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AD4130-8 Vref and AVDD info

Category: Datasheet/Specs
Product Number: AD4130-8

For the AD4130-8 ADC, I am looking for guidance on the relationship of Vref to the device supply voltages AVDD and AVSS.

From the datasheet it is not clear about this relationship, I have seen one configuration where an external 3.3V voltage reference output is connected to both AVDD and to REFIN+. Is this a valid configuration? Can you expand on the limitations of Vref vs AVDD? 

Also, what is the relationship with the 1.8V Analog LDO?

Top Replies

  • Hi,

    Yes, connecting an external 3.3V voltage reference output to both AVDD and to REFIN+ is a valid configuration. The AVDD and AVSS are used to determine or limit the reference inputs that you planning…

  • Hi,

    Yes, connecting an external 3.3V voltage reference output to both AVDD and to REFIN+ is a valid configuration. The AVDD and AVSS are used to determine or limit the reference inputs that you planning to use on your ADC; it provides the maximum and minimum REFIN voltages that you are allowed to use on your device. Please refer to the allowable REFIN voltage below which is also shown in table 3 of the datasheet specification.

    However, the voltage reference of the ADC determines the allowed differential input voltage of your device; the voltage reference dictates the full scale of your ADC. You may refer to the table 2 below of the  of the AD4130-8 datasheet (AD4130-8 (Rev. 0) (analog.com)).

    The internal 1.8 V analog LDO regulator, powered by the AVDD, is simply used to power the ADC core.

    Best Regards,

    Rod