SN74AXC8T245: 0.7V to/from 1.8V operation with 4 A to B and 4 B to A signals

Jerry Lipson

Part Number: SN74AXC8T245
Other Parts Discussed in Thread: SN74AVC8T245,

Tool/software:

I have a question related to the DIR lines and minimum 1.4V. I need to translate to/from 0.7V and 1.8V logic and the datasheet is not clear if I can set the DIR lines to have 4 A to B and 4 B to A signals with 0.7V and 1.8V logic levels. The directions will not change during operation and would like to use only one part type for all my I/O signals. Section 7.3.2 does not make it very clear whether this is possible.

2 months ago

0 Michael Ikwuyum 2 months ago

TI__Mastermind 33805 points

Hi Jerry,

The statement is due device compatibility with SN74AVC8T245 (1.2 V device with only 1 DIR pin). Device is optimized for 1.4 V if both DIR pins will be configured differently such as your case. Hence, the recommendation to use the configuration is for 1.4 V. I.e. device can work similar to the previous thread but we recommend 1.4 V, thanks.

Best Regards,

Michael.

+1 Jerry Lipson 2 months ago in reply to Michael Ikwuyum

Prodigy 100 points

The answer didn't answer if the SN74AXC8T245 will function properly translating to/from 0.7V and 1.8V with 4 channels set to inputs and 4 set to outputs (.i.e DIR1/DIR2 set to either L/H or H/H). I need to translate signals to/from a device that has to function at a 0.7V supply and 1.8V FPGA I/O. Please confirm the part will function properly under those conditions.

Jerry

+1 Michael Ikwuyum 2 months ago in reply to Jerry Lipson

TI__Mastermind 33805 points

Hi Jerry,

The part will function properly and translate if both supplies are fully ramped up and stable, thanks.

Best Regards,

Michael.

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SN74AXC8T245: 0.7V to/from 1.8V operation with 4 A to B and 4 B to A signals