SPRAD21F May   2022  – November 2024 AM620-Q1 , AM623 , AM625 , AM625-Q1 , AM625SIP , AM62A3 , AM62A3-Q1 , AM62A7 , AM62A7-Q1 , AM62P , AM62P-Q1

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1 Introduction
    1. 1.1 Application Note Usage Guidelines
      1. 1.1.1 Schematics Design Guidelines
      2. 1.1.2 Schematic Review Checklist
      3. 1.1.3 FAQ Reference for Application Note Usage Guidelines
    2. 1.2 AM62x Processor Family
      1. 1.2.1 AM625
      2. 1.2.2 AM623
      3. 1.2.3 AM625SIP
      4. 1.2.4 AM625-Q1
      5. 1.2.5 AM620-Q1
    3. 1.3 AM62Ax Processor Family
      1. 1.3.1 AM62A7
      2. 1.3.2 AM62A7-Q1
      3. 1.3.3 AM62A3
      4. 1.3.4 AM62A3-Q1
    4. 1.4 AM62Px Processor Family
      1. 1.4.1 AM62P
      2. 1.4.2 AM62P-Q1
  5. 2 Related Collaterals
    1. 2.1 Links to Commonly Available and Applicable Collaterals
      1. 2.1.1 AM625 / AM623 / AM625SIP / AM625-Q1 / AM620-Q1
      2. 2.1.2 AM62A7 / AM62A3 / AM62A7-Q1 / AM62A3-Q1
      3. 2.1.3 AM62P / AM62P-Q1
    2. 2.2 Hardware Design Considerations for Custom Board
      1. 2.2.1 AM625 / AM623 / AM625SIP / AM625-Q1 / AM620-Q1
      2. 2.2.2 AM62A7 / AM62A3 / AM62A7-Q1 / AM62A3-Q1
      3. 2.2.3 AM62P / AM62P-Q1
  6. 3 Processor Selection
    1. 3.1 Data Sheet Use Case and Version References in the Application Note
    2. 3.2 Device Selection and OPN
    3. 3.3 Peripheral Instance Naming Convention
    4. 3.4 Unused Peripherals
    5. 3.5 Device Ordering and Quality
    6. 3.6 Processor Selection Checklist
  7. 4 Power Architecture
    1. 4.1 Generating Supply Rails
      1. 4.1.1 AM625 / AM623 / AM625SIP / AM625-Q1 / AM620-Q1
        1. 4.1.1.1 Power Management IC (PMIC)
          1. 4.1.1.1.1 PMIC Checklist
          2. 4.1.1.1.2 Additional References
        2. 4.1.1.2 Discrete Power
          1. 4.1.1.2.1 DC/DC Converter
          2. 4.1.1.2.2 LDO
          3. 4.1.1.2.3 Discrete Power Checklist
      2. 4.1.2 AM62A7 / AM62A3 / AM62A7-Q1 / AM62A3-Q1
        1. 4.1.2.1 PMIC
          1. 4.1.2.1.1 PMIC Checklist
        2. 4.1.2.2 Discrete Power
          1. 4.1.2.2.1 Discrete Power Checklist
      3. 4.1.3 AM62P / AM62P-Q1
        1. 4.1.3.1 PMIC
          1. 4.1.3.1.1 PMIC Checklist
        2. 4.1.3.2 Discrete Power
          1. 4.1.3.2.1 Discrete Power Checklist
    2. 4.2 Power Control and Circuit Protection
      1. 4.2.1 Load Switch (Power Switching)
        1. 4.2.1.1 Load Switch Checklist
      2. 4.2.2 eFuse IC (Power Switching and Protection)
  8. 5 General Recommendations
    1. 5.1 Processor Performance Evaluation Module (SK - Starter Kit)
      1. 5.1.1 Evaluation Module Checklist
    2. 5.2 Device-Specific (Processor-Specific, Processor-Family Specific) SK Versus Data Sheet
      1. 5.2.1 Notes About Component Selection
        1. 5.2.1.1 Series Resistor
        2. 5.2.1.2 Parallel Pull Resistor
        3. 5.2.1.3 Drive Strength Configuration
        4. 5.2.1.4 Data Sheet Recommendations
        5. 5.2.1.5 Processor IOs - External ESD Protection
        6. 5.2.1.6 Peripheral Clock Output Series Resistors
