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SW

2.7V to 5.5V

0.4V to 3.6V

10 PF

4.7 PF

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0.5 PH

LM3242

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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

3 Description

The LM3242 is a DC-DC converter optimized for

1

•

2.7-V to 5.5-V Input Voltage Operating From

powering RF power amplifiers (PAs) from a single

Single Li-Ion Cell

lithium-ion cell; however, it may be used in many

•

6-MHz (typical) PWM Switching Frequency

other applications. It steps down an input voltage

•

0.4-V to 3.6-V Adjustable Output 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

•

750-mA Maximum Load Capability

VCON analog input for controlling power levels and

(up to 1 A in Bypass)

efficiency of the RF PA.

•

The LM3242 offers five modes of operation. In PWM

mode the device operates at a fixed frequency of

•

Automatic ECO/PWM/BP Mode Change

6 MHz (typical) which minimizes RF interference

•

Current Overload Protection

when driving medium-to-heavy loads. At light load,

the device enters into ECO mode automatically and

•

Thermal Overload Protection

operates with reduced switching frequency. In ECO

•

Soft-Start Function

mode, the quiescent current is reduced and extends

•

Small Chip Inductor in 0805 (2012) case size

the battery life. Shutdown mode turns the device off

and reduces battery consumption to 0.1 µA (typical).

2 Applications

In low-battery condition Bypass mode reduces the

voltage dropout to less than 50 mV (typical). The part

•

Battery-Powered 3G/4G RF PAs

also features a Sleep mode.

•

Battery-Powered RF Devices

The LM3242 is available in a 9-bump lead-free

•

Hand-Held Radios

DSBGA package. A high switching frequency (6 MHz)

•

RF PC Cards

allows

use

of

only

three

tiny

surface-mount

components:

one

inductor

and

two

ceramic

capacitors.

Device Information(1)

PART NUMBER

PACKAGE

BODY SIZE (MAX)

LM3242

DSBGA (9)

1.51 mm × 1.385 mm

(1) For all available packages, see the orderable addendum at

the end of the data sheet.

Typical Application

1

An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,

intellectual property matters and other important disclaimers. PRODUCTION DATA.