JAJSJ29E May   2020  – October 2024 TPS61378-Q1

PRODUCTION DATA  

  1.   1
  2. 1 特長
  3. 2 アプリケーション
  4. 3 概要
  5. 4 Device Comparison Table
  6. 5 Pin Configuration and Functions
  7. 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
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1  VCC Power Supply
      2. 7.3.2  Input Undervoltage Lockout (UVLO)
      3. 7.3.3  Enable and Soft Start
      4. 7.3.4  Shut Down
      5. 7.3.5  Switching Frequency Setting
      6. 7.3.6  Spread Spectrum Frequency Modulation
      7. 7.3.7  Adjustable Peak Current Limit
      8. 7.3.8  Bootstrap
      9. 7.3.9  Load Disconnect
      10. 7.3.10 MODE/SYNC Configuration
      11. 7.3.11 Overvoltage Protection (OVP)
      12. 7.3.12 Output Short Protection/Hiccup
      13. 7.3.13 Power-Good Indicator
      14. 7.3.14 Thermal Shutdown
    4. 7.4 Device Functional Modes
      1. 7.4.1 Forced PWM Mode
      2. 7.4.2 Auto PFM Mode
      3. 7.4.3 External Clock Synchronization
      4. 7.4.4 Down Mode
  9. 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 Programming the Output Voltage
        2. 8.2.2.2 Setting the Switching Frequency
        3. 8.2.2.3 Setting the Current Limit
        4. 8.2.2.4 Selecting the Inductor
        5. 8.2.2.5 Selecting the Output Capacitors
        6. 8.2.2.6 Selecting the Input Capacitors
        7. 8.2.2.7 Loop Stability and Compensation
          1. 8.2.2.7.1 Small Signal Model
          2. 8.2.2.7.2 Loop Compensation Design Steps
          3. 8.2.2.7.3 Selecting the Bootstrap Capacitor
          4. 8.2.2.7.4 VCC Capacitor
      3. 8.2.3 Application Curves
  10. 9 Power Supply Recommendations
  11. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  12. 11Device and Documentation Support
    1. 11.1 Device Support
      1. 11.1.1 サード・パーティ製品に関する免責事項
    2. 11.2 ドキュメントの更新通知を受け取る方法
    3. 11.3 サポート・リソース
    4. 11.4 Trademarks
    5. 11.5 用語集
    6. 11.6 静電気放電に関する注意事項
  13. 12Revision History
  14. 13Mechanical, Packaging, and Orderable Information

7.1 Overview

The TPS61378-Q1 is a fully-integrated synchronous boost converter with load disconnect function. It supports output voltage up to 18.5 V with a maximum of a 4.8-A programmable switching peak current limit. The input voltage ranges from 2.3 V to 14 V while consuming 25-µA quiescent current.

The TPS61378-Q1 utilizes the fixed-frequency peak current control scheme, which has an internal oscillator and supports adjustable switching frequency from 200 kHz to 2.2 MHz.

The TPS61378-Q1 operates with fixed-frequency pulse width modulation (PWM) from medium to heavy load. At the beginning of each switching cycle, the low-side N-MOSFET switch is turned on. The inductor current ramps up to a peak current that is determined by the output of the internal error amplifier (EA). Once the switching peak current triggers the output of the EA, the low-side N-MOSFET is turned off and the high-side N-MOSFET is turned on after a short dead time. The high-side N-MOSFET switch is not turned off until the next cycle as determined by the internal oscillator. The low-side switch turns on again after a short dead time and the switching cycle is repeated.

The TPS61378-Q1 provides either auto PFM or forced PWM for the light load operation by configuring the MODE/SYNC pin. In forced PWM mode, the switching frequency remains constant across the entire load range, which helps avoid frequency variation with load. The internal oscillator can be synchronized to an external clock applied on the MODE/SYNC pin. Spread spectrum modulation of the frequency in forced PWM mode helps optimize the EMI performance for automotive applications. In auto PFM mode, the switching frequency can decrease, resulting in higher efficiency.

The TPS61378-Q1 implements a cycle-by-cycle current limit to protect the device from overload during the boost operation phase. If the output current further increases and triggers the output voltage to fall below the input voltage, the TPS61378-Q1 enters into hiccup mode short protection.

There is a built-in soft-start time, which prevents the inrush current during the start-up. The TPS61378-Q1 also provides a power good (PG) indicator to enable the power sequence control for start-up.

The TPS61378-Q1 also has a number of protection features including output short protection, output overvoltage protection (OVP), and thermal shutdown protection (OTP).