Other NXP ProductsのトピックRe: I2C range extender PCA9507

I2C range extender PCA9507

roklipar — Sat, 31 Mar 2018 17:30:03 GMT

Hi guys.

I have two questions regarding PCA9507, I2C bus extender.

Accoding to datasheet, distance, using this IC, is limited 1400pF or 18m on port A.

My questions now are:

1. Is this limit, 18m, having PCA9507 on one side only or it has to be on both sides, if we talk about point-to-point?

2. If I have PCA9507 on both sides, is it OK to have port A towards each other, since there are rise time accelerators?

I am asking this since our board has HDMI input and output ports.

Thank you for your answers.

Enjoy the rest of the weekend.

Rok

guoweisun — Wed, 04 Apr 2018 06:00:25 GMT

Hi,

What's your meaning 'I have PCA9507 on both side '?

It can drive a load up to 1400 pF or distance of 18 m on port A, and 400 pF on port B. Capacitive load decide the distance.

Thanks!

roklipar — Wed, 04 Apr 2018 06:12:29 GMT

Meaning that PCA9507 is on master and slave side, facing, with port A, towards cable or each other.

I can understand that 1400pF is the limit which then defines the actual lenght of line or cable itself.

+-----+ +-----+

---B port ---| IC |-----A port------cable-----A port-----| IC |----B port-----

+-----+ +-----+

guoweisun — Wed, 04 Apr 2018 23:22:39 GMT

What 's your A port to A port distance?

roklipar — Thu, 05 Apr 2018 05:11:15 GMT

Port A on PCA9507 (pins 2 and 3).

EricC5 — Tue, 27 Feb 2024 21:53:11 GMT

I have the same question and I see it was not totally answered here...

Is it better to connect two PCA9507's port-A together or Port-A to B when sending I2C over a 3-foot cable?

My testing shows that Port-A to B seems to be more stable.