Power Supply Design - DC/DC Section

Project "Ultimate" 2004        
Input data Vba= 407 Vdc Average Boost Voltage    
  Vbm= 399 Vdc Minimum Boost Voltage    
  Iba= 6.6 A Average PFC output current    
  fdc= 180 kHz Switching Frequency, DC/DC Converter    
  Voutn= 27.220 Vdc Nominal DC Output Voltage    
  Voutx= 29.942 Vdc Maximum DC Output Voltage    
  Ioutn= 90.00 Adc Nominal Output Current    
  Ioutx= 99.00 Adc Maximum Output Current    
  Ddch= 0.5 % Duty Cycle head-room @ Maximum Output Voltage    
  Dicx= 99.5 % Max available PWM IC Duty Cycle Due to PWM IC  
  Effdc= 91.87 % DC/DC Efficiency    
  Effdc= 91.87 % DC/DC Efficiency, initial estimation copy from above cell  
  Irdc= 17.0 % Ripple Current, Output Ind., Nom. Output, pk-pk, % from avg    
  Im= 28.0 % Magnetizing current, primary, pk-pk, max, % from avg    
  tsw= 75 ns Voltage Rise and Fall times for bridge switches    
  Rdson= 0.379 Ohm Actual MOSFET(s) Rds ON    
  Coer= 253 pF MOSFET output capacitance @ Vba    
  VF= 1.29 V Diode(s) forward voltage at operating current    
  Vrpn= 5 mVrms Output Maximum Ripple Voltage, Nominal Output    
  Ilss= 80 % Minimum load for Soft Switch    
  kp= 2   1 for Hard Switching, 2 for Phase Shift    
  ks= 1   1 for Center Tap, 2 for Current Doubler    
  N= 0.0833   Actual Secondary to Primary Turn Ratio    
             
Intermediate Poutn= 2,450 W Maximum Output Power, DC/DC Stage    
data tdc= 5.56 us Switching Period, DC/DC Converter    
  Iavg= 7.5 A Average primary current    
  Irdcpk= 1.3 A Primary pk-pk ripple current reflected from sec.    
  Impk= 2.1 A Primary pk-pk magnetizing current    
  Idppx= 3.4 App Primary total pk-pk current    
  Itpk= 9.2 A Peak Current Bridge Switch    
  Ibchfx= 2.7 Arms DC input Capacitor, max HF ripple current    
  Vt= 2.84 V Average Voltage drop, Bridge Switches @ Nominal Output    
  Ddcx1= 96.8 % Maximum Available Duty Cycle Due to dV/dt + IC  
  Nm= 0.0838   Minimum Secondary to Primary Turn Ratio    
  Ilopk= 97.7 Apk Output Inductor Peak Current    
  Ilopp= 15.3 App Output Inductor Ripple, Peak to Peak    
  Irpr= 4.4 Arms Output Inductor Ripple, RMS    
             
Output data Iprrms= 7.6 Arms RMS Current, Transformer Primary    
  Iscrms= 45.1 Arms RMS Current, Transformer Secondary Eq. end to end-Idc  
  Loc= 0.76 uH Output Inductor, calculated    
  Lo= 0.76 uH Output Inductor, chosen    
  Comin= 391 uF Minimum Output Capacitor (Zero ESR)    
  C401= 3,240 uF Output Capacitor(s), chosen    
  Resrx= 1.1 mOhm Maximum Output Capacitor ESR (Infinite capacitance)    
  ESR1= 8.5 mOhm Output Capacitor(s) ESR, chosen    
  RLoad= 0.302 Ohm Load Resistance    
  Vrp2= 36.5 mVrms Output ripple voltage, first stage filter    
  Attn2m= 7.3   Required second stage filter attenuation    
  Llkg= 1.21 uH Leakage inductance for soft switch    
  tdlk= 41.5 ns Dead time due to leakage inductance    
  Ddcn= 86.84 % Nominal DC/DC Stage Duty Cycle    
  Ddcx= 95.31 % Max available DC/DC Stage Duty Cycle Due to dV/dt+Llkg  
             
             
             
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Comments and suggestions are welcomed. See the full spreadsheet at: ADH2450Deszg.xls

The content in languages other than English was translated by a computer software and may not be completely accurate!

Copyright © 1998-2005 SMPS Power Supplies Inc. All rights reserved.