The LM3290 step-down converter with integrated dc boost and companion LM3291 linear amplifier form Texas Instruments’ new envelope-tracking power-supply solution to support 3G and 4G LTE multimode, multiband RF power amplifiers used in smartphones and tablets. The devices combine to allow the use of envelope-tracking techniques in RF transmitters to reduce power-amplifier temperature by 20°C and reduce power consumption by 25%. Greater than 90% efficiency is achieved using advanced power tracking for LTE 25RB. The solution supports battery voltage from 2.5 to 5 V. The LM3290’s integrated dc boost converter provides maximum transmit power, supporting higher LTE data rates even at lower battery-voltage levels. There’s also support for the MIPI eTrak analog differential front-end interface for envelope tracking and a 1.8-V MIPI RFFE digital interface to simplify integration with the latest RF platforms. Seamless transition is possible between envelope tracking and average power-tracking operating modes. The devices support a minimum bandwidth of 75 MHz, improving accuracy with enhanced adjacent channel leakage ratio and noise performance.