Find out how easy it is to transfer JESD204 high speed serial data over a fiber-optic link.


Hi, I'm Ed Kohler, the Strategic Marketing Manager for Intersil's Data Converters. Today, I wanted to do a short demonstration of one of the unique capabilities that you can get from a high-speed ADC that has a JESD204B high-speed serial interface.

Now the 204B Standard has some good features, like it serializes the data, uses 8b/10b encoding, and it embeds the clock in the data stream. And these features make it really amenable to being transferred over fiber optics. I have an ADC in one station. I've got a fiber optic communications link, and then I have a receiving station to my right. So with that, let's look at the setup. It's pretty straightforward.

I've got a couple of sources. I've got an ADC and I've got a fiber optic transceiver. ADC is Intersil's ISLA222S. It's a dual-channel 12-bit converter and I've configured it to run on one lane, so both channels put the data on one lane. I'm clocking the dual converters at 150MHz from one source, and I have a 30MHz input signal that I'm splitting and putting into each channel. In one of the channels I added a 10dB attenuation, so that we can see the difference when we look at the data on the screen from channel to channel.

Now, the data is being broadcast over this fiber optic link at 4.5Gb per second. It's only one lane and typically you'd have to have a control signal going from the receiver to the transmitter, called a sync. Intersil's data converters though have the nice feature where we are allowed to software control that sync signal through the spy bus of the ADC. So we can eliminate any cabling necessary.

And on my right is our receiving station. And this station has another Avago fiber optic transceiver. It has another engineering evaluation board that bring in the high-speed serial signals into. It has my FPGA with my 204B receiver and is connected to this PC over here for displaying the data.

So the data is being displayed and, you can see, I have two channels, one is about 10dB smaller than the other. It's the same 30MHz signal in both channels. And I can change the amplitude of the signal. I can turn it on and off. I can clip the ADC. None of that that's really going to present a problem for the 204B link because it's very robust. So that concludes the demonstration.

Now, today I used our dual 12-bit, our ISLA222S, but we actually have a full portfolio from 12 to 16-bit data converters that have sample rates from 125, all the way up to 500 mega samples so there are a lot of variety of products that could fit in the same type of system. And a lot of applications that would find the system valuable. Any time you want to digitize data and then process it in a remote location is a good fit for this.

So, for instance, a large antenna array that you might find in a phased-array radar would be a good point, if you want to take on all the data, digitize it, and then do a lot of processing somewhere else. If you have to send a signal in and out of a tunnel or down a train, where you need to have a remote antenna and a remote processing unit, and possibly even in your cable internet system where you take data from the copper of wires coming out of your house and it gets put on to a fiber optic cable to be sent back up to the central office.

So, thank you for taking the time to view this demonstration and I hope you have a great day.