TCA9546A:

bahram afghani

Part Number: TCA9546A

Hi Folks,

Does this part act as a buffer, or just a switch. I like to know if we need to place a I2C buffer on the chain to be compliant with <400pF.

The data sheet says maximum allowed capacitive load is 400pF, just wanted to make sure!

Thanks,

Bahram

over 4 years ago

0 Max Robertson over 4 years ago

TI__Guru 62910 points

Hi Bahram,

This device acts as a switch rather than a buffer. That is, it conducts the "low" levels between any active channels rather than drive the "low" levels itself via a pull-down driver. So, you would need to be careful about the total capacitance accumulated on all active channels. For applications with >400 pF loading, it is probably best to use a buffered solution.

FYI, we have a new design tool for recommending I2C switch/buffer devices based on master and slave device properties and capacitive loading. You can find it here: https://dev.ti.com/gallery/view/I2CDesigner/i2c-designer/ver/1.0.0/. It may be useful in this case.

Regards,
Max

0 bahram afghani over 4 years ago in reply to Max Robertson

Prodigy 170 points

thanks Max.
bahram

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