TPS51123 Datasheet, PDF (1/33 Pages) Texas Instruments – Dual-Synchronous, Step-Down Controller with Out-of-Audio™ Operation and 100-mA LDOs for Notebook System Power

TPS51123
www.ti.com ........................................................................................................................................................................................... SLUS890 – DECEMBER 2008
Dual-Synchronous, Step-Down Controller with Out-of-Audio™ Operation and 100-mA
LDOs for Notebook System Power
FEATURES
1
•2 Wide-Input Voltage Range: 5.5 V to 28 V
• Output Voltage Range: 2 V to 5.5 V
• Built-in 100-mA 5-V/3.3-V LDO with Switches
• Built-in 1% 2-V Reference Output
• With/Without Out-of-Audio™ Mode Selectable
Light-Load and PWM only Operation
• Internal 1.6-ms Voltage Servo Softstart
• Adaptive On-Time Control Architecture with
Four Selectable Frequency Setting
• 4500 ppm/°C R_DS(on) Current Sensing
• Built-In Output Discharge
• Power Good Output
• Built-in OVP/UVP/OCP
• Thermal Shutdown (Non-latch)
• 24-Pin QFN (RGE) Package
APPLICATIONS
• Notebook Computers
• I/O Supplies
• System Power Supplies
DESCRIPTION
The TPS51123 is a cost effective, dual-synchronous
buck controller targeted for notebook system power
supply solutions. It provides 5-V and 3.3-V LDOs and
requires few external components. The TPS51123
supports high efficiency, fast transient responses and
provides a combined power-good signal.
Out-of-Audio™ mode light-load operation enables low
acoustic noise at much higher efficiency than
conventional forced PWM operation. Adaptive
on-time D-CAP™ control provides convenient and
efficient operation. The part operates with supply
input voltages ranging from 5.5 V to 28 V and
supports output voltages from 2 V to 5.5 V. The
TPS51123 is available in a 24-pin QFN package and
is specified from -40°C to 85°C ambient temperature
range.
VIN
10 mF x 2
VO2
3.3 V
3.3 mF
330 mF
EN0
13 kW
20 kW
130 kW
20 kW
220 nF
30 kW
130 kW
654321
VIN
10 mF x 2
10 mF
0.1 mF
7 VO2
8 VREG3
9 VBST2
5.1 W
10 DRVH2
TPS51123RGE
(QFN-24)
VO1 24
100 kW
PGOOD 23
VREG5
VBST1 22
0.1 mF
5.1 W
DRVH1 21
11 LL2 PowerPAD
LL1 20
12 DRVL2
DRVL1 19
3.3 mF
330 mF
VIN
5.5 V
to
28 V
VO1
5V
13 14 15 16 17 18
VREG5
33 mF
VIN
ENC
UDG-08167
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.
Out-of-Audio, D-CAP are trademarks of Texas Instruments.
2
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