ZHCSTC5A October   2023  – March 2024 LM51772

ADVANCE INFORMATION  

  1.   1
  2. 1 特性
  3. 2 应用
  4. 3 说明
  5. 4 说明（续）
  6. 5 Pin Configuration and Functions
  7. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 Handling 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
  8. 7 Parameter Measurement Information
  9. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1  Buck-Boost Control Scheme
        1. 8.3.1.1 Buck Mode
        2. 8.3.1.2 Boost Mode
        3. 8.3.1.3 Buck-Boost Mode
      2. 8.3.2  Power Save Mode
      3. 8.3.3  Programmable Conduction Mode PCM
      4. 8.3.4  Reference System
        1. 8.3.4.1 VIO LDO and nRST-PIN
      5. 8.3.5  Supply Voltage Selection – VMAX Switch and Selection Logic
      6. 8.3.6  Enable and Undervoltage Lockout
        1. 8.3.6.1 UVLO
        2. 8.3.6.2 VDET Comparator
      7. 8.3.7  Internal VCC Regulator
        1. 8.3.7.1 VCC1 Regulator
        2. 8.3.7.2 VCC2 Regulator
      8. 8.3.8  Error Amplifier and Control
        1. 8.3.8.1 Output Voltage Regulation
        2. 8.3.8.2 Internal Output Voltage Regulation
        3. 8.3.8.3 Dynamic Voltage Scaling
      9. 8.3.9  Short Circuit - Hiccup Protection
      10. 8.3.10 Current Monitor/Limiter
        1. 8.3.10.1 Overview
        2. 8.3.10.2 Output Current Limitation
        3. 8.3.10.3 Output Current Monitor
      11. 8.3.11 Oscillator Frequency Selection
      12. 8.3.12 Frequency Synchronization
      13. 8.3.13 Output Voltage Tracking
        1. 8.3.13.1 Analog Voltage Tracking
        2. 8.3.13.2 Digital Voltage Tracking
      14. 8.3.14 Slope Compensation
      15. 8.3.15 Configurable Soft Start
      16. 8.3.16 Drive Pin
      17. 8.3.17 Dual Random Spread Spectrum – DRSS
      18. 8.3.18 Gate Driver
      19. 8.3.19 Cable Drop Compensation (CDC)
      20. 8.3.20 CFG-pin and R2D Interface
      21. 8.3.21 Advanced Monitoring Features
        1. 8.3.21.1  Overview
        2. 8.3.21.2  BUSY
        3. 8.3.21.3  OFF
        4. 8.3.21.4  VOUT
        5. 8.3.21.5  IOUT
        6. 8.3.21.6  INPUT
        7. 8.3.21.7  TEMPERATURE
        8. 8.3.21.8  CML
        9. 8.3.21.9  OTHER
        10. 8.3.21.10 ILIM_OP
        11. 8.3.21.11 nFLT/nINT Pin Output
        12. 8.3.21.12 Status Byte
      22. 8.3.22 Protection Features
        1. 8.3.22.1  Thermal Shutdown (TSD)
        2. 8.3.22.2  Over Current Protection
        3. 8.3.22.3  Output Over Voltage Protection 1 (OVP1)
        4. 8.3.22.4  Output Over Voltage Protection 2 (OVP2)
        5. 8.3.22.5  Input Voltage Protection (IVP)
        6. 8.3.22.6  Input Voltage Regulation (IVR)
        7. 8.3.22.7  Power Good
        8. 8.3.22.8  Boot-Strap Under Voltage Protection
        9. 8.3.22.9  Boot-strap Over Voltage Clamp
        10. 8.3.22.10 CRC - CHECK
    4. 8.4 Device Functional Modes
      1. 8.4.1 Overview
      2. 8.4.2 Logic State Description
    5. 8.5 Programming
      1. 8.5.1 I2C Bus Operation
      2. 8.5.2 Clock Stretching
      3. 8.5.3 Data Transfer Formats
      4. 8.5.4 Single READ from a Defined Register Address
      5. 8.5.5 Sequential READ Starting from a Defined Register Address
      6. 8.5.6 Single WRITE to a Defined Register Address
      7. 8.5.7 Sequential WRITE Starting at a Defined Register Address
  10. 9 LM51772 Registers
  11. 10Application and Implementation
    1. 10.1 Application Information
    2. 10.2 Typical Application
      1. 10.2.1 Design Requirements
      2. 10.2.2 Detailed Design Procedure
        1. 10.2.2.1  Custom Design with WEBENCH Tools
        2. 10.2.2.2  Frequency
        3. 10.2.2.3  Feedback Divider
        4. 10.2.2.4  Inductor and Current Sense Resistor Selection
        5. 10.2.2.5  Output Capacitor
        6. 10.2.2.6  Input Capacitor
        7. 10.2.2.7  Slope Compensation
        8. 10.2.2.8  UVLO Divider
        9. 10.2.2.9  Soft-Start Capacitor
        10. 10.2.2.10 MOSFETs QH1 and QL1
        11. 10.2.2.11 MOSFETs QH2 and QL2
        12. 10.2.2.12 Loop Compensation
        13. 10.2.2.13 External Component Selection
      3. 10.2.3 Application Curves
    3. 10.3 Power Supply Recommendations
    4. 10.4 Layout
      1. 10.4.1 Layout Guidelines
        1. 10.4.1.1 Power Stage Layout
        2. 10.4.1.2 Gate Driver Layout
        3. 10.4.1.3 Controller Layout
      2. 10.4.2 Layout Example
  12. 11Device and Documentation Support
    1. 11.1 Documentation Support
      1. 11.1.1 Related Documentation
    2. 11.2 接收文档更新通知
    3. 11.3 支持资源
    4. 11.4 Trademarks
    5. 11.5 静电放电警告
    6. 11.6 术语表
  13. 12Revision History
  14. 13Mechanical, Packaging, and Orderable Information

