RF Sampling DAC Spurious Troubleshooting and Optimization

鬼谷清泉

RF Sampling DAC Spurious Troubleshooting and Optimization [Copy link]

The project is implemented using TI 's RF sampling devices, with four RF sampling DACs on each board . During the debugging process, the DAC output single tone was tested and it was found that there was a large spurious signal around 530k . The spurious amplitude of DAC0 and DAC1 was about -55dB , which basically met the requirements. The spurious amplitude of DAC2 and DAC3 reached about -45dB , which may affect system indicators such as EVM and needs to be checked.

3. Analysis and troubleshooting of debugging ideas

• The spurious signal of DAC generally comes from the following aspects: it may be the image of the signal, or the reference is disturbed, or the analog power supply of DAC is disturbed.
• 1. The signal image has been considered in the system design to prevent the image from falling within the effective bandwidth;
• 2. Whether the reference is disturbed or the analog power supply of the DAC is disturbed, further investigation is needed through experiments;

( 1 ) First, the DAC can generate a single tone by itself, and the near-end spurious components of each DAC output under the condition of spontaneous single tone are tested .

DAC 0

S3S4S5S6

Practical and useful information, learn from it!

鬼谷清泉

S3S4S5S6 posted on 2019-9-14 14:17 Practical dry goods, learn from it!

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楚地长歌

Thank you for the information