TXB0106: OE pin problem

Hello,

OE pin is over-voltage tolerant and can be biased to VCCA/ VCCB with no concerns (keep in mind the logic thresholds, VIH/VIL of the OE pin is still referenced to VCCA however). What is the status of VCCA/ VCCB during the time of test? Are there any waveforms/schematics that can be shared? 

Regards,
Jack

Hi Jack

This design is used in Audio signals

If the OE pin uses 1.8V, I can't see the ALC888 in Windows 10 but there is a signal at the output, so I try to use 3.3V to control the OE pin and it works normally.

The waveform is the same whether using 3.3V or 1.8V output.

Regards,

Corn Chen

Hi Corn,

I do not see anything unusual in the schematic provided though I am afraid I do understand your statement completely. What are the voltages that the I/Os at A-side and B-side are being referenced to? Any waveforms that can be provided to show the an expected waveform vs. waveform with anomaly? 

Regards,

Jack

Hi Jack

Signal.docx

Sorry Jack, my design is from 3.3V to 1.8V, not 1.8V to 3.3V

The measurements don't look different.

Could it be that the Audio signal is affected by voltage conversion?

Regards,

Corn Chen

Hi Jack

There will be no problem using OE pin with 3.3V. It will only appear when using 1.8V.

Will changing the OE pin voltage affect the bandwidth?

In addition, it was found that the signal output would disappear during measurement. Please refer to file.

TXB0106 Signal measurement.docx

Regards,

Corn Chen

Hi Corn,

No, the OE pin voltage is over-voltage tolerant and will not impact supported bandwidth of device. You may need to zoom in further to see the individual data bits as it is hard to interpret the data currently. 

Jack Guan said:

Can you check if SDI/ SDIO signals are indeed intended signals for level translation meeting section 6.6-6.10 of datasheet (minimum requirement for pulse width duration) and not crosstalk

Were we able to check on the following? 

Regards.

Jack

Hi Jack

The Audio signal frequency is 24Mbps and meets SPEC requirements.

I think the design complies with SPEC because it will be normal if the OE pin is replaced with 3.3V.

I'm measuring and trying to find any differences.

Regards,

Corn Chen

Hi Corn,

This is unusual as I would expect the 24Mbps signal to propagate through our device regardless of OE if connected to VCCA/ VCCB. Please make sure the OE ramp conditions are similar for both cases when connected to 1.8V/ 3.3V.

Is OE constantly being toggled or it is a continuous DC state? Please show OE state at the time of testing (and zoomed in waveforms to see the edges more clearly). 

Regards,

Jack 

Hi Jack

OE is a continuous DC state.

No difference was seen in the test. The output of TXB0106 is the same whether the OE uses 1.8V or 3.3V.

TXB0106 Signal measurement 1.docx

Regards,

Corn Chen

Hi Jack

There is no problem with the waveform, but I want to confirm why the OE cannot use the Audio function normally when using 1.8V according to SPEC.

Regards,

Corn Chen

Hi Corn,

I am not familiar with the "Audio function" in this case, can you elaborate further and how it is different then the provided waveforms? 

Regards,

Jack

Hi Jack

When the OE pin uses 1.8V according to SPEC, the "Audio function" will not be available, but it can be used normally when the OE pin uses 3.3V.

When OE uses 3.3V or 1.8V output, the waveforms are the same and there is no difference.

I can't find a difference in measurements.

Regards,

Corn Chen

Hi Jack

I know the OE pin has overvoltage tolerance and can be connected to the Vccb supply, but that doesn't explain why using 1.8V makes it impossible to use the Audio Function.

Because we can't find any difference between using 3.3V or 1.8V.

Regards,

Corn Chen