About AD5671R

Question

Hi 
 
 As is shown above,when Vlogic and VDD supplies of 3.3 V,all the channels can output correctly except the maximum voltage is 3.2 V.However,when Vlogic and VDD supplies of 5 V,only some of the channels can output from 3 V to 4.9 V.When I send data byte smaller than 0x99f0,which try to make the channel output the voltage lower than 3V,I failed and cannot control AD5671R again. 
 Is there anything wrong in my circuit? 
 Best Regards 
 zw

isantos · Accepted Answer

Hi, 
 Looks like the Logic level (SDA, SCL) does not meet the Vinhigh level requirement of the device. 
 Please refer to this section of the datasheet , page 4. 
 
 Since the Vlogic level is now 5V, you need at least 3.5V in order for the device to detect logic high. 
 You may want to tie Vlogic to 3.3V and Vdd to 5V. Let me know if it works. Thanks. 
 Cheers, 
 Ivan