        7. 5.2.1.7 Component Selection Checklist
      2. 5.2.2 Additional Information Regarding Reuse of SK Design
        1. 5.2.2.1 Updated SK Schematic With Design, Review and CAD Notes Added
          1. 5.2.2.1.1 AM625 / AM623
          2. 5.2.2.1.2 AM625-Q1 / AM620-Q1
          3. 5.2.2.1.3 AM625SIP
          4. 5.2.2.1.4 AM62A7 / AM62A3 / AM62A7-Q1 / AM62A3-Q1
          5. 5.2.2.1.5 AM62P / AM62P-Q1
        2. 5.2.2.2 SK Design Files Reuse
          1. 5.2.2.2.1 Reuse of SK Design Checklist
    3. 5.3 Before Beginning the Design
      1. 5.3.1  Documentation
      2. 5.3.2  Processor Pin Attributes (Pinout) Verification
      3. 5.3.3  Device Comparison and IOSET
      4. 5.3.4  RSVD Reserved Pins (Signals)
      5. 5.3.5  Note on PADCONFIG Registers
      6. 5.3.6  Processor IO (Signal) Isolation for Fail-Safe Operation
      7. 5.3.7  Reference to Device-Specific SK
      8. 5.3.8  High-Speed Interface Design Guidelines
      9. 5.3.9  Recommended Current Source or Sink for LVCMOS (GPIO) Outputs
      10. 5.3.10 Connection of Slow Ramp Inputs or Capacitors to LVCMOS IOs (Inputs or Outputs)
      11. 5.3.11 Queries and Clarifications Related to Processor During Custom Board Design
      12. 5.3.12 Before Beginning the Design
      13. 5.3.13 Device Recommendations
  9. 6 Processor-Specific Recommendations
    1. 6.1 Common (Processor Start-Up) Connection
      1. 6.1.1 Power Supply
        1. 6.1.1.1 Supply for Core and Peripherals
          1. 6.1.1.1.1 AM625 / AM623 / AM625SIP / AM625-Q1 / AM620-Q1 and AM62A7 / AM62A3 / AM62A7-Q1 / AM62A3-Q1
          2. 6.1.1.1.2 AM62P / AM62P-Q1
          3. 6.1.1.1.3 Additional Information
          4. 6.1.1.1.4 Processor Core and Peripheral Core Power Supply Checklist
          5. 6.1.1.1.5 Peripheral Analog Power Supply Checklist
        2. 6.1.1.2 Supply for IO Groups
          1. 6.1.1.2.1 AM625 / AM623 / AM625SIP / AM625-Q1 / AM620-Q1 and AM62A7 / AM62A3 / AM62A7-Q1 / AM62A3-Q1
          2. 6.1.1.2.2 AM62P / AM62P-Q1
          3. 6.1.1.2.3 Additional Information
          4. 6.1.1.2.4 Supply for IO Groups Checklist
        3. 6.1.1.3 Supply for VPP (eFuse ROM Programming)
          1. 6.1.1.3.1 VPP Checklist
        4. 6.1.1.4 Supply Connection for Partial IO Mode (Low-Power) Configuration
          1. 6.1.1.4.1 Partial IO Used
          2. 6.1.1.4.2 Partial IO Unused
          3. 6.1.1.4.3 Data Sheet Reference for Power Sequence
          4. 6.1.1.4.4 Partial IO Low Mode Checklist
        5. 6.1.1.5 Additional Information
      2. 6.1.2 Capacitors for Supply Rails
        1. 6.1.2.1 AM625 / AM623 / AM625SIP / AM625-Q1 / AM620-Q1
        2. 6.1.2.2 AM62A7 / AM62A3 / AM62A7-Q1 / AM62A3-Q1 and AM62P / AM62P-Q1
        3. 6.1.2.3 Additional Information
          1. 6.1.2.3.1 AM625 / AM623 / AM625SIP / AM625-Q1 / AM620-Q1 and AM62A7 / AM62A3 / AM62A7-Q1 / AM62A3-Q1
          2. 6.1.2.3.2 AM62P / AM62P-Q1
        4. 6.1.2.4 Capacitors for Supply Rails Checklist
      3. 6.1.3 Processor Clock
        1. 6.1.3.1 Clock Inputs
          1. 6.1.3.1.1 High Frequency Oscillator (MCU_OSC0_XI / MCU_OSC0_XO)
