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Thread: AD724 or 725 which is better and why??

  1. #26
    Robert Garcia's Butler

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    yes, 24. going by the pinout (looking at the traces), it's a sony CXA1645 or compatible chip.
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    Arakon

  2. #27
    Chin's Drinking Partner

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    Arcade 14:
    is this the same thing as the AD725, AD725AR?
    Yes. My samples arrived today, and the print on the chip reads "725AR". My 724s read "724JR". What these suffixes mean, I don't know...

  3. #28
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    RiotoftheBlood:
    Arcade 14:
    is this the same thing as the AD725, AD725AR?
    Yes. My samples arrived today, and the print on the chip reads "725AR". My 724s read "724JR". What these suffixes mean, I don't know...
    The difference in the AR and JR probably has to do with the revision of the silicon chip in the package.
    Remember 99.99999% of what I say is "pure" opinion.

  4. #29
    Robert Garcia's Butler

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    it's usually for temperature ranges and stuff like that. i.e. a JR chip might operate at -20 to +60C, an AR chip at -30 to +80C.

    my samples arrived today as well, my socket adapters should be here by the weekend.. so I can get this set up and report back.
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  5. #30
    Rugal's Thug

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    got my ad724 today and i am wondering where i can get the socket adapters you all have been talking about? maybe a link to a website and what the name of the socket is called. thanks

  6. #31
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    Arakon:
    it's usually for temperature ranges and stuff like that. i.e. a JR chip might operate at -20 to +60C, an AR chip at -30 to +80C.

    my samples arrived today as well, my socket adapters should be here by the weekend.. so I can get this set up and report back.
    Actually they usually define what the lettering after the chip number means in the data sheet. More often than not it usually defines the chip package or operating voltage for devices with multiple versions of these. But seeing as how they never define what it is suppose to be in their data sheet I would go with the guess of it being the chip rev. Because they only list one operating temperature for this device.
    This thread has actually given me an idea for a little project. Which just might be fun.
    Remember 99.99999% of what I say is "pure" opinion.

  7. #32
    Robert Garcia's Butler

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    @arcade14: these are from a german company, selling them only in germany.. they only make them in small quantities.. I suggest going with the link mentioned a few posts ago, I think it's JMKurtz's page which has info on where to find some.

    @Shred: that's why I said "and stuff"
    it differs from chip type to chip type and manufacturer, some define a load of stuff in the extra letters.

    <small>[ September 03, 2003, 08:43 PM: Message edited by: Arakon ]</small>
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  8. #33
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    Ok, back to the oscillators. Let me get this straigt. For the 725's, an external 14.31818 MHz oscillator is needed in order to supply the NTSC clock frequency to the ic. If I were using a 724, I would have to actually build the oscillator. Is this correct? Also, do I want a TTL or CMOS type oscillator?

    <small>[ September 04, 2003, 11:52 AM: Message edited by: Amithraldur ]</small>
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  9. #34
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    Amithraldur:
    Ok, back to the oscillators. Let me get this straigt. For the 725's, an external 14.31818 MHz oscillator is needed in order to supply the NTSC clock frequency to the ic. If I were using a 724, I would have to actually build the oscillator. Is this correct? Also, do I want a TTL or CMOS type oscillator?
    The data sheet calls for TTL logic levels.
    Remember 99.99999% of what I say is "pure" opinion.

  10. #35
    jamma master ry
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    hi all
    anybody ever tried with a sony cxa1145p

    i beleive they are in segas,amiga and others
    so nice and easy to find

    i might rip one from a dead sega master system 2 i have

    here is data sheets:
    <a href="http://labwww.csv.cmich.edu/luke/videogames/General/CXA1145.pdf" target="_blank">cxa1145p</a>

    <a href="http://labwww.csv.cmich.edu/luke/videogames/General/ES71145.pdf" target="_blank">ES71145 Datasheet (CXA1145 Compatible) </a>

    any one ? make_fac

  11. #36
    Robert Garcia's Butler

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    I've used the newer version, the 1645.. couldn't get a stable and color pic out of it.
    also, they need a lot more parts.
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  12. #37
    Chin's Drinking Partner

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    Yea, I've looked at quite a few... the CXA, the AD chips, NTE879 (which is a clone of the old Motorola MC1377), a TI chip... and it looks like the AD725 is the easiest to work with.

    Now if it were in DIP, that would be the shit. buttrock

    I guess it's time to learn how to solder onto pins with a 1.6mm pitch. spock I may need to take some pills to keep my hands steady or something...

    <small>[ September 04, 2003, 07:29 PM: Message edited by: RiotoftheBlood ]</small>

  13. #38
    Robert Garcia's Butler

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    I recommend soldering wires like on resistors and LEDs etc to each pin, then bend them to fit into the holes of stripboard.. that's how I did it with my 724.
    I finally found SO16-&gt;DIP adapters, tho.. they convert the chips to normal DIP size, and are rather cheap.
    --
    Arakon

  14. #39
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    Quote Originally Posted by Amithraldur View Post
    Ok, back to the oscillators. Let me get this straigt. For the 725's, an external 14.31818 MHz oscillator is needed in order to supply the NTSC clock frequency to the ic. If I were using a 724, I would have to actually build the oscillator. Is this correct?
    <small>[ September 04, 2003, 11:52 AM: Message edited by: Amithraldur ]</small>
    I know this is a very old thread but I was just looking up some information on the AD724 and this thread was one of the first hits. The information here is not correct as the AD724 is actually simpler to use than the AD725, though it does lack some advanced features.

    To be clear, you do NOT need to build some special oscillator circuit to use the 724, as stated in the data sheet here: https://www.analog.com/media/en/tech...eets/AD724.pdf
    "When a clock is not available, a low cost parallel-resonant crystal (3.58 MHz (NTSC) or 4.43 MHz (PAL)) and the AD724’s on-chip oscillator generate the necessary subcarrier clock."

    The chip already has its own oscillator, you only have to provide a crystal and depending on the crystal you *may* need to have a 'tuning' cap going to ground. You can see example wiring on page 11 (figure 16).

    Another good example of the 724 being wired up can be found here (though for PAL, you'll need to obviously change the crystal for an NTSC one and wire pin 1 to +5v to select NTSC): http://www.cpcwiki.eu/index.php/RGB_SVideo

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