We are using a AD9837 + AD5262 to generate a Sine Waveform with desired frequency and amplitude. Data is written to both the IC's by the same SPI from the 8051 Controller.
We are getting the proper response from the AD9837...Whatever frequency value expected is getting @ the Output of this IC..
But the issue we are facing now is the amplitude control of the sine wave using digi-pot AD5262 is not proper..When we try to change the amplitude, output frequency also varies..The SPI Clock frequency used is 50 KHZ..The difference between the two is Data is loaded into the AD9837 IC on the falling edge of the clock whereas data is loaded into the AD5262 on the rising edge of the clock..For some paricular values of mv, the output goes to greater than 5V and the frequency also goes in some MHZ range..I don't know why it is behaving like this..Our requirement is to generate a Sine Wave of frequency less than 50Khz and amplitude less than 2V.
Can anyone please help me in solving this...
Thanks in Advance..