Accurate design technique for self-oscillating switching regulators

On the basis of simplifying assumptions, equations are derived defining the ripple voltage and operating frequency of the self-oscillating switching regulator in terms of the supply and output voltages, hysteresis voltage, filterchoke inductance, filter capacitance, and a resistance deliberately introduced in series with the filter capacitor. The validity of the equations is checked by testing their predictions against the fundamental differential equations. Design optimisation and limitations are discussed, and an example is given.