TXS0108E: High level drop to 50~70%

Jeff YANG

Part Number: TXS0108E
Other Parts Discussed in Thread: TXB0108, TXU0304, TXU0104, TXU0204

Hi,

My customer have issue about level shift application, they using TXB0108 provide some different voltage to LCM module.

MB have a switch to choose Level Shift B side (VCCB) using 3.0 / 3.3 / 5.0V, and Level Shift A side (VCCA) is 3.0V.

At first using TXB0108 only few device can normal let signal work and LCM normal bring up.

And change to TXS0108 more device can normal work and bring up, seems depend on different B side device, may impact A side H level.

Do you have any idea for this issue?

Thanks!

Jeff

0 Clemens Ladisch over 3 years ago

Guru 317080 points

Auto-bidirectional translators necessarily have weak output drivers.

If your signals actually have a fixed direction, you should use buffered translators like the TXU0104/TXU0204/TXU0304.

0 Jeff YANG over 3 years ago in reply to Clemens Ladisch

Hi Ladisch,

For TXU0104, B side also need pull high resistor? Anything should be more care in design? thanks!

Jeff

0 Clemens Ladisch over 3 years ago in reply to Jeff YANG

Guru 317080 points

The TXU has buffered inputs and outputs, so pull-up/-down registers at any I/O pin are no problem.

0 Jeff YANG over 3 years ago in reply to Clemens Ladisch

Hi Ladisch,

You mean B side no needs pull-up/-down resistor, right?

Thanks!

Jeff

0 Clemens Ladisch over 3 years ago in reply to Jeff YANG

Guru 317080 points

The TXU itself does not need them. You circuit might need them (if you want a valid voltage when the TXU is disabled).

0 Jeff YANG over 3 years ago in reply to Clemens Ladisch

Hi Ladisch,

Got it, thanks for explain.

Jeff

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