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16 bit dac ,4 channels ,about from 500khz to 1mhz

shuxiong jia
Prodigy 50 points
Other Parts Discussed in Thread: DAC8814

1.I need to find an 16 bit DAC and 4 channel ,its Sample Rate is from 500khz to 1mhz per channel ,could you give me some advise,thank u 

2, i need to find an 14/16bit ,4/8channels ADC ,its sample rate is 1mhz per channe, give me some advise ,please

please answer my questions as soon as possible, thank u

if there is no chip meeting the requirements, just tell me. maybe i had made  mistakes

the requirements

  • 0
    Mastermind 7925 points

    Hi, 

    It is very easy to find DAC/ADC on TI page:

    http://www.ti.com/lsds/ti/analog/dataconverters/adc_dac_quick_search.page

    Regards,
    Maciej

  • 0 in reply to MaciejKucia
    Prodigy 50 points

    HI

    THANKS FOR YOUR ANSWER 

    but i find some chips datasheet dont tell me the exact sample rate

    how can i do it 

  • 0 in reply to shuxiong jia
    Mastermind 7925 points

    You need to use Nyquist theorem: for 1MHz signal you should take at least 2MSPS (2 million samples per second)

    If you click 16 bit 4 channel DAC on the table another table will open. You will be able to find devices that operate at 2MSPS or more: http://www.ti.com/lsds/ti/data-converters/digital-to-analog-converter-products.page#p84=16;16&p1021=4;4&p596=2;2500

  • 0
    TI__Mastermind 46290 points

    Shuxiong,

    What is the application you plan to use this DAC in?

    There are two ways to consider sampling time for a DAC. The first is the absolute maximum rate that you can write to the DAC data registers. This is defined by the timing requirements of the SPI interface and how long it takes to write consecutive frames. This is usually pretty fast since many devices support up to 50MHz SPI clock with minimal overhead. Alternatively, devices with parallel buses can be even faster.

    This approach does not guarantee that the output has settled to the value you intended it to, though. The settling time specification tells you how long it will take for the output to settle to your intended value down to, typically, 1/2 an LSB - which is pretty small for high resolution devices and may not be necessary for your application. You can read more about that here.

    There is a DAC that can meet your requirements called the DAC8814. This device can settle to 1/2 LSB in 1us, but the design performance depends on the selection of the output amplifier for the transimpedance stage.