TPS51225_17 Datasheet, PDF (1/31 Pages) Texas Instruments – Dual Synchronous, Step-Down Controller with 5-V and 3.3-V LDOs

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TPS51225, TPS51225B, TPS51225C
SLUSAV0B – JANUARY 2012 – REVISED SEPTEMBER 2012
Dual Synchronous, Step-Down Controller with 5-V and 3.3-V LDOs
Check for Samples: TPS51225, TPS51225B, TPS51225C
FEATURES
1
APPLICATIONS
•2 Input Voltage Range: 5.5 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 (TPS51225/C)
• OOA Light Load Operation (TPS51225B)
• 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
(TPS51225/B/C)
• Dedicated OC Setting Terminals
• Netbook, Tablet Computers
DESCRIPTION
The TPS51225/B/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 TPS51225/B/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 5.5 V to 24 V and supports
output voltages of 5.0 V and 3.3 V. The
TPS51225/B/C is available in a 20-pin, 3 mm × 3
mm, QFN package and is specified from –40°C to
85°C.
• Power Good Indicator
• 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
SKIP MODE
ALWAYS ON-LDO
PACKAGE
OUTPUT
SUPPLY
QUANTITY
TPS51225RUKR
TPS51225RUKT
TPS51225BRUKR
TPS51225BRUKT
TPS51225CRUKR
TPS51225CRUKT
EN1/ EN2
EN1/ EN2
EN1/ EN2
Auto-skip
OOA
Auto-skip
VREG3
VREG3
VREG3 & VREG5
PLASTIC Quad
Flat Pack
(20 pin QFN)
Tape and Reel
Mini reel
Tape and Reel
Mini reel
Tape and Reel
Mini reel
3000
250
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, Out-of-Audio 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 © 2012, Texas Instruments Incorporated