Synchronization of ADIS16488

Hello,

Like this article, 

synchronization of the ADIS16488 with GPS 

I also have a GPSR/IMU integrated system with the requirement of the synchronization. The sampling rate of ADIS16488 will be 200HZ, which should be synchronized with the GPSR PPS signal. However, I am confused about the meaning of the Sync clock in ADIS16488 datasheet. 

According to the description of datasheet, 

Page21

DIGITAL SIGNAL PROCESSING

GYROSCOPES/ACCELEROMETERS

...

When using the external clock option (FNCTIO_CTRL[7:4], see Ta b l e  117),

the input clock drives a 4-sample burst at a sample rate of 9.84kSPS,

which feeds into the 4x averaging/decimation filter.This results in a

data rate that is equal to the input clock frequency.

...

the data rate of ADIS16488 is controlled by the Sync Clock, right? Does it also mean the frequency of Data ready  equals to the Sync clock?  

Besides, I also have a question about the timing diagram.

In timing diagram, the Data Ready signal is triggered earlier than Sync Clock, which means the sensor data is ready before the Sync clock signal. It is odd and there should be something I miss. Could you help me clarify this?

Thanks.

  • 0
    •  Analog Employees 
    on Jun 27, 2017 4:26 PM

    Thank you for your post and for your use of the ADIS16488!  The ADIS1648x has only a "direct sync" mode, where the data ready rate will equal to that of the input signal, divided by the decimation rate (configurable, default = 1). The data ready pulse does not happen before the sync pullse. You would be right to question such an arrangement. I hope that this helps. Sorry this is so short, but I am out of the office this week. If you have any further questions, please feel free to post them here and I'll get to the missing as I can. Good luck with your project!

  • 0
    •  Analog Employees 
    on Aug 2, 2018 3:52 PM
    This question has been assumed as answered either offline via email or with a multi-part answer. This question has now been closed out. If you have an inquiry related to this topic please post a new question in the applicable product forum.

    Thank you,
    EZ Admin