The device employs AECM control, an emulated current control-based topology that combines the advantages of peak current mode control and D-CAP2 control, providing fast transient response with true fixed switching frequency. The AECM control topology supports two basic regulation modes: PFM regulation mode and PWM regulation mode. During PWM, the device operates at its nominal switching frequency in CCM or DCM. The frequency is typically approximately 1.2 MHz with a controlled frequency variation. If the load current decreases, the devices enters PFM to sustain high efficiency down to very light loads. In PFM, the switching frequency decreases with the load current. With the internal adaptive loop adjustment, the device eliminates the need for external compensation to provide a fast transient response over a wide output voltage range.