Driver for AD7606

Hi Jino,

My application is Coriolis flow meter which consists of the two parts, mechanical and electronics. Mechanical part has three coils and three magnets on it comprising three pairs. One pair is used for vibrating two stainless steel tubes. Simply,

sine wave applied to the coil that resides on a one tube to forces the two tubes vibrate on the resonant frequency that is in range of 110-130 Hz. The other two pairs used as a sensors to measure  the phase shift information between the two tube ends which is proportional to mass of a flowing media. In other words my input to the controller board comes from the two  coils. Incoming  signals are pure sine waves with the same frequency range (110-130 Hz)  . Thus, the path for one channel is:

                       Coil -> Instrumentation Amplifier -> RC filter -> ADC > Microprocessor. 

The main task is to compute phase shift between two incoming sine waves. High accuracy and resolution required  since the resolution of phase shift should be 1 micro radian.  

On my current board  I use AD7655  ADC which doesn't provide required accuracy.  I compared parameters of AD7655 vs AD7606-4 and found that the last one is much better. Even better than AD7654. 

After some research I came to this choice: 

                                        Instrumentation Amplifier -> AD8421

                                        ADC ->   AD7606-4         

As I understand  AD7606 can be directly driven by AD8421 and there is no need for extra driving op amp between ADC and AD8421.   My sampling rate is around 16 kHz.

By the way, is  the gerber file  provided with  EVAL-AD7606-4SDZ ?

        Thank you for support.

Ruben

Hi Jino,

My application is Coriolis flow meter which consists of the two parts, mechanical and electronics. Mechanical part has three coils and three magnets on it comprising three pairs. One pair is used for vibrating two stainless steel tubes. Simply,

sine wave applied to the coil that resides on a one tube to forces the two tubes vibrate on the resonant frequency that is in range of 110-130 Hz. The other two pairs used as a sensors to measure  the phase shift information between the two tube ends which is proportional to mass of a flowing media. In other words my input to the controller board comes from the two  coils. Incoming  signals are pure sine waves with the same frequency range (110-130 Hz)  . Thus, the path for one channel is:

                       Coil -> Instrumentation Amplifier -> RC filter -> ADC > Microprocessor. 

The main task is to compute phase shift between two incoming sine waves. High accuracy and resolution required  since the resolution of phase shift should be 1 micro radian.  

On my current board  I use AD7655  ADC which doesn't provide required accuracy.  I compared parameters of AD7655 vs AD7606-4 and found that the last one is much better. Even better than AD7654. 

After some research I came to this choice: 

                                        Instrumentation Amplifier -> AD8421

                                        ADC ->   AD7606-4         

As I understand  AD7606 can be directly driven by AD8421 and there is no need for extra driving op amp between ADC and AD8421.   My sampling rate is around 16 kHz.

By the way, is  the gerber file  provided with  EVAL-AD7606-4SDZ ?

        Thank you for support.

Ruben