TCA9517A: EN pin

Michiaki Tanii said:

Part Number: TCA9517A

Hello team,

 

1.      If the device is always active, is the external circuit at EN required?

EN has an internal pull-up to VCCB, so customer think the external circuit would not be required.

[Bobby] The internal pull up resistor is weak (I believe 100k with 20% tolerance). If your end equipment is going to be used in an area where there is a lot of electrical noise which may couple onto the enable pin, then I would suggest a stronger external pull up resistor and maybe even a cap. Otherwise, you can leave it as it.

 

2.      Are there any problem to connect multiple TCA9517A with parallel ?

Customer think it is ok since each TCA9517A can isolate master side.

[Bobby] It depends.... TCA9517A cannot connect to another one if B sides are connected. Can you provide a block diagram so we can verify if the connection is okay?

 

3.       Does idle state indicate the situation that they don’t transfer any data ?

[Bobby] Idle state means that SDA and SCL are both high without any communication occurring so there would be no data transfer.

 

Thank you and best regards,