I2C_EN/PIN on TMDS181

Hi team,

By the way please also clarify if it's really necessary to use a 65 kOhm resistor on the A1 pin or it's just a typo in the data sheet

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regards,
Igor

Hi Darren,

I2C_EN needs a pullup/pulldown 65k leaving the pin floated would led to a undefined state.

Regards

Hi Igor,

For pin strap mode, A1 is left floated
For I2C mode you need a pullup/pulldown, the pulldown is recommended to have a stronger pulldown.

Regards

Hi Moises,

To be more specific, if it'll be OK to use a zero-ohm resistors for A1 and I2C_EN/PIN pins?

On the figures in the section 9.2 (Typical Applications), each the pin is wired to the resistor (pullup or pulldown), similar to the other control pins nearby. This is consistent with the Pin Function table (page 5) where the logic levels for that control pins are defined as (H) Logic high (pin strapped to VCC through 65 kΩ resistor); (L) Logic Low (pin strapped to GND through 65 kΩ resistor); (for mid-level= No connect).

However, there is no mentioning of the resistors for the A1 and I2C_EN/PIN pins in the table. That pins looks more like an ordinary logic inputs that may be wired directly to GND or Vcc or may be driven by a controller's GPIOs.

A resistor usually has the Cost attribute so it'll be interesting to know if it's really necessary.

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regards,

    Igor

Hi Igor,

You could tie to GND if you are sure a change won't be needed, is a high level is needed you have to use 65k.

If I2C_EN is tied to GND, A1 is left floated

Regards