FAN5902MPX Description  

The FAN5902MPX is a synchronous, step-down DC-to-DC converter with high efficiency, and low noise, and is intended for powering radio frequency power amplifiers (RFPA) in 3G mobile handsets and other mobile applications. Over a 2.7V to 5.5V input voltage range, it can output up to 800mA of current. According to an analog input voltage provided by an external DAC that ranges from 0.2V to 1.7V, the output voltage can be dynamically adjusted from 0.4V up to 3.4V. This makes it possible to supply the RFPA with the voltage level that offers the best Power Added Efficiency (PAE). When the battery voltage falls too near to the output voltage (when VOUT=VBAT-250mV), an inbuilt bypass FET turns on automatically. To manage the inrush current and lessen the RFPA gain deviation, a slew rate controller regulates the bypass transition. With its quick transition speeds, the FAN5902MPX enables output voltage adjustments in less than 20 s. The usage of a tiny, low-value inductor with a 470nH value is made possible by the 6MHz operation of the FAN5902MPX. Excellent line and load regulation is ensured via a current-mode control loop with a quick transient response. The FAN5902MPX boosts talk/connection time and RFPA power efficiency in 3G handsets. The FAN5902MPX is offered in 12-lead MLP and 12-bump WLCSP packages.

FAN5902MPX Features

• 12-Bump WLCSP

• Thermal Shutdown 

• Input Under-Voltage Lockout

• 12-Lead MLP (0.8mm Maximum)

• 2.7V to 5.5V Input Voltage Range

• 92% Efficient Synchronous Operation 

• 100% Duty Cycle for Low Dropout Operation 

• 20μs Step Response ?30μs Bypass Transition Time

• 6MHz PWM Operation Allows 470nH Small Form Factor Inductor

• VOUT Range from 0.4V to 3.4V (or VIN) ?Up to800mA Output Current 

• 50m? Integrated Bypass FET with Controlled Slew Rate for Low Battery Voltage Operation 

FAN5902MPX Applications 

• RF PC Cards

• Battery-Powered 3G RFPAs

• Pocket PC and PDAs with Communication Capabilities

• Multiband/Multimode WCDMA/CDMA Handset RF Transceivers