SLUS670C JULY   2005  – January 2015

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
  6. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 Recommended Operating Conditions
    3. 6.3 Thermal Information
    4. 6.4 Electrical Characteristics
    5. 6.5 Typical Characteristics
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1  PWM Operation
      2. 7.3.2  Adaptive On-Time Control
      3. 7.3.3  Light Load Operation
      4. 7.3.4  Forced PWM Operation
      5. 7.3.5  5-V, 100-mA, LDO and Switchover (VREG5)
      6. 7.3.6  3.3-V, 100-mA, LDO and Switchover (VREG3)
      7. 7.3.7  2-V, 50-uA Sink - Source Reference (VREF2)
      8. 7.3.8  Low-Side Driver
      9. 7.3.9  High-Side Driver
      10. 7.3.10 Soft-Start
      11. 7.3.11 Soft-Stop
      12. 7.3.12 Powergood
      13. 7.3.13 Current Sensing and Overcurrent Protection
      14. 7.3.14 Overvoltage Protection
      15. 7.3.15 Undervoltage Protection
      16. 7.3.16 5-V Supply and UVLO Protection
      17. 7.3.17 VIN Line Sag Protection (Dynamic UVP)
      18. 7.3.18 Thermal Shutdown
    4. 7.4 Device Functional Modes
      1. 7.4.1 Current Mode
        1. 7.4.1.1 Current Mode Operation
      2. 7.4.2 D-Cap Mode
        1. 7.4.2.1 D-Cap Mode Operation
    5. 7.5 Programming
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
      3. 8.2.3 Application Curves
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Trademarks
    2. 11.2 Electrostatic Discharge Caution
    3. 11.3 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

1 Features

  • 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 Transistors
  • 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

2 Applications

    Notebook Computers System Bus and I/O

3 Description

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.

Device Information(1)

PART NUMBER PACKAGE BODY SIZE (NOM)
TPS51120 VQFN (32) 5.00 mm × 5.00 mm
  1. For all available packages, see the orderable addendum at the end of the datasheet.

Reference Design for D-CAP Mode Converter

v05074_lus670.gif