ZHCSJE4B September   2017  – February 2019 TPS61085A-Q1

PRODUCTION DATA.  

  1. 1 特性
  2. 2 应用
  3. 3 说明
    1.     Device Images
      1.      简化原理图
  4. 4 修订历史记录
  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 Thermal Information
    5. 6.5 Electrical Characteristics
    6. 6.6 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 Soft Start
      2. 7.3.2 Frequency Select Pin (FREQ)
      3. 7.3.3 Undervoltage Lockout (UVLO)
      4. 7.3.4 Thermal Shutdown
      5. 7.3.5 Overvoltage Prevention
    4. 7.4 Device Functional Modes
  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
        1. 8.2.2.1 Inductor Selection
        2. 8.2.2.2 Rectifier Diode Selection
        3. 8.2.2.3 Setting the Output Voltage
        4. 8.2.2.4 Compensation (COMP)
        5. 8.2.2.5 Input Capacitor Selection
        6. 8.2.2.6 Output Capacitor Selection
      3. 8.2.3 Application Curves
    3. 8.3 System Examples
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11器件和文档支持
    1. 11.1 器件支持
      1. 11.1.1 第三方产品免责声明
    2. 11.2 接收文档更新通知
    3. 11.3 社区资源
    4. 11.4 商标
    5. 11.5 静电放电警告
    6. 11.6 术语表
  12. 12机械、封装和可订购信息

封装选项

机械数据 (封装 | 引脚)
散热焊盘机械数据 (封装 | 引脚)
订购信息

8.2.2.2 Rectifier Diode Selection

To achieve high efficiency, a Schottky type must be used for the rectifier diode. The reverse voltage rating must be higher than the maximum output voltage of the converter. The averaged rectified forward current Iavg, the Schottky diode requirement is rated for, is equal to the output current Iout:

Equation 5. TPS61085A-Q1 iq5_lvs821.gif

Usually a Schottky diode with 2-A maximum average rectified forward current rating is sufficient for most applications. The Schottky rectifier can be selected with lower forward current capability depending on the output current Iout but must be able to dissipate the power. The dissipated power is the average rectified forward current times the diode forward voltage.

Equation 6. PD = Iavg × Vforward

Typically the diode must be able to dissipate around 500 mW depending on the load current and forward voltage. See Table 4 for few diode options. Customers must verify and validate these components for suitability with their application before using them.

Table 4. Rectifier Diode Selection

CURRENT RATING (Iavg) Vr Vforward / Iavg SUPPLIER(1) COMPONENT CODE PACKAGE TYPE
750 mA 20 V 0.425 V / 750 mA Fairchild Semiconductor FYV0704S SOT-23
1 A 20 V 0.39 V / 1 A NXP PMEG2010AEH SOD-123
1 A 20 V 0.52 V / 1 A Vishay Semiconductor B120 SMA
1 A 20 V 0.5 V / 1 A Vishay Semiconductor SS12 SMA
1 A 20 V 0.44 V / 1 A Vishay Semiconductor MSS1P2L µ-SMP
(Low Profile)