Dir1703

[dmfraser]

Be warned that TI has discontinued this part with NO warning. Standard procedure is to indicate a part is not going to be available after a certain date and marking it as "Not Recommended For New Designs".

Instead TI has simply dropped it without warning. Here is the message that TI sent me in response to my inquiry.
________________________________

Dan,

Thank you for contacting the Product Information Center at Texas Instruments. My apologies for the delayed response. The part DIR1703 is not recommended for new designs and the product group chose to remove all information from the external website. There are plans for new design and support models for the DIR parts in the future but unfortunately this does not include DIR1703. At this time there is no information as to a replacement for this device. We apologize for any inconvenience this may cause and if there is anything else that we can help you with, please let us know.

Regards,

Rodney Brown
Texas Instruments
Semiconductor Technical Support
http://www-k.ext.ti.com/sc/technical...c/americas.htm

_______________________________________

I can't blame this guy. He's just a spear carrier. However, I asked him to tell the powers that be at TI thank you for pointing out that TI is not a reliable supplier and that we should look elsewhere for our semiconductor needs.

In my case I had several products in development that used this chip, some of which were sold already and now I have to do them all over using a Cirrus chip. Tens of thousands of dollars of engineering work is out the window.

So be warned. TI cannot be trusted to give warning when a device is to be pulled. It looks like the TAS5015 PWM chip met the same fate too.

[Wodgy]

I'm surprised the tech support guy didn't send you a copy of the letter TI released when they discontinued this part. I can't find a link to it off the top of my head, but the gist of it was that the part had at least one fairly serious flaw where it would often refuse to sync to an new sample rate after having synced to an earlier one. I've also heard from someone who was using the part that it was quite flaky as to what signals it would accept. He had several customers complain that they couldn't get the receiver to sync with their CD players.

Of course, this doesn't excuse TI's behavior. The supply should not have been cut off so quickly, regardless of how severe the flaws were.

[gmarsh]

Yes... it appears that TI no longer makes digital interface receivers. Honestly, i'm not surprised.

The DIR1703 chip's data sheet is *painful* to read; I can't make much sense out of it, except that the chip doesn't have much going for it... I could be completely wrong in my following statements, but I blame the datasheet for that

The Crystal CS841x parts are a joy to use. They integrate an internal RS422 receiver and a MUX, and don't require any external crystals. And they'll recover a clock from any signal you feed them - the '8416 is happy from 32 to 192KHz and anything in between.

But the DIR1703 doesn't include a receiver, and needs an external crystal or some other clock source attached to it. And from the looks of things, you can make the chip decode 44.1/88.2 or 32/48/96, not both. I suppose you could use two crystals or another PLL to make it support both rates, but that makes the chip even more complicated to use. And what's the point? is the recovered clock of the "SpAct"-equipped chip so much better to justify the extra complication?

Obviously I haven't designed it into anything. Wouldn't surprise me if the chip disappeared just because few people were buying it.

TI makes great stuff. I'm just hoping that the next digital audio interface receiver that they come out with is far better than this one...

[dmfraser]

On the contrary, I designed the 1703 into several products and I found it very easy to use. Yes, the data sheet was confusing but the engineers at TI were helpful getting over a rough spot or two. But when building a dumb receiver, where it went straight to a D/A converter, the DIR1703 needed far less external support. The CS8414 I had difficulty figuring out.

And, the DIR1703, has no problem taking a signal from 32KHz to 96KHz and simply spitting out the I2S audio from it as well as all the necessary clocks. And I could use it as the master clock generator for the system as well. It also had a single pin I could use to switch the de-emphasis/emphasis on or off when switching between a 48K and 96K input.

The Cirrus chip needs gating to decode three lines to make this determination. The CS841x series was really meant to work with an external microcontroller while the DIR1703 was designed to work just as well in a stand alone mode.

If anyone has a basic stand alone receiver circuit for the CS8414 figured out to take between 44.1K and 96K input, please post it.

[Elso Kwak]

Hi Dan, I agree the policy of TI is extremely unfortunate and blunt. But did you have good results with your prototype and this DIR1703 chip? I would go for the AD receiver. The CS8412 had also all kinds of problems in the old days and only really sings if you do a lot in front of it and a better PLL filter and analog supply and.........

[Charles Hansen]

Originally posted by Elso Kwak
I would go for the AD receiver.

Hi Elso,

I didn't know AD (presumably Analog Devices) made a receiver chip. Do you have a part number?

Receivers must be fairly difficult to make, because not many people make them! I've done a project using one of the AKM receivers and was very pleased with the part, the data sheet, and the results. One good thing about TI entering the market was that it forced Crystal to lower their formerly outrageous prices.

Best regards,
Charles Hansen

[zinsula]

Originally posted by Charles Hansen
I didn't know AD (presumably Analog Devices) made a receiver chip. Do you have a part number?

Charles, check out the AD1892, it's a receiver with ASRC intergrated. Maybe it's this part Elso is referring to.

Cheers, Tino

[Elso Kwak]

Originally posted by Charles Hansen


Hi Elso,

I didn't know AD (presumably Analog Devices) made a receiver chip. Do you have a part number?

Receivers must be fairly difficult to make, because not many people make them! I've done a project using one of the AKM receivers and was very pleased with the part, the data sheet, and the results. One good thing about TI entering the market was that it forced Crystal to lower their formerly outrageous prices.

Best regards,
Charles Hansen

Hi Charles,
Yes I meant the Analog Devices part AD1892. Unfortunately that one is also near obsolescence now. It is an integrated receiver/sample rate converter.
Do you have a source for the AKM part for us lower echelon mortals? (not OEM)

[Jocko Homo]

Especially the input stage. You can take that RS422 stuff and shove it.

Jocko

[Elso Kwak]

Originally posted by Jocko Homo
Especially the input stage. You can take that RS422 stuff and shove it.

Jocko

Jocko, Thanks for the enlightment!