JAJSG84B January   2016  – June 2018 LP8758-E0

PRODUCTION DATA.  

  1. 1 特長
  2. 2 アプリケーション
  3. 3 概要
    1.     Device Images
      1.      概略回路図
      2.      効率と出力電流との関係
  4. 4 改訂履歴
  5. 5 Pin Configuration and Functions
    1.     Pin 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 I2C Serial Bus Timing Requirements
    7. 6.7 Switching Characteristics
    8. 6.8 Typical Characteristics
  7. 7 Detailed Description
    1. 7.1 Overview
      1. 7.1.1 Buck Information
        1. 7.1.1.1 Operating Modes
        2. 7.1.1.2 Programmability
        3. 7.1.1.3 Features
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Overview
        1. 7.3.1.1 Transition between PWM and PFM Modes
        2. 7.3.1.2 Buck Converter Load Current Measurement
        3. 7.3.1.3 Spread-Spectrum Mode
      2. 7.3.2 Power-Up
      3. 7.3.3 Regulator Control
        1. 7.3.3.1 Enabling and Disabling
        2. 7.3.3.2 Changing Output Voltage
      4. 7.3.4 Device Reset Scenarios
      5. 7.3.5 Diagnosis and Protection Features
        1. 7.3.5.1 Warnings for Diagnosis (Interrupt)
          1. 7.3.5.1.1 Output Current Limit
          2. 7.3.5.1.2 Thermal Warning
        2. 7.3.5.2 Protection (Regulator Disable)
          1. 7.3.5.2.1 Short-Circuit and Overload Protection
          2. 7.3.5.2.2 Thermal Shutdown
        3. 7.3.5.3 Fault (Power Down)
          1. 7.3.5.3.1 Undervoltage Lockout
      6. 7.3.6 Digital Signal Filtering
    4. 7.4 Device Functional Modes
      1. 7.4.1 Modes of Operation
    5. 7.5 Programming
      1. 7.5.1 I2C-Compatible Interface
        1. 7.5.1.1 Data Validity
        2. 7.5.1.2 Start and Stop Conditions
        3. 7.5.1.3 Transferring Data
        4. 7.5.1.4 I2C-Compatible Chip Address
        5. 7.5.1.5 Auto Increment Feature
    6. 7.6 Register Maps
      1. 7.6.1 Register Descriptions
        1. 7.6.1.1  OTP_REV
        2. 7.6.1.2  BUCK0_CTRL1
        3. 7.6.1.3  BUCK0_CTRL2
        4. 7.6.1.4  BUCK1_CTRL1
        5. 7.6.1.5  BUCK1_CTRL2
        6. 7.6.1.6  BUCK2_CTRL1
        7. 7.6.1.7  BUCK2_CTRL2
        8. 7.6.1.8  BUCK3_CTRL1
        9. 7.6.1.9  BUCK3_CTRL2
        10. 7.6.1.10 BUCK0_VOUT
        11. 7.6.1.11 BUCK0_FLOOR_VOUT
        12. 7.6.1.12 BUCK1_VOUT
        13. 7.6.1.13 BUCK1_FLOOR_VOUT
        14. 7.6.1.14 BUCK2_VOUT
        15. 7.6.1.15 BUCK2_FLOOR_VOUT
        16. 7.6.1.16 BUCK3_VOUT
        17. 7.6.1.17 BUCK3_FLOOR_VOUT
        18. 7.6.1.18 BUCK0_DELAY
        19. 7.6.1.19 BUCK1_DELAY
        20. 7.6.1.20 BUCK2_DELAY
        21. 7.6.1.21 BUCK3_DELAY
        22. 7.6.1.22 RESET
        23. 7.6.1.23 CONFIG
        24. 7.6.1.24 INT_TOP
        25. 7.6.1.25 INT_BUCK_0_1
        26. 7.6.1.26 INT_BUCK_2_3
        27. 7.6.1.27 TOP_STAT
        28. 7.6.1.28 BUCK_0_1_STAT
        29. 7.6.1.29 BUCK_2_3_STAT
        30. 7.6.1.30 TOP_MASK
        31. 7.6.1.31 BUCK_0_1_MASK
        32. 7.6.1.32 BUCK_2_3_MASK
        33. 7.6.1.33 SEL_I_LOAD
        34. 7.6.1.34 I_LOAD_2
        35. 7.6.1.35 I_LOAD_1
  8. 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 Application Components
          1. 8.2.2.1.1 Inductor Selection
          2. 8.2.2.1.2 Input Capacitor Selection
          3. 8.2.2.1.3 Output Capacitor Selection
      3. 8.2.3 Application Curves
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11デバイスおよびドキュメントのサポート
    1. 11.1 デバイス・サポート
      1. 11.1.1 デベロッパー・ネットワークの製品に関する免責事項
    2. 11.2 ドキュメントのサポート
      1. 11.2.1 関連資料
    3. 11.3 ドキュメントの更新通知を受け取る方法
    4. 11.4 コミュニティ・リソース
    5. 11.5 商標
    6. 11.6 静電気放電に関する注意事項
    7. 11.7 Glossary
  12. 12メカニカル、パッケージ、および注文情報

