TPS54974 Datasheet, PDF (1/18 Pages) Texas Instruments – DUAL INPUT BUS (2.5V, 3.3V) 9-A OUTPUT SYNCHRONOUS BUCK PWM SWITCHER WITH INTEGRATED FETs

Typical Size
6,4 mm X 9,7 mm
TPS54974
www.ti.com
SLVS458B – JANUARY 2003 – REVISED FEBRUARY 2005
DUAL INPUT BUS (2.5 V, 3.3 V) 9-A OUTPUT SYNCHRONOUS BUCK
PWM SWITCHER WITH INTEGRATED FETs (SWIFT™)
FEATURES
• Low Voltage Separate Power Bus
• 15-mΩ MOSFET Switches for High Efficiency
at 9-A Continuous Output
• Adjustable Output Voltage
• Externally Compensated With 1% Internal
Reference Accuracy
• Fast Transient Response
• Wide PWM Frequency: Adjustable 280 kHz to
700 kHz
• Load Protected by Peak Current Limit and
Thermal Shutdown
• Integrated Solution Reduces Board Area and
Total Cost
APPLICATIONS
• Low-Voltage, High-Density Systems
With Power Distributed at 2.5 V,
3.3 V Available
• Point-of-Load Regulation for
High-Performance
DSPs, FPGAs, ASICs, and
Microprocessors
• Broadband, Networking, and Optical
Communications Infrastructure
• Portable Computing/Notebook PCs
DESCRIPTION
As a member of the SWIFT™ family of dc/dc regu-
lators, the TPS54974 low-input voltage, high-output
current synchronous buck PWM converter integrates
all required active components. 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 pre-
vent start-up until the VIN 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 TPS54974 is available in a thermally enhanced
28-pin TSSOP (PWP) PowerPAD™ package, which
eliminates bulky heatsinks.
SIMPLIFIED SCHEMATIC
SIMPLIFIED SCHEMATIC
2.5 V or 3.3 V
Input1
PVIN
PH
TPS54974
Input2
3.3 V
VIN
BOOT
PGND
COMP
VBIAS
AGND ^VSENSE
Output
Compensation
Network
EFFICIENCY
vs
OUTPUT CURRENT
100
95
90
85
80
75
70
65
VIN = 3.3 V,
60
PVIN = 2.5 V,
V_O = 1.8 V,
55
f_s= 700 kHz
50
0 1 2 3 4 5 6 7 8 9 10
I_O - Output Current - A
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.
SWIFT, PowerPAD are trademarks of Texas Instruments.
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 © 2003–2005, Texas Instruments Incorporated