Circuits and methods to achieve a hysteretic buck-boost converter system, separating buck and boost pulses based on monitoring a difference between the output voltage of the buck-boost converter and a reference voltage (error voltage) or alternatively based on monitoring additionally coil current or load current or both currents have been disclosed. The performance of the buck-boost converter can be further improved by using an optional output voltage change block monitoring if the output voltage rises or falls. The buck-boost converter disclosed has a very simple topology without a modulator block, which is regulating the duty cycle and without frequency compensation.