Are GPIO outputs truly open-drain or are there ESD diodes to the supply rails?

Q&A Forum › Category: ESP32 › Are GPIO outputs truly open-drain or are there ESD diodes to the supply rails?

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Kent Walker asked 5 years ago

Question Tags: GPIO open-drain

2 Answers

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Sara Santos Staff answered 5 years ago

Hi.
I’m sorry for taking so long to answer your question. I missed your question.

To be honest, I’m not sure. The schematic diagrams of the boards are not clear about that. You can find the datasheet and schematic diagrams for some boards here: https://www.espressif.com/en/support/documents/technical-documents. Maybe you can find some useful information.

Is this a critical feature for your project?

Regards,
Sara

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Kent Walker answered 5 years ago

Hi Sara, thanks for your reply. I’ve been through the datasheets and found nothing so far.
I was thinking of using an OC output to control a peripheral that was supplied by a Li-ion battery, which would be fine if the battery was low (ie under 3.3V) but not so wonderful if there are ESD diodes and the battery is charged.
To be safe, I’ve decided to use an external FET to control the peripheral instead