Post Go back to editing

unable to access AD5270 RDAC by SPI

Thread Summary

The user encountered issues with the AD5270 where setting the RDAC value via SPI resulted in a constant 25kΩ resistance between A and W, and reading the RDAC value returned the default value instead of the set value. The final answer suggested adding an external pull-up resistor to the SDO pin, which the user implemented but still observed the default RDAC value. The user's schematic and SPI waveforms were provided for further analysis.
AI Generated Content
Category: Hardware
Product Number: AD5270

Dear Sir,

 I try to use AD5270 in my project, my schematic is in figure 1. however, when i send C3C2C1C0=b'0001' and D9~D0=b'0000000000' to set RDAC=0x000, the measured resistance  between A and W is always 25KOhm. The waveform of my sending command/data is in figure 2.

On the other hand, when i send C3C2C1C0=b'0010' to read RDAC in the next 16 bit SPI communication on SDO, there is no answer on SDO,  the waveform is in figure 3.

Please help me to solve this problem, thank you

Best Regards

P.S. the VDD=3.3V, VSS=GND=0V

Ctchan

figure1.

figure 2 

figure 3 

  

Parents Reply Children
No Data
More Content

Before You Switch


Switching languages will make ADI Explorer unavailable. Resume your session by switching back to English and reopening ADI Explorer.