TCA9539: ESD Issue with TCA9539PWR IO Expander

Tom Tsao

Expert 1900 points

Part Number: TCA9539

Tool/software:

Dear TI Support Team,

I am contacting you regarding an ESD susceptibility issue observed with the TCA9539PWR IO Expander. During internal testing, the device fails to pass our ESD Air Discharge test at ±10KV, with the IO Expander becoming non-functional after testing.

We would like to inquire if there are any recommendations to improve the ESD tolerance of the TCA9539PWR in our application. Are there specific design considerations, protection circuits, or external components that TI recommends to enhance the ESD robustness for this IO Expander?

Thank you for your support.

11 months ago

0 Clemens Ladisch 11 months ago

Guru 317390 points

This device is not rated for 10 kV.

You have to add external protection. Here is a list of ESD diodes; you have to choose the correct working voltage and other parameters.

0 Tyler Townsend 11 months ago

TI__Mastermind 48358 points

Hi Tom,

TCA9539's esd ratings are shown in table 6.2.

ESD +/-10kV is outside datasheet spec.

Like Clemens has suggested, to improve ESD protection, consider using some external ESD protection. TI has a team dedicated to protection devices and also support the e2e forum.

Please see CLemens' link:

ESD protection diodes product selection | TI.com

Consider these products as a start for I2C external ESD protection:

https://www.ti.com/product/ESD122

https://www.ti.com/product/TPD2E1B06

Regards,

TYler