SN74LVC244A Propagation delay time

Seishin

Genius 4135 points

Hi ,

Propagation delay time is varied in our custom circuit board.

Is there a change in the delay time in the same device?

Is there something that is considered to be the cause of that?

Regards,
Seishin

over 9 years ago

0 Cameron Phillips over 9 years ago

TI__Genius 12410 points

Seishin,

Can you give me more information about your set up? Also can you clarify on your scope shots they both say 2A3 and 2Y3. Are you saying there is a difference between parts or channels?

Also both of those propagation delays are in the min and max spec for any VCC so they are valid.

Regards,

Cameron

0 Seishin over 9 years ago in reply to Cameron Phillips

Genius 4135 points

Dear Cameron,

Thank you for the reply.

Sorry for not replying sooner.

I say the difference between the revision of the chip.

I think that there is a difference of the tpd between the old revision and the new one of chip.

However, I am aware that the value is within the specifications.

When the chip is changed to the new revision,Is the data sheet revised?

If it is possible,would you send me the original data of these tpd vs CL graphs?(Figure 1. and Figure 2. in the data sheet)

Figure 1 is data of the latest chip revision?

www.ti.com.cn/.../sn74lvc244a.pdf

Best regards,
Seishin

0 Seishin over 9 years ago in reply to Seishin

Genius 4135 points

Hi Cameron,

Any update on this?

Best regards,
Seishin

0 Cameron Phillips over 9 years ago in reply to Seishin

TI__Genius 12410 points

Seishin,

When we change the die the datasheet is not changed. The die revision point is to meet the specs of the datasheet, otherwise it would be a new part number.

We only guarantee that the device will be in between the min and max spec.

Regards,

Cameron

0 Seishin over 9 years ago in reply to Cameron Phillips

Genius 4135 points

Hi Cameron,

Thank you for the information.

We will redesign the circuit board in order to solve this problem.

Best regards,
Seishin

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SN74LVC244A Propagation delay time