JAJSB44G October   2011  – July 2018 LMZ10500

PRODUCTION DATA.  

  1. 特長
  2. アプリケーション
  3. 概要
    1.     Device Images
      1.      VIN = 3.6Vでの標準的な効率
      2.      放射EMI (CISPR22) VIN = 5V、VOUT = 1.8V、IOUT = 650mA
  4. 改訂履歴
  5. Pin Configuration and Functions
    1.     Pin Functions
  6. Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics
    6. 6.6 System Characteristics
    7. 6.7 Typical Characteristics
  7. Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Current Limit
      2. 7.3.2 Start-up Behavior and Soft Start
      3. 7.3.3 Output Short Circuit Protection
      4. 7.3.4 Thermal Overload Protection
    4. 7.4 Device Functional Modes
      1. 7.4.1 Circuit Operation
      2. 7.4.2 Input Undervoltage Detection
      3. 7.4.3 Shutdown Mode
      4. 7.4.4 EN Pin Operation
      5. 7.4.5 Internal Synchronous Rectification
      6. 7.4.6 High Duty Cycle Operation
  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
        1. 8.2.2.1 Custom Design With WEBENCH® Tools
        2. 8.2.2.2 Setting the Output Voltage
          1. 8.2.2.2.1 RT and RB Selection for Fixed VOUT
          2. 8.2.2.2.2 Output Voltage Accuracy Optimization
        3. 8.2.2.3 Dynamic Output Voltage Scaling
        4. 8.2.2.4 Integrated Inductor
        5. 8.2.2.5 Input and Output Capacitor Selection
      3. 8.2.3 Application Curves
        1. 8.2.3.1 VOUT = 1.2 V
        2. 8.2.3.2 VOUT = 1.8 V
        3. 8.2.3.3 VOUT = 2.5 V
        4. 8.2.3.4 VOUT = 3.3 V
  9. Power Supply Recommendations
    1. 9.1 Voltage Range
    2. 9.2 Current Capability
    3. 9.3 Input Connection
      1. 9.3.1 Voltage Drops
      2. 9.3.2 Stability
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
    3. 10.3 Package Considerations
  11. 11デバイスおよびドキュメントのサポート
    1. 11.1 デバイス・サポート
      1. 11.1.1 WEBENCH®ツールによるカスタム設計
    2. 11.2 ドキュメントのサポート
    3. 11.3 ドキュメントの更新通知を受け取る方法
    4. 11.4 コミュニティ・リソース
    5. 11.5 商標
    6. 11.6 静電気放電に関する注意事項
    7. 11.7 Glossary
  12. 12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

デバイスごとのパッケージ図は、PDF版データシートをご参照ください。

メカニカル・データ(パッケージ|ピン)
  • SIL|8
発注情報

RT and RB Selection for Fixed VOUT

The parameters affecting the output voltage setting are the RT, RB, and the product of the VREF voltage × GAIN. The VREF voltage is typically 2.35 V. Since VCON is derived from VREF via RT and RB,

Equation 2. VCON = VREF × RB/ (RB + RT)

After substitution,

Equation 3. VOUT = VREF × GAIN × RB/ (RB + RT)
Equation 4. RT = ( GAIN × VREF / VOUT – 1 ) x RB

The ideal product of GAIN × VREF = 5.875 V.

Choose RT to be between 80 kΩ and 300 kΩ. Then, RB can be calculated using Equation 5.

Equation 5. RB = ( VOUT / (5.875V – VOUT) ) x RT

Note that the resistance of RT should be ≥ 80 kΩ. This ensures that the VREF output current loading is not exceeded and the reference voltage is maintained. The current loading on VREF should not be greater than 30 µA.