DS90UB947-Q1: ESD diode on FPD-Link

Hi Ikram,

The previous E2E ask about the parasitic cap on ESD, but my query is the uni-directional ESD and bi-directional ESD for FPD-Link.

https://www.mouser.com/pdfdocs/AND8424-D.PDF?srsltid=AfmBOoqEOmkc175d4ROh0_AbGjpAwuigo6r3JcPZmfoDUImkZwuAxWus

Regards,

Roy

Hi Roy,

As the other previous E2E says, the ESD itself is not a requirement, and it depends on the customer's system. Although, it could be recommended for ESD protection, given that the signal integrity is not heavily affected beyond the channel specification requirements. 

As for whether to use uni-directional or bidirectional ESD protection diodes, that depends on whether the customer system needs to be protected against only positive ESD strikes, or both positive and negative ESD strikes. Ultimately it depends on the customer's requirements for ESD protection. 

Best regards,
Ikram

Hi Ikram,

After checking with ESD product line, they uni-directional ESD can also against negative ESD strikes.

https://e2e.ti.com/support/interface-group/interface/f/interface-forum/1420727/esd321-unidirectional-vs-bidirectional-esd/5444572#5444572

The difference is DC voltage sweep I-V curve.

As I know, FPD-Link signal is positive swing. Is it correct? Does it mean that we can use uni-directional ESD for FPD-Link?

Roy

Hi Roy, please give me 1-2 days to verify this and get back to you.

Best regards,
Ikram

Hi Roy, 

Please give me a little more time to check this. Since the ESD diodes are typically placed between AC capacitor and connector, we might also need to see if the DC bias will affect this.

- Ikram