TXB0106: txb0106

Yuval Fichman

Prodigy 30 points

Part Number: TXB0106
Other Parts Discussed in Thread: SN74LV4T125, SN74LVC07A

I am trying to use the TXB0106 to translate from 3.3V to 5V and drive a LED or a bus driver.

My circuit is attached

I set the A side to 0V or 3.3V and the B side stays at 3state.

Any direction how to solve this?

over 6 years ago

0 Clemens Ladisch over 6 years ago

Guru 320780 points

The schematic is unreadable.

What do you mean with "3state"? What voltage do you measure at the B1 pin?

0 Karan Kotadia over 6 years ago in reply to Clemens Ladisch

TI__Genius 16735 points

Hi,

How many channels to do you need?

If you purchase a TTL compatible buffer. You can just operate it at 5V supply and give it a 3.3V input. This will do up translation for you. Then you can just drive the LED with your buffer. Example device you can use is sn74lv4t125. More here at http://www.ti.com/logic-circuit/voltage-level-translation/unidirectional-voltage-translation/products.html

My concern is that you are using a physical switch. You will need some debounce circuitry.

https://training.ti.com/TLM-APP-DrivingLED?cu=1134826

https://training.ti.com/debounce-switch?cu=1134826

Some useful minute videos you can review.

Thanks!

-Karan

0 Yuval Fichman over 6 years ago in reply to Clemens Ladisch

Prodigy 30 points

as I understand if I set one side of the TXB0106 to a specific logic level the other side follows it and I will not able to pull it to another. when I measure using a DVM or an oscilloscope at the 5V side I see any value from 0.5V to 4V and the value changes during the mesurment that looks like an output in neither "0" nor "1".

0 Yuval Fichman over 6 years ago in reply to Karan Kotadia

Prodigy 30 points

This is just one side of the circuit the other side is translating from 5V logic to 3.3V.

also 3.3V logic can be any value above 1.6V as "1" but still be "0" for the 5V TTL logic.

0 Clemens Ladisch over 6 years ago in reply to Yuval Fichman

Guru 320780 points

The TXB output will be in the middle if there is a large DC load. It can oscillate if there is a capacitive or inductive load, such as long traces or cables.

Please show a readable schematic of your actual circuit, and tell us about the actual problem you're trying to solve.

To drive LEDs from a 3.3 V signal, you can simply open-drain buffers like the SN74LVC07A.

To convert 5 V signals to 3.3 V, you can simply use some buffers with overvoltage-tolerant inputs.

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TXB0106: txb0106