This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

DAC3482: DAC3482 output has a high spurious

Part Number: DAC3482
Other Parts Discussed in Thread: LMK04803

I am using DAC3482 to generate a 255MHz sinesoidal wave. My plan is to generate a 10MHz baseband signal and use the DAC3482 built-in mixer moving 10MHz to 255MHz.

DATACLK = 122.88MHz which comes from FPGA which is synced with data

DACCLK = 983.04MHz which comes from TI frequency synthesizer LMK04803.

The data related to frequency I delivered to corresponding registers are listed below:

1. Choose 16 interpolation.(I feel this should be 8, but when I set 8, the spurious rised.)

2. Shut-down FIFO. There is no sync and ostr signals providing to DAC.

3. 16-bit input mode(word wide).

4. MIXER_ENA and MIXER_GAIN are opened.

5. Choose CMIX and shut down NCO. CMIX mode choose Fs/4, means 983.04/4=245.76MHz.

6. Choose external reference CLK.

7. Shut down PLL.

8. Set current 20mA.

The whole data are listed below:

{0x00, 0xA810},

{0x01, 0x000E},

{0x02, 0xF062},   //mix_ena

{0x03, 0x7001},

{0x0C, 0x0400},   //qmc_gainI

{0x0D, 0x4400},   //qmc_gainQ

{0x10, 0x0000},   //phase

{0x14, 0x0000},

{0x15, 0x0000},

{0x18, 0x0000},

{0x1B, 0x8800},

{0x1E, 0x4200},

{0x1F, 0x4200},

{0x20, 0x1400},

{0x24, 0x0400},

{0x2D, 0x0004},

{0x30, 0x0000},

The there is a high spurious at 728MHz.