What is current-mode control and what are its advantages?

Current-mode control adds an inner loop sensing inductor current, comparing it to a reference derived from voltage error. The switch turns off when current reaches the reference. Advantages include: inherent cycle-by-cycle current limiting (protects against overcurrent), faster transient response (current responds immediately), simpler compensation (single pole from output capacitor), eliminates inductor pole, and automatic current sharing in paralleled converters. Slope compensation is needed above 50% duty cycle to prevent subharmonic oscillation.