AD9375 DAC Output spur

Can you reduce the TX input tone digital power level in dBFs and then check if the spurs are getting reduced?

What is the tone offset from the LO frequency? If you keep the tone at say 5MHz offset from LO, are you seeing a similar shift in spur frequencies?

Even if i reduce the tone, spurs are reducing but little (around 1dB). not more than that.

Yes, even if i change my tone close to LO(1MHz, 5Mhz) or far away (around 40Mhz), I am seeing the similar spur

Manikandan_M_M said:

even if i change my tone close to LO(1MHz, 5Mhz) or far away (around 40Mhz), I am seeing the similar spur

Are the spurs also shifting accordingly, i.e, when the tone is shifted by 5MHz, the spurs are also shifted by 5MHz? Or the spurs are still at 25KHz offset from LO?

Can you try with external LO?  Also, check the power supply of your custom board. Make sure that is clean and jitter free. 

That 25kHz is close to my LO+MSG not to my LO. If i change my LO 

Like LO = 4500MHz and Message = 10MHz . I can observe the spur at (4510Mhz -25kHz) and (4510+25kHz). 

LO=4600MHz and Message = 10MHz. I can observe the spur at (4610-25kHz) and (4610-25kHz)

I don't have any choice to provide external LO.

Even i have checked ADRV9371 EVM, from 0to 100kHz, Noise floor is around -80dBm.

Few rails have maximum peak.

Same, Noise floor we are acheiving in Custom Board. But we have peaks at 25kHz and 50kHz(Less than -80dBm). Thats the only limit

Could you let me know the API function for configuring LOOP filters of Synthesizers of RX, TX and ORX

Manikandan_M_M said:

Even if i reduce the tone, spurs are reducing but little (around 1dB). not more than that.

How much power was reduced in dBFS?. Can you reduce by -6dBFS and check.

You can use the API setRfPllLoopFilter(),  to set the PLL loop bandwidth.