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LM3243
SNVS782C – OCTOBER 2010...
Product Folder
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Technical Documents
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LM3243
SNVS782C – OCTOBER 2010 – REVISED AUGUST 2015
LM3243 High-Current Step-Down Converter for 2G, 3G, and 4G RF Power
Amplifiers
1 Features
1 Input
Voltage Range: 2.7 V to 5.5 V High-Efficiency PFM and PWM Modes With
Internal Synchronous Rectification Analog Bypass Function with Low Dropout
Resistance (45 mΩ Typical) Dynamically Adjustable Output
Voltage: 0.4 V to
3.6 V (Typical) in PFM and PWM Modes Maximum Load Current: 2.5 A in PWM Mode PWM Switching Frequency: 2.7 MHz (Average) Modulated Switching Frequency to Aid Rx Band
Compliance Operates From a Single Li-ion Cell
(2.7 V to 5.5 V) Current and Thermal Overload Protection ACB Reduces Inductor Requirements and Size Minimum Total Solution Size by Using Small
Footprint and Case Size Inductor and
Capacitors
2 Applications
Cellular Phones Hand-Held Radios RF PC Cards Battery-Powered RF Devices
3 Description
The LM3243 is a DC-DC converter optimized for powering multi-mode 2G, 3G, and 4G RF power
amplifiers (PAs) from a single Lithium-Ion cell. The LM3243 steps down an input
voltage from 2.7 V to 5.5 V to a dynamically adjustable output
voltage of 0.4 V to 3.6 V. The output
voltage is set through a VCON analog input that adjusts the output
voltage to ensure efficient operation at all power levels of the RF PA.
The LM3243 operates in constant frequency PWM mode producing a small and predictable amount of o...