SLAAEG4B October   2023  – July 2025 MSPM0C1104 , MSPM0C1105 , MSPM0C1106 , MSPM0H3216 , MSPM0L1306

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1 MSPM0C Hardware Design Check List
  5. 2 Power Supplies in MSPM0C Devices
    1. 2.1 Digital Power Supply
    2. 2.2 Analog Power Supply
    3. 2.3 Built-in Power Supply and Voltage Reference
    4. 2.4 Recommended Decoupling Circuit for Power Supply
  6. 3 Reset and Power Supply Supervisor
    1. 3.1 Digital Power Supply
    2. 3.2 Power Supply Supervisor
      1. 3.2.1 Power-On Reset (POR) Monitor
      2. 3.2.2 Brownout Reset (BOR) Monitor
      3. 3.2.3 POR and BOR Behavior During Supply Changes
  7. 4 Clock System
    1. 4.1 Internal Oscillators
      1. 4.1.1 Internal Low-Frequency Oscillator (LFOSC)
      2. 4.1.2 Internal System Oscillator (SYSOSC)
    2. 4.2 External Oscillators & External Clock Input
      1. 4.2.1 Low-Frequency Crystal Oscillator (LFXT)
      2. 4.2.2 LFCLK_IN (Digital Clock)
      3. 4.2.3 High-Frequency Crystal Oscillator (HFXT)
      4. 4.2.4 HFCLK_IN (Digital Clock)
    3. 4.3 External Clock Output (CLK_OUT)
    4. 4.4 Frequency Clock Counter (FCC)
  8. 5 Debugger
    1. 5.1 Debug Port Pins and Pinout
    2. 5.2 Debug Port Connection With Standard JTAG Connector
      1. 5.2.1 Standard XDS110
      2. 5.2.2 Lite XDS110 (MSPM0 LaunchPad™ kit)
  9. 6 Key Analog Peripherals
    1. 6.1 ADC Design Considerations
    2. 6.2 COMP and DAC Design Considerations
  10. 7 Key Digital Peripherals
    1. 7.1 Timer Resources and Design Considerations
    2. 7.2 UART and LIN Resources and Design Considerations
    3. 7.3 I2C and SPI Design Considerations
  11. 8 GPIOs
    1. 8.1 GPIO Output Switching Speed and Load Capacitance
    2. 8.2 GPIO Current Sink and Source
    3. 8.3 Open-Drain GPIOs Enable 5V Communication Without a Level Shifter
    4. 8.4 Communicate With 1.8V Devices Without a Level Shifter
    5. 8.5 Unused Pins Connection
  12. 9 Layout Guides
    1. 9.1 Power Supply Layout
    2. 9.2 Considerations for Ground Layout
      1. 9.2.1 What is Ground Noise?
    3. 9.3 Traces, Vias, and Other PCB Components
    4. 9.4 How to Select Board Layers and Recommended Stack-up
  13. 10Bootloader
  14. 11Summary
  15. 12References
  16. 13Revision History

8.4 Communicate With 1.8V Devices Without a Level Shifter

The MSPM0C series devices use a 3.3V logic level (excluding ODIO). To communicate with 1.8V devices without an external level shifter device, Figure 8-2 shows a suggested circuit for interfacing with a 1.8V device.

Suggested Communication Circuit With 1.8V Device Figure 8-2 Suggested Communication Circuit With 1.8V Device

Two MOSFETs are used in this circuit; check the VGS to make sure the MOSFET is able to fully turn on with a low RDS(on). For a 1.8V device, use less than 1.8V VGS on the MOSFET. However, do not use a very low VGS MOSFET, as this causes the MOSFET to turn on at a very small voltage (MCU logic judges as 0), resulting in communication logic error.

U1 Output and U2 Input

  1. U1 output: 1.8V high, Q1 VGS around 0, thus Q1 turn off, U2 reads 3.3V high with R4.
  2. U1 output: low, Q1 VGS near 1.8V, thus Q1 turns on, U2 reads low.

U1 Input and U2 Output

  1. U2 output: 3.3V high, U1 keeps 1.8V with R1, and Q1 turns off, thus U1 reads 1.8V high.
  2. U2 output: low, U1 keeps 1.8V with R1 at first, but the diode in the MOSFET pulls down U1 to 0.7V (diode voltage drops), and then causes VGS to be greater than the turn-on voltage, Q1 turns on, and U1 reads low.