• Resolved

MC3303: Suitable dual package of this quad op-amp

Part Number: MC3303

I'm looking for a 8-pin dual equivalent of this quad package. 

Thanks,
Kevin

  • Hello Kevin,

    Please take a look at the TL3472. It has similar supply voltage range and Vcm to the negative supply rail.

    If this device does not fit for your application, please provide additional application details. For example: actual supply voltage rails, input signal characteristics, desired output signal characteristics, bandwidth, application, schematic, accuracy requirements (e.g. offset voltage, drift, etc.), and any other details that you can provide.

    Regards,

    Pete Semig

    General Purpose Amplifier Applications

  • In reply to Pete%20Semig:

    Pete,

    Thanks for the suggestion.  This is a audio buffer amplifier for wide-band (less than 10 kHz) squelch circuitry for analog two-way radio.  It runs from a single supply, 9.6 VDC nominally. Its input and output are capacitively coupled and the non-inverting input is tied to 1/2 Vcc .  The original op-amp declares a "true differential input stage", but I don't know how important that is in this application?

    I've attached a schematic.  The first stage (noise amp) is the one in question.  

    Thanks,

    Kevin

  • In reply to Kevin Custer:

    Hello Kevin,

    Thanks for the schematic! Concerning the terminology "true differential input stage" I don't have a comment just yet. I will have to ask one of our experienced designers. This terminology appears associated with older devices. Ultimately I do not believe this will be an issue in this application. Since there are many people on vacation for the holidays it may not be until the week of 1/9 that I get a response on this.

    The common-mode range and output swing range of the MC3303 given a single 9.6V supply are 0<Vicr<7.6V and approximately 8Vpp given a 9.6V (+/-4.8V) supply as shown by Figure 2. Of course the output swing depends on a number of factors such as load but nonetheless we have an idea of the requirements for a replacement device. The BW is 1MHz and the full-power BW is 9kHz. For the TL3472 given a 9.6V supply, I see no issue with BW, full-power BW, or output swing. The input common-mode, however, is slightly less than the MC3303. It is 0V<Vicr<7.4V. If that's an issue please let me know.

    Ultimately I think it's worth evaluating the TL3472 in the application.

    Hope this helps!

    Regards,

    Pete Semig

    General Purpose Amplifier Applications

  • In reply to Pete%20Semig:

    Pete,

    Thank you so much for your time - considering the Holiday season!  I don't think the input common-mode will be an issue.  How is it that I may be able to obtain a few samples of the TL3472, as I'm not familiar with the process?

    Thanks,
    Kevin

  • In reply to Kevin Custer:

    Kevin,

    TL3472 is better amplifier than single uA741 or quad MC3303. For a dual uA741 there is also the MC1458

    For samples try https://store.ti.com/

    Regards,
    Ronald Michallick
    Linear Applications

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