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[ADALM2000] maximum input voltage

eokayama
on Oct 16, 2019

[ADALM2000]

What is the maximum input voltage that can cause damage?
I want to know about analog input and digital input.



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[edited by: eokayama at 9:56 AM (GMT 0) on 16 Oct 2019]
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  • 0 on Aug 4, 2020 4:00 PM

    I'm also curious about damage, but I need more specifics than are given on the spec sheet:

    • If someone applies 25V while the analog input range is 2.5V, will this cause damage?
    • How much voltage can be applied in the two ranges before it does cause damage?

    Thanks!

    Jack

  • +1
    •  Analog Employees 
    on Aug 5, 2020 8:12 AM in reply to jaxankey

    Hi,

    The input voltage range of the ADALM2000 depends on the specificationd of AD9963 which is the converter that provides  the ADC channels (also the DAC channels).

    In the datasheet of AD9963 the full scale input range of the ADC is 1.56Vpp differential with an absolute maximum rating from -0.3V to 2.1V.

    The ADALM2000  gain range settings for the analog input voltage divider are:

    • High gain mode: for signals from -2.5 V to +2.5V with a total gain of 0.2756
    • Low gain mode: for signals from -25 V to 25 V with a total gain of 0.026

    If someone applies 25V while in the 2.5V range this means that at the ADC input pin the voltage will be 6.89V which exceeds the absolute maximum rating specified in datasheet and may cause damage.

    Given that the absolute maximum rating is 2.1V this means that in high gain mode one can apply up to 7.61Vpp differential  (-3.8V to +3.8V) and 80.7Vpp differential (-40.35 V to +40.35 V).

    You can find more information in the reference manual for ADALM2000:

    https://wiki.analog.com/university/tools/m2k/users/reference_manual#reference_manual_understanding_the_internals

    Regards,

    Andreea

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  • +1
    •  Analog Employees 
    on Aug 5, 2020 8:12 AM in reply to jaxankey

    Hi,

    The input voltage range of the ADALM2000 depends on the specificationd of AD9963 which is the converter that provides  the ADC channels (also the DAC channels).

    In the datasheet of AD9963 the full scale input range of the ADC is 1.56Vpp differential with an absolute maximum rating from -0.3V to 2.1V.

    The ADALM2000  gain range settings for the analog input voltage divider are:

    • High gain mode: for signals from -2.5 V to +2.5V with a total gain of 0.2756
    • Low gain mode: for signals from -25 V to 25 V with a total gain of 0.026

    If someone applies 25V while in the 2.5V range this means that at the ADC input pin the voltage will be 6.89V which exceeds the absolute maximum rating specified in datasheet and may cause damage.

    Given that the absolute maximum rating is 2.1V this means that in high gain mode one can apply up to 7.61Vpp differential  (-3.8V to +3.8V) and 80.7Vpp differential (-40.35 V to +40.35 V).

    You can find more information in the reference manual for ADALM2000:

    https://wiki.analog.com/university/tools/m2k/users/reference_manual#reference_manual_understanding_the_internals

    Regards,

    Andreea

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  • 0
    •  Analog Employees 
    on Aug 5, 2020 11:31 AM in reply to andreeapop

    There is built in protection of the ADC pins provided by Schottky diodes. These  will clamp voltages above maximum ratings specified  in case of accidental connections, but you should always apply signals in the  range of the gain setting.

    Reconsidering what I said earlier about damaging the board when applying 25V in high gain mode, there may not be immediate damages because the voltage will be clamped. However, you should not rely only on this protection and use the suitable settings.

    Regards, 

    Andreea