TPS65261_15 Datasheet, PDF (1/44 Pages) Texas Instruments – TPS6526x 4.5V to 18V Input Voltage, 3A/2A/2A Output Current Triple Synchronous Step-Down Converter

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TPS65261, TPS65261-1
SLVSCD3B – DECEMBER 2013 – REVISED MAY 2014
TPS6526x 4.5V to 18V Input Voltage, 3A/2A/2A Output Current
Triple Synchronous Step-Down Converter
1 Features
•1 Operating Input Supply Voltage Range
(4.5 V to 18 V)
• Feedback Reference Voltage 0.6V±1%
• Maximum Continuous Output Current 3A/2A/2A
• Adjustable Clock Frequency from 250kHz to
2MHz
• Dedicated Enable and Soft Start Pins for Each
Buck
• Automatic Power-up/Power-down Sequence
• Pulse Skipping Mode (PSM) at Light Load
(TPS65261 only)
• Output Voltage Power Good Indicator
• Input Voltage Power Failure Indicator
• Thermal Overloading Protection
2 Applications
• DTV
• Set Top Boxes
• Home Gateway and Access Point Networks
• Wireless Routers
• Surveillance
• POS Machine
3 Description
The TPS65261, TPS65261-1 is a monolithic triple
synchronous step-down (buck) converter with
3A/2A/2A output currents. A wide 4.5V to 18V input
supply voltage range encompasses the most
intermediate bus voltages operating off 5V, 9V, 12V
or 15V power bus. The converter, with constant
frequency peak current mode, is designed to simplify
its application while giving designers options to
optimize the system according to targeted
applications. The switching frequency of the
converters can be adjusted from 250kHz to 2MHz
with an external resistor. The 180° out-of-phase
operation between Buck1 and Buck2, 3 (Buck2 and 3
run in phase) minimizes the input filter requirements.
The TPS65261, TPS65261-1 features an automatic
power sequence with connecting MODE pin to V7V
and configuring EN1/2/3 pins. The device also
features an open drain RESET signal to monitor
power down.
At light load, the TPS65261 automatically operates in
pulse skipping mode (PSM) and the TPS65261-1
operates in force continuous current mode (FCC).
PSM mode provides high efficiency by reducing
switching losses at light loads and FCC mode
reduces noise susceptibility and RF interference.
The device features overvoltage protection,
overcurrent and short-circuit protection and over-
temperature protection. A power good pin asserts
when any output voltages are out of regulation.
Device Information⁽¹⁾
PART NUMBER
PACKAGE
BODY SIZE (NOM)
TPS65261,
TPS65261-1
VQFN (32)
5.00 mm × 5.00 mm
(1) For all available packages, see the orderable addendum at
the end of the datasheet.
4 Typical Application
Vin
PVINx
LX1
VIN TPS65261
TPS65261-1
FB1
VDIV
RESET
LX2
PGOOD
ENx
FB2
MODE
SSx
ROSC
LX3
AGND
FB3
PGND
Vout1
Vout2
Vout3
100
90
80
70
60
50
40
30
20
10 ^VIN ^{= 12 V}
V_OUT = 3.3 V
0
0.01
0.1
Output Load (A)
TPS65261
1
C001
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.