SN65HVD72: Replacement with SN65HVD75DR?

Furkan Fehmi Sefiloglu

Part Number: SN65HVD72
Other Parts Discussed in Thread: SN65HVD75

Hi Team,

Can you please check and advise with request?

We use the SN65HVD72DR product for RS485 communication in our products. But there is currently a stock problem. For this reason, we are considering using the SN65HVD75DR, which allows higher speed communication.

We were unable to perform any tests on the SN65HVD75DR, so we would like to get approval from a Texas. If SN65HVD75DR is installed instead of SN65HVD72DR without making any hardware/software changes, is there any possibility of problems in communication?

Thanks in advance

Best Regards

Furkan Sefiloglu

over 3 years ago

0 Eric Hackett over 3 years ago

TI__Guru 69662 points

Furkan,

What data rate is the customer using? The only difference between these two devices is the data rate allowed, the SN65HVD75 works up to 20Mbps while the SN65HVD72 only works up to 250kbps.

Regards,

Eric Hackett

0 Nihan Arslan over 3 years ago in reply to Eric Hackett

Prodigy 50 points

Hello Eric,

Our maximum baud rate is 115200 and minimum baud rate is 9600. So we think there won't be any problem with communication. But would there be any EMI issue?

0 Eric Hackett over 3 years ago in reply to Nihan Arslan

TI__Guru 69662 points

Nihan,

The EMI should be the same between both devices. The rise and fall times are the same for either device, and you're using the same data rate as before.

Regards,

Eric Hackett

0 Nihan Arslan over 3 years ago in reply to Eric Hackett

Prodigy 50 points

I see.. I saw a post that says there might be EMI or signal integrity problem due to fast edges if there won't be any problem like that, that's a relief.

0 Clemens Ladisch over 3 years ago in reply to Nihan Arslan

Guru 277130 points

The HVD72's outputs have much slower rise/fall times (compare sections 7.7 and 7.8 of the datasheet), so the HVD75 is likely to generate more high-frequency noise.

0 Eric Hackett over 3 years ago in reply to Clemens Ladisch

TI__Guru 69662 points

Good catch Clemens, I didn't notice the heading specifically for the SN65HVD72 and SN65HVD75. But you are correct, the EMI from the faster edge rates will be higher on the SN65HVD75 compared to the SN65HVD72. Sorry for the confusion Nihan.

Regards,

Eric Hackett

Interface

Interface forum

SN65HVD72: Replacement with SN65HVD75DR?