1 Features
1• 6-MHz (typ.) PWM Switching Frequency
• Operates from a Single Li-Ion Cell (2.7 V to 5.5 V)
• Adjustable Output Voltage (0.6 V to 3.4 V)
• 750-mA Maximum Load Capability
• High Efficiency (95% typ. at 3.9 VIN, 3.3 VOUT at
500 mA)
• Automatic Eco-mode™ and PWM Mode Change
• 6-Bump DSBGA Package
• Current Overload Protection
• Thermal Overload Protection
• Soft Start Function
• CIN and COUT are 0402 (1005) Case Size and 6.3
V of Rated-Voltage Ceramic Capacitor
• Small Chip Inductor in 0805 (2012) Case Size

2 Applications
• Battery-Powered 3G and 4G Power Amplifiers
• Hand-Held Radios
• RF PC Cards
• Battery-Powered RF Devices

3 Description
The LM3241 is a DC-DC converter optimized for
powering RF power amplifiers (PAs) from a single
Lithium-Ion cell. The device can also be used in many
other applications. The device steps down an input
voltage from 2.7 V to 5.5 V to an adjustable output
voltage from 0.6 V to 3.4 V. The output voltage is set
using a VCON analog input for controlling power
levels and efficiency of the RF PA.
The LM3241 offers three 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
conditions, the device enters into Eco-mode
automatically and operates with reduced switching
frequency. In Eco-mode, the quiescent current is
reduced and extends the battery life. Shutdown mode
turns the device off and reduces battery consumption
to 0.1 μA (typical).
The LM3241 is available in a 6-bump lead-free
DSBGA package. A high-switching frequency (6
MHz) allows use of tiny surface-mount components.
Only three small external surface-mount components,
an inductor and two ceramic capacitors are required.