TLC555: Regarding propagation delay

Daisuke Higa

Part Number: TLC555

Hello support team all.

I found the following post.

[FAQ] TLC555: What are the performance differences expected for TLC555 PCN 20231130002.1? - Clock & timing forum - Clock & timing - TI E2E support forums

It seems that the propagation delay time is controlled very small in the products of the new process, but there seems to be a big gap with the data of propagation delay time in the data sheet.
Is the measurement condition different?
Or is the data in the data sheet wrong?

Also, regarding the calculation tool in the following site, could you tell me the details of the calculation formula of H period and L period with diode?
I think the delay time is substituted in the calculation formula, but since there is no specific information, I cannot verify whether the result is correct.

www.ti.com/.../TLC555CALC

The process is new and many problems occur. I would like to organize the correct information, so please cooperate.

Best regards,

16 hours ago

0 Ron Michallick 1 hour ago

TI__Guru**** 174046 points

Hello DH,

That PCN did result in delay being much shorter as described in FAQ. A later PCN 20260217004 changes design to make delays closer to original. The current data sheet is updated for this new PCN.

Daisuke Higa said:
I cannot verify whether the result is correct.

What is the desired frequency and duty cycle and what value were chosen?