EVAl-AD5679RSDZ

Hi Iordan, 

Sorry for the late response. are you using the EVAL-AD5679RSDZ with the SDP-CB1Z?

Have you set the LK1 and LK2 jumpers on board? To power from USB, select USB on LK1, and either 5V0 or 3V3 on LK2. 

Are you seeing a voltage on the VREF testpin? 

~ian

Hi iandal,

Thank you for the message,
yes I have set the USB jumper to external and the voltage jumper to external to. But I have notice that Sync signal does not go low and so the input register can not be set, because with the rising edge the value of the input register is taken to the to the input registers. I have order one another board, because this is damage.

I measured the voltage of the VREF pin it is ok 3,3 V I use 3,3 volt as reference voltage. 
Best Regards,
Iordan Pentchev.

Hi Iordan, 

For future quick checking, you could set to USB, the SDP-CB1Z could provide enough power to power-up the board and you could do the basic checking of the output voltage with SPI code. Alternatively, if you have an Digital IO module you could connect it to SPI_PMOD connector to send custom SPI commands to the device. 

If what you say is the case, we could'nt readily determine wether the problem is with the SYNC signal from the SDP-CB1Z control board, or the AD5679R device itself. 

~ian

Are you using an external 3.3V source? Do note that first you should turn off the internal reference of the AD5679R before connecting an external reference. The internal reference can be shut down using the ACE GUI or by SPI command. Before you connect an external reference and upon power up, you should see 2.5V on the VREF pin. 

Hi Iandal,

I do not use the SDP-CB1Z board, I have soldered one connector to the SPI PMOD place on the EVAL AD5679RSDZ board. I have already measured there are a connection between the SYNC signal and V+ power connector, the are no resistance between the two signals, the board is damage.

Best Regards,

Iordan Pentchev.

Hi Iandal, 

I set the board to external reference with the command 0111 to set the DB0 to 1.

Before I set to the external voltage reference I have measured the 2.5 V on the VREF test pin. 

I can still measure the 2.5 V VREF, If the VREF is internal. 

Best Regards,

Iordan Pentchev.

Hi Iordan, 

Sorry, I thought you were using the SDP and ACE software. It's unfortunate that the device got damaged. looks like the diode protection tied up to Vlogic has been busted. do make sure that the input signals on the digital pins are referenced to vlogic to avoid this. 

If you've other concerns on the AD5679R usage, please don't hesitate to ask. I suggest to open a new thread at that time. 

~ian

Hi Iandal,

yes this is very pity that the board is damage. When I get the new one board I will let you know. 

Just a question about the programming the board.  When I write to the the the DAC channels, can I use the command 0011 to write to the input registers to or this command is only to update the DAC registers with out to use the LDAC signal. Because I use 0001 command to write to the input registers and then the command 0010 to update the DAC registers. After the executing the command 0010 a voltage written to the DAC channel  must be measured on this DAC channel?  

Best regards,

Iordan Pentchev.

Hi Iordan, 

iordanPentchev said:

When I write to the the the DAC channels, can I use the command 0011 to write to the input registers to or this command is only to update the DAC registers with out to use the LDAC signal.

Yes, you can use this command to directly set the output voltage with the input code. DAC output voltage should be present. 

iordanPentchev said:

Because I use 0001 command to write to the input registers and then the command 0010 to update the DAC registers. After the executing the command 0010 a voltage written to the DAC channel  must be measured on this DAC channel? 

This is also correct, after command 0010 is issued, the target channel will reflect the code on the input register. Either it is written using the 0001 command or the default data which is 0x0000 for all channels. 

~ian

Hi Iandal, 

I confused 0x0000 voltage with the 0x0000 command!

I let you know when I will receive the new board.

Best Regards,

Iordan Pentchev.

Hi Iandal,
in our system for the AD5679R we using external VREF, after the system is switch on the VREF is immediately on the microcontroller.
How we can avoid a damage the microcontroller, when the VREF must be connected to the microcontroller after the microcontroller is set to external VREF, but in our case the VREF will be earlier on the microcontroller before switch to external VREF?
Best Regards,
Iordan Pentchev.

Hi Iandal,
in our system for the AD5679R we using external VREF, after the system is switch on the VREF is immediately on the microcontroller.
How we can avoid a damage the microcontroller, when the VREF must be connected to the microcontroller after the microcontroller is set to external VREF, but in our case the VREF will be earlier on the microcontroller before switch to external VREF?
Best Regards,
Iordan Pentchev.