Fast ADC chip with LNA/PGA/AAF

[mr_byte31]

Hi,

I am planning to use AD8285. it is a magic IC since it has all (LNA/PGA/AAF/ADC) what I need on one chip. It shall make my life easier since I don't need to have many components on my PCB. I can control the input gain and LPF.  The ADC has12 bits of accuracy up to 72 MSPS .  

The board has 4 channels but I am planning to use one channel only.

The price is $22 per chip and it is within my budget.

I found that there exist an evaluation board from Analog Device but it costs $1,155.60 !!!

does any body understand why this crazy stuff for the board?

are anyone aware about similar IC which is cheaper ?

[optikon]

Well, it doesnt seem like it is not the components on board costing that much. Maybe they build to order ? Software needed for it?
It is strangely very expensive. If you have an ADI rep, you could likely get one on loan or to keep for free, I'm guessing.

[Manuel]

The AD8285 is really a "special" product because to let you have such a high conversion rate (even granting it multiplexed) it has for the 4 main bipolar input channel the "signal treatment" as if each input is working stand alone...
This feature let you have not muxing adj time lost essentially....

It is really uncommon, so I'd avoid using it, because those features makes it really "white mosquito" ....

Personally I suggest you to move in a different direction.

take care,
X!

[mr_byte31]

Thx for the hint.

I will configure AD8285 to have one input so the MUX will not switch between different inputs.

I tried to search for a single channel IC but couldn't find any.

do you have better ICs to use?

[Manuel]

It depend on your application,

try to Check other Analog Device products.

It is not easy to find such similar product ... too specific.

Anyhow the cost of the product itself (AD8285) is close to 40$ for a single component....

In production I think you can find it close to 1/3 .. 1/4 ...

take care,
X!

[mr_byte31]

its so cheap on Aliexpress : https://www.aliexpress.us/item/3256805620126928.html

[Sideshow Bob]

its so cheap on Aliexpress : https://www.aliexpress.us/item/3256805620126928.html

If things are too good to be true, they most often are. I can not say it is a fake with 100%. But with a reel price(2000) of $10.70. Something do not quite pass the sniff test here. So I would at least approach with caution. A trick they may use use. If you order 1 they send you a good one. To lure you in

[optikon]

its so cheap on Aliexpress : https://www.aliexpress.us/item/3256805620126928.html

uh huh. lol

[Vineyards]

As we all know, buying components from Aliexpress, eBay, and the like is just a gamble. They look very similar but generally come in two flavors: potato chips and lesser-performing reverse-engineered ones. Your other options are to buy it from Digikey, Mouser, or Farnell and get shafted for good or get it directly from the producer. Component provision has always been a pain. They don't want to let hobbies and small-scale designers lay their hands on them quickly. Otherwise, big companies would plan to liquidate some surplus stocks through online stores at more reasonable prices. Instead, we observe tons of stock waiting until they become obsolete.

[Manuel]

I suggest you to use just the standard distribution chain.

Once mounted a component it can cost you more to rework than mount a new board....

Do not do silly acts.... :-D

Preserve your capitals and you will work more relaxed...

X!

[vern]

I have bought a lot of chips from Aliexpress during the chip shortage the last few years, most of them were good, but some didn't even have silicon in them.
They looked real from the outside but they were nothing but plastic and pins, no chip inside.
I also had Mosfets which were obviously outfitted with cheaper chips because they blew right away, whereas the original ones had no problems at all.
I also had reballed BGA's, they did work, but you could feel they were sandblasted when you touched the surface and the labeling was a bit off. They were of course sold as brandnew.
But as I said, mostly the chips were new and ok. When you are desparate you can take the risk, if you can buy the chips somewhere else from a source with a good reputation for a higher price I would recommend that. Saves a lot of headaches.

[Vineyards]

Well, with specific old chips whose production ceased years ago, you are guaranteed to end up with a potato chip. If it is a hot-selling new chip sold way cheaper than the original, be prepared for surprises. If you know the dealer, and if you have frequently done business in the past, he might either not sell you a fake product or accept taking it back and refunding the money you paid. It all boils down to mutual interest. Try to reward a reliable seller by returning to him for further purchases. In many cases, you can get valuable information from him about other dealers too.