SDAA280 March   2026 MSPM0G5187

 

  1.   1
  2.   Abstract
  3. 1USB Makes a Complex System Appear Simple
    1. 1.1 Why Has USB Been so Successful?
    2. 1.2 Why Does USB Look Simple?
  4. 2MSPM0 USB Silicon
    1. 2.1 How MSPM0 Devices are Documented
    2. 2.2 MSPM0 USB Module
  5. 3MSPM0 USB Hardware Design
    1. 3.1 Block Diagram
    2. 3.2 USB Mode of Operation
      1. 3.2.1 USB Device Mode: Bus Powered
      2. 3.2.2 USB Device Mode: Self-Powered
      3. 3.2.3 USB Host Mode Power Considerations
      4. 3.2.4 ESD Considerations
      5. 3.2.5 Layout Considerations
    3. 3.3 USB Clock Implementation
      1. 3.3.1 Selecting a Clock Source
      2. 3.3.2 Selecting a Clock Frequency
    4. 3.4 Example Implementation
  6. 4Software Overview
    1. 4.1 USB Stacks: Features
    2. 4.2 SysConfig Descriptor Tool
    3. 4.3 Selecting a Device Class
      1. 4.3.1 Example Process for Deciding on a USB Device Class
    4. 4.4 How to Select a Vendor ID (VID) and Product ID (PID)
      1. 4.4.1 Choosing and Obtaining VID and PID
      2. 4.4.2 Using VIDs and PIDs During Development
    5. 4.5 TinyUSB API Programmer's Guide and Examples
  7. 5Getting Started: Evaluating MSPM0 USB
  8. 6Summary
  9. 7References
  10. 8USB Glossary

3.2.3 USB Host Mode Power Considerations

Unlike the MSP430, the MSPM0Gx is capable of operating as a host in a USB design. While the majority of complexity comes from the software design of these applications, there are additional hardware requirements when it comes to designing a host.

Power is one of the main needs when designing a host device, as the host must provide 5V VBUS power to connected devices, with up to 500mA required for USB 2.0 full speed. This oftentimes means pairing the device with a dedicated power source, such as a separate switching power supply. As USB devices are often bus-powered, ensuring that the host can support the power requirements of any device is critical for consistent operation.

Protection must be considered as there is no guarantee that the device being connected is designed correctly and can introduce an overcurrent or overvoltage scenario. Integrating protection circuitry and a current sense resistor on the power line assists in verifying that the device is not exposed to such over-power situations.