JAJS427I July   2010  – October 2019 TPS63020 , TPS63021

PRODUCTION DATA.  

  1. 1 特長
  2. 2 アプリケーション
  3. 3 概要
    1.     Device Images
      1.      概略回路図
      2.      効率と出力電流との関係
  4. 4 改訂履歴
  5. 5 概要 (続き)
  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 Dynamic Voltage Positioning
      2. 8.3.2 Dynamic Current Limit
      3. 8.3.3 Device Enable
      4. 8.3.4 Power Good
      5. 8.3.5 Overvoltage Protection
      6. 8.3.6 Undervoltage Lockout
      7. 8.3.7 Overtemperature Protection
    4. 8.4 Device Functional Modes
      1. 8.4.1 Soft-start and Short Circuit Protection
      2. 8.4.2 Buck-Boost Operation
      3. 8.4.3 Control Loop
      4. 8.4.4 Power Save Mode and Synchronization
  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 Inductor Selection
        3. 9.2.2.3 Output Capacitor Selection
        4. 9.2.2.4 Input Capacitor Selection
        5. 9.2.2.5 Bypass Capacitor
      3. 9.2.3 Setting The Output Voltage
      4. 9.2.4 Application Curves
    3. 9.3 System Examples
      1. 9.3.1 Improved Transient Response for 2 A Load Current
      2. 9.3.2 Supercapacitor Backup Power Supply With Active Cell Balancing
      3. 9.3.3 Low-Power TEC Driver
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
    3. 11.3 Thermal Considerations
  12. 12デバイスおよびドキュメントのサポート
    1. 12.1 ドキュメントの更新通知を受け取る方法
    2. 12.2 デバイス・サポート
      1. 12.2.1 WEBENCHツールによるカスタム設計
      2. 12.2.2 デベロッパー・ネットワークの製品に関する免責事項
    3. 12.3 ドキュメントのサポート
      1. 12.3.1 関連資料
    4. 12.4 関連リンク
    5. 12.5 サポート・リソース
    6. 12.6 商標
    7. 12.7 静電気放電に関する注意事項
    8. 12.8 Glossary
  13. 13メカニカル、パッケージ、および注文情報

パッケージ・オプション

メカニカル・データ（パッケージ｜ピン）
サーマルパッド・メカニカル・データ
発注情報

9.2.2.2 Inductor Selection

The inductor selection is affected by several parameters such as the following:

  • Inductor ripple current
  • Output voltage ripple
  • Transition point into Power Save Mode
  • Efficiency

See Table 2 for a list of typical inductors.

For high efficiencies, the inductor must have a low DC resistance to minimize conduction losses. Especially at high-switching frequencies, the core material has a high impact on efficiency. When using small chip inductors, the efficiency is reduced mainly due to higher inductor core losses. This needs to be considered when selecting the appropriate inductor. The inductor value determines the inductor ripple current. The larger the inductor value, the smaller the inductor ripple current and the lower the conduction losses of the converter. Conversely, larger inductor values cause a slower load transient response. Use Equation 2 to avoid saturation of the inductor when calculating the peak current for the inductor in steady state operation. Only the equation which defines the switch current in boost mode is shown because this provides the highest value of current and represents the critical current value for selecting the right inductor.

Equation 1. TPS63020 TPS63021 q1_boost_lvsa92.gif
Equation 2. TPS63020 TPS63021 peak_current_boost_lvsa92.gif

where

  • D = duty cycle in boost mode
  • f = converter switching frequency (typical 2.5 MHz)
  • L = inductor value
  • η = estimated converter efficiency (use the number from the efficiency curves or 0.9 as an assumption)

NOTE

The calculation must be done for the minimum input voltage in boost mode.

Calculating the maximum inductor current using the actual operating conditions gives the minimum saturation current of the inductor needed. It is recommended to choose an inductor with a saturation current 20% higher than the value calculated using Equation 2. Table 2 lists the possible inductors.

Table 2. List of Recommended Inductors (1)

INDUCTOR VALUE [µH] SATURATION CURRENT [A] DCR [mΩ] PART NUMBER MANUFACTURER SIZE (LxWxH mm)
1.5 5.1 15 XFL4020-152ME Coilcraft 4 x 4 x 2.1
1.5 5.4 24 FDV0530S-H-1R5M muRata 5 x 5 x 3