In a board design there's a mistake in the voltage level to control a reset pin (Signal RESETB). It should be 1.8v but it is driven by a 3.3v level.

The datasheet shows the next info:

enter image description here

It looks like the max level is 3.6v for VDDIO but RESETB max. level depends of VDDIO selected, would it be properly detected the RESETB as a logic high at 3.3V?

Thanks in advance.


Adding device maximum ratings table:

enter image description here

  • \$\begingroup\$ What is VDDIO in your board? If it's 1.8 you should limit the reset voltage to that. \$\endgroup\$ – user_1818839 Feb 3 '20 at 17:33
  • \$\begingroup\$ @BrianDrummond thanks for your comment, the VDDIO is 1.8v and yes the reset voltage should be 1.8v too, but unfortunately there's a mistake and this signal is 3.3v, so I wanted to know if with the given max. ratings it would work with 3.3v without damaging the device? \$\endgroup\$ – joe Feb 3 '20 at 18:10
  • \$\begingroup\$ I'd be busy with razor blade, resistors and patch wire if it was mine. \$\endgroup\$ – user_1818839 Feb 3 '20 at 20:45

The reset input might be properly detected as a high level but it might also damage the "device". The 3.3V signal may forward-bias the input protection diodes for the digital inputs. If a large enough current flows through the diode it can damage the input pin.

You need to check the table of "Absolute Maximum Ratings" for the "device".

  • \$\begingroup\$ thanks for your answer, I added the Absolute Maximum Ratings, and it looks like it is a maximum value of 4V, even so do you think it might damage it? \$\endgroup\$ – joe Feb 3 '20 at 18:22
  • \$\begingroup\$ The RESETB input isn't shown in the part of the maximum ratings table that you are showing us, so we can't make any conclusions from the information you provided. VDDIO appears to be a supply voltage, not an I/O pin voltage. You should give us a link to the datasheet for the device. \$\endgroup\$ – Elliot Alderson Feb 3 '20 at 19:37
  • \$\begingroup\$ yes that´s right, I only posted part of the table than I thought was more related to the RESETB signal, here is the whole datasheet device: mouser.co.uk/datasheet/2/268/00001792A-467994.pdf \$\endgroup\$ – joe Feb 3 '20 at 20:57

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