wxtyz

AD5934 - perform a basic measurement?

Discussion created by wxtyz on Aug 24, 2016
Latest reply on Aug 24, 2016 by wxtyz

Hi!

 

I'm having trouble trying to verify that the device is measuring correctly when I tell it to do so.

 

I tried to replicate the information from page 15 of 32 of the datasheet but I don't get the expected results whatever I try to do. I connected a 200k resistor from Vout to Vin in place of Zunknown and a 200k resistor from Vin to RFB. PGA I set to a gain of 1, Vout range is the 2Vp-p one, Vdd=3.3V, and signal frequency 30kHz. System clock is set to external, roughly 8MHz (not that it matters, setting to internal does not work, if I don't plug anything to MCLK I don't get any output signal on Vout). I kinda followed the flowchart of fig. 24, but what I managed to read is a value arround 19700 for the magnitude, and I've changed to higher value resistors but no significant change in readings.

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