LM3242_15 Datasheet, PDF (1/32 Pages) Texas Instruments – LM3242 6-MHz, 750-mA Miniature Adjustable Step-Down DC-DC Converter With Auto Bypass for RF Power Amplifiers

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 V_IN,
3.3 V_OUT 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, 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).
In low-battery condition Bypass mode reduces the
voltage dropout to less than 50 mV (typical). The part
also features a Sleep mode.
The LM3242 is available in a 9-bump lead-free
DSBGA package. A high switching frequency (6 MHz)
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
V_IN
2.7V to 5.5V
10 PF
GPO1
DAC
VIN
BPEN
SW
EN
LM3242
FB
VCON
SGND PGND
0.5 PH
V_OUT = 2.5 x VCON
0.4V to 3.6V
4.7 PF
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.