TXB0304: bidirectional level translator sensing issue

VISHNU K

Part Number: TXB0304
Other Parts Discussed in Thread: SN74AXC4T774

Hi,

Anyone, please explain.

During our 3.3V to 1.8V level translation, When we power on the IC, we could not able to detect the JTAG lane of my FPGA,

But when we removed the level translator from the path and wired it to the JTAG debugger, it works fine too. How to debug this issue?.

Also, let me know is there any pin to pin alternate for the IC TXB0304.

0 Clemens Ladisch over 4 years ago

Guru 316920 points

To debug this issue, we need the schematic. And are there any long traces, connectors, or cables?

It is likely that the circuit violates the requirements described in sections 8.3.1 and 8.4.2 of the datasheet.

0 VISHNU K over 4 years ago

This is the total set up we are using.

0 Clemens Ladisch over 4 years ago in reply to VISHNU K

Guru 316920 points

4.7 kΩ is too strong.

For unidirectional signals, you can use a direction-controlled translator like the SN74AXC4T774, which is much more robust.

0 VISHNU K over 4 years ago in reply to Clemens Ladisch

Hi,

tried with 1K, No pullup, and also with 50K still the same issue.

bypassing the level translator, it is working fine now.

0 VISHNU K over 4 years ago in reply to VISHNU K

is there any way to solve this issue without go for a board respin?

0 Clemens Ladisch over 4 years ago in reply to VISHNU K

Guru 316920 points

There is no compatible translator in the RSV package.

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