          2. 6.1.3.1.2 Low Frequency Oscillator (WKUP_LFOSC0_XI / WKUP_LFOSC0_XO)
          3. 6.1.3.1.3 EXT_REFCLK1 (External Clock Input to Main Domain)
          4. 6.1.3.1.4 Additional Information
          5. 6.1.3.1.5 Clock Input Checklist - MCU_OSC0
          6. 6.1.3.1.6 Clock Input Checklist - WKUP_LFOSC0
        2. 6.1.3.2 Clock Outputs
          1. 6.1.3.2.1 Clock Output Checklist
      4. 6.1.4 Processor Reset
        1. 6.1.4.1 External Reset Inputs
        2. 6.1.4.2 Reset Status Outputs
        3. 6.1.4.3 Additional Information
        4. 6.1.4.4 Processor Reset Input Checklist
        5. 6.1.4.5 Processor Reset Status Output Checklist
      5. 6.1.5 Configuration of Boot Modes (for Processor)
        1. 6.1.5.1 Processor Boot Mode Inputs Isolation Buffers Use Case and Optimization
        2. 6.1.5.2 Boot Mode Selection
          1. 6.1.5.2.1 Notes for USB Boot Mode
        3. 6.1.5.3 Boot Mode Implementation Approaches
        4. 6.1.5.4 Additional Information
        5. 6.1.5.5 Configuration of Boot Modes (for Processor) Checklist
    2. 6.2 Board Debug Using JTAG and EMU
      1. 6.2.1 JTAG and EMU Used
      2. 6.2.2 JTAG and EMU Not Used
      3. 6.2.3 Additional Information
      4. 6.2.4 Board Debug Using JTAG and EMU Checklist
  10. 7 Processor Peripherals
    1. 7.1 Supply Connections for IO Groups
      1. 7.1.1 AM625 / AM623 / AM625SIP / AM625-Q1 / AM620-Q1 and AM62A7 / AM62A3 / AM62A7-Q1 / AM62A3-Q1
      2. 7.1.2 AM62P / AM62P-Q1
      3. 7.1.3 Supply Connections for IO Groups Checklist
    2. 7.2 Memory Interface (DDRSS (DDR4 / LPDDR4), MMCSD (eMMC / SD / SDIO), OSPI / QSPI and GPMC)
      1. 7.2.1 DDR Subsystem (DDRSS)
        1. 7.2.1.1 DDR4 SDRAM (Double Data Rate 4 Synchronous Dynamic Random-Access Memory)
          1. 7.2.1.1.1 AM625 / AM623 / AM625-Q1 / AM620-Q1
            1. 7.2.1.1.1.1 Memory Interface Configuration
            2. 7.2.1.1.1.2 Routing Topology and Terminations
            3. 7.2.1.1.1.3 Resistors for Control and Calibration
            4. 7.2.1.1.1.4 Capacitors for the Power Supply Rails
            5. 7.2.1.1.1.5 Data Bit or Byte Swapping
            6. 7.2.1.1.1.6 VTT Termination Schematics Reference
            7. 7.2.1.1.1.7 DDR4 Implementation Checklist
          2. 7.2.1.1.2 AM625SIP
          3. 7.2.1.1.3 AM62A7 / AM62A3 / AM62A7-Q1 / AM62A3-Q1
          4. 7.2.1.1.4 AM62P / AM62P-Q1
        2. 7.2.1.2 LPDDR4 SDRAM (Low-Power Double Data Rate 4 Synchronous Dynamic Random-Access Memory)
          1. 7.2.1.2.1 AM625 / AM623 / AM625-Q1 / AM620-Q1
            1. 7.2.1.2.1.1 Memory Interface Configuration
            2. 7.2.1.2.1.2 Routing Topology and Terminations
            3. 7.2.1.2.1.3 Resistors for Control and Calibration
            4. 7.2.1.2.1.4 Capacitors for the Power Supply Rails
            5. 7.2.1.2.1.5 Data Bit or Byte Swapping
            6. 7.2.1.2.1.6 LPDDR4 Implementation Checklist
          2. 7.2.1.2.2 AM625SIP
          3. 7.2.1.2.3 AM62A7 / AM62A3 / AM62A7-Q1 / AM62A3-Q1 and AM62P / AM62P-Q1
            1. 7.2.1.2.3.1 Memory Interface Configuration
