TXS0104E: overshot in TXS0104

Lacey Lin

Intellectual 2900 points

Part Number: TXS0104E

Hi team,

My customer use the TXS0104 to transmit the voltage of SD card bus.

The schematic is as below:

The A port is 1.8V and B port is 3.3V.

And they see the over shoot in both A port and B port as below:

A port

B port

The voltage of the overshoot will not larger than absolutely value, but it is larger than the recommend value

So can you help to analyze the cause for the overshoot?

in addition, if the overshoot voltage is larger than the recommend VIH, what may be the cause for this? Does it cause the degradation in some specs?

Lacey

Thanks a lot!

over 7 years ago

0 ShreyasRao over 7 years ago

TI__Guru 63920 points

Hi Lacey,

This is a transient event with the time scale less than 5ns, which I will not be worried about very much. The recommended value says Vcci, but for a DC value and not for the transients like these.
Let me know if you have any other questions.

0 Lacey Lin over 7 years ago in reply to ShreyasRao

TI__Intellectual 2900 points

Hi Shreyas,
1. what's the time scale? Do you mean by the one shot function?
2. So you mean we input a DC voltage to input port that larger than Vcci and this will cause the fault function of the internal circuit?

Lacey
Thanks a lot!

0 ShreyasRao over 7 years ago in reply to Lacey Lin

TI__Guru 63920 points

Hi Lacey,

Time scale on the scopeshot is 10ns/division and the other one is 2.5ns/div.
Yes, the DC input voltage at the input port is recommended not to exceed the Vcci

0 Lacey Lin over 7 years ago in reply to ShreyasRao

TI__Intellectual 2900 points

Hi Shreyas,
So you mean the overshoot is a common case.
But the test results in the datasheet don't show the overshoot.
Is this caused by the match resistor or cap load?
Lacey
Thanks a lot!

0 ShreyasRao over 7 years ago in reply to Lacey Lin

TI__Guru 63920 points

Lacey,

Overshoots/undershoots are sometimes unavoidable and common, I would be concerned when the overshoots exceed the abs max ratings.
with matched impedance, loading effects, it can be minimized.

Logic

Logic forum

TXS0104E: overshot in TXS0104