SNVSA06C March   2015  – August 2018 LP8758-B0

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Simplified Schematic
    1.     Efficiency vs Output Current (VIN = 3.7 V)
  5. 5 Revision History
  6. 6 Pin Configuration and Functions
    1.     Pin 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 I2C Serial Bus Timing Parameter
    7. 7.7 Switching Characteristics
    8. 7.8 Typical Characteristics
  8. 8 Detailed Description
    1. 8.1 Overview
      1. 8.1.1 Buck Information
        1. 8.1.1.1 Operating Modes
        2. 8.1.1.2 Features
        3. 8.1.1.3 Programmability
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Multi-Phase DC-DC Converters
        1. 8.3.1.1 Overview
        2. 8.3.1.2 Multi-Phase Operation and Phase Adding/Shedding
        3. 8.3.1.3 Transition Between PWM and PFM Modes
        4. 8.3.1.4 Multi-Phase Switcher Configurations
        5. 8.3.1.5 Buck Converter Load Current Measurement
        6. 8.3.1.6 Spread-Spectrum Mode
      2. 8.3.2 Power-Up
      3. 8.3.3 Regulator Control
        1. 8.3.3.1 Enabling and Disabling Regulator
        2. 8.3.3.2 Changing Output Voltage
      4. 8.3.4 Device Reset Scenarios
      5. 8.3.5 Diagnosis and Protection Features
        1. 8.3.5.1 Warnings for Diagnosis (Interrupt)
          1. 8.3.5.1.1 Output Current Limit
          2. 8.3.5.1.2 Thermal Warning
        2. 8.3.5.2 Protection (Regulator Disable)
          1. 8.3.5.2.1 Short-Circuit and Overload Protection
          2. 8.3.5.2.2 Thermal Shutdown
        3. 8.3.5.3 Fault (Power Down)
          1. 8.3.5.3.1 Undervoltage Lockout
      6. 8.3.6 Digital Signal Filtering
    4. 8.4 Device Functional Modes
      1. 8.4.1 Modes of Operation
    5. 8.5 Programming
      1. 8.5.1 I2C-Compatible Interface
        1. 8.5.1.1 Data Validity
        2. 8.5.1.2 Start and Stop Conditions
        3. 8.5.1.3 Transferring Data
        4. 8.5.1.4 I2C-Compatible Chip Address
        5. 8.5.1.5 Auto Increment Feature
    6. 8.6 Register Maps
      1. 8.6.1 Register Descriptions
        1. 8.6.1.1  DEV_REV
        2. 8.6.1.2  OTP_REV
        3. 8.6.1.3  BUCK0_CTRL1
        4. 8.6.1.4  BUCK0_CTRL2
        5. 8.6.1.5  BUCK1_CTRL2
        6. 8.6.1.6  BUCK2_CTRL2
        7. 8.6.1.7  BUCK3_CTRL2
        8. 8.6.1.8  BUCK0_VOUT
        9. 8.6.1.9  BUCK0_FLOOR_VOUT
        10. 8.6.1.10 BUCK0_DELAY
        11. 8.6.1.11 RESET
        12. 8.6.1.12 CONFIG
        13. 8.6.1.13 INT_TOP
        14. 8.6.1.14 INT_BUCK_0_1
        15. 8.6.1.15 INT_BUCK_2_3
        16. 8.6.1.16 TOP_STAT
        17. 8.6.1.17 BUCK_0_1_STAT
        18. 8.6.1.18 BUCK_2_3_STAT
        19. 8.6.1.19 TOP_MASK
        20. 8.6.1.20 BUCK_0_1_MASK
        21. 8.6.1.21 BUCK_2_3_MASK
        22. 8.6.1.22 SEL_I_LOAD
        23. 8.6.1.23 I_LOAD_2
        24. 8.6.1.24 I_LOAD_1
  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 Application Components
          1. 9.2.2.1.1 Inductor Selection
          2. 9.2.2.1.2 Input Capacitor Selection
          3. 9.2.2.1.3 Output Capacitor Selection
      3. 9.2.3 Application Curves
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Device Support
      1. 12.1.1 Third-Party Products Disclaimer
    2. 12.2 Documentation Support
      1. 12.2.1 Related Documentation
    3. 12.3 Receiving Notification of Documentation Updates
    4. 12.4 Community Resources
    5. 12.5 Trademarks
    6. 12.6 Electrostatic Discharge Caution
    7. 12.7 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

8.5.1.3 Transferring Data

Every byte put on the SDA line must be eight bits long, with the most significant bit (MSB) being transferred first. Each byte of data has to be followed by an acknowledge bit. The acknowledge related clock pulse is generated by the master. The master releases the SDA line (HIGH) during the acknowledge clock pulse. The LP8758 pulls down the SDA line during the 9th clock pulse, signifying an acknowledge. The LP8758 generates an acknowledge after each byte has been received.

There is one exception to the “acknowledge after every byte” rule. When the master is the receiver, it must indicate to the transmitter an end of data by not-acknowledging (“negative acknowledge”) the last byte clocked out of the slave. This “negative acknowledge” still includes the acknowledge clock pulse (generated by the master), but the SDA line is not pulled down.

NOTE

If the NRST signal is low during I2C communication the LP8758 device does not drive SDA line. The ACK signal and data transfer to the master is disabled at that time.

After the START condition, the bus master sends a chip address. This address is seven bits long followed by an eighth bit which is a data direction bit (READ or WRITE). For the eighth bit, a “0” indicates a WRITE and a “1” indicates a READ. The second byte selects the register to which the data will be written. The third byte contains data to write to the selected register.

LP8758-B0 30190622.gifFigure 18. Write Cycle (w = write; SDA = '0'), id = Device Address = 60Hex for LP8758
LP8758-B0 30190623.gif
When READ function is to be accomplished, a WRITE function must precede the READ function as shown above.
Figure 19. Read Cycle ( r = read; SDA = '1'), id = Device Address = 60Hex for LP8758