AD724 or 725 which is better and why??

John_Smith · Aug 30, 2003

Hey there! I'm planning on using an Analog Devices AD724 or AD725 in a video encoder board and wanted to know what the difference is if any between the two?

Any advice or opinions welcomed!!

Thanks
Toby

Arakon · Aug 30, 2003

the 725 needs a few less components and is simply the improved version of the 724.

John_Smith · Aug 30, 2003

Thanks Arakon! Is the quality any better with the 725 or is it just a more integrated unit (as in like you said, requires less external parts)??

Put it this way, to get my samples from Analog Devices I'm gonna have to wait like 3 weeks before they can send me the 725 but I can have the 724 right away. Is it worth waiting for the 725 or just go for the 724?

Cheers! wink

Arakon · Aug 30, 2003

I can tell you more about the 725 in 5-10 days.
that's when my samples are supposed to arrive.. got all other parts around.

JHendrix · Aug 30, 2003

I used the AD725 for my RGB circuit, works great. The main difference w/ the 725 over the 724 is that the 725 uses an oscillator to get it's signal where the 724 makes you basically build an oscillator circuit from a crystal. It's not that bad, but I liked the 725.

Also, build in the Y-Trap function of the circuit, it's a filter that REALLY improves the Composite video quality. S-Video isn't affected by it, but that is already good as hell.

Good luck with the circuit, although I reccomend you use a WIDE Surface Mount adapter to get the thing to integrate into a circuit easily.

You can see my final circuit (minus the Y-Trap filter, that's on another small board) here:

<img src="http://web.njit.edu/~jal0737/GFX/Neo-Geo/RGB%20converter.jpg" alt=" - " />

John_Smith · Aug 30, 2003

Thanks guys! JHendrix I take it the oscillator is the square shiny block on your piece of strip board right? I actually have a whole bunch of NTSC 14.31818 Mhz crystals for use with older Motorola chips but never got my damn circuit finished coz I couldn't get my hands on Chroma Bandpass filters or Luma Delay Lines. At least the AD724/725 has these integrated. I'll probably have to use them as I've ordered samples of the AD724. Umm.......expect a certain amount of friendly harassment from me once I get the chips hehehe!!

ttooddddyy · Aug 30, 2003

Anyone got a link to the AD 725 data sheet.

RiotoftheBlood · Aug 30, 2003

John_Smith:
Thanks Arakon! Is the quality any better with the 725 or is it just a more integrated unit (as in like you said, requires less external parts)??

Put it this way, to get my samples from Analog Devices I'm gonna have to wait like 3 weeks before they can send me the 725 but I can have the 724 right away. Is it worth waiting for the 725 or just go for the 724?

Cheers! wink

BTW, when I ordered my samples the site said the 725s wouldn't be ready until Sept. 9, but I received an email today that they were shipped today.

I already have 2 724s... in fact, I had them the day after I ordered.

RiotoftheBlood · Aug 30, 2003

JHendrix:
Good luck with the circuit, although I reccomend you use a WIDE Surface Mount adapter to get the thing to integrate into a circuit easily.

<img src="http://web.njit.edu/~jal0737/GFX/Neo-Geo/RGB%20converter.jpg" alt=" - " />

WIDE surface mount adapter eh? That's what I need... I really wasn't looking forward to trying to work with SOIC ICs without some kind of apapter. Can you tall me anything else about this WIDE adapter, such as where you got it?

Thanks!

[ August 30, 2003, 08:16 PM: Message edited by: RiotoftheBlood ]

RiotoftheBlood · Aug 30, 2003

ttooddddyy:
Anyone got a link to the AD 725 data sheet.

Arcade 14 · Aug 30, 2003

is this the same thing as the AD725, AD725AR?

ttooddddyy · Aug 30, 2003

RiotoftheBlood:

ttooddddyy:
Anyone got a link to the AD 725 data sheet.

Click to expand...

<a href="http://www.analog.com/UploadedFiles/Data_Sheets/774020909AD725_0.pdf" target="_blank">yes</a>

Many thanks, this forum is so so helpfull

[ August 30, 2003, 11:54 PM: Message edited by: ttooddddyy ]

Lagduf · Aug 31, 2003

RiotoftheBlood:

JHendrix:
Good luck with the circuit, although I reccomend you use a WIDE Surface Mount adapter to get the thing to integrate into a circuit easily.

