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General => General Technical Chat => Topic started by: MarkEdwards on February 25, 2012, 09:54:36 am
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I looking to sample 3 channels @5v max but I need to sample all the channels simultaneous at about 100 samples a second and 12 (14 would be better) bits.
Can anybody recommend a device or family?
Thanks.
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That Should have read 10K sample second
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If you got lot's of IO's consider parallel interface ADC's, you hook their data lines to separate ports but they all share the same control pins so they all trigger at the same time. You can reduce data line pin count to the MCU by using some multiplexors.
Alternatively look into MCU's with DMA's or advanced triggering systems like the Atmel XMEGA which have multiple SPI ports that can be triggered to start transferring on a single signal to work on 3 SPI ADCs at the same time.
The easiest and and messiest way is to use 3 MCUs controlling one ADC each, on an edge interrupt to all three MCUs they all start working the ADCs. You can use pretty much any ADC/MCU combo under the sun if you go this route.
Are you sure you need such a high resolution? If you can settle with lower resolution there are many MCU's that can sample multiple channels at the same time. dsPICs for example can sample 4 channels at the same time and then convert them in series at 10bit.
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It should be very easy to find some cheap ADCs that can do 48kHz or more sampling at 16 bits or more. (They're used in audio.)
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Almost forgot this baby from ADI:
http://www.analog.com/static/imported-files/data_sheets/AD7685.pdf (http://www.analog.com/static/imported-files/data_sheets/AD7685.pdf)
If you don't want to change MCU this is probably your best bet.
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Cheers.
@Hypernova I did look at the dsPICs and I think that there are one or two PIC24's as well but 12bits is a minimum.
I was looking more towards something like a cut down MAX11040.
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Probably got with the AD7685 types then, easy to control plus you can chain as many as you may need in the future.
If you really need a single chip solution they are all more or less the same take the ADC7606 Simultaneous-Sampling ADC series from ADI for example, at least that one is faster:
http://www.analog.com/static/imported-files/data_sheets/AD7606_7606-6_7606-4.pdf (http://www.analog.com/static/imported-files/data_sheets/AD7606_7606-6_7606-4.pdf)