TPS51275 Datasheet, PDF (1/28 Pages) Texas Instruments – Dual Synchronous, Step-Down Controller with 5-V and 3.3-V LDOs

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TPS51275, TPS51275C
SLUSB45 – JUNE 2012
Dual Synchronous, Step-Down Controller with 5-V and 3.3-V LDOs
FEATURES
1
APPLICATIONS
•2 Input Voltage Range: 5 V to 24 V
• Notebook Computers
• Output Voltages: 5 V and 3.3 V (Adjustable
Range ±10%)
• Built-in, 100-mA, 5-V and 3.3-V LDOs
• Clock Output for Charge-Pump
• ±1% Reference Accuracy
• Adaptive On-time D-CAP™ Mode Control
Architecture with 300kHz/355kHz Frequency
Setting
• Auto-skip Light Load Operation
• Internal 0.8-ms Voltage Servo Soft-Start
• Low-Side R_DS(on) Current Sensing Scheme with
4500 ppm/°C Temperature Coefficient
• Built-in Output Discharge Function
• Separate Enable Input for Switchers
• Dedicated OC Setting Terminals
• Power Good Indicator
• Tablet Computers
DESCRIPTION
The TPS51275/C 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 260-kHz VCLK output can be used to drive an
external charge pump, generating gate drive voltage
for the load switches without reducing the main
converter efficiency. The TPS51275/C supports high
efficiency, fast transient response and provides a
combined power-good signal. Adaptive on-time, D-
CAP™ control provides convenient and efficient
operation. The device operates with supply input
voltage ranging from 5 V to 24 V and supports output
voltages of 5.0 V and 3.3 V. The TPS51275/C is
available in a 20-pin, 3 mm × 3 mm, QFN package
and is specified from –40°C to 85°C.
• OVP/UVP/OCP Protection
• Non-latch UVLO/OTP Protection
• 20-Pin, 3 mm × 3 mm, QFN (RUK)
ORDERING INFORMATION⁽¹⁾
ORDERABLE
DEVICE NUMBER
ENABLE
FUNCTION
ALWAYS ON-LDO
PACKAGE
OUTPUT SUPPLY QUANTITY
TPS51275RUKR
TPS51275RUKT
TPS51275CRUKR
TPS51275CRUKT
EN1 and EN2
VREG3
VREG3 and VREG5
PLASTIC Quad Flat
Pack
(20 pin QFN)
Tape and Reel
Mini reel
Tape and Reel
Mini reel
3000
250
3000
250
(1) For the most current package and ordering information see the Package Option Addendum at the end of this document, or see the TI
website at www.ti.com.
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.
D-CAP is a trademark 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 © 2012, Texas Instruments Incorporated