TPS54917 Datasheet, PDF (1/21 Pages) Texas Instruments – 3-V TO 4-V INPUT, 9-A, SMALL SYNCHRONOUS-BUCK SWITCHER WITH INTEGRATED FETs (SWIFT™)

Typical Size
3,5 mm x 7 mm
TPS54917
www.ti.com ........................................................................................................................................................................................... SLVS847 – NOVEMBER 2008
3-V TO 4-V INPUT, 9-A, SMALL SYNCHRONOUS-BUCK
SWITCHER WITH INTEGRATED FETs (SWIFT™)
FEATURES
1
•23 13-mΩ MOSFET Switches for High Efficiency
at 9-A Continuous Output
• Adjustable Output Voltage Down to 0.9V With
1% Accuracy
• Externally Compensated for Design Flexibility
• Wide PWM Frequency: Fixed 350 kHz, 550 kHz,
or Adjustable 280 kHz to 1.6 MHz
• Synchronizable to 1.6MHz
• Load Protected by Peak Current Limit and
Thermal Shutdown
• Small 3.5mm x 7mm Package and Similar
Layout to TPS54910 Reduces Board Area and
Total Cost
• SWIFT Documentation Application Notes, and
SwitcherPro™ Software: www.ti.com/swift
APPLICATIONS
• Low-Voltage, High-Density Systems With
Power Distributed at 3.3 V
• Point of Load Regulation for High Performance
DSPs, FPGAs, ASICs, and Microprocessors
• Broadband, Networking and Optical
Communications Infrastructure
DESCRIPTION
As a member of the SWIFT™ family of dc/dc
regulators, the TPS54917 low-input voltage
high-output current synchronous buck PWM
converter offers the same features as the TPS54910
in a smaller package and higher switching frequency,
which allows for a smaller total solution. Included on
the substrate with the listed features are a true, high
performance, voltage error amplifier that enables
maximum performance under transient conditions
and flexibility in choosing the output filter L and C
components; an undervoltage-lockout circuit to
prevent start-up until the input voltage reaches 3 V;
an internally and externally set slow-start circuit to
limit in-rush currents; and a power good output useful
for processor/logic reset, fault signaling, and supply
sequencing.
The TPS54917 is available in a thermally enhanced
34 pin QFN (RUV) PowerPAD™ package, which
eliminates bulky heatsinks. TI provides evaluation
modules and the SwitcherPro™ design software tool
to aid in achieving high-performance power supply
designs to meet aggressive equipment development
cycles.
SIMPLIFIED SCHEMATIC
Input
TPS54917
VIN
PH
SS/ENA
PWRGD
RT
SYNC
BOOT
PGND
COMP
VBIAS
AGND ^VSENSE
Output
Compensation
Network
EFFICIENCY AT 700 kHz
100
95
90
85
80
75
70
65
60
V_I = 3.3 V,
55
V_O = 2.5 V
50
0 1 2 3 4 5 6 7 8 9 10 11 12
I_O − Output Current − A
1
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.
SwitcherPro, SWIFT, PowerPAD are trademarks of Texas Instruments.
2
All other trademarks are the property of their respective owners.
3
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 © 2008, Texas Instruments Incorporated