SBAS745B December 2015 – January 2023 ADS54J66
PRODUCTION DATA
In this configuration, the DDC block includes a fixed frequency ±fS / 4 complex digital mixer preceding the digital filter, so the IQ passband is approximately ±110 MHz (3 dB) centered at fS / 4. Mixing with +fS / 4 inverts the spectrum. The stop-band attenuation is approximately 90 dB and the pass-band flatness is ±0.1 dB. Figure 7-3 shows mixing operation in DDC mode 0. Table 7-3 shows corner frequencies of decimation filter in DDC mode 0. Figure 7-4 and Figure 7-5 show frequency response of the filter.
CORNERS | LOW PASS |
---|---|
–0.1 dB | 0.204 × fS |
–0.5 dB | 0.211 × fS |
–1 dB | 0.216 × fS |
–3 dB | 0.226 × fS |