This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

Need Help in Selection of ADC for High speed image sensor

Other Parts Discussed in Thread: ADS52J90, ADC10080

I Need a help on the following queries on a visible imager application.

Question 1 :

I have a CMOS image sensor which gives out analog output as differential

Vcm = 2V and Vdiff is 200mV

But if applied gain at sensor level the Vdiff may go up to 400mV

so the Analog differential voltage operates between 2-400mV to 2+400mV,

My confusion is what is maximum Vpp in ADC selection should i have to consider ? a ADC with Vpp 2.5V ?

Question 2 :

I have HCLK and VCLK for the sensor to be provided, the sensor throws a analog data out for every falling edge

the maximum limitation of HCLK is 80MHz , i can say my analog sensor samples come out at 80MHz

what should be my sampling rate for these kind of applications, should i need to follow double niquist rate here ? or is there a way i can syncronize the ADC to HCLK and get ADC output for every next rising edge of HCLK

are there any special ADC like these to help me ?

  • Hi Shyam,

    I will forward your question to our group engineer for your ADC selection.
    will reply to you soon.

    Thank you!

    Best regards,
    Chen
  • Hi Shyam,

    How are you?
    Looks like your CMOS image sensor output signals are analog output differential voltage signals. right?
    Could you give us more information?
    For example, what the signal speed (frequency) range is?
    How many channels you need for your test system?
    how many ADC bits are required?

    Thank you!

    Best regards,
    Chen
  • Hi Shyam,

    How are you?
    Also our group system engineer suggested
    please refer to ADS52J90 device.

    Thank you!
    Best regards,
    Chen
  • My inputs are only 1 , so i need only 1 channel

    i may not require such high resolution of 16/14bit

    i need both 8 bit and 10bit configurable ADC

    also clarify my doubt of Vpp

    kindly provide direct mail id, i can share datasheet over your mail, i cannot share few things on public forums

  • Hi Shyam
    Most of the ADCs that have the required resolution and sample rate are not directly compatible with the 2V common mode voltage of your sensor.
    Would it be OK to use a fully differential amplifier in between the sensor outputs and ADC inputs, to shift the common mode to match that of the ADC?
    If an amplifier can be used I would recommend an ADC like the ADC10080 or similar.
    Sampling at the sensor output pixel rate can work OK, but you will need to provide a clock circuit that can shift the ADC sample point (clock timing) earlier or later until the optimum image quality is achieved.
    I hope this is helpful.
    Best regards,
    Jim B