SLUS609J May   2004  – January 2018 TPS51116

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1. 3.1 Typical Application
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
    1.     Pin Functions
  6. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Dissipation Ratings
    5. 6.5 Thermal Information
    6. 6.6 Electrical Characteristics
    7. 6.7 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  VDDQ SMPS, Light Load Condition
      2. 7.3.2  Low-Side Driver
      3. 7.3.3  High-Side Driver
      4. 7.3.4  Current Sensing Scheme
      5. 7.3.5  PWM Frequency and Adaptive On-Time Control
      6. 7.3.6  VDDQ Output Voltage Selection
      7. 7.3.7  VTT Linear Regulator and VTTREF
      8. 7.3.8  Controling Outputs Using the S3 and S5 Pins
      9. 7.3.9  Soft-Start Function and Powergood Status
      10. 7.3.10 VDDQ and VTT Discharge Control
      11. 7.3.11 Current Protection for VDDQ
      12. 7.3.12 Current Protection for VTT
      13. 7.3.13 Overvoltage and Undervoltage Protection for VDDQ
      14. 7.3.14 Undervoltage Lockout (UVLO) Protection, V5IN (PWP), V5FILT (RGE)
      15. 7.3.15 Input Capacitor, V5IN (PWP), V5FILT (RGE)
      16. 7.3.16 Thermal Shutdown
    4. 7.4 Device Functional Modes
      1. 7.4.1 VDDQ SMPS, Dual PWM Operation Modes
      2. 7.4.2 Current Mode Operation
      3. 7.4.3 D-CAP™ Mode Operation
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 DDR3 Application With Current Mode
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1 Pin Connections
        2. 8.2.2.2 Choose the inductor
        3. 8.2.2.3 Choose rectifying (low-side) MOSFET
        4. 8.2.2.4 Choose output capacitance
        5. 8.2.2.5 Determine f0 and calculate RC
        6. 8.2.2.6 Calculate CC2
        7. 8.2.2.7 Calculate CC.
        8. 8.2.2.8 Determine the value of R1 and R2.
      3. 8.2.3 Application Curves
    3. 8.3 DDR3 Application With D−CAP™ Mode
      1. 8.3.1 Design Requirements
      2. 8.3.2 Detailed Design Procedure
        1. 8.3.2.1 Pin Connections
        2. 8.3.2.2 Choose the Components
      3. 8.3.3 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 Receiving Notification of Documentation Updates
    2. 11.2 Community Resources
    3. 11.3 Trademarks
    4. 11.4 Electrostatic Discharge Caution
    5. 11.5 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

7.3 Feature Description

The TPS51116 is an integrated power management solution which combines a synchronous buck controller, a 10-mA buffered reference and a high-current sink/source low-dropout linear regulator (LDO) in a small 20-pin HTSSOP package or a 24-pin QFN package. Each of these rails generates VDDQ, VTTREF and VTT that required with DDR/DDR2/DDR3/DDR3L/LPDDR3/DDR4 memory systems. The switch mode power supply (SMPS) portion employs external N-channel MOSFETs to support high current for DDR/DDR2/DDR3/LPDDR3/DDR4 memory VDD/VDDQ. The preset output voltage is selectable from 2.5 V or 1.8 V. User-defined output voltage is also possible and can be adjustable from 0.75 V to 3 V. Input voltage range of the SMPS is 3 V to 28 V. The SMPS runs an adaptive on-time PWM operation at high-load condition and automatically reduces frequency to keep excellent efficiency down to several mA. Current sensing scheme uses either RDS(on) of the external rectifying MOSFET for a low-cost, loss-less solution, or an optional sense resistor placed in series to the rectifying MOSFET for more accurate current limit. The output of the switcher is sensed by VDDQSNS pin to generate one-half VDDQ for the 10-mA buffered reference (VTTREF) and the VTT active termination supply. The VTT LDO can source and sink up to 3-A peak current with only 20-μF (two 10-μF in parallel) ceramic output capacitors. VTTREF tracks VDDQ/2 within ±1% of VDDQ. VTT output tracks VTTREF within ±20 mV at no load condition while ±40 mV at full load. The LDO input can be separated from VDDQ and optionally connected to a lower voltage by using VLDOIN pin. This helps reducing power dissipation in sourcing phase. TheTPS51116 is fully compatible to JEDEC DDR/DDR2 specifications at S3/S5 sleep state (see Table 2). The device offers two output discharge function alternatives when both VTT and VDDQ are disabled. The tracking discharge mode discharges VDDQ and VTT outputs through the internal LDO transistors and then VTT output tracks half of VDDQ voltage during discharge. The non-tracking discharge mode discharges outputs using internal discharge MOSFETs which are connected to VDDQSNS and VTT. The current capability of these discharge FETs are limited and discharge occurs more slowly than the tracking discharge. These discharge functions can be disabled by selecting non-discharge mode.