TCA9539-Q1: Is the IO level following VCC?

xiwen Yan

Part Number: TCA9539-Q1
Other Parts Discussed in Thread: TCAL6416, TCA6416A

Tool/software:

Is the IO level following VCC, or is it allowed as long as the voltage is less than VCC? If VCC is 3.3V, is the IO level allowed for both 1.8V and 3.3V, or can it only be 3.3V

over 1 year ago

+1 Clemens Ladisch over 1 year ago

Guru 323650 points

Voltages between V_IL and V_IH are not allowed. So you must use 3.3 V signals.

0 Tyler Townsend over 1 year ago

TI__Guru 61008 points

Hi Xiwen,

IO levels follow VCC according to your explanation.

If you need separate logic levels for the I2C and GPIO level side, then consider the TCA6416A or TCAL6416.

Given you are looking at an automotive part, we do not have TCAL6416 or TCA6416A in Q1.

However, we do have TCA6408A-Q1, but this is a 8-bit I2C IO expander and not a 16-bit.

Regards,

Tyler

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TCA9539-Q1: Is the IO level following VCC?