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
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FEATURES
DESCRIPTION
The TPS54120 combines the high-efficiency of a
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Low-Noise Output: 17 µVRMS at 100 Hz to
1 MHz
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.
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Wide Input Voltage Range: 4.5 V to 17 V
High Efficiency: 72% at 1 A, 12V Input
Excellent Load/Line Transient Response
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.
Synchronizable to External Clock: 200 kHz to
1.2 MHz
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Small Package: 3.5 mm × 5.5 mm QFN-24
APPLICATIONS
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Telecom Infrastructure
Pico and Femto Base Stations
Powering Sensitive Clocking Distribution
Circuits
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.
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Test and Measurement
Powering RF Components: VCOs, Receivers,
ADCs
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Professional Audio
FUNCTIONAL BLOCK DIAGRAM
L1
R1
R2
CDC-DC_OUT
CBOOT
BOOT PH
LDOIN LDOEN VSENSE
OUT
V(OUT)
VIN
VIN
R4
R5
PVIN
EN
COUT
ON/OFF
FB
TPS54120
RT/CLK
SS
RRT
COMP
NR
CSS
GND
CNR
C2
R3
C1
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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