A/D converter

Tomas Hrebicek

Other Parts Discussed in Thread: PGA870, CDCE72010, ADS4225

Hello,

I would like you to help me recommend few parts that are compatible with each other. I need to build a A/D converter with a sending out signal wireless. Speed of sampeling should be 100-250MSPS and at least 12 bits resolution(can be bigger). I heard that these fast converters need clock and a processor for data analizing. Then I need a RAM or something to remember such fast data comming out of the processor.
After wards I am sending this to a 1 meter distant receiver. The resever should have PC plug in and a D/A konverter for osciloscope. Thank you for your help!

Tomáš

over 14 years ago

0 Jim Brinkhurst1 over 14 years ago

TI__Mastermind 44680 points

Hi Tomas

The parametric search tool on the High Speed Data Converters page at TI.com makes it easy to locate ADCs meeting your criteria. The search below will list the converters that have >= 12 bits resolution and >=100MSPS. I also constrained this search to power consumption of < 250 mW as it sounds like you are making a battery powered wireless device.

http://focus.ti.com/paramsearch/docs/parametricsearch.tsp?family=analog&familyId=2020&uiTemplateId=NODE_STRY_PGE_T#p84=12;13;14;16&p1027=100000000;3600000000&p989typ=136;240

I hope this information is helpful. Good luck with your project.

Best regards,

Jim B

0 Tomas Hrebicek over 14 years ago in reply to Jim Brinkhurst1

Prodigy 20 points

Hello,

Thank you for your answer, it moved me forward. Lets say I would choose amplifier solution http://www.ti.com/product/ads4225 . (Yes, I need a battery powered circuit) . There is a recommendation of

PGA870 - Recommended amplifier solution, providing high IMD3 ADC driver
CDCE72010 - Recommended clocking solution, providing low jitter clock outputs to maximize converter performance.

I know that I will need the clock, but do I need the amplifier? Since the A/D converter ADS4225 is a paralel converter, what kind of memory do I need to read it and send it out as a serial signal.

One more question. Is there a guide how to make a simple AD converter in these speeds? Read analog signal, convert it and send it out. Thank you for your help.

Tomáš Hřebíček

0 Jim Brinkhurst1 over 14 years ago in reply to Tomas Hrebicek

TI__Mastermind 44680 points

Hi Tomas

I think you should spend some time determining what type of RF interface you want or need to use first. That will guide you to the type of micro-controller you can work with. Look into wireless micro-controller development kits and find out their capabilities. Once you find one that can send the required data, you can then find out if it has an onboard ADC that will work, or how to interface an ADC with that system.

You might want to start at TI's Wireless Connectivity page here: http://focus.ti.com/wireless/docs/wirelessoverview.tsp?familyId=2003&sectionId=646&tabId=2735

I hope this is helpful.

Best regards,

Jim B

Data converters

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A/D converter