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AD7864 Vdrive VDD

Product Number: AD7864

Hi, 

I would like to know what should DVDD values be when interfacing with 3.3V MCU. 

When interfacing with 3.3V MCU should Vdrive = 3.3V and DVDD be 5V. 

And what are the VOL , VOH , VIL , VIH values when Vdrive = 3.3V  and VDD =5V

Is there any other signal other than the following effected by Vdrive value?

CONVST, BUSY,EOC,FRSTDATA,RD,CS,H/S,SEL[SL1-SL4] and DATA

Basically, we are worried if there is a level translator needed when interfacing the ADC with 3.3V FPGA.

Thanking you 

With best regards

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  • Hi,

    You can check the Absolute Maximum Rating which displays the maximum values that the ADC can handle as well as the sequence of the power supply. The DVDD input value should be rated at 5V +- 5% regardless of the Vdrive value. The Vdrive pin provides the positive supply voltage for the output drivers and this will follow your logic level. When interfacing an MCU with a logic level of 3.3V, the condition of the input of the ADC should be Vdrive= 3.3V and DVDD= 5V. The DVDD is the one supplying the digital section of the ADC it doesn't affect the logic level of the digital communication.

    Regards,

    Andrei 

Reply
  • Hi,

    You can check the Absolute Maximum Rating which displays the maximum values that the ADC can handle as well as the sequence of the power supply. The DVDD input value should be rated at 5V +- 5% regardless of the Vdrive value. The Vdrive pin provides the positive supply voltage for the output drivers and this will follow your logic level. When interfacing an MCU with a logic level of 3.3V, the condition of the input of the ADC should be Vdrive= 3.3V and DVDD= 5V. The DVDD is the one supplying the digital section of the ADC it doesn't affect the logic level of the digital communication.

    Regards,

    Andrei 

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