Product details


Vin (Min) (V) 4.5 Vin (Max) (V) 18 Vout (Min) (V) 0.8 Vout (Max) (V) 17 Iout (Max) (A) 3 Iq (Typ) (uA) 20000 Switching frequency (Min) (kHz) 300 Switching frequency (Max) (kHz) 2200 Features Adjustable Current Limit, Enable, Frequency Synchronization, Phase Interleaving, Power Good, Synchronous Rectification, UVLO Adjustable, Soft Start Adjustable Operating temperature range (C) -40 to 125 Rating Catalog Regulated outputs (#) 3 open-in-new Find other Buck converters (integrated switch)

Package | Pins | Size

VQFN (RHA) 40 36 mm² 6 x 6 open-in-new Find other Buck converters (integrated switch)


  • Wide Input Supply Voltage Range (4.5 to 18 V)
  • 0.8 V, 1% Accuracy Reference
  • Continuous Loading: 3 A (Buck 1),
    2 A (Buck 2 and 3)
  • Maximum Current: 3.5 A (Buck 1),
    2.5 A (Buck 2 and 3)
  • Adjustable Switching Frequency
    300 kHz to 2.2 MHz Set by External Resistor
  • Dedicated Enable for Each Buck
  • External Synchronization Pin for Oscillator
  • External Enable/Sequencing and Soft-Start Pins
  • Adjustable Current Limit Set By External Resistor
  • Soft-Start Pins
  • Current-Mode Control With Simple Compensation Circuit
  • Powergood
  • Optional Low-Power Mode Operation for Light Loads
  • VQFN Package, 40-Pin 6 mm × 6 mm RHA
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The TPS65251 features three synchronous wide input range high efficiency buck converters. The converters are designed to simplify its application while giving the designer the option to optimize their usage according to the target application.

The converters can operate in 5-, 9-, 12- or 15-V systems and have integrated power transistors. The output voltage can be set externally using a resistor divider to any value between 0.8 V and close to the input supply. Each converter features enable pin that allows a delayed start-up for sequencing purposes, soft-start pin that allows adjustable soft-start time by choosing the soft-start capacitor, and a current limit (RLIMx) pin that enables designer to adjust current limit by selecting an external resistor and optimize the choice of inductor. The current mode control allows a simple RC compensation.

The switching frequency of the converters can either be set with an external resistor connected to ROSC pin or can be synchronized to an external clock connected to SYNC pin if needed. The switching regulators are designed to operate from 300 kHz to 2.2 MHz. 180° out of phase operation between Buck 1 and Buck 2, 3 (Buck 2 and 3 run in phase) minimizes the input filter requirements.

TPS65251 features a supervisor circuit that monitors each converter output. The PGOOD pin is asserted once sequencing is done, all PG signals are reported and a selectable end of reset time lapses. The polarity of the PGOOD signal is active high.

TPS65251 also features a light load pulse skipping mode (PSM) by allowing the LOW_P pin tied to V3V. The PSM mode allows for a reduction on the input power supplied to the system when the host processor is in standby (low-activity) mode.

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Technical documentation

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Type Title Date
* Data sheet TPS65251 4.5-V to 18-V Input, High-Current, Synchronous Step-Down Three Buck Switcher With Integrated FET datasheet (Rev. G) Feb. 16, 2018
User guide TPS65251 Buck Converter Evaluation Module User's Guide (Rev. B) May 26, 2021
Application note Measure Power Stage Gain and Slope Compensation in PCM (Peak Current Mode) BUCK (Rev. A) Apr. 01, 2019
Technical article Minimize the impact of the MLCC shortage on your power application Mar. 29, 2019
Selection guide Power Management Guide 2018 (Rev. R) Jun. 25, 2018
Application note TPS65250/1/2/3 LAYOUT GUIDE Jan. 15, 2013
Application note TPS65250/1/2/3 Output Filter Selection Guidelines Jan. 15, 2013

Design & development

For additional terms or required resources, click any title below to view the detail page where available.

Hardware development


The TPS65251EVM is designed to help the user easily evaluate and test the operation and functionality of the TPS65251 buck converters (3-ch DC/DC; Ch1: 1.2 V, 3 A; Ch2: 1.8 V, 2 A; Ch3: 3.3 V, 2 A). The EVM converts a 4.5-V to 18-V input voltage designed to a regulated Ch1 = 1.2 V, Ch2 = 1.8 V, Ch3 (...)

  • Wide input supply voltage range (4.5 V to 18 V)
  • 0.8-V, 1% accuracy reference
  • Continuous loading: 3 A (Buck 1), 2 A (Buck 2 and 3)
  • Maximum current: 3.5 A (Buck 1), 2.5 A (Buck 2 and 3)
  • Adjustable switching rrequency, 300 kHz to 2.2 MHz set-by external resistor
  • Dedicated enable for each buck
  • External (...)

Design tools & simulation

SLVM274.TSC (94 KB) - TINA-TI Reference Design
SLVM275.ZIP (8 KB) - TINA-TI Spice Model
SLVM511A.ZIP (43 KB) - PSpice Model
SLVM512.TSC (154 KB) - TINA-TI Reference Design
SLVM513.ZIP (24 KB) - TINA-TI Spice Model
SLVM519A.ZIP (31 KB) - PSpice Model
PSpice® for TI design and simulation tool
PSPICE-FOR-TI — PSpice® for TI is a design and simulation environment that helps evaluate functionality of analog circuits. This full-featured, design and simulation suite uses an analog analysis engine from Cadence®. Available at no cost, PSpice for TI includes one of the largest model libraries in the (...)
  • Leverages Cadence PSpice Technology
  • Preinstalled library with a suite of digital models to enable worst-case timing analysis
  • Dynamic updates ensure you have access to most current device models
  • Optimized for simulation speed without loss of accuracy
  • Supports simultaneous analysis of multiple products
  • (...)

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DLP4500-C350REF This reference design, featuring the DLP® 0.45” WXGA chipset and implemented in the DLP® LightCrafter™ 4500 evaluation module (EVM), enables flexible control of high resolution, accurate patterns for industrial, medical, and scientific applications. With a free USB-based GUI and (...)
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Accurate Point Cloud Generation for 3D Machine Vision Applications using DLP® Technology
TIDA-00254 The 3D Machine Vision reference design employs Texas Instruments DLP® Advanced Light Control Software Development Kit (SDK) for LightCrafter™ series controllers, which allows developers to easily construct 3D point clouds by integrating TI’s digital micromirror device (DMD (...)
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Portable, High Brightness HD Projection Display Reference Design using DLP® Technology
TIDA-00782 This reference design, featuring the DLP Pico™ 0.45-inch WXGA display chipset enables use of HD resolution for projection display applications such as accessory projectors, smart projectors, mobile Smart TV, built in projectors like projection functionality inside notebooks, laptops and hot (...)
document-generic Schematic

CAD/CAE symbols

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VQFN (RHA) 40 View options

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