• State Resolved
  • Locked Locked
  • Replies 1 reply
  • Subscribers 62 subscribers
  • Views 267 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

TPSF12C1: REFGND and IGND connection if no PE terminal (1-phase , 2 wire application)

Ken Zhang
Expert 3635 points
Part Number: TPSF12C1


hi, 

      REFGND and IGND pins are all connected with PE terminal on TPSF12C1 EVM.

     To support 1-phase(2-wire) with only L and N terminals, but without PE terminal, how to connect REFGND and IGND pins of TPSF12C1?

  • +1
    TI__Guru* 75502 points

    Hi Ken,

    The REFGND and IGND pins are connected together at the IC and referenced to chassis ground.

    Is there an existing Y-cap in this 2-wire system and does it have an effect on CM attenuation? As you know, this AEF IC effectively increases the value of the Y-capacitance, thus achieving a reduction in shunt impedance from power lines to GND. However, if there is no chassis or low-impedance connection to PE here, then AEF (which is referenced to chassis GND) may not operate as intended.

    If possible, send on a schematic of the existing EMI filter for review. You can also check filter operation by increasing the Y-cap by ~20x (similar to the effect of AEF) and see if the CM noise is reduced. Make sure to examine CM noise separately using CM/DM splitters, as the total noise as measured from the LISN is effectively both DM and CM.

    Regards,

    Tim