SLAAE75A November   2022  – March 2023 MSPM0L1105 , MSPM0L1106 , MSPM0L1303 , MSPM0L1304 , MSPM0L1304-Q1 , MSPM0L1305 , MSPM0L1305-Q1 , MSPM0L1306 , MSPM0L1306-Q1 , MSPM0L1343 , MSPM0L1344 , MSPM0L1345 , MSPM0L1346

 

  1.   Abstract
  2.   Trademarks
  3. 1 MSPM0L Hardware Design Check List
  4. 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
  5. 3 Reset and Power Supply Supervisor
    1. 3.1 Digital Power Supply
    2. 3.2 Power Supply Supervisor
  6. 4 Clock System
    1. 4.1 Internal Oscillators
    2. 4.2 External Clock Output (CLK_OUT)
    3. 4.3 Frequency Clock Counter (FCC)
  7. 5 Debugger
    1. 5.1 Debug Port Pins and Pinout
    2. 5.2 Debug Port Connection With Standard JTAG Connector
  8. 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
  9. 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
  10. 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 1.8-V Devices Without a Level Shifter
    6. 8.6 Unused Pins Connection
  11. 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
  12. 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
  13. 11References
  14. 12Revision History

6.4 COMP Design Considerations

MSPM0L comparator module (COMP) is an analog voltage comparator with general comparator functionality.

The MSPM0L Comparator module include internal and external input, you can use these structures flexibly to process your analog signals. And internal temperature sensor be able to as the COMP input directly.

Figure 6-6 Comparator Block Diagram

The MSPM0L Comparator module also include a SHORT switch which can be used to build a simple sample-and-hold for the comparator.

As shown in #FIG_NKD_5J3_GVB, the required sampling time is proportional to the size of the sampling capacitor (CS), the resistance of the input switches in series with the short switch (R­), and the resistance of the external source (RS). The sampling capacitor CS should be greater than 100 pF. The time constant, Tau, to charge the sampling capacitor CS can be calculated with the below equation.

T a u = ( R I + R S ) x C S

Depending on the required accuracy, 3 to 10 Tau should be used as the sampling time. With 3 Tau the sampling capacitor is charged to approximately 95% of the input signals voltage level, with 5 Tau it is charged to more than 99%, and with 10 Tau the sampled voltage is sufficient for 12-bit accuracy.

Figure 6-7 Comparator Short Switch