Eval-AD7609

I am using the Eval-AD7609 without the CED Board but I am not able to get a busy signal or any data output. I have provided the control signals and the power supplies through a microcontroller, the connections are shown below.

I am operating it in Parallel mode.

1. All the control signals (Read, CONVST, CS, RESET) are provided from the microcontroller to the CED connector of EVAL_AD7609. 

2. The OS pins (OS0, OS1, OS2) are set to 0 (connected to ground).

3. Vdrive is given 3.3 V and AVcc is given 5V (RANGE pin is set to be low by connecting it to ground).

4. STDY (Standby) pin is provided logic high. 

The sequence in which the signals are given.

1. First, the STDY pin is made high. 

After 1 ms

2. A reset pulse is given 

3. The Chip Select is made low.

After 10 ms

3. CONVST A is given (CONVST B is by default connected to CONVST A in EVAL board).

after 100 ms

4. READ pulses are given. 

I am not able to get the busy signal as high after the CONVST signal or any output from the output pins of the CED connector.

Parents
  • 0
    •  Analog Employees 
    on Apr 3, 2019 3:03 AM

    Hi Arushichaudhry,

        The EVAL-AD7609EDZ has SLx slots to connect digital signal is coming from the CED or from the external source. I understand you are using the external source to drive the digital signals. Are you using the SMB connectors to connect the digital signals like CONVST, SCLK and RD? Because if you are using the SMB connector some of the SLx should be placed correctly. J5 and J6 of the board also must be provided with the correct supply and the SL10 and SL9 also needs to be connected properly. The Eval-AD7609EDZ schematic should be able to locate these connections.

       Would you bale to measure the supplies AVCC and VDrive in the AD7609 pin, to make sure the part is powered up and the CONVST signal as well. Figure 2 and Figure 3 of the datasheet should be able to guide you that with the RESET and CONVST, Busy signal should go high.

    Regards,

    Jonathan

     

      

Reply
  • 0
    •  Analog Employees 
    on Apr 3, 2019 3:03 AM

    Hi Arushichaudhry,

        The EVAL-AD7609EDZ has SLx slots to connect digital signal is coming from the CED or from the external source. I understand you are using the external source to drive the digital signals. Are you using the SMB connectors to connect the digital signals like CONVST, SCLK and RD? Because if you are using the SMB connector some of the SLx should be placed correctly. J5 and J6 of the board also must be provided with the correct supply and the SL10 and SL9 also needs to be connected properly. The Eval-AD7609EDZ schematic should be able to locate these connections.

       Would you bale to measure the supplies AVCC and VDrive in the AD7609 pin, to make sure the part is powered up and the CONVST signal as well. Figure 2 and Figure 3 of the datasheet should be able to guide you that with the RESET and CONVST, Busy signal should go high.

    Regards,

    Jonathan

     

      

Children
  • Hello Jonathan, Thanks for your reply.

    The controls are supplied by an external microcontroller. No, I am not using the SMB connectors as the evaluation board is soldered in positions that require connections from the CED connector. I have connected the digital controls, power supply, and ground to the CED connector pins as per the datasheet. The connections are shown below.

    Table 1- Connections on the CED connector 

    Pins

    Corresponding connections on the J1 connector 

    Chip Select (CS)

    C10

    Read (RD)

    A9

    Conversion Start (CONVST)

    A17

    Reset

    B1

    Vdrive

    A8/B8/C8

    AVcc

    A32/B32/C32

    Ground

    A20

    OS0

    B19,

    OS1

    C14

    OS2

    C15

    Range

    C11

    Busy

    C17

    Standby (STBY)

    A15

    I have checked the power supply pins on AD7609 and they are fine. I have also captured the waveforms that I am getting on the board.

    Figure 1- Control signals verified on an oscilloscope - the signals in order are mentioned below.

    Signal 1: Chip Select (Green)

    Signal 2: CONVST (Yellow)

    Signal 3: Busy signal (Blue)

    Signal 4: Read signal (Pink)