TPD12S016: CEC pin need add an external diode or not?

Liao JengAn

Part Number: TPD12S016
Other Parts Discussed in Thread: TPD12S521,

Refer to the below link and comparing with its application schematic of TPD12S521, should we add an external reverse schottky diode on TPD12S016’s CEC pin.

And, why the pull-up(26K ohm) was integrated into the IC pin? Thank you.

https://e2e.ti.com/support/interface-group/interface/f/interface-forum/615308/tpd12s521-about-the-sch-for-tpd12s521

- TPD12S016

over 2 years ago

0 Kuno Wu over 2 years ago

TI__Mastermind 18556 points

Hi Liao JengAn,

IF you just need to pass the 'IEC61000-4-2 (Level 4) ESD Performance at all external pins', you don't need to add a external diode for it.

https://www.ti.com/lit/ug/sllu154/sllu154.pdf?ts=1666602670031&ref_url=https%253A%252F%252Fwww.ti.com%252Fproduct%252FTPD12S016

And integrate this pull-up resistor can reduce the external components, make our application more easy.

Best Regards,

Kuno

0 Liao JengAn over 2 years ago

Prodigy 110 points

Hello Kuno Wu,

Thanks for your quickly response.

According to HDMI spec and CTS (Test ID: 8-14: CEC line degradation), the sink device’s maximum CEC line leakage current should not over 1.8uA in power-off status. In general design, we pulled up the CEC line to 3.3V via 27K ohm at power on, and disconnect the pull-up path at power off. That’s why we need to add a reverse schottky to block the leakage current during the compliance test, right? Thank you.

0 Kuno Wu over 2 years ago in reply to Liao JengAn

TI__Mastermind 18556 points

Hi Liao JengAn,

Yes, you are correct.

Best Regards,

Kuno

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TPD12S016: CEC pin need add an external diode or not?