ESD321: Can ESD321 protect 3.3V tolerant USB pins?

yang yang2

Part Number: ESD321
Other Parts Discussed in Thread: STRIKE

Hello, TI expert

ESD321 is designed to protect USB pins of STM32U595 MCU. As datasheet said USB pins are not always 5V tolerant. Sometimes it is 3.3V tolerant, in this case can ESD321 do pretection to ESD strikes?

Yang

2 months ago

0 Bryan Rodriguez de San Miguel 2 months ago

TI__Expert 7010 points

Hi Yang,

The typ clamping voltage of ESD321 for an 8kV strike is 6.8V. This voltage is above the abs max rating of the device so it could damage the line.

Best,

Bryan

0 yang yang2 2 months ago in reply to Bryan Rodriguez de San Miguel

Expert 1480 points

Hi, Byran

Thanks for the reply. But as ESD321 datasheet said, it can be used as USB data line protection, does that mean 5V tolerant USB device can survive at typical 6.8V clamping voltage.

Yang

+1 Bryan Rodriguez de San Miguel 2 months ago in reply to yang yang2

TI__Expert 7010 points

Hi Yang,

No, it means that the line capacitance is low enough so that it will not interfere with USB communication. You still need to make sure that the clamping voltage is below the abs max rating of the USB data line.

In your case, the clamping voltage is above the USB line tolerance so it could damage the pin line.

Best,

Bryan

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ESD321: Can ESD321 protect 3.3V tolerant USB pins?