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.