SLAA530B March   2012  – July 2021 MSP430F5131 , MSP430F5132 , MSP430F5151 , MSP430F5152 , MSP430F5171 , MSP430F5172 , MSP430F5212 , MSP430F5214 , MSP430F5217 , MSP430F5219 , MSP430F5222 , MSP430F5224 , MSP430F5229 , MSP430F5232 , MSP430F5234 , MSP430F5237 , MSP430F5239 , MSP430F5242 , MSP430F5244 , MSP430F5247 , MSP430F5249 , MSP430F5252 , MSP430F5253 , MSP430F5254 , MSP430F5255 , MSP430F5256 , MSP430F5257 , MSP430F5258 , MSP430F5259 , MSP430F5304 , MSP430F5308 , MSP430F5309 , MSP430F5310 , MSP430F5324 , MSP430F5325 , MSP430F5326 , MSP430F5327 , MSP430F5328 , MSP430F5328-EP , MSP430F5329 , MSP430F5333 , MSP430F5335 , MSP430F5336 , MSP430F5338 , MSP430F5340 , MSP430F5341 , MSP430F5342 , MSP430F5358 , MSP430F5359 , MSP430F5418 , MSP430F5418A , MSP430F5419 , MSP430F5419A , MSP430F5435 , MSP430F5435A , MSP430F5436 , MSP430F5436A , MSP430F5437 , MSP430F5437A , MSP430F5438 , MSP430F5438A , MSP430F5438A-EP , MSP430F5500 , MSP430F5501 , MSP430F5502 , MSP430F5503 , MSP430F5504 , MSP430F5505 , MSP430F5506 , MSP430F5507 , MSP430F5508 , MSP430F5509 , MSP430F5510 , MSP430F5513 , MSP430F5514 , MSP430F5515 , MSP430F5517 , MSP430F5519 , MSP430F5521 , MSP430F5522 , MSP430F5524 , MSP430F5525 , MSP430F5526 , MSP430F5527 , MSP430F5528 , MSP430F5529 , MSP430F5630 , MSP430F5631 , MSP430F5632 , MSP430F5633 , MSP430F5634 , MSP430F5635 , MSP430F5636 , MSP430F5637 , MSP430F5638 , MSP430F5658 , MSP430F5659 , MSP430F6433 , MSP430F6435 , MSP430F6436 , MSP430F6438 , MSP430F6458 , MSP430F6459 , MSP430F6459-HIREL , MSP430F6630 , MSP430F6631 , MSP430F6632 , MSP430F6633 , MSP430F6634 , MSP430F6635 , MSP430F6636 , MSP430F6637 , MSP430F6638 , MSP430F6658 , MSP430F6659 , MSP430F6720 , MSP430F6720A , MSP430F6721 , MSP430F6721A , MSP430F6723 , MSP430F6723A , MSP430F6724 , MSP430F6724A , MSP430F6725 , MSP430F6725A , MSP430F6726 , MSP430F6726A , MSP430F6730 , MSP430F6730A , MSP430F6731 , MSP430F6731A , MSP430F6733 , MSP430F6733A , MSP430F6734 , MSP430F6734A , MSP430F6735 , MSP430F6735A , MSP430F6736 , MSP430F6736A , MSP430F6745 , MSP430F67451 , MSP430F67451A , MSP430F6745A , MSP430F6746 , MSP430F67461 , MSP430F67461A , MSP430F6746A , MSP430F6747 , MSP430F67471 , MSP430F67471A , MSP430F6747A , MSP430F6748 , MSP430F67481 , MSP430F67481A , MSP430F6748A , MSP430F6749 , MSP430F67491 , MSP430F67491A , MSP430F6749A , MSP430F67621 , MSP430F67621A , MSP430F67641 , MSP430F67641A , MSP430F6765 , MSP430F67651 , MSP430F67651A , MSP430F6765A , MSP430F6766 , MSP430F67661 , MSP430F67661A , MSP430F6766A , MSP430F6767 , MSP430F67671 , MSP430F67671A , MSP430F6767A , MSP430F6768 , MSP430F67681 , MSP430F67681A , MSP430F6768A , MSP430F6769 , MSP430F67691 , MSP430F67691A , MSP430F6769A , MSP430F6775 , MSP430F67751 , MSP430F67751A , MSP430F6775A , MSP430F6776 , MSP430F67761 , MSP430F67761A , MSP430F6776A , MSP430F6777 , MSP430F67771 , MSP430F67771A , MSP430F6777A , MSP430F6778 , MSP430F67781 , MSP430F67781A , MSP430F6778A , MSP430F6779 , MSP430F67791 , MSP430F67791A , MSP430F6779A , MSP430FR2000 , MSP430FR2032 , MSP430FR2033 , MSP430FR2100 , MSP430FR2110 , MSP430FR2111 , MSP430FR2153 , MSP430FR2155 , MSP430FR2310 , MSP430FR2311 , MSP430FR2353 , MSP430FR2355 , MSP430FR2422 , MSP430FR2433 , MSP430FR2475 , MSP430FR2476 , MSP430FR2512 , MSP430FR2522 , MSP430FR2532 , MSP430FR2533 , MSP430FR2632 , MSP430FR2633 , MSP430FR2672 , MSP430FR2673 , MSP430FR2675 , MSP430FR2676 , MSP430FR4131 , MSP430FR4132 , MSP430FR4133 , MSP430FR5041 , MSP430FR5043 , MSP430FR50431 , MSP430FR5720 , MSP430FR5721 , MSP430FR5722 , MSP430FR5723 , MSP430FR5724 , MSP430FR5725 , MSP430FR5726 , MSP430FR5727 , MSP430FR5728 , MSP430FR5729 , MSP430FR5730 , MSP430FR5731 , MSP430FR5732 , MSP430FR5733 , MSP430FR5734 , MSP430FR5735 , MSP430FR5736 , MSP430FR5737 , MSP430FR5738 , MSP430FR5739 , MSP430FR5739-EP , MSP430FR5847 , MSP430FR58471 , MSP430FR5848 , MSP430FR5849 , MSP430FR5857 , MSP430FR5858 , MSP430FR5859 , MSP430FR5867 , MSP430FR58671 , MSP430FR5868 , MSP430FR5869 , MSP430FR5870 , MSP430FR5872 , MSP430FR58721 , MSP430FR5887 , MSP430FR5888 , MSP430FR5889 , MSP430FR58891 , MSP430FR5922 , MSP430FR59221 , MSP430FR5947 , MSP430FR59471 , MSP430FR5948 , MSP430FR5949 , MSP430FR5957 , MSP430FR5958 , MSP430FR5959 , MSP430FR5962 , MSP430FR5964 , MSP430FR5967 , MSP430FR5968 , MSP430FR5969 , MSP430FR5969-SP , MSP430FR59691 , MSP430FR5970 , MSP430FR5972 , MSP430FR59721 , MSP430FR5986 , MSP430FR5987 , MSP430FR5988 , MSP430FR5989 , MSP430FR5989-EP , MSP430FR59891 , MSP430FR5992 , MSP430FR5994 , MSP430FR59941 , MSP430FR6005 , MSP430FR6007 , MSP430FR6035 , MSP430FR6037 , MSP430FR60371 , MSP430FR6041 , MSP430FR6043 , MSP430FR60431 , MSP430FR6045 , MSP430FR6047 , MSP430FR60471 , MSP430FR6820 , MSP430FR6822 , MSP430FR68221 , MSP430FR6870 , MSP430FR6872 , MSP430FR68721 , MSP430FR6877 , MSP430FR6879 , MSP430FR68791 , MSP430FR6887 , MSP430FR6888 , MSP430FR6889 , MSP430FR68891 , MSP430FR6920 , MSP430FR6922 , MSP430FR69221 , MSP430FR6927 , MSP430FR69271 , MSP430FR6928 , MSP430FR6970 , MSP430FR6972 , MSP430FR69721 , MSP430FR6977 , MSP430FR6979 , MSP430FR69791 , MSP430FR6987 , MSP430FR6988 , MSP430FR6989 , MSP430FR69891

