SN74LVC16T245: Using as bidirectional I/O

Amaru Vilches

Part Number: SN74LVC16T245

Hi,

Can I tie together all 1Bx to 2Bx? The goal is to use 1Ax as inputs (1Bx outputs) and 2Ax as outputs (2Bx inputs)? I mean can I have impedance problems tying together 1Bx and 2Bx? To achieve this 1OE, 2OE, 1DIR and 2DIR are set correctly.

Thanks!

over 4 years ago

0 Amaru Vilches over 4 years ago

Prodigy 50 points

0 Clemens Ladisch over 4 years ago in reply to Amaru Vilches

Guru 273210 points

CMOS inputs have a very high impedance, so this will work.

But the OE pins are not set correctly in the circuit above.

0 Amaru Vilches over 4 years ago in reply to Clemens Ladisch

Prodigy 50 points

Hi,

Thanks for the reply, what do you mean by not set correctly? OE are set to keep only one side (side 1 o side 2) working at a time.

Regards

0 Clemens Ladisch over 4 years ago in reply to Amaru Vilches

Guru 273210 points

When the 1B outputs are disabled, the 2B inputs will not get a valid voltage.

What is the meaning of the DIO_P5_0 signal? What is the desired effect, in both states?

0 Amaru Vilches over 4 years ago in reply to Clemens Ladisch

Prodigy 50 points

Hi,

DIO_P5_0 is a 0V-5V signal.

I want 2 cases:

- BDx in read state : 1Ax to 1Bx direction, 1OE low and 2OE high

- BDx in write state : 2Bx to 2Ax direction, 1OE high and 2OE low

0 Clemens Ladisch over 4 years ago in reply to Amaru Vilches

Guru 273210 points

Sorry, I assumed that the BDx signals are never driven from other devices, and that you wanted to copy the values from the 1Bx outputs.

If the BDx signals also change direction, then this circuit is correct.

0 Amaru Vilches over 4 years ago in reply to Clemens Ladisch

Prodigy 50 points

Thanks

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SN74LVC16T245: Using as bidirectional I/O