Hello,
I've read following valuable article: 'TI Designs: TIDA-01630 High EMC Immunity RS485 Interface Reference Design for Tamagawa Encoders'.
However, I could not find whether 'Earth' (plane under SubD-15 female connector) was connected to GND via R1 and C1 during IEC-61000-4-4 Electrical Fast Transient (EFT) test (shown with figure 18). I realize (figure 19) that TIDA-01630 connector was bonded to metal (RF) plate during test, but would like to know what was the case with R1 and C1 - have they been used (placed on pcb) or not?
If not, how was then circuit GND connected to metal plate ('Earth')?
If yes, how that affect function of C12 and C15 (figure 3) or C19 and C 22 used to further improve immunity to CM disturbances?
Thank you,
Svebor