SLAAE75B March   2023  – May 2023 MSPM0L1105 , MSPM0L1106 , MSPM0L1303 , MSPM0L1304 , MSPM0L1304-Q1 , MSPM0L1305 , MSPM0L1305-Q1 , MSPM0L1306 , MSPM0L1306-Q1 , MSPM0L1343 , MSPM0L1344 , MSPM0L1345 , MSPM0L1346

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1 MSPM0L Hardware Design Checklist
  5. 2 Power Supplies in MSPM0L 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
  7. 4 Clock System
    1. 4.1 Internal Oscillators
    2. 4.2 External Clock Output (CLK_OUT)
    3. 4.3 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
  9. 6 Key Analog Peripherals
    1. 6.1 ADC Design Considerations
    2. 6.2 OPA Design Considerations
    3. 6.3 DAC Design Considerations
    4. 6.4 COMP Design Considerations
    5. 6.5 GPAMP Design Considerations
    6. 6.6 LCD 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 High Speed GPIOs
    4. 8.4 Open-Drain GPIOs Enable 5-V Communication Without a Level Shifter
    5. 8.5 Communicate With 1.8V Devices Without a Level Shifter
    6. 8.6 Unused Pins Connection
  12. 9 Layout Guides
    1. 9.1 Power Supply Layout
    2. 9.2 Considerations for Ground Layout
    3. 9.3 Traces, Vias, and Other PCB Components
    4. 9.4 How to Select Board Layers and Recommended Stack-up
  13. 10Bootloader
    1. 10.1 Bootloader Introduction
    2. 10.2 Bootloader Hardware Design Considerations
      1. 10.2.1 Physical Communication interfaces
      2. 10.2.2 Hardware Invocation
  14. 11References
  15. 12Revision History

6.1 ADC Design Considerations

MSPM0L devices have a 12-bit, up to 1-Msps, analog-to-digital converter (ADC). The ADC supports fast 12-, 10-, and 8-bit analog-to-digital conversions. The ADC implements a 12-bit SAR core, sample/conversion mode control, and up to 4 independent conversion-and-control buffers.

ADC Input Network Figure 6-1 ADC Input Network

To achieve the desired conversion speed and keep high accuracy, set the proper sampling time in the hardware design. Sampling (sample-and-hold) time determines how long to sample a signal before digital conversion. During sample time, an internal switch lets the input capacitor charge. The required time to fully charge the capacitor is dependent on the external analog front-end (AFE) connected to the ADC input pin. Figure 6-1 shows a typical ADC model of an MSPM0L MCU. The Rin and CS/H values can be obtained from the device-specific data sheet. It is critical to understand the AFE drive capability and calculate the minimum sampling time required to sample the signal. The resistance of RPar and Rin affects tsample. Equation 1 can be used to calculate a conservative value of the minimum sample time tsample for an n-bit conversion:

Equation 1. tsample ≥ (Rpar + Rin) × ln(2n+2) × (CS/H + C1 + CPar)