Influence of output conductance on characteristic frequencies of switch mode BUCK and BOOST converter

Characteristic frequencies corresponding to poles and zeros of small-signal control-to-output transfer functions of popular DC-DC converters (BUCK and BOOST) are analyzed. The main attention is paid to influence of load conductance on the characteristic frequencies for converters working in continuous conduction mode (CCM) as well as in discontinuous conduction mode (DCM). Parasitic resistances of all converter components are included in calculations. In addition the improved description of CCMDCM boundary is presented. The calculations are verified experimentally and good consistency of the results is observed.