TPD4E02B04: Confirmation on GND connection

Abhishek singh

Expert 2000 points

Part Number: TPD4E02B04
Other Parts Discussed in Thread: STRIKE

Hi Team

we are using TPD4E02B04D in our design. I have one query if i should connect IC to digital ground ( ie refernce plane for high spped signal , GND for all digital circuit ) or

to chassis GND or EARTH ( connected to metallic body of connector and EARTH of DC power supply) .

How it will behave in both cases and why one should be preferred over other?

over 3 years ago

0 Abhishek singh over 3 years ago

Expert 2000 points

Please Find the attached schematic Chasis GND or Earth is highlighted at Type C connector.

Currently it is different from GND of IC TypeC .pdf

0 Abhishek singh over 3 years ago in reply to Abhishek singh

Expert 2000 points

Hi Team

Please update.

0 Matt Smith3 over 3 years ago in reply to Abhishek singh

TI__Expert 8471 points

Hello Abhishek,

I would recommend that you connect it to the chassis ground. The chassis ground offers a lower impedance and consistent path for ESD strike energy to leave the system. Since the digital ground is used as the reference for digital signaling, an ESD strike may interfere with that function or induce a "ground shift" (a brief change in digital ground's voltage) during an ESD event.

Please see our ESD Protection Layout Guide for additional details: https://www.ti.com/lit/an/slva680/slva680.pdf

Let me know if this answered your question. If so, please click the "Resolve" button.

Regards,
Matt Smith

0 Abhishek singh over 3 years ago in reply to Matt Smith3

Expert 2000 points

Hi Matt

Thanks for reply . You can close this query ,

I always have doubt with chassis GND and Digital GND layout . like

1) How it should be connected to power supply earth

2) Should we keep chassis GND on all layer or single layer will also works fine

3) Can i keep Digital GND below Chassis GND ( what are compromise etc)

4) It should be all round the board or only on connector side ( what is good to have and what is must to have )

etc

Can you help me by providing some documents basic rules .

0 Matt Smith3 over 3 years ago in reply to Abhishek singh

TI__Expert 8471 points

Hi Abhishek,

That layout guide I posted in my previous reply is a really good place to start. If you want more documentation, you can always visit our documentation page to find a document that fits your needs.

Regards,

Matt Smith

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TPD4E02B04: Confirmation on GND connection