            2. 7.2.1.2.3.2 Routing Topology and Terminations
            3. 7.2.1.2.3.3 Resistors for Control and Calibration
            4. 7.2.1.2.3.4 Capacitors for the Power Supply Rails
            5. 7.2.1.2.3.5 Data Bit or Byte Swapping
            6. 7.2.1.2.3.6 LPDDR4 Implementation Checklist
      2. 7.2.2 Multi-Media Card/Secure Digital (MMCSD)
        1. 7.2.2.1 MMC0 - eMMC (Embedded Multi-Media Card) Interface
          1. 7.2.2.1.1 AM625 / AM623 / AM625SIP / AM625-Q1 / AM620-Q1 and AM62A7 / AM62A3 / AM62A7-Q1 / AM62A3-Q1
            1. 7.2.2.1.1.1 IO Power Supply
            2. 7.2.2.1.1.2 eMMC (Attached Device) Reset
            3. 7.2.2.1.1.3 Signals Connection
            4. 7.2.2.1.1.4 Capacitors for the Power Supply Rails
            5. 7.2.2.1.1.5 MMC0 (eMMC) Checklist for AM62x and AM62Ax
          2. 7.2.2.1.2 AM62P / AM62P-Q1
            1. 7.2.2.1.2.1 MMC0 Used
              1. 7.2.2.1.2.1.1 IO Power Supply
              2. 7.2.2.1.2.1.2 eMMC (Attached Device) Reset
              3. 7.2.2.1.2.1.3 Signals Connection
              4. 7.2.2.1.2.1.4 Capacitors for the Power Supply Rails
            2. 7.2.2.1.2.2 MMC0 Not Used
            3. 7.2.2.1.2.3 MMC0 (eMMC) Checklist for AM62P
          3. 7.2.2.1.3 Additional Information on eMMC PHY
          4. 7.2.2.1.4 MMC0 – SD (Secure Digital) Card Interface
        2. 7.2.2.2 MMC1/MMC2 – SD (Secure Digital) Card Interface
          1. 7.2.2.2.1 IO Power Supply
          2. 7.2.2.2.2 SD Card Supply Reset and Boot Configuration
          3. 7.2.2.2.3 Signals Connection
          4. 7.2.2.2.4 ESD Protection
          5. 7.2.2.2.5 Capacitors for the Power Supply Rails
          6. 7.2.2.2.6 MMC1 SD Card Interface Checklist
        3. 7.2.2.3 MMC1 / MMC2 SDIO (Embedded) Interface
          1. 7.2.2.3.1 IO Power Supply
          2. 7.2.2.3.2 Signals Connection
          3. 7.2.2.3.3 MMC2 SDIO (Embedded) Interface Checklist
        4. 7.2.2.4 Additional Information
      3. 7.2.3 Octal Serial Peripheral Interface (OSPI) and Quad Serial Peripheral Interface (QSPI)
        1. 7.2.3.1 IO Power Supply
        2. 7.2.3.2 OSPI / QSPI Reset
        3. 7.2.3.3 Signals Connection
        4. 7.2.3.4 Loopback Clock
        5. 7.2.3.5 Interface to Multiple Devices
        6. 7.2.3.6 Capacitors for the Power Supply Rails
        7. 7.2.3.7 OSPI / QSPI Implementation Checklist
      4. 7.2.4 General-Purpose Memory Controller (GPMC)
        1. 7.2.4.1 IO Power Supply
        2. 7.2.4.2 GPMC Interface
        3. 7.2.4.3 Memory (Attached Device) Reset
        4. 7.2.4.4 Signals Connection
          1. 7.2.4.4.1 GPMC NAND
        5. 7.2.4.5 Capacitors for the Power Supply Rails
        6. 7.2.4.6 GPMC Interface Checklist
    3. 7.3 External Communication Interface (Ethernet (CPSW3G), USB2.0, PRUSS, UART and Controller Area Network (CAN))
      1. 7.3.1 Ethernet Interface Using CPSW3G (Common Platform Ethernet Switch 3-Port Gigabit)
        1. 7.3.1.1  IO Power Supply
        2. 7.3.1.2  Ethernet PHY Reset
        3. 7.3.1.3  Ethernet PHY Pin Strapping
