TXS0108E: TXS0108E does not work with SN7402 chip

Sergiy Kourashev

Part Number: TXS0108E
Other Parts Discussed in Thread: SN7402

We are using the TXS0108E to connect 3.3V logic to 5.0V logic based on SN7402. It does not work. With more than 4 SN7402 inputs VL above 1.2 V.

If HP 1670D analyzer connected to TXS0108E outputs VH drop to 2.0-2.5 V.

Does TXS0108E works with TTL ?

over 6 years ago

0 Emrys Maier over 6 years ago

TI__Guru* 96947 points

Hello Sergiy,
Can you provide a schematic or block diagram? I'm not entirely sure what you're trying to accomplish from the text above.

0 Sergiy Kourashev over 6 years ago in reply to Emrys Maier

Prodigy 20 points

Hi,

We have an old system based on SN74 series logic.

Our STM32F103VDT6 has a 3.3V logic level and we use a TXS0108EPWR to change level to 5.0V logic.
In our system default for all I/Os is Hi. Active signal is Low.
I/Os of TXS0108EPWR directly connected to SN74 logic I/Os
With more than 3 SN74 inputs connected to same I/O of TXS0108EPWR, Low level raised to 1.5-2V.

Inline image

0 Emrys Maier over 6 years ago in reply to Sergiy Kourashev

TI__Guru* 96947 points

Hey Sergiy,
It looks like the image didn't come through. There's a site that explains how to get images onto E2E here: e2e.ti.com/.../149.4-3-inserting-an-image-on-e2e

0 Emrys Maier over 6 years ago in reply to Emrys Maier

TI__Guru* 96947 points

I'm going to close out this post for now since I haven't heard back from you.

If you are able to post additional details, it will automatically re-open and notify me.

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TXS0108E: TXS0108E does not work with SN7402 chip