CN0201 ADAS3022

Dear All,

                  My question is related to CN0201 ADAS3022 , I am making DAQ

1)What will be maximum voltage range of ADAS3022 in single ended application ? 

2) do i need single ended to differential convertor for input ?

3) What will be modification in the CNP201 than?

Best Regards

Nabz

  • 0
    •  Analog Employees 
    on Dec 5, 2012 10:38 PM

    Hello Nabz,

    Did you check the ADAS3022 datasheet?

    www.analog.com/ADAS3022

    As shown in the datasheet , the typical single-ended input range is listed in the Table 1. The maximum voltage range for the ADAS3022 is ±24.576 V as specified in the Table 2.

    Regardless of the type of signal (differential or single-ended, antiphase or nonantiphase, symmetric or asymmetric), the ADAS3022 converts all signals present on its inputs in a differential fashion, like an industry-standard difference or instrumentation amplifier. So, you do not need a single-ended to differential amplifier If you are applying a single-ended input signal to any of the ADAS3022 inputs - IN0-IN7.

    What is the range of single-ended input signal that you intend to use here?

    The CN0201 highlight the power solution using a high efficiency, low ripple boost converter (ADP1613) with a single +5 V supply to generate the VDDH and VSSH supplies of the ADAS3022.  It also shows that the ADAS3022 FFT performance is not affected using this power solution.

    Hope that answers your questions.

    Regards,
    Maithil

  • Hi, I'm new here, but I'm interested in ADAS3022 device and the same question came up - what is the "wide range" of input voltages, still not clear to me. So, I want to use it as single ended device, let's suppose. So, did I understand that I can apply from -24 to +24 V on INx, using PGIA gain 0.16, internal (4.096) reference voltage and maximum supply analog voltage +/- 15Vcc ? What if I apply an external VREF bigger? how big ? My needs are to measure (maybe) some 0 to 30 Vcc inputs. Or maybe negative, 0 to -30Vcc. Less components on the PCB = better. So, can I use the ADAS3022?

    Thank you,

    regards,

    Puiu

  • 0
    •  Analog Employees 
    on Dec 14, 2012 8:32 PM

    Hi Puiu,

    If you want to use the max input voltage range (±24.576V) of the ADAS3022 using PGIA gain = 0.16, you must set the ADAS3022 common-mode voltage (COM) to 0V. In this case using a fully-differential input configuration, you can apply max 24.576 Vpp anti-phase signals on each of the inputs (INx+ and INx-) as shown in the example of figure 51 in the datasheet. For a single-ended input configuration, you can apply max 24.576 Vpp on any of the IN0-IN7 channels as shown in the example of figure 55 in the datasheet.

    Note that the differential input common-mode voltage (COM) range changes according to the maximum input range selected and the high voltage power supplies (VDDH and VSSH) as specified in the Table 2. The specified operating input voltage of any input pin (see the Specifications section) requires 2.5 V of headroom from the VDDH and VSSH supplies; therefore,

    (VSSH + 2.5 V) ≤ INx/COM ≤ (VDDH − 2.5 V)

    Whether you use the internal or external reference voltage, it should be typically 4.096V with its min/max range specified in the Table 2 (page 5) of the datasheet.

    The key advantage of the ADAS3022 is that it integrates the typical discrete multichannel data acquisition system components in a small footprint, resulting in a less complex design requirements, and hence faster time to market and lower cost for our customers.

    Hope that helps.

    Regards,
    Maithil

  • Hello Maithil,

    Thank you very much for your time and answer.

    I was hoping that ADAS3022 helps me for some simple measurement, but I still need some higher voltage to measure, as for example +/- 30Vcc (relative to GND). It might be that +/- 24Vcc shall be enough.

    Didn't get exactly the point with external reference voltage, if the range is very low, why should I use an external one? I was thinking that I "play" a little with the input range, increasing the REF voltage...Else, I have no reason to use an external one. But I still have to read deeply the spec.

    BTW, the figure 55 (you mentioned somewhere in first part) is about an input of 1.28 Vp-p, not 24.xx, but I think is about PGIA factor..

    So, as a conlcusion, if I have to measure a little higher input voltages I still have to use discrete parts (mux + PGA + ADC) instead of one single ADAS chip...

    Thank you,

    Best regards,

    Puiu

  • 0
    •  Analog Employees 
    on Dec 17, 2012 9:34 PM

    Hi Puiu,

    As I mentioned, the ADAS3022 can only use the 4.096V (internal or external) reference voltage. The main reasons for using an external 4.096V reference would be guaranteed low-drift, low noise and better accuracy. We recommned the ADR434x XFET and the ADR454x ultra low noise external voltage references for the ADAS3022.

    Using figure 51 as an example, you'll need to consider the PGIA gain factor (0.16) for the 24.576 Vpp anti-phase signals on each of the inputs (INx+ and INx-).

    Well, you could add the resistor attenuation network infront of the ADAS3022 to attenuate the +/- 30Vcc input (relative to GND) and use one of its 7 available input ranges. Note that the input of the ADAS3022 is very high-impedance > 500 MΩ.

    Regards,
    Maithil