LM3242

Product Folder Sample & Buy Technical Documents Tools & Software Support & Community LM3242 SNOSB48E – OCTOBER 2011 – REVISED AUGUST 2015 LM3242 6-MHz, 750-mA Miniature Adjustable Step-Down DC-DC Converter With Auto Bypass for RF Power Amplifiers 1 Features 1 2.7-V to 5.5-V Input Voltage Operating From Single Li-Ion Cell 6-MHz (typical) PWM Switching Frequency 0.4-V to 3.6-V Adjustable Output Voltage 750-mA Maximum Load Capability (up to 1 A in Bypass) High Efficiency (95% typical at 3.9 VIN, 3.3 VOUT at 500 mA) Automatic ECO/PWM/BP Mode Change Current Overload Protection Thermal Overload Protection Soft-Start Function Small Chip Inductor in 0805 (2012) case size 2 Applications Battery-Powered 3G/4G RF PAs Battery-Powered RF Devices Hand-Held Radios RF PC Cards 3 Description The LM3242 is a DC-DC converter optimized for powering RF power amplifiers (PAs) from a single lithium-ion cell; however, it may be used in many other applications. It steps down an input voltage from 2.7 V to 5.5 V to an adjustable output voltage from 0.4 V to 3.6 V. Output voltage is set using a VCON analog input for controlling power levels and efficiency of the RF PA. The LM3242 offers five modes of operation. In PWM mode the device operates at a fixed frequency of 6 MHz (typical) which minimizes RF interference when driving medium-to-heavy loads. At light load, the device enters into ECO mode automatically and operates with reduced switching frequency. In ECO mode, t...