GENERAL DESCRIPTION
The MAX77178/MAX77179 step-down converters are optimized for powering the power amplifier (PA) in multimode/multiband handsets for 3G/4G applications such as LTE, WCDMA, as well as other RF PA applications such as Wi-FiM and WiMAXM. The 2.5V to 5.5V input supply range supports both current and future battery chemistries. The MAX77179 uses an analog input driven by an external DAC to control the output voltage linearly for continuous PA power adjustment. The output voltage range (0.5V to VIN) supports operation with a wide variety of PAs. Fast switching frequency (8MHz, typ) allows the use of low value inductor and small ceramic output capacitors while maintaining low-ripple voltage. Efficiency is enhanced at light loads by switching to skip mode where the converter switches only as needed to service the load. Adaptive smart FET scaling further improves efficiency under all operating conditions. Other features include overcurrent and overtemperature protection, and a very low-current (0.1µA, typ) shutdown mode.
Maxim Integrated
