TCA9554: the Vih in P0-p7

dimitry chen

Part Number: TCA9554

When VCC is above 3V, then Vih is 0.8xVCC.

which is higer than my design.

could you recommend other material which have lower Vih.

0 Eric Hackett over 3 years ago

Dimitry,

What are the power rails in your system? Is it possible to supply the TCA device with the voltage rail supplying your logic?

Regards,

0 dimitry chen over 3 years ago in reply to Eric Hackett

my power rail is 5V.

Based on my understand, Vih should be around 2.x V

is there any reason TCA Vih is higher than normal Vih. (2.X V)

0 Eric Hackett over 3 years ago in reply to dimitry chen

Dimitry,

Since your VCC supply is 5V, the VIH will be 0.8*5V = 4V. The only way to change this would be to lower the VCC supply.

Regards,

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