LM3279

Product Folder Sample & Buy Technical Documents Tools & Software Support & Community LM3279 SNVS970C – MARCH 2013 – REVISED OCTOBER 2014 LM3279 Buck-Boost Converter With MIPI® RFFE Interface for 3G And 4G RF Power Amplifiers 1 Features 1 MIPI® RFFE Digital Control Interface High-Efficiency PFM and PWM Modes with Internal Seamless Transition Operates from a Single Li-Ion Cell: 2.7 V to 5.5 V Adjustable Output Voltage: – RFFE Digital Control: 0.4 V to 4.2 V – Analog Control: 0.5 V to 4.2 V 1-A Maximum Load Capability for VBATT ≥ 3.2 V, VOUT = 3.6 V 2.4-MHz (typ.) Switching Frequency Seamless Buck-Boost Mode Transition Fast Output Voltage Transition: 0.8 V to 4 V in 20 µs High-Efficiency: 95% typ. at VBATT = 3.7 V, VOUT = 3.3 V, at 300 mA Input Overcurrent Limit Output Overvoltage Clamp Internal Compensation 2 Applications 3G/4G Smartphones RF PC Cards Tablets, eBooks Readers Battery-Powered RF Devices Simplified Schematic 1.5 ÛH VBATT: 2.7V to 5.5V 10 ÛF X SW1 SW2 PVIN SVIN VOUT FB EN GPO0 GPO1 DGND LM3279 VCON SGND VIO SDATA SCLK PGND RF Control Bits VOUT: 0.4V to 4.2V 10 ÛF RF PA(s) 2 x 0.47 ÛF (PA decoupling caps) BB or RFIC 3 Description The LM3279 is a buck-boost DC/DC converter designed to generate output voltages above or below a given input voltage and is particularly suitable for Power Amplifiers operating from single-cell Li-Ion batteries in portable applications. The LM3279 has four modes of operation: Pulse Width...