7.3.5 Diagnosis and Protection Features

The LP8758-E0 is capable of providing three levels of protection features:

  • Warnings for diagnosis which sets interrupt;
  • Protection events which are disabling converter core(s); and
  • Faults which are causing the device to shutdown.
When the device detects warning or protection condition(s), the LP8758-E0 sets the flag bits indicating what protection or warning conditions have occurred, and the nINT pin is pulled low. nINT is released again after a clear of flags is complete. The nINT signal stays low until all the pending interrupts are cleared.

When a fault is detected, it is indicated by a INT_TOP.RESET_REG interrupt flag after next start-up.

Table 3. Summary of Interrupt Signals

EVENT RESULT INTERRUPT REGISTER AND BIT INTERRUPT MASK STATUS BIT RECOVERY / INTERRUPT CLEAR
Current limit triggered (20 µs debounce) No effect INT_TOP.INT_BUCKx = 1
INT_BUCKx.BUCKx_ILIM_INT = 1		 BUCKx_MASK.BUCKx_ILIM_MASK BUCKx_STAT.BUCKx_ILIM_STAT Write 1 to INT_BUCKx.BUCKx_ILIM_INT bit
Interrupt is not cleared if current limit is active
Short circuit (VOUT < 0.35 V at 1 ms after enable) or Overload (VOUT decreasing below 0.35V during operation, 1 ms debounce) Converter core disable INT_TOP.INT_BUCKx = 1
INT_BUCK_0_1.BUCKx_SC_INT = 1
or INT_BUCK_2_3.BUCKx_SC_INT = 1		 N/A N/A Write 1 to INT_BUCK_0_1.BUCKx_SC_INT or
to INT_BUCK_2_3.BUCKx_SC_INTbit
Thermal Warning No effect INT_TOP.TDIE_WARN = 1 TOP_MASK.TDIE_WARN_MASK TOP_STAT.TDIE_WARN_STAT Write 1 to INT_TOP.TDIE_WARN bit
Interrupt is not cleared if temperature is above thermal warning level
Thermal Shutdown All converter cores disabled INT_TOP.TDIE_SD = 1 N/A TOP_STAT.TDIE_SD_STAT Write 1 to INT_TOP.TDIE_SD bit
Interrupt is not cleared if temperature is above thermal shutdown level
Powergood, output voltage reaches the programmed value No effect INT_TOP.INT_BUCKx = 1
INT_BUCK_0_1.BUCKx_PG_INT = 1
or INT_BUCK_2_3.BUCKx_PG_INT = 1		 BUCK_0_1_MASK.BUCKx_PG_MASK
BUCK_2_3_MASK.BUCKx_PG_MASK		 BUCK_0_1_STAT.BUCKx_PG_STAT
BUCK_2_3_STAT.BUCKx_PG_STAT		 Write 1 to INT_BUCK_0_1.BUCKx_PG_INT bit
or to INT_BUCK_2_3.BUCKx_PG_INT bit
Load current measurement ready No effect INT_TOP.I_LOAD_READY = 1 TOP_MASK.I_LOAD_READY_MASK N/A Write 1 to INT_TOP.I_LOAD_READY bit
Start-up (NRST rising edge) Device ready for operation, registers reset to default values INT_TOP.RESET_REG = 1 TOP_MASK.RESET_REG_MASK N/A Write 1 to INT_TOP.RESET_REG bit
Glitch on supply voltage and UVLO triggered (VANA falling and rising) Immediate shutdown followed by powerup, registers reset to default values INT_TOP.RESET_REG = 1 TOP_MASK.RESET_REG_MASK N/A Write 1 to INT_TOP.RESET_REG bit
Software requested reset Immediate shutdown followed by powerup, registers reset to default values INT_TOP.RESET_REG = 1 TOP_MASK.RESET_REG_MASK N/A Write 1 to INT_TOP.RESET_REG bit