TPS51275B-1_15 Datasheet, PDF (1/31 Pages) Texas Instruments – TPS51275B-1 Dual Synchronous, Step-Down Controller With 5-V and 3.3-V LDOs

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TPS51275B-1
SLVSCT3 – MARCH 2015
TPS51275B-1 Dual Synchronous, Step-Down Controller With 5-V and 3.3-V LDOs
1 Features
•1 Input Voltage Range: 5 V to 24 V
• 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 300-kHz and 355-kHz Frequency
Setting
• Out-of-Audio™ (OOA) Light-Load Operation
• Internal 3.2-ms Voltage Servo Soft-Start
• Low-Side R_DS(on) Current Sensing Scheme
• Built-In Output Discharge Function
• Separate Enable Input for Switchers
• Dedicated OC Setting Terminals
• Power Good Indicator
• OVP, UVP, and OCP Protection
• Non-Latch UVLO and OTP Protection
• 20-Pin, 3-mm × 3-mm, WQFN (RUK) Package
2 Applications
• Notebook Computers
• Tablet Computers
• Desktop Computers
3 Description
The TPS51275B-1 device is a cost-effective, dual-
synchronous buck controller targeted for notebook
system-power supply solutions. The device has 5-V
and 3.3-V low-dropout regulators (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 TPS51275B-1 device 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 a supply input
voltage ranging from 5 to 24 V and supports output
voltages of 5 V and 3.3 V. The TPS51275B-1 device
is available in a 20-pin, 3-mm × 3-mm, WQFN
package and is specified from –40°C to 85°C.
Device Information⁽¹⁾
PART NUMBER SKIP MODE
ALWAYS ON-LDO
TPS51275B-1
OOA
VREG3 and VREG5
(1) For all available packages, see the orderable addendum at
the end of the datasheet.
4 Typical Application Diagram
V_IN
V_OUT
5V
TPS51275B-1
VIN
VBST1
VBST2
DRVH1
DRVH2
SW1
SW2
V_OUT
15 V
5-V EN
5V
Always ON
1 µF
DRVL1
VO1
VFB1
CS1
VCLK
EN1
VREG5
DRVL2
VFB2
CS2
PGOOD
EN2
VREG3
V_OUT
3.3 V
PGOOD
3.3-V EN
3.3-V Always ON
1 µF
UDG-12091
1
An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,
intellectual property matters and other important disclaimers. PRODUCTION DATA.