Dual Current Mode, Synch Step-Down Controller With 100-mA Standby Reg For Notebook System Power


Product details


Vin (Min) (V) 4.5 Vin (Max) (V) 28 Vout (Min) (V) 1 Vout (Max) (V) 5.5 Iout (Max) (A) 20 Iq (Typ) (mA) 0.75 Switching frequency (Min) (kHz) 180 Switching frequency (Max) (kHz) 500 Features Enable, Light Load Efficiency, Power Good, Synchronous Rectification Operating temperature range (C) -40 to 85 Regulated outputs (#) 2 Number of Phases 1 Rating Catalog open-in-new Find other Buck controllers (external switch)

Package | Pins | Size

VQFN (RHB) 32 25 mm² 5.0 x 5.0 VQFN (RHB) 32 25 mm² 5 x 5 open-in-new Find other Buck controllers (external switch)


  • 3.3-V and 5-V 100-mA Bootstrapped Standby
    Regulators with Independent Enables
  • Selectable D-CAP™ Mode Enables Fast Transient
    Response Less than 100 ns
  • Selectable Low Ripple Current Mode
  • Less than 1% Internal Reference Accuracy
  • Selectable PWM-only/Auto-skip Modes
  • Low-side RDS(on) Loss-less Current Sensing
  • RSENSE Accurate Current Sense Option
  • Internal Soft-Start and Integrated VOUT Discharge
  • Integrated 2-V Reference
  • Adaptive Gate Drivers with Integrated Boost Diode
  • Powergood for Each Channel with Delay Timer
  • Fault Disable Mode
  • Supply Input Voltage Range: 4.5 V to 28 V
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The TPS51120 is a highly sophisticated dual, synchronous step-down controller. It is a full featured controller designed to run directly off a three- or four-cell Li-ion battery and provide high-power and 5-V and/or 3.3-V standby regulation for all the downstream circuitry in a notebook computer system. High-current, 100-mA, 5-V or 3.3-V on-board linear regulators have glitch-free switch over function to SMPS and can be kept alive independently during standby state. The pseudo-constant frequency adaptive on-time control scheme supports full range of current mode operation including simplified loop compensation, ceramic output capacitors as well as seamless transition to reduced frequency operation at light-load condition. Optional D-CAP mode operation optimized for SP-CAP or POSCAP output capacitors allows further reduction of external compensation parts. Dynamic UVP supports VIN line sag without latch off by hitting 5-V UVP. No negative voltage appears at output voltage node during UVLO, UVP, and OCP, OTP or loss of VIN.

The TPS51120 32-pin QFN package is specified from –40°C to 85°C ambient temperature.

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Technical documentation

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Type Title Date
* Datasheet TPS51120 Dual, Synchronous Step-Down Controller With 100-mA Standby Regulators for Notebook System Power datasheet (Rev. C) Jan. 29, 2015
User guides High Performance Synchronous Buck EVM Using the TPS51120EVM-001 (Rev. A) Feb. 15, 2006

Design & development

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

Hardware development

TPS51120 Evaluation Module
document-generic User guide

The TPS51120EVM-001 evaluation module utilizes the TPS51120 in a high efficiency, dual synchronous buck converter providing 5 V at 6 A and 3.3 V at 6 A from 8 V to 25 V input. The user’s guide describes the TPS51120EVM-001 performance in D-CAP™ mode and RDS(on) current sensing.

The TPS51120 is a (...)

Design tools & simulation

SLIM108.ZIP (79 KB) - PSpice Model
SLVM103.ZIP (83 KB) - TINA-TI Spice Model
SLVM104.TSC (318 KB) - TINA-TI Reference Design

Reference designs

Synchronous Buck Converter (5V @ 5A)
PMP1967 This reference evaluation module, featuring the TPS51120, achieves low stand-by current high efficiency solution for PC I/O rails.
document-generic Schematic document-generic User guide
Sync Buck for Intel Atom E6xx Tunnel Creek (1.8V @ 5A)
PMP5855 — The PMP5855 is designed to use a regulated 12V (8V-14V) bus to produce 10 regulated outputs in sequence for an Atom E6xx Tunnel Creek Power System. The PMP5855 is specially designed to demonstrate the TPS59610 Atom E6xx CPU and GPU Vcore regulators while providing a number of test points to evaluate (...)

CAD/CAE symbols

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VQFN (RHB) 32 View options

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