SPRUJ12F August   2021  – January 2024 AM2431 , AM2432 , AM2434

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Preface: Read This First
    1. 1.1 If You Need Assistance
    2. 1.2 Important Usage Notes
  5. 2Kit Overview
    1. 2.1 Kit Contents
    2. 2.2 Key Features
    3. 2.3 Component Identification
    4. 2.4 BoosterPacks
    5. 2.5 Compliance
    6. 2.6 Security
  6. 3Board Setup
    1. 3.1 Power Requirements
      1. 3.1.1 Power Input Using USB Type-C Connector
      2. 3.1.2 Power Status LED's
      3. 3.1.3 Power Tree
      4. 3.1.4 Power Sequence
    2. 3.2 Push Buttons
    3. 3.3 Boot Mode Selection
  7. 4Hardware Description
    1. 4.1  Functional Block Diagram
    2. 4.2  BoosterPack Headers
      1. 4.2.1 Pinmux for BoosterPack
    3. 4.3  GPIO Mapping
    4. 4.4  Reset
    5. 4.5  Clock
    6. 4.6  Memory Interface
      1. 4.6.1 QSPI Interface
      2. 4.6.2 Board ID EEPROM
    7. 4.7  Ethernet Interface
      1. 4.7.1 Ethernet PHY Strapping
      2. 4.7.2 Ethernet PHY - Power, Clock, Reset, Interrupt
      3. 4.7.3 LED indication in Ethernet RJ45 Connector
    8. 4.8  USB 2.0 Interface
    9. 4.9  I2C Interface
    10. 4.10 Industrial Application LEDs
    11. 4.11 UART Interface
    12. 4.12 eQEP Interface
    13. 4.13 CAN Interface
    14. 4.14 FSI Interface
    15. 4.15 JTAG Emulation
    16. 4.16 Test Automation Interface
    17. 4.17 SPI Interface
  8. 5References
    1. 5.1 Reference Documents
    2. 5.2 Other TI Components Used in This Design
  9.   A E3 Design Changes
  10.   B Revision A Design Changes
  11.   Revision History

3.1.1 Power Input Using USB Type-C Connector

The AM243x LaunchPad is powered through a USB type-C connection. The USB Type-C source should be capable of providing 3A at 5 V and should advertise the current sourcing capability through CC1 and CC2 signals. On AM243x LP, the CC1 and CC2 from USB type-C connector are interfaced to the port controller IC (TUSB320LAIRWBR). This device uses the CC pins to determine port attach and detach, cable orientation, role detection, and port control for Type-C current mode. The CC logic detects the Type-C current mode as default, medium, or high depending on the role detected.

The Port pin is pulled down to ground with a resistor to configure it as upward facing port (UFP) mode. VBUS detection is implemented to determine a successful attach in UFP mode. The OUT1 and OUT2 pins are connected to a NOR gate. Active low on both the OUT1 and OUT2 pins advertises high current (3A) in the attached state which enables the VUSB_5V0 power switch to provide the VSYS_5V0 supply which powers other regulators and LDOs.

In UFP mode, the port controller IC constantly presents pull-down resistors on both CC pins. The port controller IC also monitors the CC pins for the voltage level corresponding to the Type-C mode current advertisement by the connected DFP. The port controller IC de-bounces the CC pins and waits for VBUS detection before successfully attaching. As a UFP, the port controller device detects and communicates the advertised current level of the DFP to the system through the OUT1 and OUT2 GPIOs.

The AM243x LP power requirement is 5 V at 3A and if the source is not capable of providing the required power, the output at the NOR gate becomes low that disables the VUSB_5V0 power switch. Therefore, if the power requirement is not met, all power supplies except VCC3V3_TA will remain in the off state. The board gets powered on completely only when the source can provide 5 V at 3A.

GUID-20210719-CA0I-RMW7-PG4C-X8CSVP6KBCWF-low.png Figure 3-2 Type-C CC Configuration
Table 3-1 Current Sourcing Capability and State of USB Type-C Cable
OUT1 OUT2 Advertisement
H H Default current in unattached state
H L Default current in attached state
L H Medium current (1.5A) in attached state
L L High current (3.0A) in attached state

The AM243x LaunchPad includes a power solution based on discrete regulators for each of the power rails. During the initial stage of the power supply, 5 V supplied by the type-C USB connector is used to generate all of the necessary voltages required by the LaunchPad.

GUID-20210718-CA0I-DZBJ-KSSC-3MZWQTMTLSSX-low.png Figure 3-3 USB Type-C Power Input

Discrete DC-DC buck regulators and LDOs are used to generate the supplies required for the AM243x system on a chip (SoC) and other peripherals

Two DC-DC buck regulators (TPS62822) are used to generate the 3.3 V main supply and VDD_CORE_0V85 from the 5 V input supply.