JAJSNC5 april   2023 LM5171-Q1

ADVANCE INFORMATION  

  1. 1 特長
  2. 2 アプリケーション
  3. 3 概要
  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
    6. 6.6 Timing Requirements
    7. 6.7 Typical Characteristics
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1  Bias Supplies and Voltage Reference (VCC, VDD, and VREF)
      2. 7.3.2  Undervoltage Lockout (UVLO) and Controller Enable or Disable
      3. 7.3.3  High Voltage Inputs (HV1, HV2)
      4. 7.3.4  Current Sense Amplifier
      5. 7.3.5  Control Commands
        1. 7.3.5.1 Channel Enable Commands (EN1, EN2)
        2. 7.3.5.2 Direction Command (DIR1 and DIR2)
        3. 7.3.5.3 Channel Current Setting Commands (ISET1 and ISET2)
      6. 7.3.6  Channel Current Monitor (IMON1, IMON2)
        1. 7.3.6.1 Individual Channel Current Monitor
        2. 7.3.6.2 Multiphase Total Current Monitoring
      7. 7.3.7  Cycle-by-Cycle Peak Current Limit (IPK)
      8. 7.3.8  Inner Current Loop Error Amplifier
      9. 7.3.9  Outer Voltage Loop Error Amplifier
      10. 7.3.10 Soft Start, Diode Emulation, and Forced PWM Control (SS/DEM1 and SS/DEM2)
        1. 7.3.10.1 Soft-Start Control by the SS/DEM Pins
        2. 7.3.10.2 DEM Programming
        3. 7.3.10.3 FPWM Programming and Dynamic FPWM and DEM Change
        4. 7.3.10.4 SS Pin as the Restart Timer
      11. 7.3.11 Gate Drive Outputs, Dead Time Programming and Adaptive Dead Time (HO1, HO2, LO1, LO2, DT/SD)
      12. 7.3.12 Emergent Latched Shutdown (DT/SD)
      13. 7.3.13 PWM Comparator
      14. 7.3.14 Oscillator (OSC)
      15. 7.3.15 Synchronization to an External Clock (SYNCI, SYNCO)
      16. 7.3.16 Overvoltage Protection (OVP)
      17. 7.3.17 Multiphase Configurations (SYNCO, OPT)
        1. 7.3.17.1 Multiphase in Star Configuration
        2. 7.3.17.2 Daisy-Chain Configurations for 2, 3, or 4 Phases parallel operations
        3. 7.3.17.3 Daisy-Chain configuration for 6 or 8 phases parallel operation
      18. 7.3.18 Thermal Shutdown
    4. 7.4 Programming
      1. 7.4.1 Dynamic Dead Time Adjustment
      2. 7.4.2 UVLO Programming
    5. 7.5 I2C Serial Interface
      1. 7.5.1 REGFIELD Registers
  8. 8 Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1 Small Signal Model
        1. 8.1.1.1 Current Loop Small Signal Model
        2. 8.1.1.2 Current Loop Compensation
        3. 8.1.1.3 Voltage Loop Small Signal Model
        4. 8.1.1.4 Voltage Loop Compensation
    2. 8.2 Typical Application
      1. 8.2.1 60-A, Dual-Phase, 48-V to 12-V Bidirectional Converter
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
          1. 8.2.1.2.1  Determining the Duty Cycle
          2. 8.2.1.2.2  Oscillator Programming
          3. 8.2.1.2.3  Power Inductor, RMS and Peak Currents
          4. 8.2.1.2.4  Current Sense (RCS)
          5. 8.2.1.2.5  Current Setting Limits (ISETx)
          6. 8.2.1.2.6  Peak Current Limit
          7. 8.2.1.2.7  Power MOSFETS
          8. 8.2.1.2.8  Bias Supply
          9. 8.2.1.2.9  Boot Strap
          10. 8.2.1.2.10 OVP
          11. 8.2.1.2.11 Dead Time
          12. 8.2.1.2.12 Channel Current Monitor (IMONx)
          13. 8.2.1.2.13 UVLO Pin Usage
          14. 8.2.1.2.14 HVx Pin Configuration
          15. 8.2.1.2.15 Loop Compensation
          16. 8.2.1.2.16 Soft Start
          17. 8.2.1.2.17 PWM to ISET Pins
        3. 8.2.1.3 Application Curves
    3. 8.3 Power Supply Recommendations
    4. 8.4 Layout
      1. 8.4.1 Layout Guidelines
      2. 8.4.2 Layout Examples
  9. 9 Device and Documentation Support
    1. 9.1 Device Support
      1. 9.1.1 Development Support
    2. 9.2 ドキュメントの更新通知を受け取る方法
    3. 9.3 サポート・リソース
    4. 9.4 Trademarks
    5. 9.5 静電気放電に関する注意事項
    6. 9.6 用語集
  10. 10Mechanical, 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

7.3.10.4 SS Pin as the Restart Timer

The SS pin also fulfills the function of a restart timer in an OVP event or following a DIR command change:

(1) Restart Timer in OVP: When OVP catches an overvoltage event (refer to Section 7.3.16), CSS1 of CH-1 is discharged immediately by the internal pulldown FET, and this FET remains ON as long as the overvoltage condition persists. When the overvoltage condition is removed and after the SS/DEM1 voltage is discharged to below 0.3 V, the pulldown is released, setting off a new soft-start cycle. The circuit may run in retry or hiccup mode if the overvoltage condition reappears. The retry frequency is determined by the CSS1 as well as the nature of the overvoltage condition.

Note that OVP only affects SS/DEM1 but not SS/DEM2. For multiphase parallel operation, connect SS/DEM1 and SS/DEM2 to enable the same hiccup mode in CH-2 as shown in Figure 7-12. For independent channel operation, an external OVP protection circuit is needed for CH-2, and that circuit must be configured to discharge SS/DEM2 to achieve OVP and also the hiccup mode operation. Figure 7-19 shows an example of such an external OVP implementation for CH-2. See Figure 7-22 and Figure 7-23 for other examples.

GUID-20230329-SS0I-RTJF-DDV8-RRPHQBS61DNQ-low.svg Figure 7-12 OVP Implementation for SS-DEM Pins Connection for Parallel Operation
GUID-20230329-SS0I-7XLQ-VKSF-XQTD2NJBDRP6-low.svg Figure 7-13 OVP Implementation for Independent Channel Operation

(2) Restart Timer after a DIR Change: When DIR dynamically flips its state from 0 to 1, or 1 to 0 during operation, CSS is first discharged to 0.3 V by the internal pulldown FET, then the pulldown is released to set off a new soft-start cycle to gradually build up the channel current in the new direction. In this way, the channel current overshoot is eliminated.

For independent channel operation, DIR1 and DIR2 can be independently controlled. For multiphase parallel operation, DIR1 and DIR2 must be tied together, and the user may also consider tying the SS/DEM1 and SS/DEM2 together.