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订购信息

8.3.20 CFG-pin and R2D Interface

The LM51772 has four register to digital channels, where the CFG1 is allocated to the ADDR/SLOPE -pin. The channels CFG3 and CFG4 are ultiplexed with the SDA/SCL pins.

The resistor selection on the CFG pins is read and latched during the power-up sequence of the device. The selection cannot be changed until the voltage on the EN or UVLO reaches the falling threshold or VCC voltage drops below the VCCT-(UVLO) threshold. The Table 8-4 shows the possible device configurations versus the different resistor values on the CFG pins.

Table 8-4 ADDR/Slope Pin (R2D-CH1) Configuration Overview
# R(CFG) / kΩ I2C/ADDR Slope Compensation
1 GND I2C ENABLED Address 0x6A Default NVM setting 0.875
2 0.511 I2C DISABLED 0.25
3 1.15 0.375
4 1.9 0.5
5 2.7 0.625
6 3.8 0.75
7 5.1 0.875
8 6.5 1
9 8.3 1.5
10 10.5 2
11 13.3 2.5
12 16.2 3
13 20.5 3.5
14 24.9 4
15 30.1 4.5
16 VCC2 I2C ENABLED Address 0x6B Default NVM setting 0.875
Table 8-5 CFG2 Pin (R2D-CH2) Configuration Overview
# R(CFG) / kΩ EN_SYNC_OUT SYNC_IN_FALLING VDET_EN PCM_EN
1 0 DISABLED DISABLED DISABLED DISABLE
2 0.511 ENABLED
3 1.15 DISABLED ENABLED
4 1.9 ENABLED
5 2.7 DISABLED DISABLED ENABLED
6 3.8 ENABLED
7 5.1 DISABLED ENABLED
8 6.5 ENABLED
9 8.3 DISABLED DISABLED DISABLED ENABLED
10 10.5 ENABLED
11 13.3 DISABLED ENABLED
12 16.2 ENABLED
13 20.5 DISABLED DISABLED ENABLED
14 24.9 ENABLED
15 30.1 DISABLED ENABLED
16 36.5 ENABLED
Table 8-6 CFG3 Pin (R2D-CH3) Configuration Overview
# R(CFG) / kΩ EN_VCC1 INC_INDUCT_De-Rate μSLEEP SCALE_DT
1 0 DISABLED DISABLED DISABLED DISABLE
2 0.511 ENABLED
3 1.15 DISABLED ENABLED
4 1.9 ENABLED
5 2.7 DISABLED DISABLED ENABLED
6 3.8 ENABLED
7 5.1 DISABLED ENABLED
8 6.5 ENABLED
9 8.3 DISABLED DISABLED DISABLED ENABLED
10 10.5 ENABLED
11 13.3 DISABLED ENABLED
12 16.2 ENABLED
13 20.5 DISABLED DISABLED ENABLED
14 24.9 ENABLED
15 30.1 DISABLED ENABLED
16 36.5 ENABLED
Table 8-7 CFG4 Pin (R2D-CH4) Configuration Overview
# R(CFG) / kΩ DRSS SCP – Hiccup Mode Negative Current Limit Current Limit
1 0 DISABLED DISABLED DISABLED DISABLE
2 0.511 ENABLED
3 1.15 DISABLED ENABLED
4 1.9 ENABLED
5 2.7 DISABLED DISABLED ENABLED
6 3.8 ENABLED
7 5.1 DISABLED ENABLED
8 6.5 ENABLED
9 8.3 DISABLED DISABLED DISABLED ENABLED
10 10.5 ENABLED
11 13.3 DISABLED ENABLED
12 16.2 ENABLED
13 20.5 DISABLED DISABLED ENABLED
14 24.9 ENABLED
15 30.1 DISABLED ENABLED
16 36.5 ENABLED