JAJSCH6C June   2016  – June 2021 TPS62135

PRODUCTION DATA  

  1. 1 特長
  2. 2 アプリケーション
  3. 3 概要
  4. 4 Revision History
  5. 5 Device Comparison Table
  6. 6 Pin Configuration and 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 Parameter Measurement Information
    1. 8.1 Schematic
  9. 9 Detailed Description
    1. 9.1 Overview
    2. 9.2 Functional Block Diagram
    3. 9.3 Feature Description
      1. 9.3.1 Precise Enable
      2. 9.3.2 Power Good (PG)
      3. 9.3.3 Pin-Selectable Output Voltage (VSEL and FB2)
      4. 9.3.4 MODE
      5. 9.3.5 Undervoltage Lockout (UVLO)
      6. 9.3.6 Thermal Shutdown
    4. 9.4 Device Functional Modes
      1. 9.4.1 Pulse Width Modulation (PWM) Operation
      2. 9.4.2 Power Save Mode Operation (PWM/PFM)
      3. 9.4.3 100% Duty-Cycle Operation
      4. 9.4.4 HICCUP Current Limit And Short Circuit Protection (TPS62135 only)
      5. 9.4.5 Current Limit And Short Circuit Protection (TPS621351 only)
      6. 9.4.6 Soft-Start / Tracking (SS/TR)
      7. 9.4.7 Output Discharge Function (TPS62135 only)
      8. 9.4.8 Starting into a Pre-Biased Load (TPS621351 only)
  10. 10Application and Implementation
    1. 10.1 Application Information
      1. 10.1.1 Programming the Output Voltage
      2. 10.1.2 External Component Selection
      3. 10.1.3 Inductor Selection
      4. 10.1.4 Capacitor Selection
        1. 10.1.4.1 Output Capacitor
        2. 10.1.4.2 Input Capacitor
        3. 10.1.4.3 Soft-Start Capacitor
      5. 10.1.5 Tracking Function
      6. 10.1.6 Output Filter and Loop Stability
    2. 10.2 Typical Applications
      1. 10.2.1 Typical Application with Adjustable Output Voltage
        1. 10.2.1.1 Design Requirements
        2. 10.2.1.2 Detailed Design Procedure
        3. 10.2.1.3 Application Curves
      2. 10.2.2 Typical Application using VSEL and FB2
        1. 10.2.2.1 Design Requirements
        2. 10.2.2.2 Detailed Design Procedure
        3. 10.2.2.3 Application Curves
    3. 10.3 System Examples
      1. 10.3.1 LED Power Supply
      2. 10.3.2 Powering Multiple Loads
      3. 10.3.3 Voltage Tracking
      4. 10.3.4 Precise Soft-Start Timing
  11. 11Power Supply Recommendations
  12. 12Layout
    1. 12.1 Layout Guidelines
    2. 12.2 Layout Example
    3. 12.3 Thermal Considerations
  13. 13Device and Documentation Support
    1. 13.1 Device Support
      1. 13.1.1 Third-Party Products Disclaimer
    2. 13.2 Receiving Notification of Documentation Updates
    3. 13.3 サポート・リソース
    4. 13.4 Trademarks
    5. 13.5 静電気放電に関する注意事項
    6. 13.6 用語集
  14. 14Mechanical, Packaging, and Orderable Information

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

9.4.4 HICCUP Current Limit And Short Circuit Protection (TPS62135 only)

The TPS62135 is protected against overload and short circuit events. If the inductor current exceeds the current limit I(LIMH), the high side switch is turned off and the low side switch is turned on to ramp down the inductor current. The high side FET turns on again only if the current in the low side FET has decreased below the low side current limit threshold. Once the high side switch current limit is triggered for 512 subsequent switching cycles, the device stops switching. After a typical delay of 800 µs, the device begins a new Soft-Start cycle. This is called HICCUP short circuit protection. TPS62135 repeats this mode until the short circuit condition disappears.

Due to internal propagation delay, the actual current can exceed the static current limit during that time. The dynamic current limit is given as:

Equation 6. GUID-442BBB0C-28E7-4045-B79B-73281CF3A871-low.gif

where:

ILIMH is the static current limit as specified in the electrical characteristics

L is the effective inductance at the peak current

VL is the voltage across the inductor (VIN - VOUT) and

tPD is the internal propagation delay of typically 50 ns.

The current limit can exceed static values, especially if the input voltage is high and very small inductances are used. The dynamic high side switch peak current can be calculated as follows:

Equation 7. GUID-3A2E8E7B-CEBC-4613-9BB3-6E94A0F83BC0-low.gif