JAJSM62 March   2022 TPS629206

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 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Mode Selection and Device Configuration (MODE/S-CONF Pin)
      2. 8.3.2 Adjustable VO Operation (External Voltage Divider)
      3. 8.3.3 Selectable VO Operation (VSET and Internal Voltage Divider)
      4. 8.3.4 Smart Enable with Precise Threshold
      5. 8.3.5 Power Good (PG)
      6. 8.3.6 Output Discharge Function
      7. 8.3.7 Undervoltage Lockout (UVLO)
      8. 8.3.8 Current Limit and Short Circuit Protection
      9. 8.3.9 Thermal Shutdown
    4. 8.4 Device Functional Modes
      1. 8.4.1 Forced Pulse Width Modulation (PWM) Operation
      2. 8.4.2 Power Save Mode Operation (Auto PFM/PWM)
      3. 8.4.3 AEE (Automatic Efficiency Enhancement)
      4. 8.4.4 100% Duty-Cycle Operation
      5. 8.4.5 Starting into a Prebiased Load
  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
        1. 9.2.2.1 Custom Design With WEBENCH® Tools
        2. 9.2.2.2 Programming the Output Voltage
        3. 9.2.2.3 External Component Selection
          1. 9.2.2.3.1 Output Filter and Loop Stability
          2. 9.2.2.3.2 Inductor Selection
          3. 9.2.2.3.3 Capacitor Selection
            1. 9.2.2.3.3.1 Output Capacitor
            2. 9.2.2.3.3.2 Input Capacitor
      3. 9.2.3 Application Curves
    3. 9.3 System Examples
      1. 9.3.1 Powering Multiple Loads
      2. 9.3.2 Inverting Buck-Boost (IBB)
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
      1. 11.2.1 Thermal Considerations
  12. 12Device and Documentation Support
    1. 12.1 Device Support
      1. 12.1.1 Third-Party Products Disclaimer
      2. 12.1.2 Development Support
        1. 12.1.2.1 Custom Design With WEBENCH® Tools
    2. 12.2 Documentation Support
      1. 12.2.1 Related Documentation
    3. 12.3 Receiving Notification of Documentation Updates
    4. 12.4 サポート・リソース
    5. 12.5 Trademarks
    6. 12.6 Electrostatic Discharge Caution
    7. 12.7 Glossary
  13. 13Mechanical, 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

8.3.8 Current Limit and Short Circuit Protection

The TPS629206 is protected against overload and short circuit events. If the inductor current exceeds the current limit, ILIM_HS, 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, ILIM_LS.

Due to internal propagation delay, the actual current can exceed the static current limit during that time. The dynamic current limit is given in Equation 1.

Equation 1. GUID-6A020AC6-F83E-40F9-AF7A-F47B26E72C6F-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).
  • 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 2. GUID-8DA03A65-D157-439C-A937-EEBEA01A79F8-low.gif

The TPS629206 also includes a low-side negative current limit (ILIM:SINK) to protect against excessive negative currents that can occur in forced PMW mode under heavy to light load transient conditions. If the negative current in the low-side switch exceeds the ILIM:SINK threshold, the low-side switch is disabled. Both the low-side and high-side switches remain off until an internal timer re-enables the high-side switch based on the selected PWM switching frequency.

CAUTION: It is recommended that the inductor be sized such that the inductor ripple current, ΔIL (see Equation 9), does not exceed 1.6 A to avoid the potential for continuous operation of the negative current limit with no output load (IO = 0 A).