ZHCSFF5G July   2016  – December  2019 TPS2660

PRODUCTION DATA.  

  1. 特性
  2. 应用
    1.     简化电路原理图
  3. 说明
    1.     –60V 电源时的反向输入极性保护
  4. 修订历史记录
  5. Device Comparison Table
  6. Pin Configuration and Functions
    1.     Pin Functions
  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 Timing Requirements
    7. 7.7 Typical Characteristics
  8. Parameter Measurement Information
  9. Detailed Description
    1. 9.1 Overview
    2. 9.2 Functional Block Diagram
    3. 9.3 Feature Description
      1. 9.3.1 Undervoltage Lockout (UVLO)
      2. 9.3.2 Overvoltage Protection (OVP)
      3. 9.3.3 Reverse Input Supply Protection
      4. 9.3.4 Hot Plug-In and In-Rush Current Control
      5. 9.3.5 Overload and Short Circuit Protection
        1. 9.3.5.1 Overload Protection
          1. 9.3.5.1.1 Active Current Limiting
          2. 9.3.5.1.2 Electronic Circuit Breaker with Overload Timeout, MODE = OPEN
        2. 9.3.5.2 Short Circuit Protection
          1. 9.3.5.2.1 Start-Up With Short-Circuit On Output
        3. 9.3.5.3 FAULT Response
          1. 9.3.5.3.1 Look Ahead Overload Current Fault Indicator
        4. 9.3.5.4 Current Monitoring
        5. 9.3.5.5 IN, OUT, RTN, and GND Pins
        6. 9.3.5.6 Thermal Shutdown
        7. 9.3.5.7 Low Current Shutdown Control (SHDN)
    4. 9.4 Device Functional Modes
  10. 10Application and Implementation
    1. 10.1 Application Information
    2. 10.2 Typical Application
      1. 10.2.1 Design Requirements
      2. 10.2.2 Detailed Design Procedure
        1. 10.2.2.1 Step by Step Design Procedure
        2. 10.2.2.2 Programming the Current-Limit Threshold—R(ILIM) Selection
        3. 10.2.2.3 Undervoltage Lockout and Overvoltage Set Point
        4. 10.2.2.4 Programming Current Monitoring Resistor—RIMON
        5. 10.2.2.5 Setting Output Voltage Ramp Time—(tdVdT)
          1. 10.2.2.5.1 Case 1: Start-Up Without Load—Only Output Capacitance C(OUT) Draws Current During Start-Up
          2. 10.2.2.5.2 Case 2: Start-Up With Load—Output Capacitance C(OUT) and Load Draws Current During Start-Up
          3. 10.2.2.5.3 Support Component Selections—RFLTb and C(IN)
      3. 10.2.3 Application Curves
    3. 10.3 System Examples
      1. 10.3.1 Acive ORing Operation
      2. 10.3.2 Field Supply Protection in PLC, DCS I/O Modules
      3. 10.3.3 Simple 24-V Power Supply Path Protection
    4. 10.4 Do's and Don'ts
  11. 11Power Supply Recommendations
    1. 11.1 Transient Protection
  12. 12Layout
    1. 12.1 Layout Guidelines
    2. 12.2 Layout Example
  13. 13器件和文档支持
    1. 13.1 器件支持
    2. 13.2 文档支持
      1. 13.2.1 相关文档
    3. 13.3 接收文档更新通知
    4. 13.4 社区资源
    5. 13.5 商标
    6. 13.6 静电放电警告
    7. 13.7 Glossary
  14. 14机械、封装和可订购信息

Undervoltage Lockout and Overvoltage Set Point

The undervoltage lockout (UVLO) and overvoltage trip point are adjusted using an external voltage divider network of R1, R2 and R3 connected between IN, UVLO, OVP and RTN pins of the device. The values required for setting the undervoltage and overvoltage are calculated by solving Equation 10 and Equation 11.

Equation 10. TPS2660 Equation_2_App.gif
Equation 11. TPS2660 Equation_3_App.gif

For minimizing the input current drawn from the power supply {I(R123) = V(IN)/(R1+R2+R3)}, it is recommended to use higher value resistance for R1, R2 and R3.

However, the leakage current due to external active components connected at resistor string can add error to these calculations. So, the resistor string current, I(R123) must be chosen to be 20x greater than the leakage current of UVLO and OVP pins.

From the device electrical specifications, V(OVPR) = 1.19 V and V(UVLOR) = 1.19 V. From the design requirements, V(OV) is 30 V and V(UV) is 18 V. To solve the equation, first choose the value of R3 = 30.1 kΩ and use Equation 10 to solve for (R1 + R2) = 728.7 kΩ. Use Equation 11 and value of (R1 + R2) to solve for R2 = 20.05 kΩ and finally R1= 708.6 kΩ.

Choose the closest standard 1% resistor values: R1 = 715 kΩ, R2 = 20 kΩ, and R3 = 30.1 kΩ.

The UVLO and the OVP pins can also be connected to the RTN pin to enable the internal default V(OV) = 33 V and V(UV) = 15 V.

The power failure is detected on falling edge of the supply. This threshold voltage is 7.5% lower than the rising threshold, V(UV). The voltage at which the device detects power fail can be calculated using Equation 12.

Equation 12. TPS2660 Equation_4_App.gif