AAT1171

600mA Voltage-Scaling Step-Down Converter for RF Power Amplifiers with Bypass Switch General Description The AAT1171 SwitchReg, a member of AnalogicTech's Total Power Management IC™ (TPMIC™) product family, has been specifically designed to dynamically control the operating voltage of a WCDMA or CDMA power amplifier inside single lithium-ion battery-powered systems. The AAT1171 outputs a voltage between 0.6V and 3.6V, thereby optimizing the amplifier efficiency at both low and high transmit levels. AAT1171 Features SwitchReg™ The AAT1171 output voltage is controlled via an analog signal from the baseband processor. It can deliver 600mA of continuous load current while maintaining a low 45µA of no load quiescent current. The 2MHz switching frequency minimizes the size of external components while keeping switching losses low. A low resistance MOSFET, typically 230mΩ, provides a low dropout voltage as the battery input voltage approaches the programmed output voltage and the converter runs at 100% duty cycle. To further improve system efficiency, an 85mΩ bypass MOSFET transistor is also included to allow the PA Applications www.DataSheet4U.com to be powered directly from the battery. WCDMA or CDMA PA in Cellular Phones, The AAT1171 feedback and control method gives Smartphones, Feature Phones, etc. excellent load regulation and transient response Express Card while maintaining small external components. The PCMCIA Data Cards output voltag...