SNVSC24 April   2021 LP8758-EA

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  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 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. 11Device and Documentation Support
    1. 11.1 Device Support
    2. 11.2 Documentation Support
      1. 11.2.1 Related Documentation
    3. 11.3 Receiving Notification of Documentation Updates
    4. 11.4 Support Resources
    5. 11.5 Trademarks
    6. 11.6 Electrostatic Discharge Caution
    7. 11.7 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information

7.3.5 Diagnosis and Protection Features

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

  • Warnings for diagnosis which sets interrupt;
  • Protection events which are disabling one or more converter cores; and
  • Faults which are causing the device to shutdown.
When the device detects one or more warning or protection conditions, the LP8758-EA 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 7-2 Summary of Interrupt Signals
EVENTRESULTINTERRUPT REGISTER AND BITINTERRUPT MASKSTATUS BITRECOVERY / INTERRUPT CLEAR
Current limit triggered (20 µs debounce)No effectINT_TOP.INT_BUCKx = 1
INT_BUCKx.BUCKx_ILIM_INT = 1		BUCKx_MASK.BUCKx_ILIM_MASKBUCKx_STAT.BUCKx_ILIM_STATWrite 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 0.35 V during operation, 1 ms debounce)Converter core disableINT_TOP.INT_BUCKx = 1
INT_BUCK_0_1.BUCKx_SC_INT = 1
or INT_BUCK_2_3.BUCKx_SC_INT = 1		N/AN/AWrite 1 to INT_BUCK_0_1.BUCKx_SC_INT or
to INT_BUCK_2_3.BUCKx_SC_INTbit
Thermal WarningNo effectINT_TOP.TDIE_WARN = 1TOP_MASK.TDIE_WARN_MASKTOP_STAT.TDIE_WARN_STATWrite 1 to INT_TOP.TDIE_WARN bit
Interrupt is not cleared if temperature is above thermal warning level
Thermal ShutdownAll converter cores disabledINT_TOP.TDIE_SD = 1N/ATOP_STAT.TDIE_SD_STATWrite 1 to INT_TOP.TDIE_SD bit
Interrupt is not cleared if temperature is above thermal shutdown level
Powergood, output voltage reaches the programmed valueNo effectINT_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 readyNo effectINT_TOP.I_LOAD_READY = 1TOP_MASK.I_LOAD_READY_MASKN/AWrite 1 to INT_TOP.I_LOAD_READY bit
Start-up (NRST rising edge)Device ready for operation, registers reset to default valuesINT_TOP.RESET_REG = 1TOP_MASK.RESET_REG_MASKN/AWrite 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 valuesINT_TOP.RESET_REG = 1TOP_MASK.RESET_REG_MASKN/AWrite 1 to INT_TOP.RESET_REG bit
Software requested resetImmediate shutdown followed by powerup, registers reset to default valuesINT_TOP.RESET_REG = 1TOP_MASK.RESET_REG_MASKN/AWrite 1 to INT_TOP.RESET_REG bit