AnsweredAssumed Answered

Can't get AD7804 to work

Question asked by vduong@slb.com on Oct 26, 2011
Latest reply on Oct 27, 2011 by Padraic

Hi All,

 

I can't seem to get the 7804 to work. I am using a NI 8451 SPI\USB to configure the 7804 and set values. I have checked the polarities and they seem ok. Maybe I have a mistake in the commands I am sending?

configure (for internal ref)...
0048
0040
4110
4510
4910
4d10
set all sub dacs
a000
a400
a800
ac00
set main dacs
23ff
27ff
2bff
2fff
wake up
0060

When I send wake up, I do see the ref come up (1.2V). And, 3.3v supply current goes from very low to 4 mA. But, all the outputs are very low. Should be 2.2V, but I see maybe 20 to 90 mV, depending on which output. Do you see anything wrong with my commands? Do you have a command set I can try?

 

Any help with be appriciate..



 

 

Vu

 

 

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