SNVSAL1C December   2017  – June 2021 LP87702-Q1

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Description (continued)
  6. 6 Pin Configuration and 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 Parameters
    7. 7.7 Typical Characteristics
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Descriptions
      1. 8.3.1  Step-Down DC/DC Converters
        1. 8.3.1.1 Overview
        2. 8.3.1.2 Transition Between PWM and PFM Modes
        3. 8.3.1.3 Buck Converter Load Current Measurement
      2. 8.3.2  Boost Converter
      3. 8.3.3  Spread-Spectrum Mode
      4. 8.3.4  Sync Clock Functionality
      5. 8.3.5  Power-Up
      6. 8.3.6  Buck and Boost Control
        1. 8.3.6.1 Enabling and Disabling Converters
        2. 8.3.6.2 Changing Buck Output Voltage
      7. 8.3.7  Enable and Disable Sequences
      8. 8.3.8  Window Watchdog
      9. 8.3.9  Device Reset Scenarios
      10. 8.3.10 Diagnostics and Protection Features
        1. 8.3.10.1 Voltage Monitorings
        2. 8.3.10.2 Interrupts
        3. 8.3.10.3 Power-Good Information to Interrupt, PG0, and PG1 Pins
          1. 8.3.10.3.1 PGx Pin Gated (Unusual) Mode
          2. 8.3.10.3.2 PGx Pin Operation in Continuous Mode
          3. 8.3.10.3.3 Summary of PG0, PG1 Gated, and Continuous Operating Modes
        4. 8.3.10.4 Warning Interrupts for System Level Diagnostics
          1. 8.3.10.4.1 Output Power Limit
          2. 8.3.10.4.2 Thermal Warning
        5. 8.3.10.5 Protections Causing Converter Disable
          1. 8.3.10.5.1 Short-Circuit and Overload Protection
          2. 8.3.10.5.2 Overvoltage Protection
          3. 8.3.10.5.3 Thermal Shutdown
        6. 8.3.10.6 Protections Causing Device Power Down
          1. 8.3.10.6.1 Undervoltage Lockout
      11. 8.3.11 OTP Error Correction
      12. 8.3.12 Operation of GPO Signals
      13. 8.3.13 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 LP8770_map Registers
  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 Buck Input Capacitor Selection
          3. 9.2.2.1.3 Buck Output Capacitor Selection
          4. 9.2.2.1.4 Boost Input Capacitor Selection
          5. 9.2.2.1.5 Boost Output Capacitor Selection
          6. 9.2.2.1.6 Supply Filtering Components
      3. 9.2.3 Current Limit vs Maximum Output Current
      4. 9.2.4 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 Third-Party Products Disclaimer
    2. 12.2 Receiving Notification of Documentation Updates
    3. 12.3 Support Resources
    4. 12.4 Trademarks
    5. 12.5 Electrostatic Discharge Caution
    6. 12.6 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

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

8.3.10 Diagnostics and Protection Features

The LP87702-Q1 provides four levels of protection features:

  • Input and output voltage information. Non-valid voltage sets interrupt or PGx signal:
    • Validity of the output voltage of BUCK or BOOST converters
    • Validity of VANA, VMON1, and VMON2 input voltages
  • Warnings causing interrupt:
    • Peak current limit detection in BUCK or BOOST converters
    • Thermal warning
  • Protection events which are disabling the converters:
    • Short-circuit and overload protection for BUCK and BOOST converters
    • Input overvoltage protection (VANAOVP)
    • Watchdog expiration (optional, depends on the watchdog settings)
    • Thermal shutdown
  • Protection events which are causing the device to shutdown:
    • Undervoltage lockout (VANAUVLO)
  • Protections not causing interrupt or converter disable:
    • Negative current limit detection in the BUCK or BOOST converters