 

  1.   Trademarks
  2. 1Introduction to ESD
    1. 1.1 Component-Level ESD Rating
      1. 1.1.1 Human Body Model (HBM)
      2. 1.1.2 Charged Device Model (CDM)
    2. 1.2 System-Level ESD Rating
    3. 1.3 ESD Waveforms
  3. 2General System-Level ESD Design Guidelines
    1. 2.1 Enclosures
      1. 2.1.1 Enclosure Openings
      2. 2.1.2 Enclosure Cables
    2. 2.2 PCB Design and Layout
      1. 2.2.1 Example Layout – Current Loop
    3. 2.3 On-Board ESD Protection Devices
      1. 2.3.1 Simple Passive Components
      2. 2.3.2 ESD Suppression Devices
      3. 2.3.3 ESD Protection Using Series Resistor
    4. 2.4 Circuit Design and Software Considerations
      1. 2.4.1 Circuit Design
      2. 2.4.2 Software Considerations
    5. 2.5 ESD Testing
  4. 3System Efficient ESD Design (SEED)
    1. 3.1 System-Level ESD Protection Methodology
      1. 3.1.1 On-Board Protection – Primary Clamp
      2. 3.1.2 On-Chip Protection – Secondary Clamp
      3. 3.1.3 Two-Stage Protection – Fundamental SEED Concept
    2. 3.2 SPICE Simulation Methodology for System-Level ESD Design
  5. 4SEED-Based IEC Protection Design and Verification – Real World Example 1
    1. 4.1 Modeling IEC Stress Waveform
    2. 4.2 Modeling TVS Device
    3. 4.3 Modeling MSP430 I/O Pin
    4. 4.4 Isolated Impedance Calculation
    5. 4.5 SPICE Simulation – SEED Method
    6. 4.6 Board-Level Verification
  6. 5System-Level ESD Protection – Real World Example 2
  7. 6Summary
  8. 7Modeling Using TLP Parameters
    1. 7.1 Modeling TVS Device Using TLP Parameters [8]
    2. 7.2 Modeling IC Interface Pin to be Protected Using TLP Parameters [8]
  9. 8References
  10.   Revision History

2.3.3 ESD Protection Using Series Resistor

Consider a system where an MSP430 IC is interfaced to an LCD that is susceptible to ESD (secondary or residual ESD stress in the system). In this case, LCD pins represent the ESD entry points in the system; so, it is recommended to place series resistors on the LCD pins. When an ESD event occurs in the system, the series resistor limits the current that finally strikes the MSP430 I/O pin. The larger the value of resistance, the lower is the residual current seen at the interface I/O pin.

Note:

If standalone resistors are used for primary ESD protection, they must withstand the full electrostatic voltage. This requires resistors that are designed for high voltages, and these usually have a larger footprint.

The series resistors can be combined with additional diodes and primary clamping devices for added protection (see the equivalent circuit shown in Figure 2-13). The diodes at the I/O pins divert the ESD current to the primary clamp (between VCC and VSS), and only the residual stress appears at the device I/O pins. The decoupling capacitor at the supply pins helps limit the initial fast transients of the ESD pulse.

GUID-D6523FB3-073F-4E12-A7C9-5524BB50080E-low.pngFigure 2-13 System-Level ESD Protection Using Series Resistors

See Section 5 for a real-world example based on this concept.

Note:

The simple series resistor protection technique works for low levels of ESD stress (secondary protection of indirect ESD or residual ESD current); however for higher ESD stress (primary protection of direct ESD), suppression devices such as TVS diodes, varistors, and polymers should be considered.