TCA39416: TCA39416DTWR delay time issue

Gary Chang

Part Number: TCA39416

Tool/software:

Hello TI team,

The customer is using the TCA39416DTWR level shifter on the I3C bus, as shown in the diagram below.

After measuring the SCL/SDA signals on both the input and output sides of the TCA39416DTWR, we observed a significant delay.

SCL/SDA signals on the input(BMC side) delay time 15.4ns

SCL/SDA signals on the output(SOC side) delay time 6ns

According to the datasheet, the channel-to-channel skew should be less than 3ns, but our measurements show a longer delay that exceeds this specification.

Could you please help us review this issue?

Thanks

4 months ago

0 Tyler Townsend 4 months ago

TI__Mastermind 48178 points

Hi Gary,

I believe channel-to-channel skew should be measured in this way:

For the falling case, an input signal is provided on both A1 and A2. The output on B1 and B2 should propagate within 3 ns of each other.

Regards,

Tyler

0 Gary Chang 4 months ago in reply to Tyler Townsend

Intellectual 490 points

Hello Tyler,

Okay, thanks.

0 Tyler Townsend 4 months ago in reply to Gary Chang

TI__Mastermind 48178 points

Hi Gary,

You're welcome. If no further questions at this time I will close the thread.

Regards,

Tyler

0 Gary Chang 4 months ago in reply to Tyler Townsend

Intellectual 490 points

Hello Tyler,

We tested the tPLH and tPHL of the CLK signal

CLK
tPLH: 5.786 nS (3~10 nS pass)
tPHL: 11.48 nS (2~9 nS fail)

Could you please help review this again? Our current measurement shows a fail on tPHL.

Do you have any suggestions?

Thanks

0 Tyler Townsend 4 months ago in reply to Gary Chang

TI__Mastermind 48178 points

Hi Gary,

Propagation delay is measured from 50% of input voltage to 50% of output voltage from low-to-high or from high-to-low voltage transitions.

See the timing waveform in the datasheet.

The measurement seems correct.

Can you confirm that the following test plan is being followed per the datasheet?

The load capacitance and resistance matter here since this is a propagation delay spec. If the test setup has more capacitive loading (also cap loading from the scope probe), then the propagation delays might be skewed.

Regards,

Tyler

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TCA39416: TCA39416DTWR delay time issue