LMH0397: SD-SDI falling edge

Yuta Nishie

Part Number: LMH0397

Hi,

Our customer is using the SD-SDI rate. And the falling edge is specked out (tf<400 ps).

Is there a register that can be designed to slow down the falling edge? If so, please tell me how to change the register address and which bits.

Best Regards,

Nishie

over 2 years ago

0 Nasser Mohammadi over 2 years ago

TI__Guru* 93570 points

Hi Nishi,

Per SMPTE specifications, SD slew rate should be greater than 400ps. LMH0397 is able to meet this requirements.

Regards, Nasser

0 Yuta Nishie over 2 years ago in reply to Nasser Mohammadi

Genius 5340 points

Hi Nasser-san,

Thank you for your reply.

I am currently using LMH0397 and have tested it and found that hundreds of devices have tf>400ps, while a few devices have tf<400ps.

Therefore, I would like to know which register can slow down tf. Can I use the User's Guide(SNLU225) method (3.14.5.2 Slew rate control) to slow down tf?

Best Regards,

Nishie

+1 Nasser Mohammadi over 2 years ago in reply to Yuta Nishie

TI__Guru* 93570 points

Greetings Nishi-San,

I am not aware of a register that can be used to slow down SD rate. Please take a look at app note below to see if you can use a small Cap to slow down SD and other data rates slew rate. I am thinking you can use a much smaller Cap value to slow down the edge rate further.

https://www.ti.com/lit/an/snla299/snla299.pdf?ts=1698876958044&ref_url=https%253A%252F%252Fwww.ti.com%252Fproduct%252FLMH0397%253FkeyMatch%253DLMH0397%2526tisearch%253Dsearch-everything%2526usecase%253DGPN

Regards, Nasser

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LMH0397: SD-SDI falling edge