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AD9251 configuration without SPI

Question asked by lotus on Dec 12, 2011
Latest reply on Dec 20, 2011 by DougI

Dear Sir/Madam:

 

We are designing ADC using dual ADC AD9251 part.  We configured this AD9251 using fixed internal reference (Vref = 1.0V).

 

The question we have is that if we want to configure AD9251 without SPI, we can do the following:

 

CSB <-> AVDD (disable SPI)

SDIO <-> AVDD (Duty cycle stabilizer enabled)

SCLK <-> AVDD (twos complement enabled)

OEB <-> AGND

PDWN <-> AGND

 

The ADC should function, right?  Is the configuration for AD9251 using SPI required for its normal operation?

 

Another question is that what happend if we connect Sense (Pin 56) to Vref (Pin 55) based on Figure 46 in AD9251? What Reference configuration will we get?

 

Thank you very much.

 

Regards,

 

Tim

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