        4. 7.3.1.4  Ethernet PHY (and MAC) Operation and Media Independent Interface (MII) Clock
          1. 7.3.1.4.1 Crystal
          2. 7.3.1.4.2 Oscillator
          3. 7.3.1.4.3 Processor Clock Output (CLKOUT0)
        5. 7.3.1.5  MAC (Data, Control and Clock) Interface Signals Connection
        6. 7.3.1.6  External Interrupt (EXTINTn)
          1. 7.3.1.6.1 External Interrupt (EXTINTn) Checklist
        7. 7.3.1.7  MAC (Media Access Controller) to MAC Interface
        8. 7.3.1.8  MDIO (Management Data Input/Output) Interface
        9. 7.3.1.9  Ethernet MDI (Medium Dependent Interface) Including Magnetics
        10. 7.3.1.10 Capacitors for the Power Supply Rails
        11. 7.3.1.11 Ethernet Interface Checklist
      2. 7.3.2 Universal Serial Bus (USB2.0)
        1. 7.3.2.1 USBn (n = 0-1) Used
          1. 7.3.2.1.1 USB Host Interface
          2. 7.3.2.1.2 USB Device Interface
          3. 7.3.2.1.3 USB Dual-Role-Device Interface
          4. 7.3.2.1.4 USB Type-C®
        2. 7.3.2.2 USBn (n = 0-1) Not Used
        3. 7.3.2.3 Additional Information
        4. 7.3.2.4 USB Interface Checklist
      3. 7.3.3 Programmable Real-Time Unit Subsystem (PRUSS)
        1. 7.3.3.1 AM625 / AM623 / AM625SIP / AM625-Q1 / AM620-Q1
          1. 7.3.3.1.1 PRU Subsystem
          2. 7.3.3.1.2 PRUSS Checklist
        2. 7.3.3.2 AM62A7 / AM62A3 / AM62A7-Q1 / AM62A3-Q1 and AM62P / AM62P-Q1
      4. 7.3.4 Universal Asynchronous Receiver/Transmitter (UART)
        1. 7.3.4.1 Universal Asynchronous Receiver/Transmitter (UART) Checklist
      5. 7.3.5 Controller Area Network (CAN)
        1. 7.3.5.1 Controller Area Network Checklist
    4. 7.4 On-board Synchronous Communication Interface (MCSPI, MCASP and I2C)
      1. 7.4.1 Multichannel Serial Peripheral Interface (MCSPI) and Multichannel Audio Serial Ports (MCASP)
        1. 7.4.1.1 MCSPI Checklist
        2. 7.4.1.2 MCASP Checklist
      2. 7.4.2 Inter-Integrated Circuit (I2C)
        1. 7.4.2.1 I2C Open-drain Output Type Buffer Checklist
        2. 7.4.2.2 I2C Emulated Open-drain Output Type Buffer Checklist
    5. 7.5 User Interface (CSIRX0, DPI, OLDI, DSI), GPIO and Hardware Diagnostics
      1. 7.5.1 Camera Serial Interface (CSI-Rx (CSI-2 port, CSIRX0 Instance))
        1. 7.5.1.1 CSIRX0 Used
        2. 7.5.1.2 CSIRX0 Not Used
        3. 7.5.1.3 CSI Checklist
      2. 7.5.2 Display Subsystem
        1. 7.5.2.1 Display Parallel Interface (DPI)
          1. 7.5.2.1.1 AM625 / AM623 / AM625SIP / AM625-Q1 and AM62A7 / AM62A3 / AM62A7-Q1 / AM62A3-Q1 and AM62P / AM62P-Q1
            1. 7.5.2.1.1.1 IO Power Supply
            2. 7.5.2.1.1.2 DPI (Attached Device) Reset
            3. 7.5.2.1.1.3 Connection
            4. 7.5.2.1.1.4 Signals Connection
            5. 7.5.2.1.1.5 Capacitors for the Power Supply Rails
            6. 7.5.2.1.1.6 DPI Checklist
          2. 7.5.2.1.2 AM620-Q1
        2. 7.5.2.2 Open LVDS Display Interface (OLDI)
          1. 7.5.2.2.1 AM625 / AM623 / AM625SIP / AM625-Q1 and AM62P / AM62P-Q1
            1. 7.5.2.2.1.1 OLDI0 Used
              1. 7.5.2.2.1.1.1 IO Power Supply
