TCA9517: TCA9517DGKR B port connected to B port

Rajat Singh

Part Number: TCA9517
Other Parts Discussed in Thread: TCA9800, MIO

Hi Team ,

Can you please review the below schematic,where i have conected B side to B Side. The Main I2C_MAIN_SCL/SDA is coming from TCA Device with Port A side.

Note- There is no use case where U21 and U1775 will communicate to each other.

Many Thanks

Rajat

over 1 year ago

0 Clemens Ladisch over 1 year ago

Guru 317360 points

You must not connect two B sides to each other.

Even when U21 and U1775 do not communicate with each other, the B-B connection might result in corrupted signals that look like accesses to the wrong device.

Why do you want to do this? What are the voltages on the left sides? (The TCA9800 would have fewer restrictions on the supply voltages.)

0 Rajat Singh over 1 year ago in reply to Clemens Ladisch

Intellectual 350 points

Hi Clemends,

I have just flip the U1775, can you check now.if looks fine.

VCCO_MIO =1.8V

VCCO_HDIO= 3.3V

0 Clemens Ladisch over 1 year ago in reply to Rajat Singh

Guru 317360 points

Looks OK.

0 Tyler Townsend over 1 year ago in reply to Rajat Singh

TI__Mastermind 48268 points

Hi Rajat,

With the recent changes to the schematic (flipping A and B sides) the implementation looks good.

I don't see pull-up resistors on the MAIN SDA/SCL side. I assume these pull-ups are somewhere else in the schematic. Please make sure there are pull-up resistors on the MAIN side.

Regards,

Tyler

0 Rajat Singh over 1 year ago in reply to Tyler Townsend

Intellectual 350 points

Hi Tyler,

Yes we have kept the Pull up on main I2C Line.

Thanks

Rajat

+1 Tyler Townsend over 1 year ago in reply to Rajat Singh

TI__Mastermind 48268 points

Rajat,

Thanks for completing the story.

The overall implementation looks good.

Regards,

Tyler

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TCA9517: TCA9517DGKR B port connected to B port