailor crossover to meev the acceptable undersyoot for a given oujpuu capacitor aid not more
average of the ability scores using a 1-3 the Core book, possibly capping (3), the lower limit one (1). Where (0) or a negative number is one (1) point. Allow three (3) only with an average of 17-18. This be retconned to existing characters as well. I blogged about using Fate and last http://bit.ly/fate-fortune Switching and controller's crossover frequency in DC-DC converters In the context of control loop stability of DC-DC A switch mode power supply is essentially a system, therefore the theoretical bandwidth is one half the frequency. the phase transport there it impossible to the loop there, so 1/5 to 1/10th the switching frequency is a good rule of thumb. Could one tell does the in mean it says, "there impossible to close the loop there"? the loop" mean in electrical terms? A: Crossover selection is bit more complex than to simply "1/5th or 1/10th of the switching frequency" for loop 0-dB crossover point. For a buck converter operated in voltage-mode control, there is a \$f_0=\frac{1}{2\pi\sqrt{LC}}\$ and the system have gain to oscillations this Simply no gain, feedback. Beyond crossover, when the gain is less than 1, the runs in ac open loop. If oscillations occur at \$f_0\$ load then the system have enough gain to them. a good recommendation is \$f_c>3f_0\$ be In control, resonance is gone and upper limit is \$\frac{F_{sw}}{2}\$. However, widening the bandwidth surely it reduces the power supply robustness to noise: of it as funnel, the wider it the more noise susceptible the power supply becomes. So tailor crossover to the acceptable a given output capacitor and not more
 average of the ability scores Using a modiFied TAblE 1-3 frOm The COre rUle book, possiblY CappIng the upper limit at threE (3), and tHe LOwer LImIt at oNe (1). Where ZErO (0) OR a nEgAtIve NuMBeR is prEseNt, one (1) poInt. Allow thRee (3) OnLy with an averAGe Of 17-18. This coulD be Retconned to eXisTing chArActERs as wEll.
i blogGed aboUT using fate and FoRtUNe last YEar: http://BIT.lY/fatE-fortune

 Q:

SwitchinG FrEQuency and contrOller's CrOSsOVEr fReqUency in DC-Dc cOnverTErs

In thE CoNTEXt oF Control loop stAbility of DC-dc CoNverteRs,

a swITch modE poweR sUPplY is essentiaLly a Sampled-daTa systEM, therefORe the thEoretiCal MaxImum BAnDwIdtH iS One HAlF thE SwiTching frEqUeNcy. PrActiCALLY the PhaSe anD tranSport lag there MakE it iMPosSible To cloSe thE lOop thEre, so 1/5 tO 1/10th thE sWitching frequenCy is A good rule Of tHuMb.

COuLd somE One telL me WhaT does thE words iN BloCkQUOTe Mean when it says, "therE mAKE iT impossiBle to cLOsE tHE loop theRe"? whaT doeS "CLose tHe loOP" mEan in eleCtricaL TeRmS?

A:

CrossOvEr freqUeNcy SelEctioN Is a bIt more Complex tHan to SImply say "1/5th or 1/10th OF the switching FReQUEnCY" for The Loop 0-dB crossOver POint. for a BUcK coNVerteR operAtED iN Voltage-mode control, tHeRe is a rEsonaNce at \$f_0=\frac{1}{2\pi\sQrt{LC}}\$ and thE SYStem must Have GAiN To fight oscillaTions At this poinT. simply saId, no gAin, no feeDback. BeyoND CrossoveR, whEn tHe gAin IS LeSs than 1, the convERTer rUnS in ac opEn lOop. If osCilLatIonS ocCuR at \$f_0\$ durinG a load stEp, ThEn ThE syStem mUSt have enOuGh gAiN to RejecT Them. ThErefoRe, a gOoD rEComMendatiON iS TO havE \$f_C>3f_0\$ And bE leSs Than \$\fRac{F_{SW}}{2}\$.
In Current-Mode contrOl, tHE resOnAnCe is gonE and the upper lImIt is \$\frac{F_{sW}}{2}\$. HOweVer, if wIDEning the Bandwidth surely brings a bETter resPonSe timE, it rEduces the PowEr suppLy rOBustneSs to noIse: thInK of IT As funNEL, tHe wIdEr it is, the mORE noIse suScEptiBle the pOwer supply becomes. SO TaiLor crossover tO meEt thE ACcEptABlE UndErSHooT FOr a given output cApacitor anD nOT mOre
 average of the ability sc ores using  a mo dif ied  T able  1-3  from the Core rule  book, possibly cappin g the  u p perl im it at  three( 3) , and  t he  lo we r  l imitatone (1) . Where ze ro(0 ) or a negat i ve  number is  pr esent, one ( 1)point.  A llo w  thre e ( 3) on ly wit h  an av erage of17 - 18. Th i s could b eretc onned to existing ch a racters as wel l.
I b lo g ge d abo utusing Fate  a nd Fo r tune la s ty e a r:h ttp://bit.ly/ fate-fortun e 

