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AD5781 - not working

Question asked by shlomib on Aug 13, 2015
Latest reply on Apr 11, 2017 by luis.montes

Hi

 

I'm using the AD5781 for the first time, programming is done by ATE (something like FPGA, but more flexible).

I'm not getting any vout, it's set to 0 constantly.

 

Below is my schematics, and the signals driven to the chip.

 

13-08-2015-05-33-19.png

 

signals from top to bottom :

 

LDAC

SDIN

SYNC

SCLK

 

In addition - RESET is toggled from 0 to 1, and remains high, after which the sync goes low.

There are 24 clock when SYNC is low, first 3 bits are '001' for write operation to DAC register,
then 18 bits of data that were calculated to produce 3.3v output, and 2 bits '0' LSB.

 

IMG_7392.JPG

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