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Original question:

CD4504B: 3.3 V to 15 V Translator with CD 4504

CD4504B: CD4504B

Varunesh Kumar
Intellectual 850 points
Part Number: CD4504B
Other Parts Discussed in Thread: SN74LV6T17, OPA4197, TXH0137D-Q1

Hi Clemens

Thank you for your prompt answers as always.

While your answer was meticulous and rigorous and I thank you for that ,

if I were to reduce my Source & Sink requirements to 5 mA Max,  which would be

adequate for my IGBT Drivers while accepting a Vds of 2.5 Volts @ Vdd of 15 V,

Vcc as 3.3 V and Mode Selected as TTL to CMOS , this IC looks reasonably okay

as per the Fig 11 on Pp 3-244

Can you please have a re-look ?

Can avoid having to use Two Packages as one from 3.3 V to say 5V , then using this IC to +15V

Best regards

Varun

  • 0
    Guru 263990 points

    The output drive strength is independent from the input supply voltage.

    5 mA would be possible at 15 V, but only in the typical case at 25 °C. The worst case is as low as 2.4 mA. (See the IOL/IOH characteristics.)

  • 0 in reply to Clemens Ladisch
    Intellectual 850 points

    Hi Clemens

    Thanks again for a prompt reply.

    1. Fully agree that the O/P Drive is dependent only on Vdd which is 15V

        For a 13.5 V O/P , it is 2.4 mA @125*C , but that will be for a Vds of 1.5 V

    2. If I am prepared to accept a Vds of 2.5 V ( Vo as 12.5 V )

        Fig 5 does seem to indicate a 5 mA sourcing capability

        ( My temp would be well below 85*c too )

    3. Fig 11 is not very crisply clear, but it does seem to indicate

        for a CMOS operation, a 3.3 V as Vcc and 15 V as Vdd in that

        shaded area

    4. I do not want to seem to belabour a point , but this could be

        an universal problem in Power Elex, that is translating a 3.3 V

        to 15 V with about 5 mA of S & S, Six Nos 

    5. The alternatives seem to be either a combo of SN74LV6T17

        ( 3.3 V to say 5 V ) followed by CD4504 , or any peripheral Driver

        TPL7407 will require additional Resistor array & possibly another

        peripheral driver

    6. If a Six Ch Low side Driver was available , accepting 3.3 V Inputs,

        Board space could be saved

    7.On the side, my issue of OPA4197 availability was solved when TI Stores

       finally rec'd their quota , and we picked up our lot from there

       FYI , that lot of 250 Nos with reduced SR, was from a UK based source

       Maybe TI could try & investigate this endemic , just thought

       will bring to your attention.

    8. We also had this availability issue with VFC110AP(-2)

        We had picked up some 250 Nos from Rochester's office in S'pore

        Surprisingly , it works fine till 2 MHz but it's linearity goes for

       a toss between 2 & 3.5 MHz.

       We sent 5 Nos to Rochester , USA with our detailed report.

        Their reply was (a) That they do not manufacture that IC , but is

        manufactured by TI, and (b) they do not have the Set up for checking

        V to F Linearity till 3.5 MHz !!

        Disappointing to say the least !!

    Dunno when will TI receive it's quota...

    Thanks again for your valuable support , as always

    Varun

  • 0 in reply to Varunesh Kumar
    TI__Mastermind 26790 points

    Hi Varun,

    To further help clarify, could you help reach out to your TI quality representative for the devices in question?

    I would further recommend considering TXH0137D-Q1 for the level-shifting translation, thanks.

    Best Regards,

    Michael.

  • +1 in reply to Michael Ikwuyum
    Intellectual 850 points

    Thanks Mike

    Could I have their Email ID's please ?

    BR

    Varun

  • +1 in reply to Varunesh Kumar
    TI__Mastermind 26790 points

    Hi Varun,

    You may reach out to the LAMPS team / muzaffar@ti.com to help further clarify the OPA4197 and VFC110AP concerns, thanks.

    Best Regards,

    Michael.

  • 0 in reply to Michael Ikwuyum
    Intellectual 850 points

    Thanks Mike.

    Shall send a detailed mail to Muzaffar with the VFC Reports.

    We are closed for Diwali this week , and as soon as we do open shall do.

    Thanks once again to all of you at TI for such prompt responses

    BR

    Varun

  • +1 in reply to Varunesh Kumar
    TI__Mastermind 26790 points

    Hi Varun,

    You are welcome as we are always glad to help, and happy holidays.

    Best Regards,

    Michael.

  • +1 in reply to Michael Ikwuyum
    Intellectual 850 points

    Many Thanks and same to you , Mike