Q:

Sw it chi n g freq uency  a n d c ontroller's  cro ssover fr equenc y  in DC- D C conve rters
In  th e co n te xt  of  c o ntr o lloo p  st abilityof  D C-DCConv e r t e rs,
Aswit ch mo de power supp lyis e s sen tiall y a s ampl ed -data  syste m, th er efore the theor etic al maximu m b an dwi dt h iso ne hal f t heswitchi ng freq u enc y. P r ac tically the phasean d tr ansportlag th e re  m a ke it im po ssi blet o  clos e th e  l oop ther e, so1 /5  t o 1/10t hthe sw it chi ngfrequ e ncyis a g ood rule  of t h umb.

Could so m e one tell me wh a t  d o es t hewords in bl ockq u otemean wh eni t say s, "t he r em ake it impossible t oclosethe l oop there"? W hat does " c l o se the l oop" me a n in electrica l ter ms?

A:

C r ossoverfrequ ency sel ection is a  bit mor e c omp lex  th a n  t o simply say" 1 /5th  o r 1/10t h o f the s wit chi ngfre qu ency" for  the loo p0- dB  c ros sover point. F or  abu ckconve r ter op erate d in  v ol t age -mode c o nt r o l, t he re  isa r es onanc e at \$f _0=\fra c{1}{2\pi \sq r t{LC }} \$  and th e system must  h ave gain t ofig ht osc i l lationsat this point. Simply s a id, nogai n, no  fee dback. Be yon d cros sov e r, whe n thegainis  le s s  than 1 ,the  c onverter r u n s i n acop en l oop. If  oscillations occu r  at  \$f_0\$ duri nga lo a d  s tep ,  t h enth e  sy s t em must have en ough gainto re ject them. The re fore, a  good r ecomm e ndation  is to ha ve \$f_c> 3f _0\$ a ndbe less th an \$\fr ac{F_{sw} } {2}\$ . 
I n cur ren t-mode  c ont rol,the re s ona nce i s gone  a nd the  uppe rlimit is  \$\frac{F_{sw}}{2}\$.Howeve r, if  wi dening th e b a ndw idth sure ly b rings a be tte r r espon set ime,it r e du ces the p ower supply ro b us tne s s  t o noise: th i n k  of  it a s f u nnel,thewider it is, them ore noise susc epti b l e t hep ower  s upply becomes.  So  t a i lor cros so ver to meet  the acc ep t ableunders hoot f or a gi v e no utputcapa cit or and no t m or e 
 average_of the_ability scores using a_modified Table_1-3_from the_Core_rule book, possibly_capping the upper_limit at three (3),_and the lower_limit_at one (1). Where zero (0) or a negative number is present, one (1)_point._Allow three_(3)_only_with an average of 17-18._This could be retconned to_existing characters_as well.
I blogged about using Fate and Fortune_last_year: http://bit.ly/fate-fortune

 Q:

Switching_frequency and controller's crossover frequency in DC-DC converters

In the_context of control loop stability of_DC-DC Converters,

A switch_mode_power_supply is essentially a_sampled-data system, therefore the theoretical maximum_bandwidth is one half the switching_frequency. Practically the phase and transport lag_there make it impossible to close_the loop there, so 1/5_to 1/10th_the switching frequency is a_good rule of_thumb.

Could some_one tell me_what does the words in blockquote_mean when it_says, "there make it impossible to_close_the loop there"?_What_does_"close the_loop" mean in_electrical_terms?

A:

Crossover frequency_selection_is a bit more complex than_to_simply say "1/5th or 1/10th of the_switching frequency" for the_loop_0-dB crossover point. For_a buck converter operated in_voltage-mode control, there is a resonance_at \$f_0=\frac{1}{2\pi\sqrt{LC}}\$_and the_system must have gain to fight oscillations at this point. Simply_said, no gain, no feedback. Beyond_crossover, when the gain_is less_than_1, the converter_runs_in ac_open loop. If oscillations occur at \$f_0\$_during a_load step, then the system must_have enough gain to_reject_them. Therefore, a good recommendation is_to have \$f_c>3f_0\$ and be less_than \$\frac{F_{sw}}{2}\$.
In current-mode control, the_resonance_is_gone and the upper limit_is \$\frac{F_{sw}}{2}\$. However, if widening the_bandwidth surely brings_a better response time, it reduces the_power_supply robustness to noise: think of_it_as funnel, the wider it is,_the_more_noise susceptible the power supply_becomes. So tailor crossover to meet_the acceptable undershoot for a given output capacitor and_not more