Stability analysis and evaluation of ESR for hysteresis controlled buck converter

Buck converter using hysteresis controller has been widely used for power supply in industry applications owing to its instantaneous load transient. However the equivalent series resistance (ESR) of output capacitor has a significant effect for the stability performance. In this paper, the critical value of ESR is analyzed and calculated in the hysteresis controlled buck converter. Finally, simulation results indicate that the larger output capacitor ESR is necessary to make sure the converter operate normally, otherwise, the converter will operate abnormally.