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The following FAQ applies to AM243x LaunchPad (LP-AM243), AM263x LaunchPad (LP-AM263), AM243x General Purpose Evaluation Module (TMDS243GPEVM, TMDS243EVM), AM263x Control Card (TMDSCNCD263).
1. Do the Sitara MCU evaluation modules (EVM) and LaunchPads (LP) have any power requirements?
2. What is the EVM/LP Power-on sequence after a type-C connection is established?
3. What should be done if the Power-good status LEDs are not glowing following the type-C connection?
4. How does the EVM/LP handle a type-C connection to supply power to the board?
5. How does the TUSB320 Port Controller determine the current mode?
6. Can I use a USB type-A to USB type-C cable to supply power to the board?
7. Are all USB type-C to USB type-C connections capable of high current?
8. Are all USB type-C cables rated for 5V/3A?
9. Can I use a >15W universal wall adapter that uses a DC barrel jack with a DC barrel jack to USB type-C adapter?
10. What is the recommended solution for powering Sitara MCU evaluation modules and LaunchPads?
1. Do the Sitara MCU evaluation modules (EVM) and LaunchPads (LP) have any power requirements?
Sitara MCU LP/EVM’s require a 5V/3A supply. The USB Type-C Port Controller (TUSB320) only enables the device power tree's Power-on sequencing once when a high current (3A) is detected.
2. What is the EVM/LP Power-on sequence after a type-C connection is established?
Sitara MCU LP/EVM's have a USB channel configuration (CC) controller (TUSB320). The CC controller is able to negotiate with the host type-C connection and determine the current mode that is being advertised. If the Current mode is advertising 3A then the EVM/LP will initiate the power on sequence and the power good status LEDs will glow.
3. What should be done if the Power-good status LEDs are not glowing following the type-C connection?
For information on where the power-good status LEDs are located on the board then refer to the device User Guide's Power Status LEDs chapter. If the LEDs are not behaving as expected, then refer to the sequence diagram from the former question.
4. How does the EVM/LP handle a type-C connection to supply power to the board?
Sitara MCU LP/EVMs make use of a USB Type-C Port Controller (TUSB320) to determine cable connection and orientation. The Port Controller also controls GPIO outputs to the level of current being supplied by the connection. Type-C connections are classified into three different levels for 5 volts:
5. How does the TUSB320 Port Controller determine the current mode?
The voltage level on the channel configuration (CC) inputs is what determines the current mode. A USB connection makes use of a voltage divider to advertise what kind of cable and receptacle is being used for the USB connection.
The host supply port will have a pull-up resistor, Rp, on the CC signal and the TUSB320 has a pulldown resistor, Rd, which creates a voltage divider. The voltage measured on CC will determine if the TUSB320 recognizes a 5V/3A supply.
|
Voltage range on CC |
Current Mode |
Current value |
|
0.25V < CC < 0.61V |
Default |
Up to 500mA |
|
0.7V < CC < 1.16V |
Medium |
Up to 1.5A |
|
1.31 < CC < 2.04V |
High |
Up to 3A |
The resistance value of Rd will always be 5.1kΩ. The resistance value of Rp is determined by the type of USB connection.
|
USB Connection |
Rp |
Current mode |
Compatible with Sitara MCU EVM’s |
|
5V 3A power adapter with USB-C receptacle |
10 kΩ |
High |
Yes |
|
5V 3A power adapter with captive USB-C cable |
10 kΩ |
High |
Yes |
|
5V 1.5A power adapter with USB-C receptacle |
22 kΩ |
Medium |
No |
|
5V 1.5A power adapter with captive USB-C cable |
22 kΩ |
Medium |
No |
|
USB 3.1 Type-A to USB type-C |
56 kΩ |
Default |
No |
|
USB 2.0 Type-A to USB type-C |
56 kΩ |
Default |
No |
|
USB Micro-B to USB type-C |
56 kΩ |
Default |
No |
6. Can I use a USB type-A to USB type-C cable to supply power to the board?
USB type-A ports will NEVER be able to supply 3A and so any type-A to type-C cables or adapters will always result in the EVM/LP not being powered.
7. Are all USB type-C to USB type-C connections capable of high current?
Not all type-C PC ports or wall adapters are capable of high current. There are many PC type-C USB ports and wall adapters that are only capable of 1.5A or less. The thunderbolt type-C USB ports capable of 5V/3A. Additionally, PC USB type-C ports with a battery in the USB logo are capable of Power Delivery and therefore capable of 5V/3A.
8. Are all USB type-C cables rated for 5V/3A?
All certified USB type-C cables are rated for at least 5V/3A.
9. Can I use a >15W universal wall adapter that uses a DC barrel jack with a DC barrel jack to USB type-C adapter?
Universal wall adapters such as the one pictured below that are >15W are not guaranteed to work with Sitara MCU boards and are not recommended.
10. What is the recommended solution for powering Sitara MCU evaluation modules and LaunchPads?
TI recommends using a 15W Power adapter with a captive USB-C cable such as the Raspberry Pi 15W USB-C Power Supply.
