TCA39306: connection in star configuration

Lars Tischendorf

Part Number: TCA39306
Other Parts Discussed in Thread: TCA9517A, TCA9517, PCA9306, TCA9406, LSF0102, TXS0102

I will replace the TCA9517A with this new TCA39306.

But I use start configuration of multiple TCA9517A. Multiple A-Sides are connetcted together.

Can I replace only one of this TCA9517 with the TCA39306. I havn't found any reference to star configuration in the data sheet.

But the old I2C translators always had restrictions and fixed rules in the star configuration.

over 4 years ago

+1 Lars Tischendorf over 4 years ago

Prodigy 110 points

Lars Tischendorf said:
start configuration

I mean "star configuration"

+1 Clemens Ladisch over 4 years ago

Guru 320310 points

The TCA39306 is a passive switch. Like other such devices (PCA9306, TCA9406, LSF0102, TXS0102), it can be used in any configuration.

The I/Os are not buffered, so each switch will introduce an additonal voltage drop into the line, and each I²C device must be able to sink the current through all pull-up resistors.

+1 Eric Schott1 over 4 years ago in reply to Lars Tischendorf

TI__Guru 53535 points

Hi Lars,

Clemens is right here. For use of true buffers, the side-to-side connections can restrict certain configurations. For passive switches like these, capacitive bus load and total voltage drop across series components is the more restrictive aspect. When swapping between these switches, I don't expect any of these aspects to become an issue if they were not previously.

Let us know if you have any more questions.

Regards,
Eric Schott

+1 Lars Tischendorf over 4 years ago

Prodigy 110 points

Thank you for the quick and meaningful answers. I think I know what to do now.

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TCA39306: connection in star configuration