              2. 7.5.2.2.1.1.2 OLDI (Attached Device) Reset
              3. 7.5.2.2.1.1.3 OLDI Interface Compatibility
              4. 7.5.2.2.1.1.4 Capacitors for the Power Supply Rails
              5. 7.5.2.2.1.1.5 OLDI Checklist
            2. 7.5.2.2.1.2 OLDI0 Not Used
            3. 7.5.2.2.1.3 Additional Information
          2. 7.5.2.2.2 AM620-Q1 and AM62A7 / AM62A3 / AM62A7-Q1 / AM62A3-Q1
        3. 7.5.2.3 Display Serial Interface (DSI)
          1. 7.5.2.3.1 AM625 / AM623 / AM625SIP / AM625-Q1 / AM620-Q1 and AM62A7 / AM62A3 / AM62A7-Q1 / AM62A3-Q1
          2. 7.5.2.3.2 AM62P / AM62P-Q1
            1. 7.5.2.3.2.1 DSITX0 Used
              1. 7.5.2.3.2.1.1 DSITX0 Checklist
            2. 7.5.2.3.2.2 DSITX0 Not Used
      3. 7.5.3 General Purpose Input/Output (GPIO)
        1. 7.5.3.1 Availability of CLKOUT on Processor GPIO
        2. 7.5.3.2 Connection and External Buffering
        3. 7.5.3.3 Additional Information
        4. 7.5.3.4 GPIO Checklist
      4. 7.5.4 On-board Hardware Diagnostics
        1. 7.5.4.1 Monitoring of On-board Supply Voltages Using Processor Voltage Monitors
          1. 7.5.4.1.1 Voltage Monitor Pins Used
            1. 7.5.4.1.1.1 Voltage Monitor Checklist
          2. 7.5.4.1.2 Voltage Monitor Pins Not Used
        2. 7.5.4.2 Internal Temperature Monitoring
          1. 7.5.4.2.1 Internal Temperature Monitoring Checklist
        3. 7.5.4.3 Connection of Error Signal Output (MCU_ERRORn)
        4. 7.5.4.4 High Frequency Oscillator (MCU_OSC0) Clock Loss Detection
    6. 7.6 Verifying Board Level Design Issues
      1. 7.6.1 Processor Pin Configuration Using PinMux Tool
      2. 7.6.2 Schematics Configurations
      3. 7.6.3 Connecting Supply Rails to Pullups
      4. 7.6.4 Peripheral (Subsystem) Clock Outputs
      5. 7.6.5 General Board Bring-up and Debug
        1. 7.6.5.1 Clock Output for Board Bring-Up, Test, or Debug
        2. 7.6.5.2 Additional Information
        3. 7.6.5.3 General Board Bring-up and Debug Checklist
  11. 8 Layout Notes (Added on the Schematic)
    1. 8.1 Layout Checklist
  12. 9 Custom Board Design Simulation
  13. 10Additional References
    1. 10.1 FAQ Covering AM6xx Processor Family
    2. 10.2 FAQs - Processor Product Family Wise and Sitara Processor Families
    3. 10.3 Processor Attached Devices
  14. 11Summary
  15. 12References
    1. 12.1 AM625 / AM623 / AM625SIP / AM625-Q1 / AM620-Q1
    2. 12.2 AM62A7 / AM62A3 / AM62A7-Q1 / AM62A3-Q1
    3. 12.3 AM62P / AM62P-Q1
    4. 12.4 Common for all Processor Families
    5. 12.5 Master List of Available FAQs - Processor Family Wise
    6. 12.6 Master List of Available FAQs - Sitara Processor Families
    7. 12.7 FAQs Including Software Related
    8. 12.8 FAQs for Attached Devices
  16. 13Terminology
  17. 14Revision History
6.1.1.3.1 VPP Checklist

General

Review and verify the following for the custom schematic design:

  1. Above sections, including relevant application notes and FAQ links
  2. Pin attributes, signal description and electrical specifications
  3. Electrical characteristics and additional available information
