• 2.7V to 5.5V input voltage range
• DAC-adjustable output voltage down to 0.3V
• 600mA output current in PWM mode
• Internally protected 40mΩ bypass switch
• Allows direct connection of battery to load
• Over 95% efficient
• Fully integrated MOSFET switches
• Constant 2MHz PWM operation
• Internal soft-start
• 1% line and load regulation
• <1µA shutdown current
• Under-voltage lockout
• Thermal shutdown and current limit protection
• –40°C to +125°C junction temperature range

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, 40mΩ, 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. 

The MIC2224 operates from a 2.7V to 5.5V input, making it ideal for single cell Li-Ion applications. The device features built-in power MOSFETs that can supply up to 600mA of output current in PWM mode, or over 1A in bypass mode. The MIC2224 can operate with a maximum duty cycle of 100% for use in low-dropout conditions.