Robust Stability Analysis of the PWM Push-Pull DC–DC Converter

In this letter, robust stability analysis of the closed-loop pulsewidth modulated push-pull DC-DC converter with a state feedback control is presented using simple frequency-domain conditions based on the Hermite-Biehler theorem. The proposed technique for checking robust stability is efficient, since there is no need to calculate all the uncertain values of the system and hence no need to formulate and test all four Kharitonov polynomials.