Ceramic capacitors are highly suitable and preferred for lots power converter applications, such as digital cameras, netbooks, smartphones, and tablet computers due to their small size, low output voltage ripple, and high reliability requirements. The ESR of ceramic capacitors is substantially lower than that of tantalum equivalents. A low ESR prevents overheating of the device and circuit, thus increasing the overall reliability. However, ceramic capacitors contain a small output voltage ripple with a low ESR which may result in subharmonic oscillations for constant frequency on-time control circuit, so it is a design challenge. A quick dynamic response of ripple-based constant frequency on-time control circuit with virtual inductor current ripple for buck converter is showed in this chapter. The concept uses the capacitor and the resistor in a series to filter out the output voltage at load transient to dynamically change the width of on-time to prevent the V OUT from dropping markedly. Finally, 12-V input voltage, 3.3-V output voltage, and 60-W output power with the quick dynamic response for the integrated circuit of the proposed buck converter are implemented to verify its viability and superiority.