ZHCSQ16 December   2022 TPS22995

PRODUCTION DATA  

  1. 1 特性
  2. 2 应用
  3. 3 说明
  4. 4 Revision History
  5. 5 Pin Configuration and 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 (VBIAS = 5 V)
    6. 6.6  Electrical Characteristics (VBIAS = 3.3 V)
    7. 6.7  Electrical Characteristics (VBIAS = 1.5 V)
    8. 6.8  Switching Characteristics (VBIAS = 5 V)
    9. 6.9  Switching Characteristics (VBIAS = 3.3 V)
    10. 6.10 Switching Characteristics (VBIAS = 1.5 V)
    11. 6.11 Typical Characteristics
  7. 7 Parameter Measurement Information
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Adjustable Slew Rate
      2. 8.3.2 Quick Output Discharge
      3. 8.3.3 ON and OFF Control
      4. 8.3.4 Thermal Shutdown
    4. 8.4 Device Functional Modes
  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
      3. 9.2.3 Application Performance Plots
    3. 9.3 Power Supply Recommendations
    4. 9.4 Layout
      1. 9.4.1 Layout Guidelines
      2. 9.4.2 Layout Example
  10. 10Device and Documentation Support
    1. 10.1 接收文档更新通知
    2. 10.2 支持资源
    3. 10.3 Trademarks
    4. 10.4 Electrostatic Discharge Caution
    5. 10.5 术语表
  11. 11Mechanical, Packaging, and Orderable Information

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机械数据 (封装 | 引脚)
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订购信息

9.2.2 Detailed Design Procedure

When the switch is enabled, the output capacitors must be charged up from 0 V to VIN. This charge arrives in the form of inrush current. Use the equation below to calculate inrush current.

Equation 3. IINRUSH = CL × dVOUT/dt

where

  • CL is the output capacitance.
  • dVOUT is the change in VOUT during the ramp-up of the output voltage when device is enabled.
  • dt is the rise time in VOUT during the ramp-up of the output voltage when the device is enabled.
The TPS22995 offers an adjustable rise time for VOUT, allowing the user to control the inrush current during turn-on. The appropriate rise time can be calculated using the design requirements and the inrush current equation as shown below.
Equation 4. 200 mA = 47uF × 5.5 V/dt

where

Equation 5. dt = 1292 us

The TPS22995 has very fast rise times with CT pin open. The typical rise time is 127 μs at VBIAS = 5.5 V, VIN = 5.5 V, RL = 100 Ω, and CL = 0.1 µF. This rise time results in an inrush current of 1.59 A. According to Table 8-1, using RT = 10 kΩ results in a rise time of 1520 us, which limits the inrush current to 176 mA. Alternatively, can be used to determine the capacitor needed.