SLAAET8A April   2025  – December 2025 MSPM0C1103 , MSPM0C1103-Q1 , MSPM0C1104 , MSPM0C1104-Q1 , MSPM0C1105 , MSPM0C1106 , MSPM0C1106-Q1 , MSPM0G1105 , MSPM0G1106 , MSPM0G1107 , MSPM0G1505 , MSPM0G1506 , MSPM0G1507 , MSPM0G1518 , MSPM0G1519 , MSPM0G3105 , MSPM0G3105-Q1 , MSPM0G3106 , MSPM0G3106-Q1 , MSPM0G3107 , MSPM0G3107-Q1 , MSPM0G3505 , MSPM0G3505-Q1 , MSPM0G3506 , MSPM0G3506-Q1 , MSPM0G3507 , MSPM0G3507-Q1 , MSPM0G3518 , MSPM0G3518-Q1 , MSPM0G3519 , MSPM0G3519-Q1 , MSPM0G3529-Q1 , MSPM0H3216 , MSPM0H3216-Q1 , MSPM0L1105 , MSPM0L1106 , MSPM0L1116 , MSPM0L1117 , MSPM0L1227 , MSPM0L1227-Q1 , MSPM0L1228 , MSPM0L1228-Q1 , MSPM0L1303 , MSPM0L1304 , MSPM0L1304-Q1 , MSPM0L1305 , MSPM0L1305-Q1 , MSPM0L1306 , MSPM0L1306-Q1 , MSPM0L1343 , MSPM0L1344 , MSPM0L1345 , MSPM0L1346 , MSPM0L2227 , MSPM0L2227-Q1 , MSPM0L2228 , MSPM0L2228-Q1

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
  5. 2EMC and EMC Standards
    1. 2.1 EMC
      1. 2.1.1 EMS
      2. 2.1.2 EMI
    2. 2.2 EMC Standards
      1. 2.2.1 EMC Standards Category
    3. 2.3 EMC and IC Electrical Reliability in TI
  6. 3EMC Improvement Guidelines Summary
    1. 3.1 PCB Design Guidelines
    2. 3.2 Firmware Guidelines
  7. 4EMC Improvement Features on MSPM0
    1. 4.1 Susceptibility Protection Features
      1. 4.1.1 POR and BOR
      2. 4.1.2 NMI and Hard Fault
      3. 4.1.3 I/O ESD and Settings
    2. 4.2 Emission Reduction Features
      1. 4.2.1 Clock Source
      2. 4.2.2 Power Modes
      3. 4.2.3 Package
  8. 5Analysis for EMS Test
    1. 5.1 Root Cause Analysis
      1. 5.1.1 Permanent Damage
      2. 5.1.2 Recoverable Malfunction
    2. 5.2 Debug Flow
  9. 6Analysis for EMI Test
    1. 6.1 Root Cause Analysis
      1. 6.1.1 Power Line
      2. 6.1.2 External Vcore
    2. 6.2 Debug Flow
  10. 7Summary
  11. 8References
  12. 9Revision History

4.2.1 Clock Source

Clock signals are a primary source of EMI in microcontroller systems. Clock noise propagates through the power supply introduced into the system, and also directly emits from the MCU package, contributing to radiated EMI.

For clock noise, clock frequency and current consumption are two critical factors to evaluate influence. The clock frequency determines the noise spectrum range. The current consumption serves as a reliable indicator of overall noise strength. High clock frequency and high current consumption typically increases clock noise.

The MSPM0 microcontroller series has flexible clock selection for users. Several internal and external oscillators are provided for generating low to high frequency clocks to be used by the system. A summary of the MSPM0 clock frequency and current consumptions is provided below for users.

Note: When enabling the external HFXT, remember to disable the SYSOSC.
Table 4-5 Clock Sources of MSPM0G
Clock TypeClock SourceClock Frequency RangeTest ConditionsTypical Current Consumption
SYSPLL InternalUp to 80MHzfSYSPLLREF=32MHz, fVCO=160MHz316uA
SYSOSC ≃4-32MHzfSYSOSC=4MHz20uA
fSYSOSC=32MHz80uA
fSYSOSC=32MHz, Enable ROSC90uA
LFOSC 32.768kHzLFOSC=32.768kHz300nA
HFXT External≃4-48MHzfHFXT=4MHz, Rm=300Ω, CL=12pF75uA
fHFXT=48MHz, Rm=30Ω, CL=12pF, Cm=6.26fF, Lm=1.76mH600uA
LFXT32.768kHzXT1DRIVE=0, LOWCAP=1200nA

Internal clock sources have shorter circuit trace and is shielded by MCU structure compared with external clock sources. External clock sources have lower clock jitter, which is also an important emission noise source. As a result, this is hard compare the emission noise between internal and external clock sources.

The general conclusion is that lower clock frequency generates lower emission noise. Internal and external clock selection are case-by-case. To overcome the noise level in typical frequency point, users can also adjust the oscillator frequency.