The MIC2224 is a high efficiency 2MHz PWM synchronous buck switching regulator optimized for powering 2.5G and 3G CDMA RF Power Amplifiers. The output voltage of MIC2224 can be dynamically adjusted with an external DAC to maximize PA efficiency versus required output power. When the PA requires the highest power, the DAC can be used to enable a low on-resistance, 40m, bypass switch that powers the PA directly from the battery. The 2MHz PWM operation of MIC2224 allows the smallest possible components. It also allows the device to easily meet stringent W-CDMA VOUT response specifications.