TPS54120 Datasheet, PDF (1/31 Pages) Texas Instruments – Low-Noise, 1-A Power Supply

TPS54120
www.ti.com
SBVS180C – JANUARY 2012 – REVISED JUNE 2012
Low-Noise, 1-A Power Supply
with Integrated DC-DC Converter and Low-Dropout Regulator
FEATURES
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• Low-Noise Output: 17 µV_RMS at 100 Hz to
1 MHz
• Wide Input Voltage Range: 4.5 V to 17 V
• High Efficiency: 72% at 1 A, 12V Input
• Excellent Load/Line Transient Response
• Synchronizable to External Clock: 200 kHz to
1.2 MHz
• Small Package: 3.5 mm × 5.5 mm QFN-24
APPLICATIONS
• Telecom Infrastructure
• Pico and Femto Base Stations
• Powering Sensitive Clocking Distribution
Circuits
• Test and Measurement
• Powering RF Components: VCOs, Receivers,
ADCs
• Professional Audio
DESCRIPTION
The TPS54120 combines the high-efficiency of a
step-down switching (dc-dc) converter with a high
power-supply rejection (PSR), low-noise, low-dropout
regulator (LDO) to provide an ultra low-noise power
supply that delivers quiet power rails to noise-
sensitive applications.
With a wide input range of 4.5 V to 17 V, the
TPS54120 is ideally suited for systems with 12-V
power busses, and supports a 1-A continuous output
current. The output voltage can be set from 0.8 V to
6.0 V using external resistors. The dc-dc converter
and LDO are completely configurable, allowing the
TPS54120 to be used in a wide range of low-noise
applications. In addition, the TPS54120 includes
features such as softstart, switching frequency
synchronization, and a power-good signal.
The device is available in a space-saving, 3.5-mm ×
5.5-mm QFN package, and is specified to operate
over a –40°C to +125°C junction temperature range.
FUNCTIONAL BLOCK DIAGRAM
L1
R1
R2
C_BOOT
C_{DC-DC_OUT}
V_IN
ON/OFF
R_RT
C_SS
C2
BOOT PH
VIN
PVIN
EN
RT/CLK
SS
COMP
R3
C1
LDOIN LDOEN VSENSE
OUT
TPS54120
FB
NR
GND
V_(OUT)
R4
C_OUT
R5
C_NR
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Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Copyright © 2012, Texas Instruments Incorporated