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Original question:

SN74LV1T04: 26 MHz Clock Level Translator

2N7001T: 20MHz Clock Translator

Y.Ottey
Mastermind 6145 points
Part Number: 2N7001T

Dear all,

I would like to ask about 2N7001T.

Our customer is considering using 2N7001T to change the clock signal of 1.8V (20MHz) to the clock signal of 3.3V as shown in the figure below.
Can the 2N7001T be used for the above purposes?

When I confirm the post of E2E, there is the following link, and 2N7001T was introduced as an IC that can convert the clock signal of 26MHz,

so I think that it can be used for the conversion of the clock signal of 20MHz.

https://e2e.ti.com/support/logic/f/151/p/703024/2591605?tisearch=e2e-sitesearch&keymatch=2N7001T#2591605

Besr Regards,

Y.Ottey

  • 0
    Guru 243110 points

    Yes, the 2N7001T supports a 20 MHz signals at these voltages.

  • 0 in reply to Clemens Ladisch
    Mastermind 6145 points

    Dear Ladisch,

    Thank you for your reply.

    Dear TI team,

    I want you to answer my question.
    Is it the same answer as Mr. Ladisch above?

    Regards,

    Y.Ottey

  • 0 in reply to Y.Ottey
    TI__Mastermind 42600 points

    Hey Y.Ottey,

    Yes.

  • 0 in reply to Dylan Hubbard
    Mastermind 6145 points

    Dear Dylan,

    Thank you for your reply.

    I would like to ask adding question.

    When converting from 1.8V to 3.3V at 20MHz, what is the difference between the rising rate (falling rate) ⊿V/⊿t of the input and output waveforms?

    Regards,

    Y.Ottey

  • 0 in reply to Y.Ottey
    TI__Mastermind 42600 points

    Hey Ottey,

    I'm a little unclear on your question. Are you asking about the recommended input transition rate spec?

  • 0 in reply to Dylan Hubbard
    Mastermind 6145 points

    Hey Dylan

    Thank you for your reply.

    My explanation was insufficient.
    I would like to know how much difference between ⊿Vin/⊿tin and ⊿Vout/⊿tout comes out when converting the voltage level of 20MHz clock from 1.8V to 3.3V.
    (Of course, the condition is that the recommended value of Input transition rise rate is max.100ns/V.)

    I am glad if you can tell me because the reference value is okay.

    Regards,

    Y.Ottey

  • 0 in reply to Y.Ottey
    TI__Mastermind 42600 points

    Hey Ottey,

    This is tough to quantify as the input transition rate doesn't really have anything to do with our device other than the added capacitance from the input, not only that but output transition rate isn't something we have spec'd for this device. As long as trace capacitance is fairly low, its likely that these transition rates will be fairly similar and shouldn't violate any maximum input transition rate specs downstream.

  • 0 in reply to Dylan Hubbard
    Mastermind 6145 points

    Dear Dylan

    Thank you for your reply.

    I have additional questions.

    I was told the other day that it is possible to convert the voltage level of the 20MHz clock from 1.8V to 3.3V using the 2N7001T, but when I checked the data sheet, there was no specification for the frequency of operable signals.
    Is there any reason to support the 20MHz clock?
    (Or, if you can show the reason in the data sheet, please let me know.)

    Our customers are considering the 2N7001T and I have been asked by them why the 2N7001T can support a 20MHz clock, so I would be happy to let you know.

    Regards,

    Y.Ottey

  • 0 in reply to Y.Ottey
    Guru 243110 points

    At these voltages, the maximum propagation delay (tpd) is 14 ns. A 20 MHz clock has 25 ns between signal edges.

  • 0 in reply to Clemens Ladisch
    Mastermind 6145 points

    Dear Ladisch,

    Thank you for your reply.

    As shown in the figure below, when you input a 20MHz clock (25 ns between signal edges), the tpd of the device is max.14ns, so there is no delay of more than a half cycle of the clock. Is it all right to recognize that it corresponds to?

    In other words, is it okay to recognize that a clock with a time between signal edges of 14ns or less (frequency 36MHz or more) is not supported?

    Dear TI teams,

    The reason why it supports the 20MHz clock is considered above, but is it correct?

    Regards,

    Y.Ottey

  • 0 in reply to Y.Ottey
    Guru 243110 points

    Correct.

    But using tpd to derive the maximum frequency results only in a theoretical minimum; the actual maximum frequency is likely to be higher than 36 MHz because the input can change even before the output has finished driving to the target voltage. But TI has not specified this.

  • 0 in reply to Clemens Ladisch
    Mastermind 6145 points

    Dear Ladisch

    Thank you for your reply.

    I understand your answer.

    Dear TI team

    Is the reason why 2N7001T supports 20MHz clock is Ladisch's opinion?
    If you have any other, please let me know.

    Regards,

    Y.Ottey

  • 0 in reply to Y.Ottey
    TI__Mastermind 42600 points

    Hi Ottey,

    Clemens only provided a method for a rough estimation which is not a method I personally use. I know this device can run 20 MHz since i've seen be used in higher frequency applications with no issues. You can always use the dedicated EVM to test this yourself.