The spurious-free dynamic range (SFDR) is more relevant parameter in the communication industry, but this is also a practical indicator that can be clearly seen in the frequency domain (Figure 2-6). This parameter helps in understanding how significant the injected noise is compared to the signal of the interest.

The test procedure and the configuration are similar to those in the previous example, but not identical. The input voltage V_IN is a 10kHz sinewave with 2V_PP amplitude. This signal represents the signal of the interest. The AWG injects a modulated V_REF, as in the previous example.

Figure 2-7 shows SFDR performance of the ratiometric configuration compared to the non-ratiometric configuration. The default non-ratiometric configuration dynamic range, which is determined by the ratio between the injected noise and the signal of interest, remains practically constant.