P82B715: 2 IC connected together using I2C (P82B715 and PCF8575) - any issue?

Poh Kok Keng

Genius 5512 points

Part Number: P82B715
Other Parts Discussed in Thread: PCF8575,

Dar Sir/Madam,

May I check with you:

We have 2 IC connected together using I2C (P82B715 and PCF8575)
P82B715 is a I2C buffer, Vcc is 5V.
PCF8575 is an IO expander, Vcc is 3.3V
We connected their I2C together and pull up to 3.3V.
So far our prototype boards are working without any issue but is the connection correct? We are afraid of other intermittent issue during mass production!

Best Regards,

kpk

0 Chris Ayoub over 3 years ago

Hi Kpk,

You can absolutely use these devices together. If you send me a schematic I can look over it for you.

My one question is are you using two P82B715 to drive an I2C signal over a long cable (high capacitance)? Or are you just looking to buffer a signal?

Best,

Chris

0 Poh Kok Keng over 3 years ago in reply to Chris Ayoub

Genius 5512 points

hi Chris,

I have send the schematic to you privately. Kindly help to review. thx

0 Chris Ayoub over 3 years ago in reply to Poh Kok Keng

Hi Kpk,

You can email me at c-ayoub@ti.com and we can talk about the schematic offline. Since we are moving this to offline I will close the thread.

Best,

Chris

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