Switching Converter Boost Converter Buck/Boost Converter Buck Converter + V IN - + V OUT - I IN IOIO

iLiL i L,max i L,min I L,crit ILIL T S = t 1 +t 2 t 1 =DT S t 2 =(1-D)T S m2m2 m1m1 Buck-Boost Converter : Inductor Current

iLiL ILIL i L,max i L,min T S = t 1 +t 2 t 1 =DT S t 2 =(1-D)T S Buck-Boost Converter : Switch Current ILIL

i D = -i O ILIL i L,max i L,min T S = t 1 +t 2 t 1 =DT S t 2 =(1-D)T S B/B Converter : Forward Diode Current ILIL

-i C ILIL IOIO T S = t 1 +t 2 t 1 =DT S t 2 =(1-D)T S B/B Converter: Capacitor Current – High P o 0 -  Q +  Q

i D ILIL IOIO T S = t 1 +t 2 t1t1 t2t2 B/B Converter: Capacitor Current – Low P o 0  Q +  Q I L,max txtx

ParameterModeBuckBoostBuck/Boost V O RangeC/D0 < V O /V IN < 1V O /V IN > 1V O /V IN < 0 I IN C/DI O (V O /V IN ) I L (max) CI O + I O,cr I O + I IN,cr (I O + I O,cr )(V O -V IN )/V IN D(V O -V IN )/V IN I L (min)CI O - I O,cr I IN - I IN,cr (I O - I O,cr )(V O -V IN )/V IN C/D Boundary I IN,cr C/D(V O /V IN ) 2 (V IN - V O )/2Lf(V IN /V O )(V O - V IN )/2Lf(V O /(V O - V IN )) 2 (V IN /2Lf) I L,cr C/DI O,cr I IN,cr (V O /(V O - V IN ))(V IN /2Lf) I O,cr C/D(V O /V IN )(V IN - V O )/2Lf(V IN /V O ) 2 (V O - V IN )/2Lf(V IN /(V O -V IN )) 2 (V O /2Lf) Duty Cycle CV O /V IN (V O -V IN )/V O V O / (V O -V IN ) D(V O -V IN )/V O V O / (V O -V IN ) 11 C(V IN –V O )/V IN V IN /V O V IN / (V IN -V O ) D (V IN - V O )/V IN V IN /V O V IN / (V IN -V O ) 22 D Reverse diode for V IN < 0 DCM if I O /I O,cr < 1 Switching Converter Parameters