  4. Implementation of on-board supply or provision provided to connect external supply
  5. An LDO is recommended (use of FET switch or load switch is not allowed or recommended)
  6. Choose on-board LDO that supports a minimum of 400mA current, has excellent load current transient response, and quick output discharge (active discharge)
  7. Required bulk and bypass capacitors are provided (follow SK schematics)
  8. On-board LDO has provision to be enabled by processor IO
  9. When external supply is connected, add bulk and decoupling capacitor provision on the processor board near to the processor VPP pin and provided a TP to connect the external supply
  10. External supply follows the recommended power sequence and slew rate requirements as per the data sheet
  11. The external supply timing is controlled by a processor IO
  12. Leave the processor VPP supply pin floating (HiZ) or grounded during power-up sequences, power-down sequences, and normal device operation

Schematics Review

Follow the below list for the custom schematic design:

  1. A dedicated LDO or PMIC output is used
  2. Nominal voltage connected to VPP is 1.8V and supports current rating as per data sheet requirements
  3. Selected LDO specifications including load current transient response is similar to the LDO used on the SK schematics
  4. Processor IO is used to control the EN of the LDO and the required pull is provided
  5. Verify the if EN pull holds the LDO is in off-state during power cycling
  6. When an adjustable LDO is used, verify the output voltage configuration, output slew and use of over voltage protection
  7. A series resistor is provided to isolate the processor VPP supply from the LDO for testing the timing or LDO output
  8. Supply rail connected follow the processor ROC

Additional

  1. Always provide provision on the processor board to connect VPP supply (On Board or external supply).
  2. Select an LDO with fast transient response and connect LDO output to the processor VPP pin with a low loop inductance path to source the high transient load current, where the VPP pin never drops below the minimum operating voltage.
  3. Enable the VPP only during eFuse programming. Connecting the VPP supply to a continuous 1.8V supply rail is not a allowed or recommended or supported option.
  4. Due to the transient load current requirement during eFuse programming, using load switch or FET switch is not a recommended approach. A load switch or FET switch is likely to have too much voltage drop that is not compensated when using an LDO.
  5. If the use case requires use of load switch or FET switch, characterize the system by measuring the voltage on the processor VPP pin during programming and verify supply never drops below the ROC minimum limit. Several variables in the path of VPP can cause the supply to be out of the ROC when using load switch or FET and must be without characterized before implementing. Check or test if the load switch or FET switch violates the maximum VPP power-up slew rate limit of 6000V per second defined in the data sheet.