An Alpha and Omega Semiconductor app note for their AOZ101X buck controller using peak current mode control. Link here (PDF)
A Buck converter consists of the power stage and feedback control circuit. The power stage includes power switch and output filter. It converts a higher input voltage to a lower output voltage. The feedback control circuit regulates the output voltage by modulating the power switch duty cycle.
Stable operation of switching mode DC/DC converter requires an adequate loop gain and phase margin in frequency domain. This application note provides an overview of the control circuit small-signal modeling, power stage modeling and feedback compensation design.