Click to expand...

WIDE surface mount adapter eh? That's what I need... I really wasn't looking forward to trying to work with SOIC ICs without some kind of apapter. Can you tall me anything else about this WIDE adapter, such as where you got it?

Thanks!

Yes, if you purchased your wide surface mount adapter online i too would like to know where you got it. Thanks!

Edit: I stopped being lazy and searched for "wide soic adapter" on google and what do you know but i came up with JHendrix's page! Fortunately he has a link on his page to a company that sells such an adapter. JHendrix is helping members out when he isnt even trying

[ August 31, 2003, 04:53 AM: Message edited by: Lagduf ]

Arakon · Aug 31, 2003

unfortunately I had no luck finding an affordable solution for those in germany.. would someone sell me 2 or 3 of those adapters? I can send the money via paypal and would pay shipping of course.

RiotoftheBlood · Aug 31, 2003

Lagduf:

RiotoftheBlood:

JHendrix:
Good luck with the circuit, although I reccomend you use a WIDE Surface Mount adapter to get the thing to integrate into a circuit easily.

Click to expand...

WIDE surface mount adapter eh? That's what I need... I really wasn't looking forward to trying to work with SOIC ICs without some kind of apapter. Can you tall me anything else about this WIDE adapter, such as where you got it?

Thanks!

Click to expand...

Yes, if you purchased your wide surface mount adapter online i too would like to know where you got it. Thanks!

Edit: I stopped being lazy and searched for "wide soic adapter" on google and what do you know but i came up with JHendrix's page! Fortunately he has a link on his page to a company that sells such an adapter. JHendrix is helping members out when he isnt even trying

buttrock

I did find something similar at digi-key... although they are $70 there! That's a bit ridiculous...

<img src="http://www.logicalsys.com/prodpics/18so1083.jpg" alt=" - " />

Arakon · Sep 1, 2003

those are actually programming adapters, and the socket is the expensive part.. since the chip doesn't need to be swapped all the time, those would be a waste of money.

Amithraldur · Sep 1, 2003

[ September 01, 2003, 09:14 PM: Message edited by: Amithraldur ]

ttooddddyy · Sep 2, 2003

I want one.
Could anybody recommend a supplier for the 725.
I was going to get get a jork for my project but would rather build my own (even if it costs more)
Any links to suppliers appreciated..

Arakon · Sep 2, 2003

order 2 free samples off analog.com.

ttooddddyy · Sep 2, 2003

Arakon:
order 2 free samples off analog.com.

Thanks for the tip Arakon, I registered with AD and tried ordering the samples but get a reply that they do not ship to my country

Emailed them to see if there is a way around that.

NeoGML · Sep 2, 2003

erm...

excuse my ignorance, but what exactly is an AD725/724?

some kind of IC?

what does it do?

supergoose · Sep 2, 2003

afaik ... it's a chip, that is used for converting rgb to composite & s-video. just have a look at the datasheet.

btw ... i'm interested in your projects and might want to order my own samples.

most important :
will it be better than a jrok encoder?

JHendrix · Sep 2, 2003

supergoose79:
afaik ... it's a chip, that is used for converting rgb to composite & s-video. just have a look at the datasheet.

btw ... i'm interested in your projects and might want to order my own samples.

most important :
will it be better than a jrok encoder?

I don't know how good the JROK is, hell it may be based off the same chip for all I know, but I can tell you that the S-Video output on my supergun is extremely good. A few people from around here have seen it and can attest to it looking good.

supergoose · Sep 2, 2003

the jrok's chip seems to be different. (at least the shape)

well ... Winston_Goh once told me, that the super famicom's encoder can be used, too. never had a chance to test it, though.

RiotoftheBlood · Sep 2, 2003

Whatever is in the JROK, it's not the AD725 or AD725 for that matter. The JROK's IC has more pins. I'm too lazy to go look... but I'm certain it has more. Maybe 24 pins total?

[ September 02, 2003, 06:51 PM: Message edited by: RiotoftheBlood ]

AD724 or 725 which is better and why??

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