TIDUEY9 April   2021

 

  1.   Description
  2.   Resources
  3.   Features
  4.   Applications
  5.   5
  6. 1System Description
  7. 2System Overview
    1. 2.1 Block Diagram
    2. 2.2 Design Considerations
    3. 2.3 Highlighted Products
      1. 2.3.1 LP8770
        1. 2.3.1.1 Safety Features
          1. 2.3.1.1.1 Window Watchdog
          2. 2.3.1.1.2 Voltage Monitoring
      2. 2.3.2 AWR1843/xWR6843 mmWave Sensor Solution
    4. 2.4 System Design
      1. 2.4.1 Hardware Block Diagram
      2. 2.4.2 Software Components
        1. 2.4.2.1 Secondary Bootloader (SBL)
        2. 2.4.2.2 mmWaveLink APIs
        3. 2.4.2.3 mmWave Safety Diagnostic Library (SDL)
        4. 2.4.2.4 mmWave SDK Software Block Diagram
  8. 3Hardware, Software, Testing Requirements, and Test Results
    1. 3.1 Hardware Requirements
    2. 3.2 Test Setup
    3. 3.3 Test Results
  9. 4Design and Documentation Support
    1. 4.1 Design Files
      1. 4.1.1 Schematics
      2. 4.1.2 BOM
    2. 4.2 Tools and Software
    3. 4.3 Documentation Support
    4. 4.4 Support Resources
    5. 4.5 Trademarks
  10. 5About the Author

2.3.1 LP8770

The LP87702-Q1 helps meet the power management requirements of the latest platforms, particularly in automotive radar and camera and industrial radar applications. The device contains two step-down DC/DC converters, and a 5-V boost converter/bypass switch. To support safety critical applications. the device integrates two voltage monitoring inputs for external power supplies, and a window watchdog.

LP8770 Features

  • AEC-Q100 Qualified for Automotive Applications:
    • Device Temperature Grade 1: –40°C to +125°C, TA
  • FMEDA and Functional Safety Manual available to support your ASIL compliant system designs
  • Two Inputs for External Voltage Monitoring
  • Two Programmable Power-Good Signals
  • Dedicated Reference Voltage for Diagnostics
  • Window Watchdog With Reset Output
  • External Clock Input to Synchronize Switching
  • Spread-Spectrum Modulation
  • Programmable Start-up and Shutdown Delays and Sequencing With Enable Signal
  • Two High-Efficiency Step-Down DC/DC converters:
    • Maximum Output Current 3.5 A
    • 2-MHz, 3-MHz, or 4-MHz Switching Frequency
    • Auto PWM/PFM and Forced-PWM Operations
    • Output Voltage = 0.7 V to 3.36 V
  • 5-V Boost Converter With Bypass-Mode Option:
    • Maximum Output Current 600 mA
  • Configurable General Purpose Outputs (GPOs)
  • I2C-Compatible Interface Supporting Standard (100 kHz), Fast (400 kHz), Fast+ (1 MHz), and High-Speed (3.4 MHz) Modes

LP87702-Q1 features include diagnostics, monitoring and protections for both device internal and system level operation:

  • Soft start
  • Input undervoltage lockout
  • Programmable undervoltage or window (over- and undervoltage) monitoring for the input (from VANA pin)
  • Programmable undervoltage or window (over- and undervoltage) monitoring for the buck and boost converter outputs
  • Two inputs (VMONx) with programmable undervoltage or window (over- and undervoltage) thresholds, for monitoring external rails in the system
  • One dedicated power-good output (PG0) to which selected monitoring signals can be combined
  • Second programmable power-good output (PG1), multiplexed with general purpose output (GPO1)
  • Power good flags with maskable interrupt
  • Programmable window watchdog
  • Buck and boost converter overload detection
  • Thermal warning with two selectable thresholds
  • Thermal shutdown