SLVSDV6C November   2017  – November 2019 TPS62821 , TPS62822 , TPS62823

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Typical Application Schematic space space space space
      2.      Efficiency vs Output Current space
  4. 4 Revision History
  5. 5 Device Comparison Table
  6. 6 Pin Configuration and Functions
    1.     Pin Functions
  7. 7 Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 ESD Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information
    5. 7.5 Electrical Characteristics
    6. 7.6 Typical Characteristics
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Enable / Shutdown and Output Discharge
      2. 8.3.2 Soft-Start
      3. 8.3.3 Power Good (PG)
      4. 8.3.4 Undervoltage Lockout (UVLO)
      5. 8.3.5 Thermal Shutdown
    4. 8.4 Device Functional Modes
      1. 8.4.1 Pulse Width Modulation (PWM) Operation
      2. 8.4.2 Power Save Mode (PSM) Operation
      3. 8.4.3 Minimum Duty Cycle and 100% Mode Operation
      4. 8.4.4 Current Limit and Short Circuit Protection
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1 Custom Design With WEBENCH® Tools
        2. 9.2.2.2 Setting the Adjustable Output Voltage
        3. 9.2.2.3 Feed-forward Capacitor Selection
        4. 9.2.2.4 Output Filter Selection
        5. 9.2.2.5 Inductor Selection
        6. 9.2.2.6 Output Capacitor Selection
        7. 9.2.2.7 Input Capacitor Selection
      3. 9.2.3 Application Curves
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Device Support
      1. 12.1.1 Third-Party Products Disclaimer
    2. 12.2 Related Links
    3. 12.3 Receiving Notification of Documentation Updates
    4. 12.4 Community Resources
    5. 12.5 Trademarks
    6. 12.6 Electrostatic Discharge Caution
    7. 12.7 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

9.2.2.5 Inductor Selection

The TPS6282x is designed to work with inductors of 470nH nominal and can be used with 1µH inductors as well. The inductor has to be selected for adequate saturation current and a low dc resistance (DCR). The minimum inductor current rating, that is needed under static load conditions is calculated using Equation 6 and Equation 7.

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Equation 6. TPS62821 TPS62822 TPS62823 SLVSDV6_eqILmin.gif

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Equation 7. TPS62821 TPS62822 TPS62823 SLVSDV6_eqdeltaIL.gif

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This calculation gives the minimum saturation current of the inductor needed and an additional margin is recommended to cover dynamic overshoot due to startup or load transients. Inductors are available in different dimensions. Choosing the smallest size might result in less efficiency due to larger DCR and ac losses. The following inductors have been tested with the TPS6282x:

Table 4. List of Recommended Inductors

TYPE Nominal INDUCTANCE (1) Saturation Current and DC Resistance Dimensions [mm] Manufacturer(3)
max. ISAT [A](2) max. RDC [mΩ]
HTEN20161T-R47MDR 0.47 4.8 32 2.0 x 1.6 x 1.0 Cyntec
HTEH20121T-R47MSR 0.47 4.6 25 2.0 x 1.2 x 1.0 Cyntec
DFE201610E - R47M 0.47 4.8 32 2.0 x 1.6 x 1.0 muRata
DFE201210S - R47M 0.47 4.8 32 2.0 x 1.2 x 1.0 muRata
TFM201610ALM-R47MTAA 0.47 5.1 34 2.0 x 1.6 x 1.0 TDK
TFM201610ALC-R47MTAA 0.47 5.2 25 2.0 x 1.6 x 1.0 TDK
XFL4015-471ME 0.47 6.6 8.36 4.0 x 4.0 x 1.6 Coilcraft
(1) Inductance Tolerance ±20%
(2) ΔL/L≈30%
(3) See Third-party Products disclaimer.