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ADC IC recommend

Ray Vincent Aranzaso
Mastermind 18180 points
Other Parts Discussed in Thread: ADS7042

Hi,

Good Day. I have a customer who is working with ADC. Please se below his query for your reference. Thank you very much.

we want to choose an ADC, it can support Event-driven sampling mode.

The ADC input is a impulse signal with 10ns rise time and 30ns fall time. We will use a high speed comparators to distinguish the rise edge of impulse signal, then delay the out put of speed comparators a tiny time to trigger ADC to sampling MAX voltage of impulse signal.

Frequency of impulse signal is less than 200KHz,but each pulse interval uncertain. By simulation we know the acquisition time of ADC is a limiting factor. 

ADC ENOB is greater than 8bit.

Which ADC is suitable?

Best Regards,

Ray Vincent

  • 0
    TI__Mastermind 47440 points

    Hi Ray,

    If I understand the customer requirement, then they want to acquire the signal in 1ns or 2ns period.  If you want to directly acquire in this short of a time frame, you would need to look at a high speed ADC with sample rates of 500Msps or more.

    I suggest the customer look at a peak-detect amplifier that can capture the peak value of the impulse signal, and then a standard 12b, 1Msps ADC such as ADS7042 could acquire the result.

    Below is an example circuit, but would need modified with much higher bandwidth amplifiers to support the fast rise/fall time of the impulse.

    Regards,
    Keith Nicholas
    Precision ADC Applications